Investigation of contrast agent dosage for perfusion-weighted MRI

International Nuclear Information System (INIS)

Erb, G.; Benner, T.; Heiland, S.; Reith, W.; Sartor, K.; Forsting, M.

1997-01-01

Purpose: In this study we investigated, whether increasing the dosage of a paramagnetic contrast agent results in a stronger signal decrease in T 2 *-weighted perfusion sequences and therefore more meaningful parameter maps. Material and methods: In a prospective study bolus injection of gadolinium-DTPA was performed at dosages of 0.1, 0.2, and 0.3 mmol/kg body weight (BW) in 10 patients each. Before, during and after bolus injection 40 T 2 *-weighted images of a reference brain slice were acquired within 65.6 seconds on a 1.0 T clinical scanner and perfusion parameters were calculated. Results: Due to the limited signal decrease during bolus passage and the resulting low signal-difference-to-noise ratio (ΔS/N) no reliable differentiation of gray and white matter was possible at a contrast agent dosage of 0.1 mmol/kg BW. Only at higher dosages, both, signal decrease and ΔS/N were strong enough to allow differentiation of gray and white matter and to yield reliable parameter maps. Conclusion: For meaningful MR perfusion imaging at 1.0 T and with the given sequence a contrast agent dosage of at least 0.2 mmol/kg BW is necessary, if a 0.5-molar contrast agent is used. (orig.) [de

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

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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.

Dynamic iterative beam hardening correction (DIBHC) in myocardial perfusion imaging using contrast-enhanced computed tomography.

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Stenner, Philip; Schmidt, Bernhard; Allmendinger, Thomas; Flohr, Thomas; Kachelrie, Marc

2010-06-01

In cardiac perfusion examinations with computed tomography (CT) large concentrations of iodine in the ventricle and in the descending aorta cause beam hardening artifacts that can lead to incorrect perfusion parameters. The aim of this study is to reduce these artifacts by performing an iterative correction and by accounting for the 3 materials soft tissue, bone, and iodine. Beam hardening corrections are either implemented as simple precorrections which cannot account for higher order beam hardening effects, or as iterative approaches that are based on segmenting the original image into material distribution images. Conventional segmentation algorithms fail to clearly distinguish between iodine and bone. Our new algorithm, DIBHC, calculates the time-dependent iodine distribution by analyzing the voxel changes of a cardiac perfusion examination (typically N approximately 15 electrocardiogram-correlated scans distributed over a total scan time up to T approximately 30 s). These voxel dynamics are due to changes in contrast agent. This prior information allows to precisely distinguish between bone and iodine and is key to DIBHC where each iteration consists of a multimaterial (soft tissue, bone, iodine) polychromatic forward projection, a raw data comparison and a filtered backprojection. Simulations with a semi-anthropomorphic dynamic phantom and clinical scans using a dual source CT scanner with 2 x 128 slices, a tube voltage of 100 kV, a tube current of 180 mAs, and a rotation time of 0.28 seconds have been carried out. The uncorrected images suffer from beam hardening artifacts that appear as dark bands connecting large concentrations of iodine in the ventricle, aorta, and bony structures. The CT-values of the affected tissue are usually underestimated by roughly 20 HU although deviations of up to 61 HU have been observed. For a quantitative evaluation circular regions of interest have been analyzed. After application of DIBHC the mean values obtained deviate by

Validation of Perfusion Quantification with 3D Gradient Echo Dynamic Contrast-Enhanced Magnetic Resonance Imaging Using a Blood Pool Contrast Agent in Skeletal Swine Muscle.

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Stefan Hindel

Full Text Available The purpose of our study was to validate perfusion quantification in a low-perfused tissue by dynamic contrast-enhanced magnetic resonance imaging (DCE-MRI with shared k-space sampling using a blood pool contrast agent. Perfusion measurements were performed in a total of seven female pigs. An ultrasonic Doppler probe was attached to the right femoral artery to determine total flow in the hind leg musculature. The femoral artery was catheterized for continuous local administration of adenosine to increase blood flow up to four times the baseline level. Three different stable perfusion levels were induced. The MR protocol included a 3D gradient-echo sequence with a temporal resolution of approximately 1.5 seconds. Before each dynamic sequence, static MR images were acquired with flip angles of 5°, 10°, 20°, and 30°. Both static and dynamic images were used to generate relaxation rate and baseline magnetization maps with a flip angle method. 0.1 mL/kg body weight of blood pool contrast medium was injected via a central venous catheter at a flow rate of 5 mL/s. The right hind leg was segmented in 3D into medial, cranial, lateral, and pelvic thigh muscles, lower leg, bones, skin, and fat. The arterial input function (AIF was measured in the aorta. Perfusion of the different anatomic regions was calculated using a one- and a two-compartment model with delay- and dispersion-corrected AIFs. The F-test for model comparison was used to decide whether to use the results of the one- or two-compartment model fit. Total flow was calculated by integrating volume-weighted perfusion values over the whole measured region. The resulting values of delay, dispersion, blood volume, mean transit time, and flow were all in physiologically and physically reasonable ranges. In 107 of 160 ROIs, the blood signal was separated, using a two-compartment model, into a capillary and an arteriolar signal contribution, decided by the F-test. Overall flow in hind leg muscles

Real-time contrast ultrasound muscle perfusion imaging with intermediate-power imaging coupled with acoustically durable microbubbles.

Science.gov (United States)

Seol, Sang-Hoon; Davidson, Brian P; Belcik, J Todd; Mott, Brian H; Goodman, Reid M; Ammi, Azzdine; Lindner, Jonathan R

2015-06-01

There is growing interest in limb contrast-enhanced ultrasound (CEU) perfusion imaging for the evaluation of peripheral artery disease. Because of low resting microvascular blood flow in skeletal muscle, signal enhancement during limb CEU is prohibitively low for real-time imaging. The aim of this study was to test the hypothesis that this obstacle can be overcome by intermediate- rather than low-power CEU when performed with an acoustically resilient microbubble agent. Viscoelastic properties of Definity and Sonazoid were assessed by measuring bulk modulus during incremental increases in ambient pressure to 200 mm Hg. Comparison of in vivo microbubble destruction and signal enhancement at a mechanical index (MI) of 0.1 to 0.4 was performed by sequential reduction in pulsing interval from 10 to 0.05 sec during limb CEU at 7 MHz in mice and 1.8 MHz in dogs. Destruction was also assessed by broadband signal generation during passive cavitation detection. Real-time CEU perfusion imaging with destruction-replenishment was then performed at 1.8 MHz in dogs using an MI of 0.1, 0.2, or 0.3. Sonazoid had a higher bulk modulus than Definity (66 ± 12 vs 29 ± 2 kPa, P = .02) and exhibited less inertial cavitation (destruction) at MIs ≥ 0.2. On in vivo CEU, maximal signal intensity increased incrementally with MI for both agents and was equivalent between agents except at an MI of 0.1 (60% and 85% lower for Sonazoid at 7 and 1.8 MHz, respectively, P power imaging coupled with a durable microbubble contrast agent. Copyright © 2015 American Society of Echocardiography. All rights reserved.

Perfusion imaging with magnetic-susceptibility contrast media

International Nuclear Information System (INIS)

Rosen, B.R.; Belliveau, J.W.; Betteridge, D.; Cohen, M.S.; Weisskoff, R.M.; Vevea, J.M.; Rzedzian, R.P.; Brady, T.J.

1989-01-01

In animal models, transient signal los on T2-weighted images has been well documented following intravenous injection of high-magnetic-susceptibility contrast agents that are compartmentalized within the brain intravascular space. These signal changes have been correlated with physiologic parameters, such as blood flow and volume. The advent of whole-body single-shot imaging capability, coupled with the approval of paramagnetic contrasts agents for human use, has enabled the authors to demonstrate susceptibility contrast in the human brain, allowing for generation of functional images. With use of a 1.5-T imaging system gradient-echo images (TE = 60 msec) were acquired in 75 msec. Sequential single-sections images were sampled every 1 second following bolus administration of 0.1 mmol/kg of Gd-DTPA

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.

Parallel imaging for first-pass myocardial perfusion

NARCIS (Netherlands)

Irwan, Roy; Lubbers, Daniel D.; van der Vleuten, Pieter A.; Kappert, Peter; Gotte, Marco J. W.; Sijens, Paul E.

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

Ventilation-perfusion lung imaging in diaphragmatic paralysis

International Nuclear Information System (INIS)

Chopra, S.K.; Taplin, G.V.

1977-01-01

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

Magnetic resonance cardiac perfusion imaging-a clinical perspective

International Nuclear Information System (INIS)

Hunold, Peter; Schlosser, Thomas; Barkhausen, Joerg

2006-01-01

Coronary artery disease (CAD) with its clinical appearance of stable or unstable angina and acute myocardial infarction is the leading cause of death in developed countries. In view of increasing costs and the rising number of CAD patients, there has been a major interest in reliable non-invasive imaging techniques to identify CAD in an early (i.e. asymptomatic) stage. Since myocardial perfusion deficits appear very early in the ''ischemic cascade'', a major breakthrough would be the non-invasive quantification of myocardial perfusion before functional impairment might be detected. Therefore, there is growing interest in other, target-organ-specific parameters, such as relative and absolute myocardial perfusion imaging. Magnetic resonance (MR) imaging has been proven to offer attractive concepts in this respect. However, some important difficulties have not been resolved so far, which still causes uncertainty and prevents the broad application of MR perfusion imaging in a clinical setting. This review explores recent technical developments in MR hardware, software and contrast agents, as well as their impact on the current and future clinical status of MR imaging of first-pass myocardial perfusion imaging. (orig.)

Magnetic resonance cardiac perfusion imaging-a clinical perspective

Energy Technology Data Exchange (ETDEWEB)

Hunold, Peter; Schlosser, Thomas; Barkhausen, Joerg [University Hospital, Department of Diagnostic and Interventional Radiology and Neuroradiology, Essen (Germany)

2006-08-15

Coronary artery disease (CAD) with its clinical appearance of stable or unstable angina and acute myocardial infarction is the leading cause of death in developed countries. In view of increasing costs and the rising number of CAD patients, there has been a major interest in reliable non-invasive imaging techniques to identify CAD in an early (i.e. asymptomatic) stage. Since myocardial perfusion deficits appear very early in the ''ischemic cascade'', a major breakthrough would be the non-invasive quantification of myocardial perfusion before functional impairment might be detected. Therefore, there is growing interest in other, target-organ-specific parameters, such as relative and absolute myocardial perfusion imaging. Magnetic resonance (MR) imaging has been proven to offer attractive concepts in this respect. However, some important difficulties have not been resolved so far, which still causes uncertainty and prevents the broad application of MR perfusion imaging in a clinical setting. This review explores recent technical developments in MR hardware, software and contrast agents, as well as their impact on the current and future clinical status of MR imaging of first-pass myocardial perfusion imaging. (orig.)

Parametric imaging of tumor perfusion and neovascular morphology using ultrasound

Science.gov (United States)

Hoyt, Kenneth

2015-03-01

A new image processing strategy is detailed for the simultaneous measurement of tumor perfusion and neovascular morphology parameters from a sequence of dynamic contrast-enhanced ultrasound (DCE-US) images. A technique for locally mapping tumor perfusion parameters using skeletonized neovascular data is also introduced. Simulated images were used to test the neovascular skeletonization technique and variance (error) of relevant parametric estimates. Preliminary DCE-US image datasets were collected in 6 female patients diagnosed with invasive breast cancer and using a Philips iU22 ultrasound system equipped with a L9-3 MHz transducer and Definity contrast agent. Simulation data demonstrates that neovascular morphology parametric estimation is reproducible albeit measurement error can occur at a lower signal-to-noise ratio (SNR). Experimental results indicate the feasibility of our approach to performing both tumor perfusion and neovascular morphology measurements from DCE-US images. Future work will expand on our initial clinical findings and also extent our image processing strategy to 3-dimensional space to allow whole tumor characterization.

Evaluation of optimized magnetic resonance perfusion imaging scanning time window after contrast agent injection for differentiating benign and malignant breast lesions.

Science.gov (United States)

Dong, Jie; Wang, Dawei; Ma, Zhenshen; Deng, Guodong; Wang, Lanhua; Zhang, Jiandong

2017-03-01

The aim of the study was evaluate the 3.0 T magnetic resonance (MR) perfusion imaging scanning time window following contrast injection for differentiating benign and malignant breast lesions and to determine the optimum scanning time window for increased scanner usage efficiency and reduced diagnostic adverse risk factors. A total of 52 women with breast abnormalities were selected for conventional MR imaging and T1 dynamic-enhanced imaging. Quantitative parameters [volume transfer constant (K trans ), rate constant (K ep ) and extravascular extracellular volume fraction (V e )] were calculated at phases 10, 20, 30, 40 and 50, which represented time windows at 5, 10, 15, 20 and 25 min, respectively, following injection of contrast agent. The association of the parameters at different phases with benign and malignant tumor diagnosis was analyzed. MR perfusion imaging was verified as an effective modality in the diagnosis of breast malignancies and the best scanning time window was identified: i) Values of K trans and K ep at all phases were statistically significant in differentiating benign and malignant tumors (P0.05); ii) values of V e in benign tumors increased with phase number, but achieved no obvious changes at different phases in malignant tumors; iii) the optimum scanning time window of breast perfusion imaging with 3.0 T MR was between phases 10 and 30 (i.e., between 5 and 15 min after contrast agent injection). The variation trend of V e values at different phases may serve as a diagnostic reference for differentiating benign and malignant breast abnormalities. The most efficient scanning time window was indicated to be 5 min after contrast injection, based on the observation that the V e value only had statistical significance in diagnosis at stage 10. However, the optimal scanning time window is from 5 to 15 min following the injection of contrast agent, since that the variation trend of V e is able to serve as a diagnostic reference.

Arterio-venous anastomoses in mice affect perfusion measurements with dynamic contrast enhanced CT

International Nuclear Information System (INIS)

Gabra, Peter; Lee, Ting-Yim; Shen, Gang; Xuan, Jim

2010-01-01

Accurate measurement of perfusion with dynamic contrast enhanced CT requires an arterial input curve (AIC) uncontaminated by venous sources. Arterio-venous anastomoses (AVAs) are sources of contamination if contrast is injected intravenously. We seek to identify AVAs in mice and associated errors in perfusion measurements. Six transgenic mice with spontaneous prostate tumor were scanned with a micro-CT scanner (GE Healthcare (GE)) using a high resolution anatomical and a lower resolution perfusion protocol. For the anatomical protocol, a CT scan was performed during injection of an iodinated contrast agent (Hypaque) into a tail vein. Images covering the thoracic, abdominal and pelvic regions at an isotropic resolution of 175 µm were reconstructed and rendered in 3D to show the arterial and venous tree (Advantage Window, GE). For the perfusion protocol, each mouse was continuously scanned for 40 s and the contrast agent (Hypaque) was injected via a tail vein 5 s into scanning. Tumor images were reconstructed every second. Tumor blood flow (BF) and volume (BV) maps were calculated with CT perfusion software (GE) using AIC measured either from abdominal aorta (AA) or tail (caudal) artery (TA). In all mice, there was an AVA from the bifurcation of the inferior vena cava to the tail artery shunting venous blood and portion of the contrast agent injected into the tail vein into the TA. Contrast arrival time at the TA preceded that at the AA by 3.3 ± 0.5 s (P < 0.05). Mean tumor BV and BF values calculated with AA versus TA were 10.0 ± 1.8 versus 4.8 ± 2.1 ml (100 g) −1 (P < 0.05) and 108.8 ± 26.5 versus 33.0 ± 8.5 ml min −1 100 g −1 (P < 0.05), respectively. AVA in the murine pelvic region can result in inaccurate and more variable measurements of pelvic organ/tissue perfusion when the tail artery is used as the AIC

Myocardial perfusion imaging by digital subtraction angiography

International Nuclear Information System (INIS)

Kadowaki, Hiroyuki; Ishikawa, Kinji; Ogai, Toshihiro; Katori, Ryo

1986-01-01

Several methods of digital subtraction angiography (DSA) were compared to determine which could better visualize regional myocardial perfusion using coronary angiography in seven patients with myocardial infarction, two with angina pectoris and five with normal coronary arteries. Satisfactory DSA was judged to be achieved if the shape of the heart on the mask film was identical to that on the live film and if both films were exactly superimposed. To obtain an identical mask film in the shape of each live film, both films were selected from the following three phases of the cardiac cycle; 1) at the R wave of the electrocardiogram, 2) 100 msec before the R wave, and 3) 200 msec before the R wave. The last two were superior for obtaining mask and live films which were similar in shape, because the cardiac motion in these phases was relatively small. Using these mask and live films, DSA was performed either with the continuous image mode (CI mode) or the time interval difference mode (TID mode). The overall perfusion of contrast medium through the artery to the vein was adequately visualized using the CI mode. Passage of contrast medium through the artery, capillary and vein was visualized at each phase using TID mode. Subtracted images were displayed and photographed, and the density of the contrast medium was adequate to display contour lines as in a relief map. Using this DSA, it was found that regional perfusion of the contrast medium was not always uniform in normal subjects, depending on the typography of the coronary artery. In all patients with anterior myocardial infarction, low perfusion was observed at the infarcted portion compared to the non-infarcted myocardium. In patients with inferior myocardial infarction, this low perfusion area was not observed because right coronary angiography was not subjected to DSA in this study. (J.P.N.)

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

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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.)

Erbium-Based Perfusion Contrast Agent for Small-Animal Microvessel Imaging

Directory of Open Access Journals (Sweden)

Justin J. Tse

2017-01-01

Full Text Available Micro-computed tomography (micro-CT facilitates the visualization and quantification of contrast-enhanced microvessels within intact tissue specimens, but conventional preclinical vascular contrast agents may be inadequate near dense tissue (such as bone. Typical lead-based contrast agents do not exhibit optimal X-ray absorption properties when used with X-ray tube potentials below 90 kilo-electron volts (keV. We have developed a high-atomic number lanthanide (erbium contrast agent, with a K-edge at 57.5 keV. This approach optimizes X-ray absorption in the output spectral band of conventional microfocal spot X-ray tubes. Erbium oxide nanoparticles (nominal diameter 4000 Hounsfield units, and perfusion of vessels < 10 μm in diameter was demonstrated in kidney glomeruli. The described new contrast agent facilitated the visualization and quantification of vessel density and microarchitecture, even adjacent to dense bone. Erbium’s K-edge makes this contrast agent ideally suited for both single- and dual-energy micro-CT, expanding potential preclinical research applications in models of musculoskeletal, oncological, cardiovascular, and neurovascular diseases.

Differentiating benign and malignant breast lesions with T2*-weighted first pass perfusion imaging

International Nuclear Information System (INIS)

Kvistad, K.A.; Smenes, E.; Haraldseth, O.; Lundgren, S.; Fjoesne, H.E.; Smethurst, H.B.

1999-01-01

Purpose: Invasive breast carcinomas and fibroadenomas are often difficult to differentiate in dynamic contrast-enhanced T1-weighted MR imaging of the breast, because both tumors can enhance strongly after contrast injection. The purpose of this study was to evaluate whether the addition of T2*-weighted first pass perfusion imaging can increase the differentiation of malignant from benign lesions. Material and Methods: Nine patients with invasive carcinomas and 10 patients with contrast enhancing fibroadenomas were examined by a dynamic contrast-enhanced T1-weighted 3D sequence immediately followed by a single slice T2*-weighted first pass perfusion sequence positioned in the contrast-enhancing lesion. Results: The carcinomas and the fibroadenomas were impossible to differentiate based on the contrast enhancement characteristics in the T1-weighted sequence. The signal loss in the T2*-weighted perfusion sequence was significantly stronger in the carcinomas than in the fibroadenomas (p=0.0004). Conclusion: Addition of a T2*-weighted first pass perfusion sequence with a high temporal resolution can probably increase the differentiation of fibroadenomas from invasive carcinomas in contrast-enhanced MR imaging of the breast. (orig.)

Structural and perfusion magnetic resonance imaging of the lung in cystic fibrosis

International Nuclear Information System (INIS)

Amaxopoulou, Christina; Gnannt, Ralph; Kellenberger, Christian J.; Higashigaito, Kai; Jung, Andreas

2018-01-01

Because of its absence of ionising radiation and possibility for obtaining functional information, MRI is promising for assessing lung disease in children who require repetitive imaging for long-term follow-up. To describe MRI findings in children with cystic fibrosis and evaluate semi-quantitative dynamic contrast-enhanced lung perfusion. We retrospectively compared lung MRI in 25 children and young adults with cystic fibrosis (median age 3.7 years) to 12 children (median age 2 years) imaged for other pathologies. MRI at 1.5 T included respiratory-gated sequences and contrast-enhanced lung perfusion imaging. We described and graded any morphologic change. Signal enhancement and time to peak values of perfusion abnormalities were compared to those of normally enhancing lung parenchyma. Frequent findings in patients with cystic fibrosis were bronchial wall thickening (24/25, 96%), areas of consolidation (22/25, 88%), enlarged lymph nodes (20/25, 80%), bronchiectasis (5/25, 20%) and mucus plugging (3/25, 12%). Compared to normally enhancing lung, perfusion defects (21/25, 84%), characterised by decreased enhancement, showed prolonged time to peak. Areas of consolidation showed increased enhancement. While time to peak of procedure-related atelectasis was not significantly different from that of normal lung, disease-related consolidation showed prolonged time to peak (P=0.01). Lung MRI demonstrates structural and perfusion abnormalities in children and young people with cystic fibrosis. Semi-quantitative assessment of dynamic contrast-enhanced perfusion imaging might allow differentiation between procedure-related atelectasis and disease-related consolidation. (orig.)

Structural and perfusion magnetic resonance imaging of the lung in cystic fibrosis

Energy Technology Data Exchange (ETDEWEB)

Amaxopoulou, Christina; Gnannt, Ralph; Kellenberger, Christian J. [University Children' s Hospital Zuerich, Department of Diagnostic Imaging, Zuerich, CH (Switzerland); University Children' s Hospital Zuerich, Children' s Research Center, Zuerich (Switzerland); Higashigaito, Kai [University Hospital Zuerich, Institute of Diagnostic and Interventional Radiology, Zuerich (Switzerland); Jung, Andreas [University Children' s Hospital Zuerich, Children' s Research Center, Zuerich (Switzerland); University Children' s Hospital Zuerich, Division of Pneumology, Zuerich (Switzerland)

2018-02-15

Because of its absence of ionising radiation and possibility for obtaining functional information, MRI is promising for assessing lung disease in children who require repetitive imaging for long-term follow-up. To describe MRI findings in children with cystic fibrosis and evaluate semi-quantitative dynamic contrast-enhanced lung perfusion. We retrospectively compared lung MRI in 25 children and young adults with cystic fibrosis (median age 3.7 years) to 12 children (median age 2 years) imaged for other pathologies. MRI at 1.5 T included respiratory-gated sequences and contrast-enhanced lung perfusion imaging. We described and graded any morphologic change. Signal enhancement and time to peak values of perfusion abnormalities were compared to those of normally enhancing lung parenchyma. Frequent findings in patients with cystic fibrosis were bronchial wall thickening (24/25, 96%), areas of consolidation (22/25, 88%), enlarged lymph nodes (20/25, 80%), bronchiectasis (5/25, 20%) and mucus plugging (3/25, 12%). Compared to normally enhancing lung, perfusion defects (21/25, 84%), characterised by decreased enhancement, showed prolonged time to peak. Areas of consolidation showed increased enhancement. While time to peak of procedure-related atelectasis was not significantly different from that of normal lung, disease-related consolidation showed prolonged time to peak (P=0.01). Lung MRI demonstrates structural and perfusion abnormalities in children and young people with cystic fibrosis. Semi-quantitative assessment of dynamic contrast-enhanced perfusion imaging might allow differentiation between procedure-related atelectasis and disease-related consolidation. (orig.)

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

International Nuclear Information System (INIS)

Eichinger, Monika; Puderbach, Michael; Zuna, Ivan; Kauczor, Hans-Ulrich; Fink, Christian; Gahr, Julie; Mueller, Frank-Michael; Ley, Sebastian; Plathow, Christian; Tuengerthal, Siegfried

2006-01-01

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

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

Magnetic Resonance Imaging of Ventilation and Perfusion in the Lung

Science.gov (United States)

Prisk, Gordon Kim (Inventor); Hopkins, Susan Roberta (Inventor); Buxton, Richard Bruce (Inventor); Pereira De Sa, Rui Carlos (Inventor); Theilmann, Rebecca Jean (Inventor); Cronin, Matthew Vincent (Inventor)

2017-01-01

Methods, devices, and systems are disclosed for implementing a fully quantitative non-injectable contrast proton MRI technique to measure spatial ventilation-perfusion (VA/Q) matching and spatial distribution of ventilation and perfusion. In one aspect, a method using MRI to characterize ventilation and perfusion in a lung includes acquiring an MR image of the lung having MR data in a voxel and obtaining a breathing frequency parameter, determining a water density value, a specific ventilation value, and a perfusion value in at least one voxel of the MR image based on the MR data and using the water density value to determine an air content value, and determining a ventilation-perfusion ratio value that is the product of the specific ventilation value, the air content value, the inverse of the perfusion value, and the breathing frequency.

Magnetic Particle Imaging for Real-Time Perfusion Imaging in Acute Stroke.

Science.gov (United States)

Ludewig, Peter; Gdaniec, Nadine; Sedlacik, Jan; Forkert, Nils D; Szwargulski, Patryk; Graeser, Matthias; Adam, Gerhard; Kaul, Michael G; Krishnan, Kannan M; Ferguson, R Matthew; Khandhar, Amit P; Walczak, Piotr; Fiehler, Jens; Thomalla, Götz; Gerloff, Christian; Knopp, Tobias; Magnus, Tim

2017-10-24

The fast and accurate assessment of cerebral perfusion is fundamental for the diagnosis and successful treatment of stroke patients. Magnetic particle imaging (MPI) is a new radiation-free tomographic imaging method with a superior temporal resolution, compared to other conventional imaging methods. In addition, MPI scanners can be built as prehospital mobile devices, which require less complex infrastructure than computed tomography (CT) and magnetic resonance imaging (MRI). With these advantages, MPI could accelerate the stroke diagnosis and treatment, thereby improving outcomes. Our objective was to investigate the capabilities of MPI to detect perfusion deficits in a murine model of ischemic stroke. Cerebral ischemia was induced by inserting of a microfilament in the internal carotid artery in C57BL/6 mice, thereby blocking the blood flow into the medial cerebral artery. After the injection of a contrast agent (superparamagnetic iron oxide nanoparticles) specifically tailored for MPI, cerebral perfusion and vascular anatomy were assessed by the MPI scanner within seconds. To validate and compare our MPI data, we performed perfusion imaging with a small animal MRI scanner. MPI detected the perfusion deficits in the ischemic brain, which were comparable to those with MRI but in real-time. For the first time, we showed that MPI could be used as a diagnostic tool for relevant diseases in vivo, such as an ischemic stroke. Due to its shorter image acquisition times and increased temporal resolution compared to that of MRI or CT, we expect that MPI offers the potential to improve stroke imaging and treatment.

Semi-automatic motion compensation of contrast-enhanced ultrasound images from abdominal organs for perfusion analysis

Czech Academy of Sciences Publication Activity Database

Schafer, S.; Nylund, K.; Saevik, F.; Engjom, T.; Mézl, M.; Jiřík, Radovan; Dimcevski, G.; Gilja, O.H.; Tönnies, K.

2015-01-01

Roč. 63, AUG 1 (2015), s. 229-237 ISSN 0010-4825 R&D Projects: GA ČR GAP102/12/2380 Institutional support: RVO:68081731 Keywords : ultrasonography * motion analysis * motion compensation * registration * CEUS * contrast-enhanced ultrasound * perfusion * perfusion modeling Subject RIV: FS - Medical Facilities ; Equipment Impact factor: 1.521, year: 2015

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...

Tumor Vessel Compression Hinders Perfusion of Ultrasonographic Contrast Agents

Directory of Open Access Journals (Sweden)

Mirco Galiè

2005-05-01

Full Text Available Contrast-enhanced ultrasound (CEUS is an advanced approach to in vivo assessment of tumor vascularity and is being increasingly adopted in clinical oncology. It is based on 1- to 10 μm-sized gas microbubbles, which can cross the capillary beds of the lungs and are effective echo enhancers. It is known that high cell density, high transendothelial fluid exchange, and poorly functioning lymphatic circulation all provoke solid stress, which compresses vessels and drastically reduces tumor blood flow. Given their size, we supposed that the perfusion of microbubbles is affected by anatomic features of tumor vessels more than are contrast agents traditionally used in dynamic contrast-enhanced magnetic resonance imaging (DCE-MRI. Here, we compared dynamic information obtained from CEUS and DCE-MRI on two experimental tumor models exhibiting notable differences in vessel anatomy. We found that tumors with small, flattened vessels show a much higher resistance to microbubble perfusion than to MRI contrast agents, and appear scarcely vascularized at CEUS examination, despite vessel volume adequate for normal function. Thus, whereas CEUS alone could induce incorrect diagnosis when tumors have small or collapsed vessels, integrated analysis using CEUS and DCE-MRI allows in vivo identification of tumors with a vascular profile frequently associated with malignant phenotypes.

Perfusion quantification in contrast-enhanced ultrasound (CEUS)--ready for research projects and routine clinical use.

Science.gov (United States)

Tranquart, F; Mercier, L; Frinking, P; Gaud, E; Arditi, M

2012-07-01

With contrast-enhanced ultrasound (CEUS) now established as a valuable imaging modality for many applications, a more specific demand has recently emerged for quantifying perfusion and using measured parameters as objective indicators for various disease states. However, CEUS perfusion quantification remains challenging and is not well integrated in daily clinical practice. The development of VueBox™ alleviates existing limitations and enables quantification in a standardized way. VueBox™ operates as an off-line software application, after dynamic contrast-enhanced ultrasound (DCE-US) is performed. It enables linearization of DICOM clips, assessment of perfusion using patented curve-fitting models, and generation of parametric images by synthesizing perfusion information at the pixel level using color coding. VueBox™ is compatible with most of the available ultrasound platforms (nonlinear contrast-enabled), has the ability to process both bolus and disruption-replenishment kinetics loops, allows analysis results and their context to be saved, and generates analysis reports automatically. Specific features have been added to VueBox™, such as fully automatic in-plane motion compensation and an easy-to-use clip editor. Processing time has been reduced as a result of parallel programming optimized for multi-core processors. A long list of perfusion parameters is available for each of the two administration modes to address all possible demands currently reported in the literature for diagnosis or treatment monitoring. In conclusion, VueBox™ is a valid and robust quantification tool to be used for standardizing perfusion quantification and to improve the reproducibility of results across centers. © Georg Thieme Verlag KG Stuttgart · New York.

[Myocardial perfusion imaging by digital subtraction angiography].

Science.gov (United States)

Kadowaki, H; Ishikawa, K; Ogai, T; Katori, R

1986-03-01

Several methods of digital subtraction angiography (DSA) were compared to determine which could better visualize regional myocardial perfusion using coronary angiography in seven patients with myocardial infarction, two with angina pectoris and five with normal coronary arteries. Satisfactory DSA was judged to be achieved if the shape of the heart on the mask film was identical to that on the live film and if both films were exactly superimposed. To obtain an identical mask film in the shape of each live film, both films were selected from the following three phases of the cardiac cycle; at the R wave of the electrocardiogram, 100 msec before the R wave, and 200 msec before the R wave. The last two were superior for obtaining mask and live films which were similar in shape, because the cardiac motion in these phases was relatively small. Using these mask and live films, DSA was performed either with the continuous image mode (CI mode) or the time interval difference mode (TID mode). The overall perfusion of contrast medium through the artery to the vein was adequately visualized using the CI mode. Passage of contrast medium through the artery, capillary and vein was visualized at each phase using TID mode. Subtracted images were displayed and photographed, and the density of the contrast medium was adequate to display contour lines as in a relief map. Using this DSA, it was found that regional perfusion of the contrast medium was not always uniform in normal subjects, depending on the typography of the coronary artery.(ABSTRACT TRUNCATED AT 250 WORDS)

Laser doppler perfusion imaging

International Nuclear Information System (INIS)

Waardell, K.

1992-01-01

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

Non-contrast-enhanced perfusion and ventilation assessment of the human lung by means of fourier decomposition in proton MRI.

Science.gov (United States)

Bauman, Grzegorz; Puderbach, Michael; Deimling, Michael; Jellus, Vladimir; Chefd'hotel, Christophe; Dinkel, Julien; Hintze, Christian; Kauczor, Hans-Ulrich; Schad, Lothar R

2009-09-01

Assessment of regional lung perfusion and ventilation has significant clinical value for the diagnosis and follow-up of pulmonary diseases. In this work a new method of non-contrast-enhanced functional lung MRI (not dependent on intravenous or inhalative contrast agents) is proposed. A two-dimensional (2D) true fast imaging with steady precession (TrueFISP) pulse sequence (TR/TE = 1.9 ms/0.8 ms, acquisition time [TA] = 112 ms/image) was implemented on a 1.5T whole-body MR scanner. The imaging protocol comprised sets of 198 lung images acquired with an imaging rate of 3.33 images/s in coronal and sagittal view. No electrocardiogram (ECG) or respiratory triggering was used. A nonrigid image registration algorithm was applied to compensate for respiratory motion. Rapid data acquisition allowed observing intensity changes in corresponding lung areas with respect to the cardiac and respiratory frequencies. After a Fourier analysis along the time domain, two spectral lines corresponding to both frequencies were used to calculate the perfusion- and ventilation-weighted images. The described method was applied in preliminary studies on volunteers and patients showing clinical relevance to obtain non-contrast-enhanced perfusion and ventilation data.

Myocardial first pass perfusion imaging with gadobutrol: impact of parallel imaging algorithms on image quality and signal behavior.

Science.gov (United States)

Theisen, Daniel; Wintersperger, Bernd J; Huber, Armin; Dietrich, Olaf; Reiser, Maximilian F; Schönberg, Stefan O

2007-07-01

To implement parallel imaging algorithms in fast gradient recalled echo sequences for myocardial perfusion imaging and evaluate image quality, signal-to-noise ratio (SNR), contrast-enhancement ratio (CER), and semiquantitative perfusion parameters. In 20 volunteers, myocardial perfusion imaging with gadobutrol was performed at rest using an accelerated TurboFLASH sequence (TR 2.3 milliseconds, TE 0.93 milliseconds, flip angle [FA] 15 degrees) with GRAPPA, R=2. A nonaccelerated TurboFLASH sequence with similar scan parameters served as standard of reference. Artifacts were assessed qualitatively. SNR, CER, and CNR were calculated and semiquantitative perfusion parameters were determined from fitted SI-time curves. Phantom measurements yielded significant higher SNR for nonaccelerated images (Pimages (Pimages for artifacts by 2 board-certified radiologists yielded a significant reduction in dark rim artifacts with GRAPPA, R=2 (P<0.001). The application of GRAPPA with an acceleration factor of R=2 leads to a significant reduction of dark rim artifacts in fast gradient recalled echo sequences.

Perfusion magnetic resonance imaging provides additional information as compared to anatomical imaging for decision-making in vestibular schwannoma

International Nuclear Information System (INIS)

Kleijwegt, M.C.; Mey, A.G.L. van der; Wiggers-deBruine, F.T.; Malessy, M.J.A; Osch, M.J.P. van

2016-01-01

•DSC/ASL-MRI can be acquired in growing VS with sufficient image quality.•In most patients DSC and ASL techniques provide similar qualitative scores.•These techniques can be of importance in future decision-making. DSC/ASL-MRI can be acquired in growing VS with sufficient image quality. In most patients DSC and ASL techniques provide similar qualitative scores. These techniques can be of importance in future decision-making. The added value of perfusion MRI for decision-making in vestibular schwannoma (VS) patients is unknown. MRI offers two perfusion methods: the first employing contrast agent (dynamic susceptibility contrast (DSC)-MRI) that provides information on cerebral blood volume (CBV) and cerebral blood flow (CBF), the second by magnetic labeling of blood (arterial spin labeling (ASL)-MRI), providing CBF-images. The goal of the current study is to investigate whether DSC and ASL perfusion MRI provides complimentary information to current anatomical imaging in treatment selection process of VS. Nine patients with growing VS with extrameatal diameter >9 mm were included (>2 mm/year and 20% volume expansion/year) and one patient with 23 mm extrameatal VS without growth. DSC and ASL perfusion MRI were obtained on 3 T MRI. Perfusion in VS was scored as hyperintense, hypointense or isointense compared to the contralateral region. Seven patients showed hyperintense signal on DSC and ASL sequences. Three patients showed iso- or hypointense signal on at least one perfusion map (1 patient hypointense on both DSC-MRI and ASL; 1 patient isointense on DSC-CBF; 1 patient isointense on ASL). All patients showed enhancement on post-contrast T1 anatomical scan. Perfusion MR provides additional information compared to anatomical imaging for decision-making in VS

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

Energy Technology Data Exchange (ETDEWEB)

Miyasaka, Takashi [Toho Univ., Tokyo (Japan). School of Medicine

1997-09-01

The effects of smoking on ventilation-perfusion lung scintigrams were investigated. The subjects comprised 40 healthy males (28 smokers and 12 nonsmokers) without a history of cardiopulmonary disease and with normal chest radiographs. After acquisition of planar images of ventilation lung scintigrams with 370 MBq of {sup 133}Xe gas, planar images and SPECT images of pulmonary perfusion flow were obtained using 185 MBq of {sup 99m}Tc-MAA. Planar imaging showed perfusion defects in only 5 smokers. In contrast, 16 subjects were found to have perfusion defects on SPECT images (p<0.05), indicating the usefulness of SPECT images in detecting minor vascular damage of the lung. Although perfusion defects were common in the smokers (p<0.05), their relationship to the BRINKMAN index was uncertain. The perfusion defects found in the smokers were nonsegmental and commonly involved the right upper lobe. Ventilation scans revealed only delayed washout of {sup 133}Xe in 4 smokers, suggesting that smoking-induced abnormal perfusion on SPECT appears earlier than impaired ventilation on scintigrams. (author)

Reproducibility of rest and exercise stress contrast-enhanced calf perfusion magnetic resonance imaging in peripheral arterial disease

Directory of Open Access Journals (Sweden)

Jiji Ronny S

2013-01-01

Full Text Available Abstract Background The purpose was to determine the reproducibility and utility of rest, exercise, and perfusion reserve (PR measures by contrast-enhanced (CE calf perfusion magnetic resonance imaging (MRI of the calf in normal subjects (NL and patients with peripheral arterial disease (PAD. Methods Eleven PAD patients with claudication (ankle-brachial index 0.67 ±0.14 and 16 age-matched NL underwent symptom-limited CE-MRI using a pedal ergometer. Tissue perfusion and arterial input were measured at rest and peak exercise after injection of 0.1 mM/kg of gadolinium-diethylnetriamine pentaacetic acid (Gd-DTPA. Tissue function (TF and arterial input function (AIF measurements were made from the slope of time-intensity curves in muscle and artery, respectively, and normalized to proton density signal to correct for coil inhomogeneity. Perfusion index (PI = TF/AIF. Perfusion reserve (PR = exercise TF/ rest TF. Intraclass correlation coefficient (ICC was calculated from 11 NL and 10 PAD with repeated MRI on a different day. Results Resting TF was low in NL and PAD (mean ± SD 0.25 ± 0.18 vs 0.35 ± 0.71, p = 0.59 but reproducible (ICC 0.76. Exercise TF was higher in NL than PAD (5.5 ± 3.2 vs. 3.4 ± 1.6, p = 0.04. Perfusion reserve was similar between groups and highly variable (28.6 ± 19.8 vs. 42.6 ± 41.0, p = 0.26. Exercise TF and PI were reproducible measures (ICC 0.63 and 0.60, respectively. Conclusion Although rest measures are reproducible, they are quite low, do not distinguish NL from PAD, and lead to variability in perfusion reserve measures. Exercise TF and PI are the most reproducible MRI perfusion measures in PAD for use in clinical trials.

Tumor Vessel Compression Hinders Perfusion of Ultrasonographic Contrast Agents1

Science.gov (United States)

Galiè, Mirco; D'Onofrio, Mirko; Montani, Maura; Amici, Augusto; Calderan, Laura; Marzola, Pasquina; Benati, Donatella; Merigo, Flavia; Marchini, Cristina; Sbarbati, Andrea

2005-01-01

Abstract Contrast-enhanced ultrasound (CEUS) is an advanced approach to in vivo assessment of tumor vascularity and is being increasingly adopted in clinical oncology. It is based on 1- to 10 µm-sized gas microbubbles, which can cross the capillary beds of the lungs and are effective echo enhancers. It is known that high cell density, high transendothelial fluid exchange, and poorly functioning lymphatic circulation all provoke solid stress, which compresses vessels and drastically reduces tumor blood flow. Given their size, we supposed that the perfusion of microbubbles is affected by anatomic features of tumor vessels more than are contrast agents traditionally used in dynamic contrast-enhanced magnetic resonance imaging (DCE-MRI). Here, we compared dynamic information obtained from CEUS and DCE-MRI on two experimental tumor models exhibiting notable differences in vessel anatomy. We found that tumors with small, flattened vessels show a much higher resistance to microbubble perfusion than to MRI contrast agents, and appear scarcely vascularized at CEUS examination, despite vessel volume adequate for normal function. Thus, whereas CEUS alone could induce incorrect diagnosis when tumors have small or collapsed vessels, integrated analysis using CEUS and DCE-MRI allows in vivo identification of tumors with a vascular profile frequently associated with malignant phenotypes. PMID:15967105

Tissue Necrosis Monitoring for HIFU Ablation with T1 Contrast MRI Imaging

Science.gov (United States)

Hwang, San-Chao; Yao, Ching; Kuo, Ih-Yuan; Tsai, Wei-Cheng; Chang, Hsu

2011-09-01

In MR-guided HIFU ablation, MTC (Magnetization Transfer Contrast) or perfusion imaging is usually used after ablation to evaluate the ablated area based on the thermally induced necrosis contrast. In our MR-guided HIFU ablation study, a T1 contrast MRI scan sequence has been used to distinguish between necrotic and non-necrotic tissue. The ablation of porcine meat in-vitro and in-vivo pig leg muscle show that the necrotic area of T1 contrast MRI image coincides with the photographs of sliced specimen. The sequence is considerably easier to apply than MTC or perfusion imaging, while giving good necrosis contrast. In addition, no injection of contrast agent is needed, allowing multiple scans to be applied throughout the entire ablation procedure.

Comparison between perfusion computed tomography and dynamic contrast-enhanced magnetic resonance imaging in assessing glioblastoma microvasculature

Energy Technology Data Exchange (ETDEWEB)

Jia, Zhong Zheng, E-mail: jzz2397@163.com [Department of Radiology, Affiliated Hospital of Nantong University, No. 20 Xisi Road Nantong 226001, Jiangsu (China); Shi, Wei, E-mail: sw740104@hotmail.com [Department of Neurosurgery, Affiliated Hospital of Nantong University, 20 Xisi Road, Nantong 226001, Jiangsu (China); Shi, Jin Long, E-mail: shij_ns@163.com [Department of Neurosurgery, Affiliated Hospital of Nantong University, 20 Xisi Road, Nantong 226001, Jiangsu (China); Shen, Dan Dan, E-mail: 1021121084@qq.com [Department of Radiology, Affiliated Hospital of Nantong University, No. 20 Xisi Road Nantong 226001, Jiangsu (China); Gu, Hong Mei, E-mail: guhongmei71@163.com [Department of Radiology, Affiliated Hospital of Nantong University, No. 20 Xisi Road Nantong 226001, Jiangsu (China); Zhou, Xue Jun, E-mail: 56516400@qq.com [Department of Radiology, Affiliated Hospital of Nantong University, No. 20 Xisi Road Nantong 226001, Jiangsu (China)

2017-02-15

Purpose: Perfusion computed tomography (PCT) and dynamic contrast-enhanced magnetic resonance imaging (DCE-MRI) provide independent measurements of biomarkers related to tumor perfusion. The aim of this study was to compare the two techniques in assessing glioblastoma microvasculature. Materials and methods: Twenty-five patients diagnosed with glioblastoma (14 males and 11 females; 51 ± 11 years old, ranging from 33 to 70 years) were includede in this prospective study. All patients underwent both PCT and DCE-MRI. Imaging was performed on a 256-slice CT scanner and a 3-T MRI system. PCT yielded permeability surface-area product (PS) using deconvolution physiological models; meanwhile, DCE-MRI determined volume transfer constant (K{sup trans}) using the Tofts-Kermode compartment model. All cases were submitted to surgical intervention, and CD105-microvascular density (CD105-MVD) was measured in each glioblastoma specimen. Then, Spearman’s correlation coefficients and Bland-Altman plots were obtained for PS, K{sup trans} and CD105-MVD. P < 0.05 was considered statistically significant. Results: Tumor PS and K{sup trans} values were correlated with CD105-MVD (r = 0.644, P < 0.001; r = 0.683, P < 0.001). In addition, PS was correlated with K{sup trans} in glioblastoma (r = 0.931, P < 0.001). Finally, Bland-Altman plots showed no significant differences between PS and K{sup trans} (P = 0.063). Conclusion: PCT and DCE-MRI measurements of glioblastoma perfusion biomarkers have similar results, suggesting that both techniques may have comparable utility. Therefore, PCT may serve as an alternative modality to DCE-MRI for the in vivo evaluation of glioblastoma microvasculature.

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.)

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

International Nuclear Information System (INIS)

Le Bihan, D.

2008-01-01

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.)

Computed tomography perfusion imaging denoising using Gaussian process regression

International Nuclear Information System (INIS)

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

2012-01-01

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. (note)

Usefulness of perfusion MR imaging in hyperacute ischemic stroke

International Nuclear Information System (INIS)

Park, Ji Hoon; Kim, Jae Hyoung; Shin, Tae Min; Lee, Eun Ja; Chung, Sung Hoon; Choi, Nack Cheon; Lim, Byeong Hoon; Kim, In One

1998-01-01

Perfusion MR imaging is a new technique for the assessment of acute ischemic stroke. The aim of this study was to evaluate the usefulness of this imaging in hyperacute ischemic stroke in comparison with conventional CT and MR imaging. Eight patients presenting the symptoms of acute ischemic stroke due to middle cerebral artery occlusion were included in this study. Within 2 hours of initial CT scan and 6 hours after the onset of stroke, perfusion MR imaging was performed in all patients using a single-section dynamic contrast-enhanced T2*-weighted imager in conjunction with conventional routine MR imaging and MR angiography. Cerebral blood volume (CBV) maps were then obtained from dynamic MR imaging data by using numerical integration techniques. The findings of CBV maps were compared with those of initial and follow-up CT or MR images. The findings of CBV maps were obviously abnormal in all patients, as compared with normal or focal subtle abnormal findings seen on initial CT and MR images. CBV in the occluded arterial territory was lower in all eight patients;two had focal regions of increased CBV within the affected territory, indicating reperfusion hyperemia. In all patients, regions of abnormal CBV were eventually converted to infarctions on follow-up images. Perfusion MR imaging was useful for the evaluation of hemodynamic change occurring during cerebral perfusion in hyperacute ischemic stroke, and prediction of the final extent of infarction. These results suggest that pertusion MR imaging can play an important role in the diagnosis and management of hyperacute ischemic stroke.=20

Dynamic contrast-enhanced perfusion studies of the brain with snapshot FLASH

International Nuclear Information System (INIS)

Finelli, D.A.; Kiefer, B.; Deimling, M.; Loeffler, W.; Haase, A.; Schuierer, G.

1989-01-01

This paper discusses how MR imaging with Gd-DTPA can improve the diagnostic accuracy of brain examinations. Conventional T1-weighted spin-echo sequences have been most satisfactory for depicting lesion enhancement following Gd-DTPA administration, however, the ability to examine the blood pool and early biodistribution phases has been limited. A new ultrafast MR imaging technique called Snapshot FLASH allows one to acquire entire images in 125-900 msec, with strong T1- or T2-weighted contrast. With this imaging technique, one can observe differential perfusion to the gray matter, while matter, and brain lesions during the first seconds following Gd-DTPA administration

Diffusion and Perfusion Magnetic Resonance Imaging:Fundamentals and Advances

OpenAIRE

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...

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

Energy Technology Data Exchange (ETDEWEB)

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

2013-05-15

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

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.)

The preliminary study of CT cerebral perfusion imaging in transient ischemic attacks

International Nuclear Information System (INIS)

Lu Jie; Li Kuncheng; Du Xiangying

2002-01-01

Objective: To probe the application of CT cerebral perfusion imaging on transient ischemic attacks (TIA). Methods: Conventional CT and CT cerebral perfusion imaging were performed on 5 normal adults and 20 patients with clinically diagnosed TIA. After regular CT examination, dynamic scans of 40 seconds were performed on selected slice (usually on the basal ganglia slice), while 40 ml non-ionic contrast material were bolus injected through antecubital vein with. These dynamic images were processed with the 'Perfusion CT' software package on a PC based workstation. Cerebral blood flow (CBF) and time to peak (TP) enhancement were measured within specific regions of the brain on CT perfusion images. Quantitative analysis was performed for these images. Results: A gradient of perfusion between gray matter and white matter was showed on cT perfusion images in normal adults and TIA patients. CBF and TP for normal cortical and white matter were 378.2 ml·min -1 ·L -1 , 7.8 s and 112.5 ml·min -1 ·L -1 , 9.9 s, respectively. In 20 cases with TIA, persisting abnormal perfusion changes corresponding to clinical symptoms were found in 15 cases with prolonged TP. Other 5 cases showed normal results. TP of affected side (11.8 +- 4.4) s compared with that of the contralateral side (9.1 +- 3.1) s was significantly prolonged (t = 5.277, P -1 · -1 ] and contralateral side [(229.1 +- 41.4) ml·min -1 ·L -1 ]. Conclusion: Perfusion CT provides valuable hemodynamic information and shows the extent of perfusion disturbances for patients with TIA

Arterial spin-labeling perfusion imaging of childhood meningitis: a case series.

Science.gov (United States)

Wong, Alex Mun-Ching; Yeh, Chih-Hua; Liu, Ho-Ling; Lin, Kuang-Lin; Wang, Huei-Shyong; Toh, Cheng-Hong

2016-03-01

Conventional magnetic resonance imaging (MRI), which is mainly used to detect complications, is ineffective in determining the neurological status of patients with meningitis. Hemodynamic change in the brain may be more indicative of the neurological status but few imaging studies have verified this. Arterial spin-labeling (ASL) perfusion, a noninvasive MR method requiring no contrast agent injection, can be used to measure cerebral blood flow (CBF). We describe three pediatric patients with meningitis, who all showed regions of increased CBF on perfusion imaging. One patient, presenting with headache and conscious disturbance, had CBF changes in the frontal, temporal, and occipital regions. The other two patients, presenting with hallucinations, memory deficits, and seizures, had CBF changes in the frontal and temporal regions. ASL perfusion imaging may be helpful in assessing patients with meningitis, demonstrating CBF changes more strongly correlating with the neurological status, and detecting active brain abnormalities.

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

International Nuclear Information System (INIS)

Ida, Kentaro; Akaki, Shiro; Sei, Tetsuro; Kanazawa, Susumu; Tsunoda, Masatoshi

2006-01-01

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

Blood Perfusion in Human Eyelid Skin Flaps Examined by Laser Speckle Contrast Imaging-Importance of Flap Length and the Use of Diathermy.

Science.gov (United States)

Nguyen, Cu Dinh; Hult, Jenny; Sheikh, Rafi; Tenland, Kajsa; Dahlstrand, Ulf; Lindstedt, Sandra; Malmsjö, Malin

2017-10-11

It is well known that blood perfusion is important for the survival of skin flaps. As no study has been conducted to investigate how the blood perfusion in human eyelid skin flaps is affected by the flap length and diathermy, the present study was carried out to investigate these in patients. Fifteen upper eyelids were dissected as part of a blepharoplastic procedure, releasing a 30-mm long piece of skin, while allowing the 5 mm wide distal part of the skin to remain attached, to mimic a skin flap (hereafter called a "skin flap"). Blood perfusion was measured before and after repeated diathermy, using laser speckle contrast imaging. Blood perfusion decreased from the base to the tip of the flap: 5 mm from the base, the perfusion was 69%, at 10 mm it was 40%, at 15 mm it was 20%, and at 20 mm it was only 13% of baseline values. Diathermy further decreased blood perfusion (measured 15 mm from the base) to 13% after applying diathermy for the first time, to 6% after the second and to 4% after the third applications of diathermy. Blood perfusion falls rapidly with distance from the base of skin flaps on the human eyelid, and diathermy reduces blood perfusion even further. Clinically, it may be advised that flaps with a width of 5 mm be no longer than 15 mm (i.e., a width:length ratio of 1:3), and that the use of diathermy should be carefully considered.

Sporadic insulinomas on volume perfusion CT: dynamic enhancement patterns and timing of optimal tumour-parenchyma contrast

Energy Technology Data Exchange (ETDEWEB)

Zhu, Liang; Xue, Hua-dan; Liu, Wei; Wang, Xuan; Sun, Hao; Li, Ping; Jin, Zheng-yu [Peking Union Medical College Hospital, Department of Radiology, Beijing (China); Wu, Wen-ming; Zhao, Yu-pei [Peking Union Medical College Hospital, Department of General Surgery, Beijing (China)

2017-08-15

To assess enhancement patterns of sporadic insulinomas on volume perfusion CT (VPCT), and to identify timing of optimal tumour-parenchyma contrast. Consecutive patients who underwent VPCT for clinically suspected insulinomas were retrospectively identified. Patients with insulinomas confirmed by surgery were included, and patients with familial syndromes were excluded. Two radiologists evaluated VPCT images in consensus. Tumour-parenchyma contrast at each time point was measured, and timing of optimal contrast was determined. Time duration of hyperenhancement (tumour-parenchyma contrast >20 Hounsfield units, HU) was recorded. Perfusion parameters were evaluated. Three dynamic enhancement patterns were observed in 63 tumours: persistent hyperenhancement (hyperenhancement time window ≥10 s) in 39 (61.9%), transient hyperenhancement (hyperenhancement <10 s) in 19 (30.2%) and non-hyperenhancement in 5 (7.9%). Timing of optimal contrast was 9 s after abdominal aorta threshold (AAT) of 200 HU, with tumour-parenchyma contrast of 77.6 ± 57.2 HU. At 9 s after AAT, 14 (22.2%) tumours were non-hyperenhancing, nine of which had missed transient hyperenhancement. Insulinomas with transient and persistent hyperenhancement patterns had significantly increased perfusion. Insulinomas have variable enhancement patterns. Tumour-parenchyma contrast is time-dependent. Optimal timing of enhancement is 9 s after AAT. VPCT enables tumour detection even if the hyperenhancement is transient. (orig.)

Application of parametric ultrasound contrast agent perfusion studies for differentiation of hyperplastic adrenal nodules from adenomas—Initial study

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Slapa, Rafal Z., E-mail: rz.slapa@gmail.com [Diagnostic Imaging Department, Medical University of Warsaw, Second Faculty of Medicine with English and Physiotherapy Divisions, Warsaw (Poland); Kasperlik–Zaluska, Anna A. [Endocrinology Department, Center for Postgraduate Medical Education, Bielanski Hospital, Warsaw (Poland); Migda, Bartosz [Diagnostic Imaging Department, Medical University of Warsaw, Second Faculty of Medicine with English and Physiotherapy Divisions, Warsaw (Poland); Otto, Maciej [Department of General, Vascular and Transplant Surgery, Medical University of Warsaw, First Faculty of Medicine, Warsaw (Poland); Jakubowski, Wiesław S. [Diagnostic Imaging Department, Medical University of Warsaw, Second Faculty of Medicine with English and Physiotherapy Divisions, Warsaw (Poland)

2015-08-15

Highlights: • Adrenal masses may differ on parametric perfusion ultrasound. • Hyperplastic nodules present distinctive patterns on CEUS in regard to adenomas. • Adrenal lesions perfusion should be further investigated with different modalities. - Abstract: Objectives: To evaluate the possibilities of differentiation of non-malignant adrenal masses with the application of the new technique for the evaluation of enhancement after administration of an ultrasound contrast agent: parametric imaging. Patients and Methods: 34 non-malignant adrenal masses in 29 patients were evaluated in a dynamic examination after the administration of ultrasound contrast agent with parametric imaging. Patterns on parametric imaging of arrival time were evaluated. The final diagnosis was based on CT, MRI, biochemical studies, follow up and/or histopathology examination. Results: The study included: 12 adenomas, 10 hyperplastic nodules, 7 myelolipomas, 3 pheochromocytomas, hemangioma with hemorrhage and cyst. The pattern of peripheral laminar inflow of Sonovue on parametric images of arrival time of was 100% sensitive for hyperplastic nodules and 83% specific in regard to adenomas. Conclusions: Parametric contrast enhanced ultrasound may accurately differentiate hyperplastic adrenal nodules from adenomas and could be complementary to CT or MRI. Incorporation of perfusion studies to CT or MRI could possibly enable one-shop complete characterization of adrenal masses. This could deliver additional information in diagnostics of patients with Conn Syndrome and warrants further studies in this cohort of patients.

Application of parametric ultrasound contrast agent perfusion studies for differentiation of hyperplastic adrenal nodules from adenomas—Initial study

International Nuclear Information System (INIS)

Slapa, Rafal Z.; Kasperlik–Zaluska, Anna A.; Migda, Bartosz; Otto, Maciej; Jakubowski, Wiesław S.

2015-01-01

Highlights: • Adrenal masses may differ on parametric perfusion ultrasound. • Hyperplastic nodules present distinctive patterns on CEUS in regard to adenomas. • Adrenal lesions perfusion should be further investigated with different modalities. - Abstract: Objectives: To evaluate the possibilities of differentiation of non-malignant adrenal masses with the application of the new technique for the evaluation of enhancement after administration of an ultrasound contrast agent: parametric imaging. Patients and Methods: 34 non-malignant adrenal masses in 29 patients were evaluated in a dynamic examination after the administration of ultrasound contrast agent with parametric imaging. Patterns on parametric imaging of arrival time were evaluated. The final diagnosis was based on CT, MRI, biochemical studies, follow up and/or histopathology examination. Results: The study included: 12 adenomas, 10 hyperplastic nodules, 7 myelolipomas, 3 pheochromocytomas, hemangioma with hemorrhage and cyst. The pattern of peripheral laminar inflow of Sonovue on parametric images of arrival time of was 100% sensitive for hyperplastic nodules and 83% specific in regard to adenomas. Conclusions: Parametric contrast enhanced ultrasound may accurately differentiate hyperplastic adrenal nodules from adenomas and could be complementary to CT or MRI. Incorporation of perfusion studies to CT or MRI could possibly enable one-shop complete characterization of adrenal masses. This could deliver additional information in diagnostics of patients with Conn Syndrome and warrants further studies in this cohort of patients

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.)

Influence of amplitude-related perfusion parameters in the parotid glands by non-fat-saturated dynamic contrast-enhanced magnetic resonance imaging

Energy Technology Data Exchange (ETDEWEB)

Chiu, Su-Chin [Graduate Institute of Biomedical Electronics and Bioinformatics, National Taiwan University, Taipei 106, Taiwan, Republic of China and Department of Radiology, Tri-Service General Hospital, Taipei 114, Taiwan (China); Cheng, Cheng-Chieh [Department of Radiology, Brigham and Women’s Hospital, Harvard Medical School, Boston, Massachusetts 02115 (United States); Chang, Hing-Chiu [Department of Diagnostic Radiology, The University of Hong Kong (Hong Kong); Chung, Hsiao-Wen [Graduate Institute of Biomedical Electronics and Bioinformatics, National Taiwan University, Taipei 106, Taiwan (China); Department of Radiology, Tri-Service General Hospital, Taipei 114, Taiwan (China); Department of Radiology, National Defense Medical Center, Taipei 114, Taiwan (China); Chiu, Hui-Chu [Ph.D. Program of Technology Management, Chung Hua University, Hsinchu 300, Taiwan (China); Liu, Yi-Jui [Department of Automatic Control Engineering, Feng-Chia University, Taichung 407, Taiwan (China); Hsu, Hsian-He; Juan, Chun-Jung, E-mail: peterjuancj@yahoo.com.tw [Department of Radiology, Tri-Service General Hospital, Taipei 114, Taiwan and Department of Radiology, National Defense Medical Center, Taipei 114, Taiwan (China)

2016-04-15

Purpose: To verify whether quantification of parotid perfusion is affected by fat signals on non-fat-saturated (NFS) dynamic contrast-enhanced magnetic resonance imaging (DCE-MRI) and whether the influence of fat is reduced with fat saturation (FS). Methods: This study consisted of three parts. First, a retrospective study analyzed DCE-MRI data previously acquired on different patients using NFS (n = 18) or FS (n = 18) scans. Second, a phantom study simulated the signal enhancements in the presence of gadolinium contrast agent at six concentrations and three fat contents. Finally, a prospective study recruited nine healthy volunteers to investigate the influence of fat suppression on perfusion quantification on the same subjects. Parotid perfusion parameters were derived from NFS and FS DCE-MRI data using both pharmacokinetic model analysis and semiquantitative parametric analysis. T tests and linear regression analysis were used for statistical analysis with correction for multiple comparisons. Results: NFS scans showed lower amplitude-related parameters, including parameter A, peak enhancement (PE), and slope than FS scans in the patients (all with P < 0.0167). The relative signal enhancement in the phantoms was proportional to the dose of contrast agent and was lower in NFS scans than in FS scans. The volunteer study showed lower parameter A (6.75 ± 2.38 a.u.), PE (42.12% ± 14.87%), and slope (1.43% ± 0.54% s{sup −1}) in NFS scans as compared to 17.63 ± 8.56 a.u., 104.22% ± 25.15%, and 9.68% ± 1.67% s{sup −1}, respectively, in FS scans (all with P < 0.005). These amplitude-related parameters were negatively associated with the fat content in NFS scans only (all with P < 0.05). Conclusions: On NFS DCE-MRI, quantification of parotid perfusion is adversely affected by the presence of fat signals for all amplitude-related parameters. The influence could be reduced on FS scans.

Influence of amplitude-related perfusion parameters in the parotid glands by non-fat-saturated dynamic contrast-enhanced magnetic resonance imaging

International Nuclear Information System (INIS)

Chiu, Su-Chin; Cheng, Cheng-Chieh; Chang, Hing-Chiu; Chung, Hsiao-Wen; Chiu, Hui-Chu; Liu, Yi-Jui; Hsu, Hsian-He; Juan, Chun-Jung

2016-01-01

Purpose: To verify whether quantification of parotid perfusion is affected by fat signals on non-fat-saturated (NFS) dynamic contrast-enhanced magnetic resonance imaging (DCE-MRI) and whether the influence of fat is reduced with fat saturation (FS). Methods: This study consisted of three parts. First, a retrospective study analyzed DCE-MRI data previously acquired on different patients using NFS (n = 18) or FS (n = 18) scans. Second, a phantom study simulated the signal enhancements in the presence of gadolinium contrast agent at six concentrations and three fat contents. Finally, a prospective study recruited nine healthy volunteers to investigate the influence of fat suppression on perfusion quantification on the same subjects. Parotid perfusion parameters were derived from NFS and FS DCE-MRI data using both pharmacokinetic model analysis and semiquantitative parametric analysis. T tests and linear regression analysis were used for statistical analysis with correction for multiple comparisons. Results: NFS scans showed lower amplitude-related parameters, including parameter A, peak enhancement (PE), and slope than FS scans in the patients (all with P < 0.0167). The relative signal enhancement in the phantoms was proportional to the dose of contrast agent and was lower in NFS scans than in FS scans. The volunteer study showed lower parameter A (6.75 ± 2.38 a.u.), PE (42.12% ± 14.87%), and slope (1.43% ± 0.54% s"−"1) in NFS scans as compared to 17.63 ± 8.56 a.u., 104.22% ± 25.15%, and 9.68% ± 1.67% s"−"1, respectively, in FS scans (all with P < 0.005). These amplitude-related parameters were negatively associated with the fat content in NFS scans only (all with P < 0.05). Conclusions: On NFS DCE-MRI, quantification of parotid perfusion is adversely affected by the presence of fat signals for all amplitude-related parameters. The influence could be reduced on FS scans.

TU-CD-BRA-08: Single-Energy Computed Tomography-Based Pulmonary Perfusion Imaging: Proof-Of-Principle in a Canine Model

Energy Technology Data Exchange (ETDEWEB)

Yamamoto, T; Boone, J [University of California Davis School of Medicine, Sacramento, CA (United States); Kent, M; Wisner, E [University of California Davis School of Veterinary Medicine, Davis, CA (United States); Fujita, Y [Tokai University, Isehara (Japan)

2015-06-15

Purpose: Pulmonary perfusion imaging has provided significant insights into pulmonary diseases, and can be useful in radiotherapy. The purpose of this study was to prospectively establish proof-of-principle in a canine model for single-energy CT-based perfusion imaging, which has the potential for widespread clinical implementation. Methods: Single-energy CT perfusion imaging is based on: (1) acquisition of inspiratory breath-hold CT scans before and after intravenous injection of iodinated contrast medium, (2) deformable image registration (DIR) of the two CT image data sets, and (3) subtraction of the pre-contrast image from post-contrast image, yielding a map of Hounsfield unit (HU) enhancement. These subtraction image data sets hypothetically represent perfused blood volume, a surrogate for perfusion. In an IACUC-approved clinical trial, we acquired pre- and post-contrast CT scans in the prone posture for six anesthetized, mechanically-ventilated dogs. The elastix algorithm was used for DIR. The registration accuracy was quantified using the target registration errors (TREs) for 50 pulmonary landmarks in each dog. The gradient of HU enhancement between gravity-dependent (ventral) and non-dependent (dorsal) regions was evaluated to quantify the known effect of gravity, i.e., greater perfusion in ventral regions. Results: The lung volume difference between the two scans was 4.3±3.5% on average (range 0.3%–10.1%). DIR demonstrated an average TRE of 0.7±1.0 mm. HU enhancement in lung parenchyma was 34±10 HU on average and varied considerably between individual dogs, indicating the need for improvement of the contrast injection protocol. HU enhancement in ventral (gravity-dependent) regions was found to be greater than in dorsal regions. A population average ventral-to-dorsal gradient of HU enhancement was strong (R{sup 2}=0.94) and statistically significant (p<0.01). Conclusion: This canine study demonstrated relatively accurate DIR and a strong ventral

TU-CD-BRA-08: Single-Energy Computed Tomography-Based Pulmonary Perfusion Imaging: Proof-Of-Principle in a Canine Model

International Nuclear Information System (INIS)

Yamamoto, T; Boone, J; Kent, M; Wisner, E; Fujita, Y

2015-01-01

Purpose: Pulmonary perfusion imaging has provided significant insights into pulmonary diseases, and can be useful in radiotherapy. The purpose of this study was to prospectively establish proof-of-principle in a canine model for single-energy CT-based perfusion imaging, which has the potential for widespread clinical implementation. Methods: Single-energy CT perfusion imaging is based on: (1) acquisition of inspiratory breath-hold CT scans before and after intravenous injection of iodinated contrast medium, (2) deformable image registration (DIR) of the two CT image data sets, and (3) subtraction of the pre-contrast image from post-contrast image, yielding a map of Hounsfield unit (HU) enhancement. These subtraction image data sets hypothetically represent perfused blood volume, a surrogate for perfusion. In an IACUC-approved clinical trial, we acquired pre- and post-contrast CT scans in the prone posture for six anesthetized, mechanically-ventilated dogs. The elastix algorithm was used for DIR. The registration accuracy was quantified using the target registration errors (TREs) for 50 pulmonary landmarks in each dog. The gradient of HU enhancement between gravity-dependent (ventral) and non-dependent (dorsal) regions was evaluated to quantify the known effect of gravity, i.e., greater perfusion in ventral regions. Results: The lung volume difference between the two scans was 4.3±3.5% on average (range 0.3%–10.1%). DIR demonstrated an average TRE of 0.7±1.0 mm. HU enhancement in lung parenchyma was 34±10 HU on average and varied considerably between individual dogs, indicating the need for improvement of the contrast injection protocol. HU enhancement in ventral (gravity-dependent) regions was found to be greater than in dorsal regions. A population average ventral-to-dorsal gradient of HU enhancement was strong (R"2=0.94) and statistically significant (p<0.01). Conclusion: This canine study demonstrated relatively accurate DIR and a strong ventral

Perfusion MR imaging of the heart with TrueFISP

International Nuclear Information System (INIS)

Schreiber, W.G.; Schmitt, M.; Kalden, P.; Mohrs, O.; Kreitner, K.F.; Thelen, M.; Horstick, G.; Gumbrich, T.; Petersen, S.; Voigtlaender, T.

2001-01-01

Objective: Development and test of a saturation-recovery TrueFISP (SR-Trufi) pulse sequence for myocardial perfusion MR imaging (MRI) using improved gradient hardware. Material and methods: Measurements were performed on a 1.5 T scanner with prototype gradients (50 mT/m, minimum rise time 300 μs). T 1 -weighted first-pass MRI of Gd-DTPA (0.025 μmol/kg) kinetics in the myocardium was performed using an SR-Trufi pulse sequence (T R /T E /α=2.6 ms/1.4 ms/55 ) with a saturation preparation of TD-30 ms before the TrueFISP readout. Measurements were performed in volunteers (n=4) and in a pig model of chronic ischemia (n=1). Results: In phantoms, the signal intensity was linear with contrast concentration up to 0.9 mmol/kg Gd-DTPA. MR images obtained with SR-Trufi had a good image quality and high spatial resolution of 2.1 mmx2.1 mm. Differences of the contrast agent's kinetics between a subendocardial perfusion deficit and neighboring myocardium were well visible on both MR images and signal-time curves derived from the region-of-interest analysis. Conclusion: SR-Trufi appears to be an interesting new technique for the assessment of myocardial microcirculation using dedicated cardiovascular MR systems. (orig.) [de

Assessment of the effects of different sample perfusion procedures on phase-contrast tomographic images of mouse spinal cord

Science.gov (United States)

Stefanutti, E.; Sierra, A.; Miocchi, P.; Massimi, L.; Brun, F.; Maugeri, L.; Bukreeva, I.; Nurmi, A.; Begani Provinciali, G.; Tromba, G.; Gröhn, O.; Giove, F.; Cedola, A.; Fratini, M.

2018-03-01

Synchrotron X-ray Phase Contrast micro-Tomography (SXrPCμT) is a powerful tool in the investigation of biological tissues, including the central nervous system (CNS), and it allows to simultaneously detect the vascular and neuronal network avoiding contrast agents or destructive sample preparations. However, specific sample preparation procedures aimed to optimize the achievable contrast- and signal-to-noise ratio (CNR and SNR, respectively) are required. Here we report and discuss the effects of perfusion with two different fixative agents (ethanol and paraformaldehyde) and with a widely used contrast medium (MICROFIL®) on mouse spinal cord. As a main result, we found that ethanol enhances contrast at the grey/white matter interface and increases the contrast in correspondence of vascular features and fibres, thus providing an adequate spatial resolution to visualise the vascular network at the microscale. On the other hand, ethanol is known to induce tissue dehydration, likely reducing cell dimensions below the spatial resolution limit imposed by the experimental technique. Nonetheless, neurons remain well visible using either perfused paraformaldehyde or MICROFIL® compound, as these latter media do not affect tissues with dehydration effects. Paraformaldehyde appears as the best compromise: it is not a contrast agent, like MICROFIL®, but it is less invasive than ethanol and permits to visualise well both cells and blood vessels. However, a quantitative estimation of the relative grey matter volume of each sample has led us to conclude that no significant alterations in the grey matter extension compared to the white matter occur as a consequence of the perfusion procedures tested in this study.

Perfusion of surgical cavity wall enhancement in early post-treatment MR imaging may stratify the time-to-progression in glioblastoma.

Directory of Open Access Journals (Sweden)

Ji Eun Park

Full Text Available To determine if perfusion in surgical cavity wall enhancement (SCWE obtained in early post-treatment MR imaging can stratify time-to-progression (TTP in glioblastoma.This study enrolled 60 glioblastoma patients with more than 5-mm-thick SCWEs as detected on contrast-enhanced MR imaging after concurrent chemoradiation therapy. Two independent readers categorized the shape and perfusion state of SCWEs as nodular or non-nodular and as having positive or negative perfusion compared with the contralateral grey matter on arterial spin labeling (ASL. The perfusion fraction on ASL within the contrast-enhancing lesion was calculated. The independent predictability of TTP was analyzed using the Kaplan-Meier method and Cox proportional hazards modelling.The perfusion fraction was higher in the non-progression group, significantly for reader 2 (P = 0.03 and borderline significantly for reader 1 (P = 0.08. A positive perfusion state and (P = 0.02 a higher perfusion fraction of the SCWE were found to become an independent predictor of longer TTP (P = 0.001 for reader 1 and P < 0.001 for reader 2. The contrast enhancement pattern did not become a TTP predictor.Assessment of perfusion in early post-treatment MR imaging can stratify TTP in patients with glioblastoma for adjuvant temozolomide therapy. Positive perfusion in SCWEs can become a predictor of a longer TTP.

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.

Assessment of perfusion by dynamic contrast-enhanced imaging using a deconvolution approach based on regression and singular value decomposition.

Science.gov (United States)

Koh, T S; Wu, X Y; Cheong, L H; Lim, C C T

2004-12-01

The assessment of tissue perfusion by dynamic contrast-enhanced (DCE) imaging involves a deconvolution process. For analysis of DCE imaging data, we implemented a regression approach to select appropriate regularization parameters for deconvolution using the standard and generalized singular value decomposition methods. Monte Carlo simulation experiments were carried out to study the performance and to compare with other existing methods used for deconvolution analysis of DCE imaging data. The present approach is found to be robust and reliable at the levels of noise commonly encountered in DCE imaging, and for different models of the underlying tissue vasculature. The advantages of the present method, as compared with previous methods, include its efficiency of computation, ability to achieve adequate regularization to reproduce less noisy solutions, and that it does not require prior knowledge of the noise condition. The proposed method is applied on actual patient study cases with brain tumors and ischemic stroke, to illustrate its applicability as a clinical tool for diagnosis and assessment of treatment response.

A Prospective Evaluation of T2-Weighted First-Pass Perfusion MR Imaging In Diagnosing Breast Neoplasms

Institute of Scientific and Technical Information of China (English)

XiaoJuanUu; RenyouZhai; TaoJiang; LiWang

2004-01-01

OBJECTIVE To compare the results from breast cancer patients who undergo T2-weighted first-pass perfusion imaging after dynamic contrast-enhanced T1-weighted imaging during the same examination,and to evaluate if T2-weighted imaging can provide additional diagnostic information over that obtained with Tl-weiahted imaaina.METHODS Twenty-nine patients with breast lesions verified by pathology (benign 12, malignant 17) underwent MR imaging with dynamic contrast-enhanced Tl-weighted imaging of the entire breasts,immediately followed by 6-sections of T2-weighted first-pass perfusion imaging of the lesions. The diagnostic indices were acquired by individual 3D Tl-weighted enhancement rate criterion and the T2 signalintensity loss rate criterion. The sensitivity and specificity were calculated and the 2 methods were compared.RESULTS With the dynamic contrast-enhanced T1-weighted imaging there was a significant differences breast lesions (t=2.563, P=0.016)overlap between the signal intensitybetween the benign and malignant However we found a considerable increase in the carcinomas and thatin the benign lesions, for a sensitivity of 94% and a specificity of 25%.With T2-weighted first-pass perfusion imaging, there was a very significant difference between the benign and malignant breast lesions(t=4.777,P<0.001), and the overlap between the signal intensity decrease in the carcinomas and that of the benign lesions on the T2-weighted images was less pronounced than the overlap in the T1-weighted images, for a sensitivity of 88% and a specificity of 75%.CONCLUSION T2-weighted first-pass perfusion imaging may help differentiate between benign and malignant breast lesions with a higher level of specificity. The combination of T1-weighted and T2-weighted imaging is feasible in a single patient examination and may improve breast MR imaging.

An Exploratory Study Into the Role of Dynamic Contrast-Enhanced Magnetic Resonance Imaging or Perfusion Computed Tomography for Detection of Intratumoral Hypoxia in Head-and-Neck Cancer

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Newbold, Kate [Royal Marsden Hospital, Sutton (United Kingdom); Castellano, Isabel [Institute of Cancer Research, London (United Kingdom); Charles-Edwards, Elizabeth [Institute of Cancer Research, Sutton, Surrey (United Kingdom); Mears, Dorothy; Sohaib, Aslam [Royal Marsden Hospital, Sutton (United Kingdom); Leach, Martin [Institute of Cancer Research, Sutton, Surrey (United Kingdom); Rhys-Evans, Peter; Clarke, Peter; Fisher, Cyril [Royal Marsden Hospital, London (United Kingdom); Harrington, Kevin [Institute of Cancer Research, London (United Kingdom); Royal Marsden Hospital, London (United Kingdom); Nutting, Christopher [Royal Marsden Hospital, London (United Kingdom)

2009-05-01

Purpose: Hypoxia in patients with head-and-neck cancer (HNC) is well established and known to cause radiation resistance and treatment failure in the management of HNC. This study examines the role of parameters derived from dynamic contrast-enhanced magnetic resonance imaging (DCE-MRI) and perfusion computed tomography (CT) as surrogate markers of intratumoral hypoxia, defined by using the exogenous marker of hypoxia pimonidazole and the endogenous marker carbonic anhydrase 9 (CA9). Methods and Materials: Patients with HNC underwent preoperative DCE-MRI, perfusion CT, and pimonidazole infusion. Imaging parameters were correlated with pimonidazole and CA9 staining. The strength of correlations was tested by using a two-tailed Spearman's rank correlation coefficient. Results: Twenty-three regions of interest were analyzed from the 7 patients who completed the DCE-MRI studies. A number of statistically significant correlations were seen between DCE-MRI parameters (volume transfer between blood plasma and extracellular extravascular space [EES], volume of EES, rate constant between EES and blood plasma, time at arrival of contrast inflow, time to peak, average gradient, and time to onset) and areas with a pimonidazole score of 4. In the case of CA9 staining, only a weak correlation was shown with wash-in rate. There were no significant correlations between perfusion CT parameters and pimonidazole staining or CA9 expression. Conclusion: Intratumoral hypoxia in patients with HNC may be predicted by using DCE-MRI; however, perfusion CT requires further investigation.

Pulmonary MR angiography and perfusion imaging—A review of methods and applications

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Johns, Christopher S.; Swift, Andrew J.; Hughes, Paul J.C. [University of Sheffield (United Kingdom); Ohno, Yoshiharu [Division of Functional and Diagnostic Imaging Research, Department of Radiology, KobeUniversity Graduate School of Medicine, Kobe, Hyogo (Japan); Schiebler, Mark [UW-Madison School of Medicine and Public Health, Madison, WI (United States); Wild, Jim M., E-mail: j.m.wild@sheffield.ac.uk [University of Sheffield (United Kingdom)

2017-01-15

Highlights: • This article represents an overview of the methodology and clinical applications of pulmonary MRA and perfusion imaging. • Both contrast enhanced and non-contrast enhanced metholodology for MRA and perfusion are covered. • The current clinical uses and future directions of MRA and MR perfusion are discussed. - Abstract: The pulmonary vasculature and its role in perfusion and gas exchange is an important consideration in many conditions of the lung and heart. Currently the mainstay of imaging of the vasculature and perfusion of the lungs lies with CT and nuclear medicine perfusion scans, both of which require ionizing radiation exposure. Improvements in MRI techniques have increased the use of MRI in pulmonary vascular imaging. Here we review MRI methods for imaging the pulmonary vasculature and pulmonary perfusion, both using contrast enhanced and non-contrast enhanced methodology. In many centres pulmonary MR angiography and dynamic contrast enhanced perfusion MRI are now well established in the routine workflow of patients particularly with pulmonary hypertension and thromboembolic disease. However, these imaging modalities offer exciting new directions for future research and clinical use in other respiratory diseases where consideration of pulmonary perfusion and gas exchange can provide insight in to pathophysiology.

Pulmonary MR angiography and perfusion imaging—A review of methods and applications

International Nuclear Information System (INIS)

Johns, Christopher S.; Swift, Andrew J.; Hughes, Paul J.C.; Ohno, Yoshiharu; Schiebler, Mark; Wild, Jim M.

2017-01-01

Highlights: • This article represents an overview of the methodology and clinical applications of pulmonary MRA and perfusion imaging. • Both contrast enhanced and non-contrast enhanced metholodology for MRA and perfusion are covered. • The current clinical uses and future directions of MRA and MR perfusion are discussed. - Abstract: The pulmonary vasculature and its role in perfusion and gas exchange is an important consideration in many conditions of the lung and heart. Currently the mainstay of imaging of the vasculature and perfusion of the lungs lies with CT and nuclear medicine perfusion scans, both of which require ionizing radiation exposure. Improvements in MRI techniques have increased the use of MRI in pulmonary vascular imaging. Here we review MRI methods for imaging the pulmonary vasculature and pulmonary perfusion, both using contrast enhanced and non-contrast enhanced methodology. In many centres pulmonary MR angiography and dynamic contrast enhanced perfusion MRI are now well established in the routine workflow of patients particularly with pulmonary hypertension and thromboembolic disease. However, these imaging modalities offer exciting new directions for future research and clinical use in other respiratory diseases where consideration of pulmonary perfusion and gas exchange can provide insight in to pathophysiology.

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

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Anna Luisa Di Stefano

2014-01-01

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

Diffusion and perfusion imaging of bone marrow

International Nuclear Information System (INIS)

Biffar, Andreas; Dietrich, Olaf; Sourbron, Steven; Duerr, Hans-Roland; Reiser, Maximilian F.; Baur-Melnyk, Andrea

2010-01-01

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.

Brain Perfusion SPECT Imaging in Sturge - Weber Syndrome : Comparison with MR Imaging

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Ryu, Jin Sook; Choi, Yun Young; Moon, Dae Hyuk; Yang, Seoung Oh; Ko, Tae Sung; Yoo, Shi Joon; Lee, Hee Kyung

1996-01-01

The purpose of this study was evaluate the characteristic perfusion changes in patients with Sturge-Weber syndrome by comparison of the findings of brain MR images and perfusion SPECT images. 99m Tc-HMPAO or 99m Tc-ECD interictal brain SPECTs were performed on 5 pediatric patients with Struge-Weber syndrome within 2 weeks after MR imaging. Brain SPECTs of three patients without calcification showed diminished perfusion in the affected area on MR image. A 3 month-old patient without brain atrophy or calcification demonstrated paradoxical hyperperfusion in the affected hemisphere, and follow-up perfusion SPECT revealed decreased perfusion in the same area. The other patient with advanced calcified lesion and atrophy on MR image showed diffusely decreased perfusion in the affected hemisphere, but a focal area of increased perfusion was also noted in the ipsilateral temporal lobe on SPECT. In conclusion, brain perfusion of the affected area of Sturge-Weber syndrome patients was usually diminished, but early or advanced patients may show paradoxical diffuse or focal hyperperfusion in the affected hemisphere. Further studies are needed for better understanding of these perfusion changes and pathophysiology of Struge-Weber syndrome.

Enhanced magnetic resonance pulmonary perfusion imaging in diagnosing pulmonary embolism: preliminary investigation

International Nuclear Information System (INIS)

Huang Xiaoyong; Du Jing; Zhang Zhaoqi; Guo Xi; Yan Zixu; Jiang Hong; Wang Wei

2005-01-01

Objective: This study was designed to investigate the sensitivity and specificity of magnetic resonance pulmonary perfusion imaging (MRPP) in diagnosing pulmonary embolism (PE) compared with enhanced magnetic resonance pulmonary angiography (MRPA) and pulmonary radionuclide perfusion imaging. Methods: Fourteen patients were definitely diagnosed as PE, whose ages were from 19 to 71 years old and mean 45.5 ± 19.8 years old. All patients under went MRPA and MRPP and 3 patients were examined again after thrombolytic treatment. Five patients underwent pulmonary radionuclide perfusion imaging. Setting ROI in top, middle, bottom of lung area and abnormal area respectively, we detected signal intensity and time-signal curve to obtain the transformation rate of signal (TROS) during perfusion peak value. Results: In 14 pulmonary embolism patients, MRPA found 62 branches of pulmonary artery obstruction. Fifty-five abnormal pulmonary perfusion zones were found by MRPP, and the above results were very alike. The coincidence was 88.71%. In 14 cases, MRPP could show 25 subsegments lesion below segments. In 5 patients who had both results Of MRPP and ECT at the same time. MRPP shows 33 perfusion defect zones and 37 segments were found by ECT, the sensitivity was 89.19%. After thrombolytic treatment, both the status of the affected pulmonary artery improved markedly and perfusion defect zones reduced obviously in 3 cases by MRPP and MRPA. TROS in normal perfusion zones perfusion defect zones and low perfusion zones had significant difference (t=22.882, P<0.01). Conclusion: Contrast enhanced MR pulmonary perfusion can show both perfusion defect zones and low perfusion zones in pulmonary embolism. Time-signal curve can show the period of maximum no perfusion zones in pulmonary artery embolism zones. And the amplitude of fluctuation is small with miminum TROS. MRPP has significant values especially in showing pulmonary artery embolism in segments and subsegments. Using both MRPP and

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

International Nuclear Information System (INIS)

Kim, Yeo Eun; Lim, Joon Seok; Kim, Myeong Jin; Kim, Ki Whang; Choi, Jun Jeong; Kim, Dae Hong; Myoung, Sung Min

2013-01-01

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 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 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 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 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 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.

Solitary pulmonary nodules: Comparison of dynamic first-pass contrast-enhanced perfusion area-detector CT, dynamic first-pass contrast-enhanced MR imaging, and FDG PET/CT.

Science.gov (United States)

Ohno, Yoshiharu; Nishio, Mizuho; Koyama, Hisanobu; Seki, Shinichiro; Tsubakimoto, Maho; Fujisawa, Yasuko; Yoshikawa, Takeshi; Matsumoto, Sumiaki; Sugimura, Kazuro

2015-02-01

To prospectively compare the capabilities of dynamic perfusion area-detector computed tomography (CT), dynamic magnetic resonance (MR) imaging, and positron emission tomography (PET) combined with CT (PET/CT) with use of fluorine 18 fluorodeoxyglucose (FDG) for the diagnosis of solitary pulmonary nodules. The institutional review board approved this study, and written informed consent was obtained from each subject. A total of 198 consecutive patients with 218 nodules prospectively underwent dynamic perfusion area-detector CT, dynamic MR imaging, FDG PET/CT, and microbacterial and/or pathologic examinations. Nodules were classified into three groups: malignant nodules (n = 133) and benign nodules with low (n = 53) or high (n = 32) biologic activity. Total perfusion was determined with dual-input maximum slope models at area-detector CT, maximum and slope of enhancement ratio at MR imaging, and maximum standardized uptake value (SUVmax) at PET/CT. Next, all indexes for malignant and benign nodules were compared with the Tukey honest significant difference test. Then, receiver operating characteristic analysis was performed for each index. Finally, sensitivity, specificity, and accuracy were compared with the McNemar test. All indexes showed significant differences between malignant nodules and benign nodules with low biologic activity (P Dynamic perfusion area-detector CT is more specific and accurate than dynamic MR imaging and FDG PET/CT in the diagnosis of solitary pulmonary nodules in routine clinical practice. © RSNA, 2014.

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

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Juan, Chun-Jung; Chen, Cheng-Yu.; Hsueh, Chun-Jen; Huang, Guo-Shu; Jen, Yee-Min; Liu, Hua-Shan; Wang, Chao-Ying; Chung, Hsiao-Wen; Liu, Yi-Jui; Chou, Yu-Ching; Chai, Yao-Te

2009-01-01

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

Evaluation of contrast wash-in and peak enhancement in adenosine first pass perfusion CMR in patients post bypass surgery

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Schnackenburg Bernhard

2010-05-01

Full Text Available Abstract Background Adenosine first pass perfusion cardiovascular magnetic resonance (CMR yields excellent results for the detection of significant coronary artery disease (CAD. In patients with coronary artery bypass grafts (CABG the kinetics of a contrast bolus may by altered only due to different distances through the bypass grafts compared to native vessels, thereby possibly imitating a perfusion defect. The aim of the study was to evaluate semiquantitative perfusion parameters in order to assess possible differences in epicardial contrast kinetics in areas supplied by native coronaries and CABG, both without significant stenosis. Methods Twenty patients with invasive exclusion of significant CAD (control group and 38 patients with CABG without angiographically significant (≥50% stenosis in unbypassed coronaries or grafts were retrospectively included in the study. They underwent adenosine first pass (0.05 mmol/kg Gd-DTPA perfusion (3 short axis views/heart beat and late gadolinium enhancement (LGE imaging 1 day before invasive coronary angiography. Areas perfused by native coronaries and/or the different bypasses were identified in X-ray angiography using the 16 segment model. In each of these areas upslope and maximal signal intensity (SImax relative to the left ventricular parameters, time to 50% maximal signal intensity (TSI50%max and time to maximal signal intensity (TSImax were calculated. Results In areas perfused by coronary arteries with bypasses compared to native coronaries relative upslope and relative SImax did not show a significant difference. TSI50%max and TSImax in native coronaries and bypasses were 7.2s ± 1.9s vs. 7.5s ± 1.9s (p max resulted in a significant (p Conclusion Adenosine perfusion CMR in patients post CABG may be associated with a short delay in contrast arrival. However, once the contrast is in the myocardium there is similar wash-in kinetics and peak enhancement. Therefore, since the delay is only short

A pilot trial on pulmonary emphysema quantification and perfusion mapping in a single-step using contrast-enhanced dual-energy computed tomography.

Science.gov (United States)

Lee, Choong Wook; Seo, Joon Beom; Lee, Youngjoo; Chae, Eun Jin; Kim, Namkug; Lee, Hyun Joo; Hwang, Hye Jeon; Lim, Chae-Hun

2012-01-01

To know whether contrast-enhanced dual-energy computed tomography angiography (DECTA) can be used for simultaneous assessment of emphysema quantification and regional perfusion evaluation. We assessed 27 patients who had pulmonary emphysema and no pulmonary embolism on visual assessment of CT images, among 584 consecutive patients who underwent DECTA for the evaluation of pulmonary embolism. Virtual noncontrast (VNC) images were generated by modifying the "Liver VNC" application in a dedicated workstation. Using in-house software, the low-attenuation area below 950HU (LAA950), the 15th percentile attenuation (15pctlVNC) and the mean lung attenuation (MeanVNC) were calculated. The "Lung PBV" application was used to assess perfusion, and the low-iodine area below 5HU (LIA5), the 15th percentile iodine (15pctlIodine), and the mean iodine value (MeanIodine) were calculated from iodine map images. The correlation between VNC parameters and pulmonary function test data (available in 22 patients) and the correlation between VNC and iodine map parameters (all included 27 patients) were assessed. Color-coded map of VNC image were compared with iodine map images for the evaluation of regional heterogeneity. We observed moderate correlations between LAA950 and predicted %FEV1 (rs = -0.47, P VNC images. We observed moderate correlations between quantitative parameters on VNC images and pulmonary function test data, and also observed moderate correlations between the severity of parenchymal destruction, as determined from VNC images, and perfusion status, as determined from iodine maps. Therefore, the contrast-enhanced DECTA can be used for the emphysema quantification and regional perfusion evaluation by using the VNC images and iodine map, simultaneously.

[MRI methods for pulmonary ventilation and perfusion imaging].

Science.gov (United States)

Sommer, G; Bauman, G

2016-02-01

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

MRI methods for pulmonary ventilation and perfusion imaging

International Nuclear Information System (INIS)

Sommer, G.; Bauman, G.

2016-01-01

Separate assessment of respiratory mechanics, gas exchange and pulmonary circulation is essential for the diagnosis and therapy of pulmonary diseases. Due to the global character of the information obtained clinical lung function tests are often not sufficiently specific in the differential diagnosis or have a limited sensitivity in the detection of early pathological changes. The standard procedures of pulmonary imaging are computed tomography (CT) for depiction of the morphology as well as perfusion/ventilation scintigraphy and single photon emission computed tomography (SPECT) for functional assessment. Magnetic resonance imaging (MRI) with hyperpolarized gases, O 2 -enhanced MRI, MRI with fluorinated gases and Fourier decomposition MRI (FD-MRI) are available for assessment of pulmonary ventilation. For assessment of pulmonary perfusion dynamic contrast-enhanced MRI (DCE-MRI), arterial spin labeling (ASL) and FD-MRI can be used. Imaging provides a more precise insight into the pathophysiology of pulmonary function on a regional level. The advantages of MRI are a lack of ionizing radiation, which allows a protective acquisition of dynamic data as well as the high number of available contrasts and therefore accessible lung function parameters. Sufficient clinical data exist only for certain applications of DCE-MRI. For the other techniques, only feasibility studies and case series of different sizes are available. The clinical applicability of hyperpolarized gases is limited for technical reasons. The clinical application of the techniques described, except for DCE-MRI, should be restricted to scientific studies. (orig.) [de

Meta-Analysis of Stress Myocardial Perfusion Imaging

Science.gov (United States)

2017-06-06

Coronary Disease; Echocardiography; Fractional Flow Reserve, Myocardial; Hemodynamics; Humans; Magnetic Resonance Imaging; Myocardial Perfusion Imaging; Perfusion; Predictive Value of Tests; Single Photon Emission Computed Tomography; Positron Emission Tomography; Multidetector Computed Tomography; Echocardiography, Stress; Coronary Angiography

Assmentment of myocardial perfusion by magnetic resonance imaging: on the way to clinical application

International Nuclear Information System (INIS)

Fischer, S.E.; Lorenz, C.H.

1997-01-01

Magnetic resonance imaging detects the flow of contrast - enhanced blood and even allows the quantitative assessment of myocardial perfusion. The clinical application of this method is being held back by the difficulties in image evaluation and the limitation of standard techniques to the acquisition of a single slice per heart beat cycle. Recent developments in scanner hardware as well as in image acquisition techniques open up the possibility of assessing myocardial perfusion over the entire heart with a spatial resolution in the range of 2 mm. As an example of such a new scanning strategy, a segmented gradient-echo recalled echo planar imaging sequence with preceding saturation is discussed and results in a patient with an infarction are presented. The clinical use of perfusion assessment covering the entire heart for the diagnosis of coronary artery disease is enhanced by the flexibility of magnetic resonance imaging for the assessment of functional cardiac parameters. (orig.) [de

Perfusion MRI of brain tumours: a comparative study of pseudo-continuous arterial spin labelling and dynamic susceptibility contrast imaging

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Jaernum, Hanna; Steffensen, Elena G.; Simonsen, Carsten Wiberg; Jensen, Finn Taagehoej [Aalborg Hospital/Aarhus University Hospital, Department of Radiology, Aalborg (Denmark); Knutsson, Linda [Lund University, Department of Medical Radiation Physics, Lund (Sweden); Fruend, Ernst-Torben [Aalborg Hospital/Aarhus University Hospital, Department of Radiology, Aalborg (Denmark); GE Healthcare - Applied Science Lab Europe, Aalborg (Denmark); Lundbye-Christensen, Soeren [Aalborg Hospital/Aarhus University Hospital, Department of Cardiology, Center for Cardiovascular Research, Aalborg (Denmark); Shankaranarayanan, Ajit [Global Applied Science Lab, GE Healthcare, Menlo Park, CA (United States); Alsop, David C. [Beth Israel Deaconess Medical Center and Harvard Medical School, Boston, MA (United States); Larsson, Elna-Marie [Aalborg Hospital/Aarhus University Hospital, Department of Radiology, Aalborg (Denmark); Uppsala University Hospital, Department of Radiology, Uppsala (Sweden)

2010-04-15

The purpose of this study was to compare the non-invasive 3D pseudo-continuous arterial spin labelling (PC ASL) technique with the clinically established dynamic susceptibility contrast perfusion magnetic resonance imaging (DSC-MRI) for evaluation of brain tumours. A prospective study of 28 patients with contrast-enhancing brain tumours was performed at 3 T using DSC-MRI and PC ASL with whole-brain coverage. The visual qualitative evaluation of signal enhancement in tumour was scored from 0 to 3 (0 = no signal enhancement compared with white matter, 3 = pronounced signal enhancement with equal or higher signal intensity than in grey matter/basal ganglia). The extent of susceptibility artefacts in the tumour was scored from 0 to 2 (0 = no susceptibility artefacts and 2 = extensive susceptibility artefacts (maximum diameter > 2 cm)). A quantitative analysis was performed with normalised tumour blood flow values (ASL nTBF, DSC nTBF): mean value for region of interest (ROI) in an area with maximum signal enhancement/the mean value for ROIs in cerebellum. There was no difference in total visual score for signal enhancement between PC ASL and DSC relative cerebral blood flow (p = 0.12). ASL had a lower susceptibility-artefact score than DSC-MRI (p = 0.03). There was good correlation between DSC nTBF and ASL nTBF values with a correlation coefficient of 0.82. PC ASL is an alternative to DSC-MRI for the evaluation of perfusion in brain tumours. The method has fewer susceptibility artefacts than DSC-MRI and can be used in patients with renal failure because no contrast injection is needed. (orig.)

Perfusion-weighted MR imaging of uterine leiomyoma

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Takase, Hiroyasu; Munechika, Hirotsugu [Showa Univ., Tokyo (Japan). School of Medicine

2001-06-01

Serial images of uterine leiomyoma in gradient-echo, echo-planar, magnetic resonance imaging were taken to draw a {delta}R2{sup *} curve after intravenous bolus injection of Gd-DTPA. The {delta}R2{sup *} integral was calculated from a {delta}R2{sup *} curve to have relative perfusion of uterine leiomyoma. We then, evaluated the amount of perfusion correlated with MR findings, size and number of leiomyoma or the clinical symptoms and established that perfusion was correlated positively with the findings of T2 weighted images and clinical symptoms but not with other MR findings or size and number of leiomyoma. In conclusion, we presumed that the clinical symptoms could be reduced by decreasing of an amount of perfusion of uterine leiomyoma in some means. However, it remained uncertain why severe clinical symptoms were associated with a high amount of perfusion in uterine leiomyomas. (author)

The comparison of nitroglycerin interventional dual-isotope myocardium perfusion imaging and 201Tl re-injection imaging to detect viable myocardium

International Nuclear Information System (INIS)

Gao Zhou; Shi yu; Chen Hongyan; Jia Shaowei

2002-01-01

Objective: Employing the differences in physical properties of 99m Tc-MIBI and 201 Tl, the authors discuss the contrast result of nitroglycerin interventional dual-isotope myocardium perfusion imaging and 201 Tl re-injection imaging to detect viable myocardium so that authors can enhance the image quality and shorten the examination time. Method: 34 OMI patients took the 99m Tc-MIBI and 201 Tl dual-isotope myocardium perfusion imaging and 201 Tl re-injection imaging respectively in two weeks. During the peak of normal dipyridamole stress i.v. 201 Tl 100 MBq was given and myocardium imaging was taken 15 min later. The dual-isotope group was given nitroglycerin 1mg under the tongue. Five min later, i.v. 99m Tc-MIBI 1110 mBq was given. In 201 Tl re-injection group i.v. 201 Tl 40 MBq was given 4 hour later and were imaged. Among the 34 OMI patients, 19 patients undertook another 99m Tc-MIBI static imaging. Results: There are no obvious differences between nitroglycerin interventional dual-isotope myocardium perfusion imaging and 201 Tl re-injection imaging in detection rate of viable myocardium, χ 2 =0.823, p>0.25. But they have great difference in perfusion changed sectional myocardium absorb rate, t=2.73, p 2 =27.867, p 201 Tl re-injection imaging

Computerized analysis of brain perfusion parameter images

International Nuclear Information System (INIS)

Turowski, B.; Haenggi, D.; Wittsack, H.J.; Beck, A.; Aurich, V.

2007-01-01

Purpose: The development of a computerized method which allows a direct quantitative comparison of perfusion parameters. The display should allow a clear direct comparison of brain perfusion parameters in different vascular territories and over the course of time. The analysis is intended to be the basis for further evaluation of cerebral vasospasm after subarachnoid hemorrhage (SAH). The method should permit early diagnosis of cerebral vasospasm. Materials and Methods: The Angiotux 2D-ECCET software was developed with a close cooperation between computer scientists and clinicians. Starting from parameter images of brain perfusion, the cortex was marked, segmented and assigned to definite vascular territories. The underlying values were averages for each segment and were displayed in a graph. If a follow-up was available, the mean values of the perfusion parameters were displayed in relation to time. The method was developed under consideration of CT perfusion values but is applicable for other methods of perfusion imaging. Results: Computerized analysis of brain perfusion parameter images allows an immediate comparison of these parameters and follow-up of mean values in a clear and concise manner. Values are related to definite vascular territories. The tabular output facilitates further statistic evaluations. The computerized analysis is precisely reproducible, i. e., repetitions result in exactly the same output. (orig.)

Quantitative pulmonary perfusion imaging with 3-dimensional, contrast-enhanced MR: regional difference in the perfusion parameters of healthy volunteers

International Nuclear Information System (INIS)

Kim, Song Soo; Seo, Joon Beom; Kim, Nam Kuk; Do, Kyung Hyun; Lee, Young Kyung; Song, Jae Woo; Lee, Jin Seong; Kim, Jin Hwan

2007-01-01

We wanted to evaluate the regional differences in such perfusion parameters as pulmonary blood flow (PBF), mean transit time (MTT) and pulmonary blood volume (PBV) in the entire lung of healthy volunteers with using three-dimensional, contrast-enhanced MR imaging (3D CEMRI). Six healthy volunteers underwent dynamic 3D CEMRI (TR/TE 2.7/0.6 msec; flip angle 40 .deg. ; matrix 128 x 96; reconstructed matrix 256 x 192; rectangular field of view 450 x 315 mm; coronal 100-150mm-thick x 10 slabs; temporal resolution 1.0 sec; 35 dynamic phases) For all subjects, 2 mL of Gd-DTPA mixed with 3 ml of physiologic saline was administered as a bolus at a rate of 5 mL/sec, and this was followed by 20 mL of physiologic saline flush. From the signal intensity-time curves, the PBF, MTT and PBV maps were generated using indicator dilution theories and the central volume principle on a pixel-by-pixel basis. A total of 54 round, 1-cm sized ROIs were placed in the lung in each subject (6 ROIs per slab x 9 slices except for the most posterior slab). The regional differences of the measured parameters were statistically evaluated in the gravitational direction and in the upper-mid-lower direction by one-way ANOVA tests. The calculated PBF, MTT and PBV in the entire lung were 141.8 ± 53.4 mL/100 mL/min (mean ± SD), 5.35 ± 1.38 sec, and 13.4 ± 6.48 mL/100mL, respectively. In the gravitational direction, there was a significant increase in the PBF and PBV as it goes to the posterior direction (ρ < 0.05). No statistical difference was found in PBF or PBV between the upper, mid and lower lung zone areas. Regional difference in the various perfusion parameters of the lung in healthy volunteers can be quantitatively assessed with performing 3D CEMRI

Magnetic resonance perfusion and diffusion imaging characteristics of transient bone marrow edema, avascular necrosis and subchondral insufficiency fractures of the proximal femur

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Mueller, Dirk, E-mail: d.mueller@uk-koeln.de [Department of Radiology, University of Cologne (Germany); Department of Radiology, Technische Universität München (Germany); Schaeffeler, Christoph, E-mail: schaeffeler@me.com [Department of Radiology, Cantonal Hospital Graubuenden, Chur (Switzerland); Department of Radiology, Cantonal Hospital Graubuenden, Chur (Switzerland); Baum, Thomas, E-mail: thomas-baum@gmx.de [Department of Radiology, Technische Universität München (Germany); Walter, Flavia, E-mail: flavia_walter2000@yahoo.de [Department of Radiology, Technische Universität München (Germany); Rechl, Hans, E-mail: rechl@tum.de [Department of Orthopaedics, Technische Universität München (Germany); Rummeny, Ernst J., E-mail: rummeny@tum.de [Department of Radiology, Technische Universität München (Germany); Woertler, Klaus, E-mail: klaus.woertler@tum.de [Department of Radiology, Technische Universität München (Germany)

2014-10-15

Highlights: • DCE-MRI may add information to the pathophysiology of bone marrow edema (BME) of the proximal femur. • Patients with transient bone marrow edema (TBME) or subchondral insufficiency fractures (SIF) and avascular osteonecrosis (AVN) showed different MR perfusion patterns. • Perfusion characteristics suggest different pathophysiology for AVN compared with TBME or SIF. • Diffusion weighted imaging (DWI) was not able to discriminate necrotic from edematous bone marrow. • DWI is of limited value to evaluate BME of the proximal femur. - Abstract: Purpose: To evaluate magnetic resonance (MR) perfusion and diffusion imaging characteristics in patients with transient bone marrow edema (TBME), avascular necrosis (AVN), or subchondral insufficiency fractures (SIF) of the proximal femur. Materials and methods: 29 patients with painful hip and bone marrow edema pattern of the proximal femur on non-contrast MR imaging were examined using diffusion-weighted and dynamic gadolinium-enhanced sequences. Apparent diffusion coefficients (ADCs) and perfusion parameters were calculated for different regions of the proximal femur. Regional distribution and differences in ADC values and perfusion parameters were evaluated. Results: Seven patients presented with TBME, 15 with AVN and seven with SIF of the proximal femur. Perfusion imaging showed significant differences for maximum enhancement values (E{sub max}), slope (E{sub slope}) and time to peak (TTP) between the three patient groups (p < 0.05). In contrast, no significant differences for ADC values were calculated when comparing TBME, AVN, and SIF patients. Conclusion: Diffusion weighted imaging of bone marrow of the proximal femur did not show significant differences between patients with TBME, AVN or SIF. In contrast, MR perfusion imaging demonstrated significant differences for the different patient groups and may as a complementary imaging technique add information to the understanding of the pathophysiology

Magnetic resonance perfusion and diffusion imaging characteristics of transient bone marrow edema, avascular necrosis and subchondral insufficiency fractures of the proximal femur

International Nuclear Information System (INIS)

Mueller, Dirk; Schaeffeler, Christoph; Baum, Thomas; Walter, Flavia; Rechl, Hans; Rummeny, Ernst J.; Woertler, Klaus

2014-01-01

Highlights: • DCE-MRI may add information to the pathophysiology of bone marrow edema (BME) of the proximal femur. • Patients with transient bone marrow edema (TBME) or subchondral insufficiency fractures (SIF) and avascular osteonecrosis (AVN) showed different MR perfusion patterns. • Perfusion characteristics suggest different pathophysiology for AVN compared with TBME or SIF. • Diffusion weighted imaging (DWI) was not able to discriminate necrotic from edematous bone marrow. • DWI is of limited value to evaluate BME of the proximal femur. - Abstract: Purpose: To evaluate magnetic resonance (MR) perfusion and diffusion imaging characteristics in patients with transient bone marrow edema (TBME), avascular necrosis (AVN), or subchondral insufficiency fractures (SIF) of the proximal femur. Materials and methods: 29 patients with painful hip and bone marrow edema pattern of the proximal femur on non-contrast MR imaging were examined using diffusion-weighted and dynamic gadolinium-enhanced sequences. Apparent diffusion coefficients (ADCs) and perfusion parameters were calculated for different regions of the proximal femur. Regional distribution and differences in ADC values and perfusion parameters were evaluated. Results: Seven patients presented with TBME, 15 with AVN and seven with SIF of the proximal femur. Perfusion imaging showed significant differences for maximum enhancement values (E max ), slope (E slope ) and time to peak (TTP) between the three patient groups (p < 0.05). In contrast, no significant differences for ADC values were calculated when comparing TBME, AVN, and SIF patients. Conclusion: Diffusion weighted imaging of bone marrow of the proximal femur did not show significant differences between patients with TBME, AVN or SIF. In contrast, MR perfusion imaging demonstrated significant differences for the different patient groups and may as a complementary imaging technique add information to the understanding of the pathophysiology of

Imaging Human Brain Perfusion with Inhaled Hyperpolarized 129Xe MR Imaging.

Science.gov (United States)

Rao, Madhwesha R; Stewart, Neil J; Griffiths, Paul D; Norquay, Graham; Wild, Jim M

2018-02-01

Purpose To evaluate the feasibility of directly imaging perfusion of human brain tissue by using magnetic resonance (MR) imaging with inhaled hyperpolarized xenon 129 ( 129 Xe). Materials and Methods In vivo imaging with 129 Xe was performed in three healthy participants. The combination of a high-yield spin-exchange optical pumping 129 Xe polarizer, custom-built radiofrequency coils, and an optimized gradient-echo MR imaging protocol was used to achieve signal sensitivity sufficient to directly image hyperpolarized 129 Xe dissolved in the human brain. Conventional T1-weighted proton (hydrogen 1 [ 1 H]) images and perfusion images by using arterial spin labeling were obtained for comparison. Results Images of 129 Xe uptake were obtained with a signal-to-noise ratio of 31 ± 9 and demonstrated structural similarities to the gray matter distribution on conventional T1-weighted 1 H images and to perfusion images from arterial spin labeling. Conclusion Hyperpolarized 129 Xe MR imaging is an injection-free means of imaging the perfusion of cerebral tissue. The proposed method images the uptake of inhaled xenon gas to the extravascular brain tissue compartment across the intact blood-brain barrier. This level of sensitivity is not readily available with contemporary MR imaging methods. © RSNA, 2017.

Effects of high-fat diet and losartan on renal cortical blood flow using contrast ultrasound imaging.

Science.gov (United States)

Declèves, Anne-Emilie; Rychak, Joshua J; Smith, Dan J; Sharma, Kumar

2013-11-01

Obesity-related kidney disease occurs as a result of complex interactions between metabolic and hemodynamic effects. Changes in microvascular perfusion may play a major role in kidney disease; however, these changes are difficult to assess in vivo. Here, we used perfusion ultrasound imaging to evaluate cortical blood flow in a mouse model of high-fat diet-induced kidney disease. C57BL/6J mice were randomized to a standard diet (STD) or a high-fat diet (HFD) for 30 wk and then treated either with losartan or a placebo for an additional 6 wk. Noninvasive ultrasound perfusion imaging of the kidney was performed during infusion of a microbubble contrast agent. Blood flow within the microvasculature of the renal cortex and medulla was derived from imaging data. An increase in the time required to achieve full cortical perfusion was observed for HFD mice relative to STD. This was reversed following treatment with losartan. These data were concurrent with an increased glomerular filtration rate in HFD mice compared with STD- or HFD-losartan-treated mice. Losartan treatment also abrogated fibro-inflammatory disease, assessed by markers at the protein and messenger level. Finally, a reduction in capillary density was found in HFD mice, and this was reversed upon losartan treatment. This suggests that alterations in vascular density may be responsible for the elevated perfusion time observed by imaging. These data demonstrate that ultrasound contrast imaging is a robust and sensitive method for evaluating changes in renal microvascular perfusion and that cortical perfusion time may be a useful parameter for evaluating obesity-related renal disease.

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

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Mark A Lum

Full Text Available To evaluate the ability of IA MR perfusion to characterize meningioma blood supply.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.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.

Mobile phone based laser speckle contrast imager for assessment of skin blood flow

Science.gov (United States)

Jakovels, Dainis; Saknite, Inga; Krievina, Gita; Zaharans, Janis; Spigulis, Janis

2014-10-01

Assessment of skin blood flow is of interest for evaluation of skin viability as well as for reflection of the overall condition of the circulatory system. Laser Doppler perfusion imaging (LDPI) and laser speckle contrast imaging (LASCI) are optical techniques used for assessment of skin perfusion. However, these systems are still too expensive and bulky to be widely available. Implementation of such techniques as connection kits for mobile phones have a potential for primary diagnostics. In this work we demonstrate simple and low cost LASCI connection kit for mobile phone and its comparison to laser Doppler perfusion imager. Post-occlusive hyperemia and local thermal hyperemia tests are used to compare both techniques and to demonstrate the potential of LASCI device.

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

DEFF Research Database (Denmark)

Nielsen, Gitte; Hansen, Thomas Fritz; Dirks, Christina G

2004-01-01

with acute transmural myocardial infarction were studied using a Turbo-fast low angle shot (FLASH) MRI sequence to monitor the first pass of an extravascular contrast agent (CA), gadolinium diethylene triamine pentaacetic acid (Gd-DTPA). Quantitation of perfusion, expressed as Ki (mL/100 g/minute), in five...

Perfusion MRI in CNS disease: current concepts

International Nuclear Information System (INIS)

Essig, M.; Giesel, F.; Le-Huu, M.; Stieltjes, B.; Tengg, H. von; Weber, M.-A.

2004-01-01

Today there are several indications for cerebral perfusion MRI. The major indications routinely used in increasing numbers of imaging centers include cerebrovascular disease, tumor imaging and recently psychiatric disorders. Perfusion MRI is based on the injection of a gadolinium chelate and the rapid acquisition of images as the bolus of contrast agent passes through the blood vessels in the brain. The contrast agent causes a signal change; this signal change over time can be analysed to measure cerebral hemodynamics. The quality of brain perfusion studies is very dependent on the contrast agent used: a robust and strong signal decrease with a compact bolus is needed. MultiHance (gadobenate dimeglumine, Gd-BOPTA) is the first of a new class of paramagnetic MR contrast agents with a weak affinity for serum proteins. Due to the interaction of Gd-BOPTA with serum albumin, MultiHance presents with significantly higher T1- and T2-relaxivities enabling a sharper bolus profile. This article reviews the indications of perfusion MRI and the performance of MultiHance in MR perfusion of different diseases. Previous studies using perfusion MRI for a variety of purposes required the use of double dose of contrast agent to achieve a sufficiently large signal drop to enable the acquisition of a clear input function and the calculation of perfusion rCBV and rCBF maps of adequate quality. Recent studies with Multi-Hance suggest that only a single dose of this agent is needed to cause a signal drop of about 30% which is sufficient to allow the calculation of high quality rCBV and rCBF maps. (orig.)

Single-energy computed tomography-based pulmonary perfusion imaging: Proof-of-principle in a canine model

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Yamamoto, Tokihiro, E-mail: toyamamoto@ucdavis.edu [Department of Radiation Oncology, University of California Davis School of Medicine, Sacramento, California 95817 (United States); Kent, Michael S.; Wisner, Erik R. [Department of Surgical and Radiological Sciences, University of California Davis School of Veterinary Medicine, Davis, California 95616 (United States); Johnson, Lynelle R.; Stern, Joshua A. [Department of Medicine and Epidemiology, University of California Davis School of Veterinary Medicine, Davis, California 95616 (United States); Qi, Lihong [Department of Public Health Sciences, University of California Davis, Davis, California 95616 (United States); Fujita, Yukio [Department of Radiation Oncology, Tokai University, Isehara, Kanagawa 259-1193 (Japan); Boone, John M. [Department of Radiology, University of California Davis School of Medicine, Sacramento, California 95817 (United States)

2016-07-15

Purpose: Radiotherapy (RT) that selectively avoids irradiating highly functional lung regions may reduce pulmonary toxicity, which is substantial in lung cancer RT. Single-energy computed tomography (CT) pulmonary perfusion imaging has several advantages (e.g., higher resolution) over other modalities and has great potential for widespread clinical implementation, particularly in RT. The purpose of this study was to establish proof-of-principle for single-energy CT perfusion imaging. Methods: Single-energy CT perfusion imaging is based on the following: (1) acquisition of end-inspiratory breath-hold CT scans before and after intravenous injection of iodinated contrast agents, (2) deformable image registration (DIR) for spatial mapping of those two CT image data sets, and (3) subtraction of the precontrast image data set from the postcontrast image data set, yielding a map of regional Hounsfield unit (HU) enhancement, a surrogate for regional perfusion. In a protocol approved by the institutional animal care and use committee, the authors acquired CT scans in the prone position for a total of 14 anesthetized canines (seven canines with normal lungs and seven canines with diseased lungs). The elastix algorithm was used for DIR. The accuracy of DIR was evaluated based on the target registration error (TRE) of 50 anatomic pulmonary landmarks per subject for 10 randomly selected subjects as well as on singularities (i.e., regions where the displacement vector field is not bijective). Prior to perfusion computation, HUs of the precontrast end-inspiratory image were corrected for variation in the lung inflation level between the precontrast and postcontrast end-inspiratory CT scans, using a model built from two additional precontrast CT scans at end-expiration and midinspiration. The authors also assessed spatial heterogeneity and gravitationally directed gradients of regional perfusion for normal lung subjects and diseased lung subjects using a two-sample two-tailed t

Single-energy computed tomography-based pulmonary perfusion imaging: Proof-of-principle in a canine model.

Science.gov (United States)

Yamamoto, Tokihiro; Kent, Michael S; Wisner, Erik R; Johnson, Lynelle R; Stern, Joshua A; Qi, Lihong; Fujita, Yukio; Boone, John M

2016-07-01

Radiotherapy (RT) that selectively avoids irradiating highly functional lung regions may reduce pulmonary toxicity, which is substantial in lung cancer RT. Single-energy computed tomography (CT) pulmonary perfusion imaging has several advantages (e.g., higher resolution) over other modalities and has great potential for widespread clinical implementation, particularly in RT. The purpose of this study was to establish proof-of-principle for single-energy CT perfusion imaging. Single-energy CT perfusion imaging is based on the following: (1) acquisition of end-inspiratory breath-hold CT scans before and after intravenous injection of iodinated contrast agents, (2) deformable image registration (DIR) for spatial mapping of those two CT image data sets, and (3) subtraction of the precontrast image data set from the postcontrast image data set, yielding a map of regional Hounsfield unit (HU) enhancement, a surrogate for regional perfusion. In a protocol approved by the institutional animal care and use committee, the authors acquired CT scans in the prone position for a total of 14 anesthetized canines (seven canines with normal lungs and seven canines with diseased lungs). The elastix algorithm was used for DIR. The accuracy of DIR was evaluated based on the target registration error (TRE) of 50 anatomic pulmonary landmarks per subject for 10 randomly selected subjects as well as on singularities (i.e., regions where the displacement vector field is not bijective). Prior to perfusion computation, HUs of the precontrast end-inspiratory image were corrected for variation in the lung inflation level between the precontrast and postcontrast end-inspiratory CT scans, using a model built from two additional precontrast CT scans at end-expiration and midinspiration. The authors also assessed spatial heterogeneity and gravitationally directed gradients of regional perfusion for normal lung subjects and diseased lung subjects using a two-sample two-tailed t-test. The mean TRE

Single-energy computed tomography-based pulmonary perfusion imaging: Proof-of-principle in a canine model

International Nuclear Information System (INIS)

Yamamoto, Tokihiro; Kent, Michael S.; Wisner, Erik R.; Johnson, Lynelle R.; Stern, Joshua A.; Qi, Lihong; Fujita, Yukio; Boone, John M.

2016-01-01

Purpose: Radiotherapy (RT) that selectively avoids irradiating highly functional lung regions may reduce pulmonary toxicity, which is substantial in lung cancer RT. Single-energy computed tomography (CT) pulmonary perfusion imaging has several advantages (e.g., higher resolution) over other modalities and has great potential for widespread clinical implementation, particularly in RT. The purpose of this study was to establish proof-of-principle for single-energy CT perfusion imaging. Methods: Single-energy CT perfusion imaging is based on the following: (1) acquisition of end-inspiratory breath-hold CT scans before and after intravenous injection of iodinated contrast agents, (2) deformable image registration (DIR) for spatial mapping of those two CT image data sets, and (3) subtraction of the precontrast image data set from the postcontrast image data set, yielding a map of regional Hounsfield unit (HU) enhancement, a surrogate for regional perfusion. In a protocol approved by the institutional animal care and use committee, the authors acquired CT scans in the prone position for a total of 14 anesthetized canines (seven canines with normal lungs and seven canines with diseased lungs). The elastix algorithm was used for DIR. The accuracy of DIR was evaluated based on the target registration error (TRE) of 50 anatomic pulmonary landmarks per subject for 10 randomly selected subjects as well as on singularities (i.e., regions where the displacement vector field is not bijective). Prior to perfusion computation, HUs of the precontrast end-inspiratory image were corrected for variation in the lung inflation level between the precontrast and postcontrast end-inspiratory CT scans, using a model built from two additional precontrast CT scans at end-expiration and midinspiration. The authors also assessed spatial heterogeneity and gravitationally directed gradients of regional perfusion for normal lung subjects and diseased lung subjects using a two-sample two-tailed t

Laser Speckle Contrast Imaging: theory, instrumentation and applications.

Science.gov (United States)

Senarathna, Janaka; Rege, Abhishek; Li, Nan; Thakor, Nitish V

2013-01-01

Laser Speckle Contrast Imaging (LSCI) is a wide field of view, non scanning optical technique for observing blood flow. Speckles are produced when coherent light scattered back from biological tissue is diffracted through the limiting aperture of focusing optics. Mobile scatterers cause the speckle pattern to blur; a model can be constructed by inversely relating the degree of blur, termed speckle contrast to the scatterer speed. In tissue, red blood cells are the main source of moving scatterers. Therefore, blood flow acts as a virtual contrast agent, outlining blood vessels. The spatial resolution (~10 μm) and temporal resolution (10 ms to 10 s) of LSCI can be tailored to the application. Restricted by the penetration depth of light, LSCI can only visualize superficial blood flow. Additionally, due to its non scanning nature, LSCI is unable to provide depth resolved images. The simple setup and non-dependence on exogenous contrast agents have made LSCI a popular tool for studying vascular structure and blood flow dynamics. We discuss the theory and practice of LSCI and critically analyze its merit in major areas of application such as retinal imaging, imaging of skin perfusion as well as imaging of neurophysiology.

Imaging of ventilation/perfusion ratio by gated regional spirometry

International Nuclear Information System (INIS)

Touya, J.J.; Jones, J.P.; Price, R.R.; Patton, J.A.; Erickson, J.J.; Rollo, F.D.

1981-01-01

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

Hepatic blood perfusion estimated by dynamic contrast-enhanced computed tomography in pigs

DEFF Research Database (Denmark)

Winterdahl, Michael; Sørensen, Michael; Keiding, Inger Susanne

2012-01-01

The aim of this study was to determine whether dynamic contrast-enhanced computed tomography (DCE-CT) and the slope method can provide absolute measures of hepatic blood perfusion from the hepatic artery (HA) and portal vein (PV) at experimentally varied blood flow rates.......The aim of this study was to determine whether dynamic contrast-enhanced computed tomography (DCE-CT) and the slope method can provide absolute measures of hepatic blood perfusion from the hepatic artery (HA) and portal vein (PV) at experimentally varied blood flow rates....

Application of differential interference contrast with inverted microscopes to the in vitro perfused nephron.

Science.gov (United States)

Horster, M; Gundlach, H

1979-12-01

The study of in vitro perfused individual nephron segments requires a microscope which provides: (1) easy access to the specimen for measurement of cellular solute flux and voltage; (2) an image with high resolution and contrast; (3) optical sectioning of the object at different levels; and (4) rapid recording of the morphological phenomena. This paper describes an example of commercially available apparatus meeting the above requirements, and illustrates its efficiency. The microscope is of the inverted type (Zeiss IM 35) equipped with differential-interference-contrast (DIC) with a long working distance, and an automatically controlled camera system. The microscopic image exhibits cellular and intercellular details in the unstained transporting mammalian nephron segments despite their tubular structure and great thickness and makes obvious function-structure correlations (e.g. cell volume changes); luminal and contraluminal cell borders are well resolved for controlled microelectrode impalement.

Analysis of microvascular perfusion with multi-dimensional complete ensemble empirical mode decomposition with adaptive noise algorithm: Processing of laser speckle contrast images recorded in healthy subjects, at rest and during acetylcholine stimulation.

Science.gov (United States)

Humeau-Heurtier, Anne; Marche, Pauline; Dubois, Severine; Mahe, Guillaume

2015-01-01

Laser speckle contrast imaging (LSCI) is a full-field imaging modality to monitor microvascular blood flow. It is able to give images with high temporal and spatial resolutions. However, when the skin is studied, the interpretation of the bidimensional data may be difficult. This is why an averaging of the perfusion values in regions of interest is often performed and the result is followed in time, reducing the data to monodimensional time series. In order to avoid such a procedure (that leads to a loss of the spatial resolution), we propose to extract patterns from LSCI data and to compare these patterns for two physiological states in healthy subjects: at rest and at the peak of acetylcholine-induced perfusion peak. For this purpose, the recent multi-dimensional complete ensemble empirical mode decomposition with adaptive noise (MCEEMDAN) algorithm is applied to LSCI data. The results show that the intrinsic mode functions and residue given by MCEEMDAN show different patterns for the two physiological states. The images, as bidimensional data, can therefore be processed to reveal microvascular perfusion patterns, hidden in the images themselves. This work is therefore a feasibility study before analyzing data in patients with microvascular dysfunctions.

Preliminary study of single contrast enhanced dual energy heart imaging using dual-source CT

International Nuclear Information System (INIS)

Peng Jin; Zhang Longjiang; Zhou Changsheng; Lu Guangming; Ma Yan; Gu Haifeng

2009-01-01

Objective: To evaluate the feasibility and preliminary applications of single contrast enhanced dual energy heart imaging using dual-source CT (DSCT). Methods: Thirty patients underwent dual energy heart imaging with DSCT, of which 6 cases underwent SPECT or DSA within one week. Two experienced radiologists assessed image quality of coronary arteries and iodine map of myocardium. and correlated the coronary artery stenosis with the perfusion distribution of iodine map. Results: l00% (300/300) segments reached diagnostic standards. The mean score of image for all patients was 4.68±0.57. Mural coronary artery was present in 10 segments in S cases, atherosclerotic plaques in 32 segments in 12 cases, of which 20 segments having ≥50% stenosis, 12 segments ≤50% stenosis; dual energy CT coronary angiography was consistent with the DSA in 3 patients. 37 segmental perfusion abnormalities on iodine map were found in 15 cases, including 28 coronary blood supply segment narrow segment and 9 no coronary stenosis (including three negative segments in SPECD. Conclusion: Single contrast enhanced dual energy heart imaging can provide good coronary artery and myocardium perfusion images in the patients with appropriate heart rate, which has a potential to be used in the clinic and further studies are needed. (authors)

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.

Pulmonary ventilation and perfusion imaging with dual-energy CT

Energy Technology Data Exchange (ETDEWEB)

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

2010-12-15

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

Quantitative perfusion modeling in cardiac in-vivo nuclear magnetic resonance (NMR) imaging

International Nuclear Information System (INIS)

Carme, Sabin Charles

2004-01-01

A parametrical analysis of contrast agent distribution is proposed to interpret first pass MR images and to quantify the myocardial perfusion. We are concerned with the correction of spatial intensity variations in images. Furthermore, we are interested in the application of a robust NMR signal processing technique and deconvolution techniques adapted to low signal-to-noise ratio. Data sets were provided, close to clinical conditions, using in-vivo experiments applying several pharmacological stresses on ischemic pigs presenting a stenosis of the left circumflex coronary artery. The agreement and accuracy measurements between observers are respectively 57.1% and 53.1% for visual analysis, and 81.2% and 81.1% for parametric map analysis. A linear relationship between perfusion parameters and radioactive microspheres is established for low blood flows [fr

Ventilation perfusion radionuclide imaging in cryptogenic fibrosing alveolitis

International Nuclear Information System (INIS)

Bourke, S.J.; Hawkins, T.; Keavey, P.M.; Gascoigne, A.D.; Corris, P.A.

1993-01-01

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 2 or A-aO 2 gradient. The appearances were atypical of pulmonary embolism in eight patients. (Author)

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.)

Multimodality functional imaging of spontaneous canine tumors using 64Cu-ATSM and 18FDG PET/CT and dynamic contrast enhanced perfusion CT

International Nuclear Information System (INIS)

Hansen, Anders E.; Kristensen, Annemarie T.; Law, Ian; McEvoy, Fintan J.; Kjær, Andreas; Engelholm, Svend A.

2012-01-01

Purpose: To compare the distribution and uptake of the hypoxia tracer 64 Cu-diacetyl-bis(N 4 -methylthiosemicarbazone) ( 64 Cu-ATSM) PET/CT, FDG PET/CT and dynamic contrast enhanced perfusion CT (DCE-pCT) in spontaneous canine tumors. In addition 64 Cu-ATSM distribution over time was evaluated. Methods and materials: Nine spontaneous cancer-bearing dogs were prospectively enrolled. FDG (1 h pi.) and 64 Cu-ATSM (3 and 24 h pi.) PET/CT were performed over three consecutive days. DCE-pCT was performed on day 2. Tumor uptake of FDG and 64 Cu-ATSM was assessed semi-quantitatively and the distribution of FDG, 64 Cu-ATSM and CT perfusion parameters correlated. Results: 64 Cu-ATSM distribution on scans performed 24 h apart displayed moderate to strong correlation; however, temporal changes were observed. The spatial distribution pattern of 64 Cu-ATSM between scans was moderately to strongly positively correlated to FDG, whereas the correlation of CT perfusion parameters to FDG and to 64 Cu-ATSM yielded more varying results. Conclusions: 64 Cu-ATSM uptake was positively correlated to FDG. 64 Cu-ATSM was found to be relatively stable between PET scans performed at different time points, important temporal changes were however observed in hypo-perfused regions. These findings potentially indicate that prolonged uptake periods for 64 Cu-ATSM imaging may be needed. Although a moderate to strong correlation between 64 Cu-ATSM and FDG PET/CT is observed, the two tracers provide different biological information with an overlapping spatial distribution.

Absolute quantification of regional renal blood flow in swine by dynamic contrast-enhanced magnetic resonance imaging using a blood pool contrast agent.

Science.gov (United States)

Lüdemann, Lutz; Nafz, Benno; Elsner, Franz; Grosse-Siestrup, Christian; Meissler, Michael; Kaufels, Nicola; Rehbein, Hagen; Persson, Pontus B; Michaely, Henrik J; Lengsfeld, Philipp; Voth, Matthias; Gutberlet, Matthias

2009-03-01

To evaluate for the first time in an animal model the possibility of absolute regional quantification of renal medullary and cortical perfusion by dynamic contrast-enhanced magnetic resonance imaging (DCE-MRI) using a blood pool contrast agent. A total of 18 adult female pigs (age, 16-22 weeks; body weight, 45-65 kg; no dietary restrictions) were investigated by DCE-MRI. Absolute renal blood flow (RBF) measured by an ultrasound transit time flow probe around the renal vein was used as the standard of reference. An inflatable stainless cuff placed around the renal artery near its origin from the abdominal aorta was used to reduce RBF to 60%, 40%, and 20% of the baseline flow. The last measurement was performed with the cuff fully reopened. Absolute RBF values during these 4 perfusion states were compared with the results of DCE-MRI performed on a 1.5-T scanner with an 8-channel phased-array surface coil. All scans were acquired in breath-hold technique in the coronal plane using a field of view of 460 mm.Each dynamic scan commenced with a set of five 3D T1-weighted gradient echo sequences with different flip angles (alpha = 2 degrees, 5 degrees, 10 degrees, 20 degrees, 30 degrees): TE, 0.88 milliseconds; TR, 2.65 milliseconds; slice thickness, 8.8 mm for 4 slices; acquisition matrix, 128 x 128; and acquisitions, 4. These data served to calculate 3D intrinsic longitudinal relaxation rate maps (R10) and magnetization (M0). Immediately after these images, the dynamic 3D T1-weighted gradient echo images were acquired with the same parameters and a constant alpha = 30 degrees, half Fourier, 1 acquisition, 64 frames, a time interval of 1.65 seconds between each frame, and a total duration of 105.6. Three milliliters of an albumin-binding blood pool contrast agent (0.25 mmol/mL gadofosveset trisodium, Vasovist, Bayer Schering Pharma AG, Berlin, Germany) was injected at a rate of 3 mL/s. Perfusion was calculated using the arterial input function from the aorta, which was

Multimodality functional imaging of spontaneous canine tumors using 64CU-ATSM and 18FDG PET/CT and dynamic contrast enhanced perfusion CT

DEFF Research Database (Denmark)

Hansen, Anders E; Kristensen, Annemarie T; Law, Ian

2012-01-01

To compare the distribution and uptake of the hypoxia tracer (64)Cu-diacetyl-bis(N(4)-methylthiosemicarbazone) ((64)Cu-ATSM) PET/CT, FDG PET/CT and dynamic contrast enhanced perfusion CT (DCE-pCT) in spontaneous canine tumors. In addition (64)Cu-ATSM distribution over time was evaluated.......To compare the distribution and uptake of the hypoxia tracer (64)Cu-diacetyl-bis(N(4)-methylthiosemicarbazone) ((64)Cu-ATSM) PET/CT, FDG PET/CT and dynamic contrast enhanced perfusion CT (DCE-pCT) in spontaneous canine tumors. In addition (64)Cu-ATSM distribution over time was evaluated....

Myocardial perfusion SPECT imaging in patients with myocardial bridging

International Nuclear Information System (INIS)

Fang Wei; Qiu Hong; Yang Weixian; Wang Feng; He Zuoxiang

2008-01-01

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

The role of dynamic susceptibility contrast-enhanced perfusion MR imaging in differentiating between infectious and neoplastic focal brain lesions: results from a cohort of 100 consecutive patients.

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Valdeci Hélio Floriano

Full Text Available BACKGROUND AND PURPOSE: Differentiating between infectious and neoplastic focal brain lesions that are detected by conventional structural magnetic resonance imaging (MRI may be a challenge in routine practice. Brain perfusion-weighted MRI (PWI may be employed as a complementary non-invasive tool, providing relevant data on hemodynamic parameters, such as the degree of angiogenesis of lesions. We aimed to employ dynamic susceptibility contrast-enhanced perfusion MR imaging (DSC-MRI to differentiate between infectious and neoplastic brain lesions by investigating brain microcirculation changes. MATERIALS AND METHODS: DSC-MRI perfusion studies of one hundred consecutive patients with non-cortical neoplastic (n = 54 and infectious (n = 46 lesions were retrospectively assessed. MRI examinations were performed using a 1.5-T scanner. A preload of paramagnetic contrast agent (gadolinium was administered 30 seconds before acquisition of dynamic images, followed by a standard dose 10 seconds after starting imaging acquisitions. The relative cerebral blood volume (rCBV values were determined by calculating the regional cerebral blood volume in the solid areas of lesions, normalized to that of the contralateral normal-appearing white matter. Discriminant analyses were performed to determine the cutoff point of rCBV values that would allow the differentiation of neoplastic from infectious lesions and to assess the corresponding diagnostic performance of rCBV when using this cutoff value. RESULTS: Neoplastic lesions had higher rCBV values (4.28±2.11 than infectious lesions (0.63±0.49 (p<0.001. When using an rCBV value <1.3 as the parameter to define infectious lesions, the sensitivity of the method was 97.8% and the specificity was 92.6%, with a positive predictive value of 91.8%, a negative predictive value of 98.0%, and an accuracy of 95.0%. CONCLUSION: PWI is a useful complementary tool in distinguishing between infectious and neoplastic brain

Cerebral perfusion imaging in HIV positive patients

International Nuclear Information System (INIS)

Kundley, Kshama; Chowdhury, D.; Lele, V.R.; Lele, R.D.

1998-01-01

Full text: Twelve human immunodeficiency virus (HIV) positive patients were studied by SPECT cerebral perfusion imaging 1 hour post injection of 15 mCi of 99m Tc-ECD under ideal conditions with a triple head gamma camera (Prism 3000 X P LEUHR), fanbeam collimators followed by Folstein Mini Mental Status Examination (FMMSE) and AIDS dementia complex (ADC) staging on the same day. All 12 patients were male, in the age range of 23-45 y (mean 31 y). The infected status was diagnosed by ELISA (10 patients) or Western blot (5 patients). The interval between diagnosis and imaging ranged from 1 month - 35 months (mean 15.3 months). Two patients were alcoholic and 2 were smokers. None of them had CNS disorder clinically. ADC staging and FMMSE could be performed in 4 patients. Two patients were normal (stage 0) and 2 were subclinical (stage 0.5) on ADC staging. FMMSE revealed normal or near normal status (mean score 35; maximum score 36). Cerebral perfusion images were interpreted simultaneously by 3 observers blind towards history and examination using semi-quantitative and quantitative methods by consensus. It revealed multiple areas of hypoperfusion, viz. temporal (11 patients (91 %), parietal 10 patients (83%), frontal 9 patients (75%, pre and post central gyrus 7 patients (58%), occipital 6 patients (50%) cingulate gyrus and cerebellum 5 patients (41%) and thalamic in 2 patients (16%). Hyper perfusion in caudate nuclei was noted in 10 patients (83%). The study reveals presence of multiple perfusion abnormalities on cerebral perfusion imaging in HIV positive patients who have normal/near normal mental status suggesting precedence of perfusion abnormality over clinically apparent mental deficit

Assessment of regional lung functional impairment with co-registered respiratory-gated ventilation/perfusion SPET-CT images: initial experiences

International Nuclear Information System (INIS)

Suga, Kazuyoshi; Yasuhiko, Kawakami; Zaki, Mohammed; Yamashita, Tomio; Seto, Aska; Matsumoto, Tsuneo; Matsunaga, Naofumi

2004-01-01

In this study, respiratory-gated ventilation and perfusion single-photon emission tomography (SPET) were used to define regional functional impairment and to obtain reliable co-registration with computed tomography (CT) images in various lung diseases. Using a triple-headed SPET unit and a physiological synchroniser, gated perfusion SPET was performed in a total of 78 patients with different pulmonary diseases, including metastatic nodules (n=15); in 34 of these patients, it was performed in combination with gated technetium-99m Technegas SPET. Projection data were acquired using 60 stops over 120 for each detector. Gated end-inspiration and ungated images were reconstructed from 1/8 data centered at peak inspiration for each regular respiratory cycle and full respiratory cycle data, respectively. Gated images were registered with tidal inspiration CT images using automated three-dimensional (3D) registration software. Registration mismatch was assessed by measuring 3D distance of the centroid of the nine selected round perfusion-defective nodules. Gated SPET images were completed within 29 min, and increased the number of visible ventilation and perfusion defects by 9.7% and 17.2%, respectively, as compared with ungated images; furthermore, lesion-to-normal lung contrast was significantly higher on gated SPET images. In the nine round perfusion-defective nodules, gated images yielded a significantly better SPET-CT match compared with ungated images (4.9±3.1 mm vs 19.0±9.1 mm, P<0.001). The co-registered SPET-CT images allowed accurate perception of the location and extent of each ventilation/perfusion defect on the underlying CT anatomy, and characterised the pathophysiology of the various diseases. By reducing respiratory motion effects and enhancing perfusion/ventilation defect clarity, gated SPET can provide reliable co-registered images with CT images to accurately characterise regional functional impairment in various lung diseases. (orig.)

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

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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

Automatic Detection of Myocardial Boundaries in MR Cardio Perfusion Images

NARCIS (Netherlands)

Spreeuwers, Luuk; Breeuwer, Marcel

2001-01-01

Cardiovascular diseases often result in reduced blood perfusion of the myocardium (MC). Recent advances in MR allow fast recordingof contrast enhanced myocardial perfusion scans. For perfusion analysis the myocardial boundaries must be traced. Currently this is done manually. In this paper a method

Improved visualization of delayed perfusion in lung MRI

International Nuclear Information System (INIS)

Risse, Frank; Eichinger, Monika; Kauczor, Hans-Ulrich; Semmler, Wolfhard; Puderbach, Michael

2011-01-01

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

Basic consideration of diffusion/perfusion imaging

International Nuclear Information System (INIS)

Tamagawa, Yoichi; Kimura, Hirohiko; Matsuda, Tsuyoshi; Kawamura, Yasutaka; Nakatsugawa, Shigekazu; Ishii, Yasushi; Sakuma, Hajime; Tsukamoto, Tetsuji.

1990-01-01

In magnetic resonance imaging (MRI), microscopic motion of biological system such as molecular diffusion of water and microcirculation of blood in the capillary network (perfusion) has been proposed to cause signal attenuation as an intravoxel incoherent motion (IVIM). Quantitative imaging of the IVIM phenomenon was attempted to generate from a set of spin-echo (SE) sequences with or without sensitization by motion probing gradient (MPG). The IVIM imaging is characterized by a parameter, apparent diffusion coefficient (ADC), which is an integration of both the diffusion and the perfusion factor on voxel-by-voxel basis. Hard ware was adjusted to avoid image artifact mainly produced by eddy current. Feasibility of the method was tested using bottle phantom filled with water at different temperature and acetone, and the calculated ADC values of these media corresponded well with accepted values of diffusion. The method was then applied to biological system to investigate mutual participation of diffusion/perfusion on the ADC value. The result of tumor model born on nude mouse suggested considerable participation of perfusion factor which immediately disappeared after sacrificing the animal. Meanwhile, lower value of sacrificed tissue without microcirculation was suggested to have some restriction of diffusion factor by biological tissue. To substantiate the restriction effect on the diffusion, a series of observation have made on a fiber phantom, stalk of celory with botanical fibers and human brain with nerve fibers, in applying unidirectional MPG along the course of these banch of fiber system. The directional restriction effect of diffusion along the course of fiber (diffusion anisotrophy) was clearly visualized as directional change of ADC value. The present method for tissue characterization by diffusion/perfusion on microscopic level will provide a new insight for evaluation of functional derangement in human brain and other organs. (author)

Application of a Simplified Method for Estimating Perfusion Derived from Diffusion-Weighted MR Imaging in Glioma Grading.

Science.gov (United States)

Cao, Mengqiu; Suo, Shiteng; Han, Xu; Jin, Ke; Sun, Yawen; Wang, Yao; Ding, Weina; Qu, Jianxun; Zhang, Xiaohua; Zhou, Yan

2017-01-01

Purpose : To evaluate the feasibility of a simplified method based on diffusion-weighted imaging (DWI) acquired with three b -values to measure tissue perfusion linked to microcirculation, to validate it against from perfusion-related parameters derived from intravoxel incoherent motion (IVIM) and dynamic contrast-enhanced (DCE) magnetic resonance (MR) imaging, and to investigate its utility to differentiate low- from high-grade gliomas. Materials and Methods : The prospective study was approved by the local institutional review board and written informed consent was obtained from all patients. From May 2016 and May 2017, 50 patients confirmed with glioma were assessed with multi- b -value DWI and DCE MR imaging at 3.0 T. Besides conventional apparent diffusion coefficient (ADC 0,1000 ) map, perfusion-related parametric maps for IVIM-derived perfusion fraction ( f ) and pseudodiffusion coefficient (D*), DCE MR imaging-derived pharmacokinetic metrics, including K trans , v e and v p , as well as a metric named simplified perfusion fraction (SPF), were generated. Correlation between perfusion-related parameters was analyzed by using the Spearman rank correlation. All imaging parameters were compared between the low-grade ( n = 19) and high-grade ( n = 31) groups by using the Mann-Whitney U test. The diagnostic performance for tumor grading was evaluated with receiver operating characteristic (ROC) analysis. Results : SPF showed strong correlation with IVIM-derived f and D* ( ρ = 0.732 and 0.716, respectively; both P simplified method to measure tissue perfusion based on DWI by using three b -values may be helpful to differentiate low- from high-grade gliomas. SPF may serve as a valuable alternative to measure tumor perfusion in gliomas in a noninvasive, convenient and efficient way.

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

International Nuclear Information System (INIS)

Savvopoulou, Vasiliki; Vlahos, Lampros; Moulopoulos, Lia Angela; Maris, Thomas G.

2008-01-01

To investigate the influence of age, sex and spinal level on perfusion parameters of normal lumbar bone marrow with dynamic contrast-enhanced MRI (DCE MRI). Sixty-seven subjects referred for evaluation of low back pain or sciatica underwent DCE MRI of the lumbar spine. After subtraction of dynamic images, a region of interest (ROI) was placed on each lumbar vertebral body of all subjects, and time intensity curves were generated. Consequently, perfusion parameters were calculated. Statistical analysis was performed to search for perfusion differences among lumbar vertebrae and in relation to age and sex. Upper (L1, L2) and lower (L3, L4, L5) vertebrae showed significant differences in perfusion parameters (p<0.05). Vertebrae of subjects younger than 50 years showed significantly higher perfusion compared to vertebrae of older ones (p<0.05). Vertebrae of females demonstrated significantly increased perfusion compared to those of males of corresponding age (p<0.05). All perfusion parameters, except for washout (WOUT), showed a mild linear correlation with age. Time to maximum slope (TMSP) and time to peak (TTPK) showed the same correlation with sex (0.22< r<0.32, p<0.05). Our results indicate increased perfusion of the upper compared to the lower lumbar spine, of younger compared to older subjects and of females compared to males. (orig.)

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

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

2008-09-15

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

Assessment of cerebral perfusion with dynamic susceptibility contrast

International Nuclear Information System (INIS)

Takahashi, Kiyohiko; Naito, Isao; Nozokido, Takeshi; Sato, Takaaki; Takatama, Shin; Kimura, Tokunori

2004-01-01

Accurate measurements of arterial input function (AIF) are indispensable for the quantification of perfusion parameters such as mean transit time (MTT), cerebral blood volume (CBV), and cerebral blood flow (CBF). Quantification trials of cerebral perfusion using the disconsolation method with dynamic susceptibility contrast MRI (DSC-MRI) have been reported on. Accurately measuring AIF with DSC-MRI is difficult due to non-linearity and the limited dynamic range between ΔR 2 * and the concentration of contrast media. In this study, we assessed simple methods while using various parameters calculated by the tissue time intensity curve without measuring AIF. The parameters used were appearance time of contrast media (AT), 1'st moment (MT1), the full width at half maximum (FWHM), and up slope at maximum gradient (US). Difference of the appearance time (delta AT) and the CBFratio between the regions in question and the contralateral regions obtained by MT1, FWHM and US were assessed in 38 stroke patients. The CBF calculated by the linear scaling method using the signal of the ASL (ASL, CBF) was used as the standard for a correlation study. The delta AT in patients with middle cerebral artery occlusions supplied by retrograde flow indicated a significantly greater value as compared to patients with other lesions with antegrade flow. US CBF indicated the best correlation among the three CBFs obtained by MT1, FWHM and US. Both the ASL CBFratio and the US CBFratio correlated with delta AT, with the ASL CBFratio being predominant. The CBVratio-CBFratio map showed that the CBVratio tended to decrease when the CBFratio decreased. The map is useful in clinical analysis of cerebral perfusion due to its simplicity and ability to alleviate AIF dependent errors. The validity of the proposed method still needs to be examined by comparing it to the deconvolution method with DSC-MRI, since DSC-MRI can correct the effect of AIF. It might also be compared to Xenon CT, which is less

Heterogeneity of pulmonary perfusion as a mechanistic image-based phenotype in emphysema susceptible smokers.

Science.gov (United States)

Alford, Sara K; van Beek, Edwin J R; McLennan, Geoffrey; Hoffman, Eric A

2010-04-20

Recent evidence suggests that endothelial dysfunction and pathology of pulmonary vascular responses may serve as a precursor to smoking-associated emphysema. Although it is known that emphysematous destruction leads to vasculature changes, less is known about early regional vascular dysfunction which may contribute to and precede emphysematous changes. We sought to test the hypothesis, via multidetector row CT (MDCT) perfusion imaging, that smokers showing early signs of emphysema susceptibility have a greater heterogeneity in regional perfusion parameters than emphysema-free smokers and persons who had never smoked (NS). Assuming that all smokers have a consistent inflammatory response, increased perfusion heterogeneity in emphysema-susceptible smokers would be consistent with the notion that these subjects may have the inability to block hypoxic vasoconstriction in patchy, small regions of inflammation. Dynamic ECG-gated MDCT perfusion scans with a central bolus injection of contrast were acquired in 17 NS, 12 smokers with normal CT imaging studies (SNI), and 12 smokers with subtle CT findings of centrilobular emphysema (SCE). All subjects had normal spirometry. Quantitative image analysis determined regional perfusion parameters, pulmonary blood flow (PBF), and mean transit time (MTT). Mean and coefficient of variation were calculated, and statistical differences were assessed with one-way ANOVA. MDCT-based MTT and PBF measurements demonstrate globally increased heterogeneity in SCE subjects compared with NS and SNI subjects but demonstrate similarity between NS and SNI subjects. These findings demonstrate a functional lung-imaging measure that provides a more mechanistically oriented phenotype that differentiates smokers with and without evidence of emphysema susceptibility.

Comparison of MR imaging after administration of dysprosium-based magnetic-susceptibility contrast media with diffusion-weighted MR imaging in evaluation of regional cerebral ischemia

International Nuclear Information System (INIS)

Moseley, M.E.; Kucharczyk, J.; Kurhanewicz, J.; Mintorovitch, J.; Cohen, Y.; Rocklage, S.; Quay, S.C.; Norman, D.

1989-01-01

This paper reports on a study to establish whether a nonionic T2-shortening contrast agent, Dy-DTPA-bis(methylamide) (Dy-DTPA-BMA), would facilitate early detection of stroke-induced cerebral perfusion deficits. The sensitivity of susceptibility-enhanced MR imaging was compared with that of diffusion-weighted MR imaging in the same cats subjected to unilateral occlusion of the middle cerebral artery (MCA). A 2-T unit, equipped with self-shielded gradient coils (± 20 G/cm, 15-cm bore size), was used in conjunction with an 8.5-cm inner diameter low-pass bird cage proton imaging coil. Diffusion-weighted images displayed increased signal intensity in the ischemic MCA territory less than 1 hour after occlusion, whereas T2-weighted MR images without contrast enhancement usually failed to depict injury for 2--3 hours after toke. With contrast administration (0.5 mmoles/kg of Dy-DTPA-BMA), however, T2-weighted images revealed perfusion deficits (hyperintensity) within 1 hour after MCA occlusion, and these corresponded to the anatomic regions of ischemic injury shown on diffusion-weighted MR images

Perfusion MR imaging for differentiation of benign and malignant meningiomas

International Nuclear Information System (INIS)

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

2008-01-01

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.)

Multi-slice spiral CT perfusion imaging of chronic obstructive pulmonary disease

International Nuclear Information System (INIS)

Shao Yanhui; Qian Nong; Xue Yuejun; Dao Yinhong

2008-01-01

Objective: To evaluate the diagnostic value of multi-slice spiral CT (MSCT) perfusion imaging in chronic obstructive pulmonary disease (COPD). Methods: Twenty COPD patients and 20 volunteers underwent 8-row detector spiral CT (MSCT) perfusion imaging using cine scan mode with 5 mm slice thickness, 0.5 s rotation time and a total scan time of 45 s with 5 s intervals. 60 ml contrast agent (300 nag I/ml) were administered at a rate of 4 ml/s from the forearm superficial vein. The imaging data were transferred to a workstation. A time-density curve and pseudo-color map were generated automatically with GE CT perfusion 3 software, the blood flow (BF), blood volume (BV), mean transit time (MTT) and permeability surface (PS) were measured. Results: Time-density curve was flatter and the peak of the curve was obviously lower in COPD patients than the volunteers. The BF, BV, PS in COPD patients was (24.77±11.49) ml·min -1 ·100 g -1 , (2.48±1.02) ml/100 g and (2.75±1.13) ml· min -1 ·100 g -1 respectively. In volunteers was (290.14±107.59) ml·min -1 ·100 g -1 , (16.51 ± 5.98) ml/100 g, (8.80±3.03) ml·min -1 ·100 g -1 respectively. The MTT in COPD patients and volunteers was (10.58±4.85) s and (4.50±1.71)s respectively. The BF, BV and PS in COPD patients was lower than the volunteers, the MTY was higher (P<0.01). Conclusion: MSCT perfusion imaging is helpful for the diagnosis of COPD. (authors)

Myocardial perfusion imaging with dual energy CT

Energy Technology Data Exchange (ETDEWEB)

Jin, Kwang Nam [Division of Cardiovascular Imaging, Department of Radiology and Radiological Science, Medical University of South Carolina, Charleston, SC (United States); Department of Radiology, SMG-SNU Boramae Medical Center, Seoul (Korea, Republic of); De Cecco, Carlo N. [Division of Cardiovascular Imaging, Department of Radiology and Radiological Science, Medical University of South Carolina, Charleston, SC (United States); Caruso, Damiano [Division of Cardiovascular Imaging, Department of Radiology and Radiological Science, Medical University of South Carolina, Charleston, SC (United States); Department of Radiological Sciences, Oncology and Pathology, University of Rome “Sapienza”, Rome (Italy); Tesche, Christian [Division of Cardiovascular Imaging, Department of Radiology and Radiological Science, Medical University of South Carolina, Charleston, SC (United States); Department of Cardiology and Intensive Care Medicine, Heart Center Munich-Bogenhausen, Munich (Germany); Spandorfer, Adam; Varga-Szemes, Akos [Division of Cardiovascular Imaging, Department of Radiology and Radiological Science, Medical University of South Carolina, Charleston, SC (United States); Schoepf, U. Joseph, E-mail: schoepf@musc.edu [Division of Cardiovascular Imaging, Department of Radiology and Radiological Science, Medical University of South Carolina, Charleston, SC (United States); Division of Cardiology, Department of Medicine, Medical University of South Carolina, Charleston, SC (United States)

2016-10-15

Highlights: • Stress dual-energy sCTMPI offers the possibility to directly detect the presence of myocardial perfusion defects. • Stress dual-energy sCTMPI allows differentiating between reversible and fixed myocardial perfusion defects. • The combination of coronary CT angiography and dual-energy sCTMPI can improve the ability of CT to detect hemodynamically relevant coronary artery disease. - Abstract: 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.

Functional and perfusion magnetic resonance imaging at 3 tesla

International Nuclear Information System (INIS)

Klarhoefer, M.

2001-03-01

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 flow velocity measurements in the human finger showed that the use of a strong, small-bore gradient system permits short echo times that reduce flow artefacts and allows high spatial resolution in order to keep systematic errors due to partial volume effects small. With regard to the perfusion investigations an inversion recovery snapshot-FLASH sequence was implemented, which allowed the acquisition of T1 parameter maps of the human brain within a few seconds. The accuracy of this method was demonstrated in test objects. The perfusion investigations with FAIR showed good qualitative results, whereas the quantitative analysis did not yield reproducible findings. A reason for the poor results could be the low signal-to-noise ratio (SNR) of the FAIR images or an incomplete global inversion of the magnetization due to the transmission characteristics of the radio-frequency coil. The BASE sequence that did not require a global inversion yielded quantitative perfusion

3D pulmonary perfusion MRI and MR angiography of pulmonary embolism in pigs after a single injection of a blood pool MR contrast agent

International Nuclear Information System (INIS)

Fink, Christian; Ley, Sebastian; Puderbach, Michael; Plathow, Christian; Kauczor, Hans-Ulrich; Bock, Michael

2004-01-01

The purpose of this study was to assess the feasibility of contrast-enhanced 3D perfusion MRI and MR angiography (MRA) of pulmonary embolism (PE) in pigs using a single injection of the blood pool contrast Gadomer. PE was induced in five domestic pigs by injection of autologous blood thrombi. Contrast-enhanced first-pass 3D perfusion MRI (TE/TR/FA: 1.0 ms/2.2 ms/40 ; voxel size: 1.3 x 2.5 x 4.0 mm 3 ; TA: 1.8 s per data set) and high-resolution 3D MRA (TE/TR/FA: 1.4 ms/3.4 ms/40 ; voxel size: 0.8 x 1.0 x 1.6 mm 3 ) was performed during and after a single injection of 0.1 mmol/kg body weight of Gadomer. Image data were compared to pre-embolism Gd-DTPA-enhanced MRI and post-embolism thin-section multislice CT (n=2). SNR measurements were performed in the pulmonary arteries and lung. One animal died after induction of PE. In all other animals, perfusion MRI and MRA could be acquired after a single injection of Gadomer. At perfusion MRI, PE could be detected by typical wedge-shaped perfusion defects. While the visualization of central PE at MRA correlated well with the CT, peripheral PE were only visualized by CT. Gadomer achieved a higher peak SNR of the lungs compared to Gd-DTPA (21±8 vs. 13±3). Contrast-enhanced 3D perfusion MRI and MRA of PE can be combined using a single injection of the blood pool contrast agent Gadomer. (orig.)

Brain perfusion CT in acute stroke: current status

Energy Technology Data Exchange (ETDEWEB)

Koenig, Matthias E-mail: matthias.koenig@ruhr-uni-bochum.de

2003-03-01

Dynamic perfusion CT has become a widely accepted imaging modality for the diagnostic workup of acute stroke patients. Although compared with standard spiral CT the use of multislice CT has broadened the range from which perfusion data may be derived in a single scan run. The advent of multidetector row technology has not really overcome the limited 3D capability of this technique. Multidetector CT angiography (CTA) of the cerebral arteries may in part compensate for this by providing additional information about the cerebrovascular status. This article describes the basics of cerebral contrast bolus scanning with a special focus on optimization of contrast/noise in order to ensure high quality perfusion maps. Dedicated scan protocols including low tube voltage (80 kV) as well as the use of highly concentrated contrast media are amongst the requirements to achieve optimum contrast signal from the short bolus passage through the brain. Advanced pre and postprocessing algorithms may help reduce the noise level, which may become critical in unconscious stroke victims. Two theoretical concepts have been described for the calculation of tissue perfusion from contrast bolus studies, both of which can be equally employed for brain perfusion imaging. For each perfusion model there are some profound limitations regarding the validity of perfusion values derived from ischemic brain areas. This makes the use of absolute quantitative cerebral blood flow (CBF) values for the discrimination of the infarct core from periinfarct ischemia questionable. Multiparameter imaging using maps of CBF, cerebral blood volume (CBV), and a time parameter of the local bolus transit enables analyzing of the cerebral perfusion status in detail. Perfusion CT exceeds plain CT in depicting cerebral hypoperfusion at its earliest stage yielding a sensitivity of about 90% for the detection of embolic and hemodynamic lesions within cerebral hemispheres. Qualitative assessment of brain perfusion can be

Brain perfusion imaging with iodinated amines

International Nuclear Information System (INIS)

Kung, H.F.

1989-01-01

Traditional nuclear medicine brain study using 99m Tc pertechnetate, glucoheptonate or diethlenetriaminepentacetic acid (DTPA) and planar imaging has experienced a significant decline in the past 10 years. This is mainly due to the introduction of X-ray CT and more recently the nuclear magnetic resonance (NMR) imaging, by which detailed morphology of the brain, including the detection of breakdown of the blood-brain barrier, can be obtained. The nuclear medicine brain imaging is only prescribed as a complementary test when X-ray CT is negative or equivocal and clinical suspicion remains. The attention of nuclear medicine brain imaging has been shifted from the detection of the breakdown of the blood-brain barrier to the study of brain function-perfusion, metabolism, and receptor binding, etc. The functional brain imaging provides diagnostic information usually unattainable by other radiological techniques. In this article, the iodinated amines as brain perfusion imaging agents are reviewed. Potential clinical application of these agents is discussed

Dynamic CT myocardial perfusion imaging identifies early perfusion abnormalities in diabetes and hypertension : Insights from a multicenter registry

NARCIS (Netherlands)

Vliegenthart, Rozemarijn; De Cecco, Carlo N.; Wichmann, Julian L.; Meinel, Felix G.; Pelgrim, Gert Jan; Tesche, Christian; Ebersberger, Ullrich; Pugliese, Francesca; Bamberg, Fabian; Choe, Yeon Hyeon; Wang, Yining; Schoepf, U. Joseph

2016-01-01

Background: To identify patients with early signs of myocardial perfusion reduction, a reference base for perfusion measures is needed. Objective: To analyze perfusion parameters derived from dynamic computed tomography perfusion imaging (CTPI) in patients with suspected coronary artery disease

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

Clinical evaluation of pulmonary perfusion MRI using FAIR (flow-sensitive alternating inversion recovery)-HASTE (Half-Fourier Single-Shot TurboSE) method

International Nuclear Information System (INIS)

Togami, Izumi; Sasai, Nobuya; Tsunoda, Masatoshi; Sei, Tetsurou; Sato, Shuhei; Yabuki, Takayuki; Hiraki, Yoshio

2002-01-01

The FAIR-HASTE method is a kind of noninvasive perfusion MR imaging obtained without the use of contrast media. By subtracting a flow-insensitive image from a flow-sensitive image, contrast enhancement of inflowing blood achieved. In the present study, we applied pulmonary perfusion FAIR-HASTE sequence for 23 patients with various pulmonary diseases, and compared the findings with those by pulmonary perfusion scintigraphy and Gadolinium perfusion MRI. Pulmonary perfusion imaging with the FAIR-HASTE method was possible in all clinical cases, and the findings corresponded well to those obtained by perfusion MRI using contrast media or pulmonary scintigraphy. The FAIR-HASTE method is a promising method for the evaluation of pulmonary perfusion. (author)

Susceptibility contrast imaging of CO2-induced changes in the blood volume of the human brain

DEFF Research Database (Denmark)

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

1996-01-01

PURPOSE: To investigate changes in the regional cerebral blood volume (rCBV) in human subjects during rest and hypercapnia by MR imaging, and to compare the results from contrast-enhanced and noncontrast-enhanced susceptibility-weighted imaging. MATERIAL AND METHODS: Five healthy volunteers (aged...... in cerebral hemodynamics than noncontrast-enhanced imaging. The results of the deconvolution analysis suggested that perfusion calculation by conventional tracer kinetic methods may be impracticable because of nonlinear effects in contrast-enhanced MR imaging....

Simultaneous Multiagent Hyperpolarized ¹³C Perfusion Imaging

DEFF Research Database (Denmark)

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

2014-01-01

in simulations. "Tripolarized" perfusion MRI methods were applied to initial preclinical studies with differential conditions of vascular permeability, in normal mouse tissues and advanced transgenic mouse prostate tumors. Results: Dynamic imaging revealed clear differences among the individual tracer...... distributions. Computed permeability maps demonstrated differential permeability of brain tissue among the tracers, and tumor perfusion and permeability were both elevated over values expected for normal tissues. Conclusion: Tripolarized perfusion MRI provides new molecular imaging measures for specifically...

Computed Tomography Perfusion Imaging for the Diagnosis of Hepatic Alveolar Echinococcosis

Science.gov (United States)

Sade, Recep; Kantarci, Mecit; Genc, Berhan; Ogul, Hayri; Gundogdu, Betul; Yilmaz, Omer

2018-01-01

Objective: Alveolar echinococcosis (AE) is a rare life-threatening parasitic infection. Computed tomography perfusion (CTP) imaging has the potential to provide both quantitative and qualitative information about the tissue perfusion characteristics. The purpose of this study was the examination of the characteristic features and feasibility of CTP in AE liver lesions. Material and Methods: CTP scanning was performed in 25 patients who had a total of 35 lesions identified as AE of the liver. Blood flow (BF), blood volume (BV), portal venous perfusion (PVP), arterial liver perfusion (ALP), and hepatic perfusion indexes (HPI) were computed for background liver parenchyma and each AE lesion. Results: Significant differences were detected between perfusion values of the AE lesions and background liver tissue. The BV, BF, ALP, and PVP values for all components of the AE liver lesions were significantly lower than the normal liver parenchyma (p<0.01). Conclusions: We suggest that perfusion imaging can be used in AE of the liver. Thus, the quantitative knowledge of perfusion parameters are obtained via CT perfusion imaging. PMID:29531482

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

Energy Technology Data Exchange (ETDEWEB)

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

2012-02-15

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

Dynamic MR cardiac perfusion studies in patients with acquired heart diseases

International Nuclear Information System (INIS)

Finelli, D.A.; Adler, L.P.; Paschal, C.B.; Haacke, E.M.

1990-01-01

The combination of ultrafast scanning techniques with contrast administration has opened new venues for MR imaging relating to the physiology of organ perfusion. Regional cardiac perfusion determinations lend important additional information to the morphologic and functional data provided by conventional cardiac MR imaging. The authors of this paper studied 10 patients with acquired heart diseases, including ischemic heart disease, cardiomyopathy, ventricular hypertrophy, and cardiac tumor, using conventional spin-echo imaging, cine gradient-echo imaging, and dynamic Gd-DTPA--enhanced perfusion imaging with an ultrafast, inversion-recovery, Turbo-fast low-angle shot sequence. This technique enables analysis of the first pass and early biodistribution phases following contrast administration, information that has been correlated with cardiac catheterization, single photo emission CT (SPECT), and administration emission tomographic (PET) data

Ventilation and perfusion display in a single image

International Nuclear Information System (INIS)

Lima, J.J.P. de; Botelho, M.F.R.; Pereira, A.M.S.; Rafael, J.A.S.; Pinto, A.J.; Marques, M.A.T.; Pereira, M.C.; Baganha, M.F.; Godinho, F.

1991-01-01

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

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

International Nuclear Information System (INIS)

Bauman, Grzegorz; Puderbach, Michael; Heimann, Tobias; Kopp-Schneider, Annette; Fritzsching, Eva; Mall, Marcus A.; Eichinger, Monika

2013-01-01

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

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

Energy Technology Data Exchange (ETDEWEB)

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

2013-12-01

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

Dynamic CT myocardial perfusion imaging

International Nuclear Information System (INIS)

Caruso, Damiano; Eid, Marwen; Schoepf, U. Joseph; Jin, Kwang Nam; Varga-Szemes, Akos; Tesche, Christian; Mangold, Stefanie

2016-01-01

Highlights: • CT myocardial perfusion provides functional assessment of the myocardium. • CCTA is limited in determining the hemodynamic significance of coronary stenosis. • CT-MPI can accurately detect hemodynamically significant coronary artery stenosis. - Abstract: 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.

Dynamic CT myocardial perfusion imaging

Energy Technology Data Exchange (ETDEWEB)

Caruso, Damiano [Division of Cardiovascular Imaging, Department of Radiology and Radiological Science, Medical University of South Carolina, Charleston, SC (United States); Department of Radiological Sciences, Oncological and Pathological Sciences, University of Rome “Sapienza”, Latina (Italy); Eid, Marwen [Division of Cardiovascular Imaging, Department of Radiology and Radiological Science, Medical University of South Carolina, Charleston, SC (United States); Schoepf, U. Joseph, E-mail: schoepf@musc.edu [Division of Cardiovascular Imaging, Department of Radiology and Radiological Science, Medical University of South Carolina, Charleston, SC (United States); Division of Cardiology, Department of Medicine, Medical University of South Carolina, Charleston, SC (United States); Jin, Kwang Nam [Division of Cardiovascular Imaging, Department of Radiology and Radiological Science, Medical University of South Carolina, Charleston, SC (United States); Department of Radiology, Seoul Metropolitan Government-Seoul National University Boramae Medical Center, Seoul (Korea, Republic of); Varga-Szemes, Akos [Division of Cardiovascular Imaging, Department of Radiology and Radiological Science, Medical University of South Carolina, Charleston, SC (United States); Tesche, Christian [Division of Cardiovascular Imaging, Department of Radiology and Radiological Science, Medical University of South Carolina, Charleston, SC (United States); Department of Cardiology and Intensive Care Medicine, Heart Center Munich-Bogenhausen, Munich (Germany); Mangold, Stefanie [Division of Cardiovascular Imaging, Department of Radiology and Radiological Science, Medical University of South Carolina, Charleston, SC (United States); Department of Diagnostic and Interventional Radiology, University Hospital of Tuebingen, Tuebingen (Germany); and others

2016-10-15

Highlights: • CT myocardial perfusion provides functional assessment of the myocardium. • CCTA is limited in determining the hemodynamic significance of coronary stenosis. • CT-MPI can accurately detect hemodynamically significant coronary artery stenosis. - Abstract: 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.

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.)

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

International Nuclear Information System (INIS)

Michallek, Florian; Dewey, Marc

2014-01-01

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.)

Hepatic artery perfusion imaging

International Nuclear Information System (INIS)

Thrall, J.H.; Gyves, J.W.; Ziessman, H.A.; Ensminger, W.D.

1985-01-01

Organ and region-selective intra-arterial chemotherapy have been used for more than two decades to treat malignant neoplasms in the extremities, head and neck region, pelvis, liver, and other areas. Substantial evidence of improved response to regional chemotherapy now exists, but there are stringent requirements for successful application of the regional technique. First, the chemotherapeutic agent employed must have appropriate pharmacokinetic and pharmacodynamic properties. Second, the drug must be reliably delivered to the tumor-bearing area. This typically requires an arteriographic assessment of the vascular supply of the tumor, followed by placement of a therapeutic catheter and confirmation that the ''watershed'' perfusion distribution from the catheter truly encompasses the tumor. Optimal catheter placement also minimizes perfusion of nontarget organs. Radionuclide perfusion imaging with technetium 99m-labeled particles, either microspheres or macroaggregates of albumin, has become the method of choice for making these assessments. Catheter placement itself is considered by many to represent a type of ''therapeutic'' intervention. However, once the catheter is in the hepatic artery the radionuclide perfusion technique can be used to assess adjunctive pharmacologic maneuvers designed to further exploit the regional approach to chemotherapy. This chapter presents the technetium Tc 99m macroaggregated albumin method for assessing catheter placement and the pharmacokinetic rationale for regional chemotherapy, and discusses two promising avenues for further intervention

Intravoxel incoherent motion perfusion imaging in acute stroke: initial clinical experience

International Nuclear Information System (INIS)

Federau, C.; Becce, F.; Maeder, P.; Meuli, R.; Sumer, S.; Wintermark, M.; O'Brien, K.

2014-01-01

Intravoxel incoherent motion (IVIM) imaging is an MRI perfusion technique that uses a diffusion-weighted sequence with multiple b values and a bi-compartmental signal model to measure the so-called pseudo-diffusion of blood caused by its passage through the microvascular network. The goal of the current study was to assess the feasibility of IVIM perfusion fraction imaging in patients with acute stroke. Images were collected in 17 patients with acute stroke. Exclusion criteria were onset of symptoms to imaging >5 days, hemorrhagic transformation, infratentorial lesions, small lesions 2 . Image quality was assessed by two radiologists, and quantitative analysis was performed in regions of interest placed in the stroke area, defined by thresholding the apparent diffusion coefficient maps, as well as in the contralateral region. IVIM perfusion fraction maps showed an area of decreased perfusion fraction f in the region of decreased apparent diffusion coefficient. Quantitative analysis showed a statistically significant decrease in both IVIM perfusion fraction f (0.026 ± 0.019 vs. 0.056 ± 0.025, p = 2.2 . 10 -6 ) and diffusion coefficient D compared with the contralateral side (3.9 ± 0.79 . 10 -4 vs. 7.5 ± 0.86 . 10 -4 mm 2 /s, p = 1.3 . 10 -20 ). IVIM perfusion fraction imaging is feasible in acute stroke. IVIM perfusion fraction is significantly reduced in the visible infarct. Further studies should evaluate the potential for IVIM to predict clinical outcome and treatment response. (orig.)

Dynamic Susceptibility Contrast Perfusion Magnetic Resonance Imaging Demonstrates Reduced Periventricular Cerebral Blood Flow in Dogs with Ventriculomegaly

Directory of Open Access Journals (Sweden)

Martin J. Schmidt

2017-08-01

Full Text Available The nature of ventriculomegaly in dogs is still a matter of debate. Signs of increased intraventricular pressure and atrophy of the cerebral white matter have been found in dogs with ventriculomegaly, which would imply increased intraventricular pressure and, therefore, a pathological condition, i.e., to some extent. Reduced periventricular blood flow was found in people with high elevated intraventricular pressure. The aim of this study was to compare periventricular brain perfusion in dogs with and without ventriculomegaly using perfusion weighted-magnetic-resonance-imaging to clarify as to whether ventriculomegaly might be associated with an increase in intraventricular pressure. Perfusion was measured in 32 Cavalier King Charles spaniels (CKCS with ventriculomegaly, 10 CKCSs were examined as a control group. Cerebral blood flow (CBF was measured using free-hand regions of interest (ROI in five brain regions: periventricular white matter, caudate nucleus, parietal cortex, hippocampus, and thalamus. CBF was significantly lower in the periventricular white matter of the dogs with ventriculomegaly (p = 0.0029 but not in the other ROIs. Reduction of periventricular CBF might imply increase of intraventricular pressure in ventriculomegaly.

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.

Astrocytic tumour grading: a comparative study of three-dimensional pseudocontinuous arterial spin labelling, dynamic susceptibility contrast-enhanced perfusion-weighted imaging, and diffusion-weighted imaging

International Nuclear Information System (INIS)

Xiao, Hua-Feng; Chen, Zhi-Ye; Wang, Yu-Lin; Wang, Yan; Ma, Lin; Lou, Xin; Gui, Qiu-Ping; Shi, Kai-Ning; Zhou, Zhen-Yu; Zheng, Dan-Dan

2015-01-01

We hypothesized that three-dimensional pseudocontinuous arterial spin labelling (pCASL) may have similar efficacy in astrocytic tumour grading as dynamic susceptibility contrast-enhanced perfusion-weighted imaging (DSC-PWI), and the grading accuracy may be further improved when combined with apparent diffusion coefficient (ADC) values. Forty-three patients with astrocytic tumours were studied using diffusion weighted imaging (DWI), pCASL, and DSC-PWI. Histograms of ADC and normalized tumour cerebral blood flow values (nCBF on pCASL and nrCBF on DSC-PWI) were measured and analyzed. The mean 10 % ADC value was the DWI parameter that provided the best differentiation between low-grade astrocytoma (LGA) and high-grade astrocytoma (HGA). The nCBF and nrCBF (1.810 ± 0.979 and 2.070 ± 1.048) in LGA were significantly lower than those (4.505 ± 2.270 and 5.922 ± 2.630) in HGA. For differentiation between LGA and HGA, the cutoff values of 0.764 x 10 -3 mm 2 /s for mean 10 % ADC, 2.374 for nCBF, and 3.464 for nrCBF provided the optimal accuracy (74.4 %, 86.1 %, and 88.6 %, respectively). Combining the ADC values with nCBF or nrCBF could further improve the grading accuracy to 97.7 % or 95.3 %, respectively. pCASL is an alternative to DSC-PWI for astrocytic tumour grading. The combination of DWI and contrast-free pCASL offers a valuable choice in patients with risk factors. (orig.)

Astrocytic tumour grading: a comparative study of three-dimensional pseudocontinuous arterial spin labelling, dynamic susceptibility contrast-enhanced perfusion-weighted imaging, and diffusion-weighted imaging

Energy Technology Data Exchange (ETDEWEB)

Xiao, Hua-Feng [302 Hospital of Chinese People' s Liberation Army, Department of Radiology, Beijing (China); Chen, Zhi-Ye; Wang, Yu-Lin; Wang, Yan; Ma, Lin [People' s Liberation Army General Hospital, Department of Radiology, Beijing (China); Lou, Xin [People' s Liberation Army General Hospital, Department of Radiology, Beijing (China); University of California, Department of Neurology, Los Angeles, CA (United States); Gui, Qiu-Ping [People' s Liberation Army General Hospital, Department of Pathology, Beijing (China); Shi, Kai-Ning; Zhou, Zhen-Yu; Zheng, Dan-Dan [General Electric Healthcare (China) Co., Ltd., Beijing; Wang, Danny J.J. [University of California, Department of Neurology, Los Angeles, CA (United States)

2015-12-15

We hypothesized that three-dimensional pseudocontinuous arterial spin labelling (pCASL) may have similar efficacy in astrocytic tumour grading as dynamic susceptibility contrast-enhanced perfusion-weighted imaging (DSC-PWI), and the grading accuracy may be further improved when combined with apparent diffusion coefficient (ADC) values. Forty-three patients with astrocytic tumours were studied using diffusion weighted imaging (DWI), pCASL, and DSC-PWI. Histograms of ADC and normalized tumour cerebral blood flow values (nCBF on pCASL and nrCBF on DSC-PWI) were measured and analyzed. The mean 10 % ADC value was the DWI parameter that provided the best differentiation between low-grade astrocytoma (LGA) and high-grade astrocytoma (HGA). The nCBF and nrCBF (1.810 ± 0.979 and 2.070 ± 1.048) in LGA were significantly lower than those (4.505 ± 2.270 and 5.922 ± 2.630) in HGA. For differentiation between LGA and HGA, the cutoff values of 0.764 x 10{sup -3} mm{sup 2}/s for mean 10 % ADC, 2.374 for nCBF, and 3.464 for nrCBF provided the optimal accuracy (74.4 %, 86.1 %, and 88.6 %, respectively). Combining the ADC values with nCBF or nrCBF could further improve the grading accuracy to 97.7 % or 95.3 %, respectively. pCASL is an alternative to DSC-PWI for astrocytic tumour grading. The combination of DWI and contrast-free pCASL offers a valuable choice in patients with risk factors. (orig.)

Quantitative Renal Cortical Perfusion in Human Subjects with Magnetic Resonance Imaging Using Iron-Oxide Nanoparticles: Influence of T1 Shortening

Energy Technology Data Exchange (ETDEWEB)

Morell, A.; Ahlstrom, H.; Schoenberg, S.O.; Abildgaard, A.; Bock, M.; Bjoernerud, A. (Dept. of Diagnostic Radiology, Uppsala Univ. Hospital, Uppsala (Sweden))

2008-10-15

Background: Using conventional contrast agents, the technique of quantitative perfusion by observing the transport of a bolus with magnetic resonance imaging (MRI) is limited to the brain due to extravascular leakage. Purpose: To perform quantitative perfusion measurements in humans with an intravascular contrast agent, and to estimate the influence of the T1 relaxivity of the contrast agent on the first-pass response. Material and Methods: Renal cortical perfusion was measured quantitatively in six patients with unilateral renal artery stenosis using a rapid gradient double-echo sequence in combination with an intravenous bolus injection of NC100150 Injection, an intravascular contrast agent based on iron-oxide nanoparticles. The influence of T1 relaxivity was measured by comparing perfusion results based on single- and double-echo data. Results: The mean values of cortical blood flow, cortical blood volume, and mean transit time in the normal kidneys were measured to 339+-60 ml/min/100 g, 41+-8 ml/100 g, and 7.3+-1.0 s, respectively, based on double-echo data. The corresponding results based on single-echo data, which are not compensated for the T1 relaxivity, were 254+-47 ml/min/100 g, 27+-3 ml/100 g, and 6+-1.2 s, respectively. Conclusion: The use of a double-echo sequence enabled elimination of confounding T1 effects and consequent systematic underestimation of the perfusion.

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.

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...

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.

Application of a Simplified Method for Estimating Perfusion Derived from Diffusion-Weighted MR Imaging in Glioma Grading

Directory of Open Access Journals (Sweden)

Mengqiu Cao

2018-01-01

Full Text Available Purpose: To evaluate the feasibility of a simplified method based on diffusion-weighted imaging (DWI acquired with three b-values to measure tissue perfusion linked to microcirculation, to validate it against from perfusion-related parameters derived from intravoxel incoherent motion (IVIM and dynamic contrast-enhanced (DCE magnetic resonance (MR imaging, and to investigate its utility to differentiate low- from high-grade gliomas.Materials and Methods: The prospective study was approved by the local institutional review board and written informed consent was obtained from all patients. From May 2016 and May 2017, 50 patients confirmed with glioma were assessed with multi-b-value DWI and DCE MR imaging at 3.0 T. Besides conventional apparent diffusion coefficient (ADC0,1000 map, perfusion-related parametric maps for IVIM-derived perfusion fraction (f and pseudodiffusion coefficient (D*, DCE MR imaging-derived pharmacokinetic metrics, including Ktrans, ve and vp, as well as a metric named simplified perfusion fraction (SPF, were generated. Correlation between perfusion-related parameters was analyzed by using the Spearman rank correlation. All imaging parameters were compared between the low-grade (n = 19 and high-grade (n = 31 groups by using the Mann-Whitney U test. The diagnostic performance for tumor grading was evaluated with receiver operating characteristic (ROC analysis.Results: SPF showed strong correlation with IVIM-derived f and D* (ρ = 0.732 and 0.716, respectively; both P < 0.001. Compared with f, SPF was more correlated with DCE MR imaging-derived Ktrans (ρ = 0.607; P < 0.001 and vp (ρ = 0.397; P = 0.004. Among all parameters, SPF achieved the highest accuracy for differentiating low- from high-grade gliomas, with an area under the ROC curve value of 0.942, which was significantly higher than that of ADC0,1000 (P = 0.004. By using SPF as a discriminative index, the diagnostic sensitivity and specificity were 87.1% and 94

Magnetic susceptibility imaging with a nonionic contrast agent

International Nuclear Information System (INIS)

Cacheris, W.; Rocklage, S.M.; Quay, S.; Dow, W.; Love, D.; Worah, D.; Lim, K.

1988-01-01

The magnetic susceptibility mechanism for MR imaging contrast enhancement has the advantage of providing useful information, such as cerebral blood flow, without crossing the blood-brain barrier. In this paper the authors report the use of a highly effective, relatively nontoxic chelate as a magnetic susceptibility agent. Dy-DTPA-bis(methylamide) (Dy-DTPA-BMA) has an extremely low acute toxicity (LD-50, intravenous, mice ∼ 40 mmol/kg). Doses of 1 mmol/kg and 2 mmol/kg Dy-DTPA-BMA lowered the initial signal intensity 63% to 57%, respectively. The utility of this technique in detecting areas of reduced blood flow within the brain was demonstrated by imaging a rabbit with a cerebral perfusion deficit

Application of dynamic susceptibility contrast-enhanced perfusion in temporal lobe epilepsy

Energy Technology Data Exchange (ETDEWEB)

Xing, Wu; Wang, Xiaoyi; Xie, Fangfang; Liao, Weihua [Dept. of Radiology, Xiangya Hospital of Central South Univ., Changsha (China)], e-mail: doctoring@sina.com

2013-02-15

Background: Accurately locatithe epileptogenic focus in temporal lobe epilepsy (TLE) is important in clinical practice. Single-photon emission computed tomography (SPECT) and positron-emission tomography (PET) have been widely used in the lateralization of TLE, but both have limitations. Magnetic resonance perfusion imaging can accurately and reliably reflect differences in cerebral blood flow and volume. Purpose: To investigate the diagnostic value of dynamic susceptibility contrast-enhanced (DSC) perfusion magnetic resonance imaging (MRI) in the lateralization of the epileptogenic focus in TLE. Material and Methods: Conventional MRI and DSC-MRI scanning was performed in 20 interictal cases of TLE and 20 healthy volunteers. The relative cerebral blood volume (rCBV) and relative cerebral blood flow (rCBF) of the bilateral mesial temporal lobes of the TLE cases and healthy control groups were calculated. The differences in the perfusion asymmetry indices (AIs), derived from the rCBV and rCBF of the bilateral mesial temporal lobes, were pared between the two groups. Results: In the control group, there were no statistically significant differences between the left and right sides in terms of rCBV (left 1.55 {+-} 0.32, right 1.57 {+-} 0.28) or rCBF (left 99.00 {+-} 24.61, right 100.38 {+-} 23.46) of the bilateral mesial temporal lobes. However, in the case group the ipsilateral rCBV and rCBF values (1.75 {+-} 0.64 and 96.35 {+-} 22.63, respectively) were markedly lower than those of the contralateral side (2.01 {+-} 0.79 and 108.56 {+-} 26.92; P < 0.05). Both the AI of the rCBV (AIrCBV; 13.03 {+-} 10.33) and the AI of the rCBF (AIrCBF; 11.24 {+-} 8.70) of the case group were significantly higher than that of the control group (AIrCBV 5.55 {+-} 3.74, AIrCBF 5.12 {+-} 3.48; P < 0.05). The epileptogenic foci of nine patients were correctly lateralized using the 95th percentile of the AIrCBV and AIrCBF of the control group as the normal upper limits. Conclusion: In

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)

Dosimetry in myocardial perfusion imaging

International Nuclear Information System (INIS)

Toledo, Janine M.; Trindade, Bruno; Ribeiro, Tarcisio P.C.

2011-01-01

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)

Scintigraphic and MR perfusion imaging in preoperative evaluation for lung volume reduction surgery. Pilot study results

International Nuclear Information System (INIS)

Johkoh, Takeshi; Mueller, N.L.; Kavanagh, P.V

2000-01-01

To compare MR perfusion imaging with perfusion scintigraphy in the evaluation of patients with pulmonary emphysema being considered for lung volume reduction surgery. Six patients with pulmonary emphysema and two normal individuals were evaluated by MR perfusion imaging, perfusion scintigraphy, and selective bilateral pulmonary angiography. MR images were obtained with an enhanced fast gradient recalled echo with three-dimensional Fourier transformation technique (efgre 3D) (6.3/1.3; flip angle, 30 deg C; field of view, 45-48 cm; matrix, 256 x 160). The presence or absence of perfusion defects in each segment was evaluated by two independent observers. Using angiography as the gold standard, the sensitivity, specificity, and accuracy of MR perfusion imaging in detecting focal perfusion abnormalities were 90%, 87%, and 89%, respectively, while those of perfusion scintigraphy were 71%, 76%, and 71%, respectively. The diagnostic accuracy of MR perfusion imaging was significantly higher than that of scintigraphy (p<0.001, McNemar test). There was good agreement between two observers for MR perfusion imaging (kappa statistic, 0.66) and only moderate agreement for perfusion scintigraphy (kappa statistic, 0.51). MR perfusion imaging is superior to perfusion scintigraphy in the evaluation of pulmonary parenchymal perfusion in patients with pulmonary emphysema. (author)

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

International Nuclear Information System (INIS)

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

Magnetic resonance imaging perfusion is associated with disease severity and activity in multiple sclerosis

Energy Technology Data Exchange (ETDEWEB)

Sowa, Piotr [Oslo University Hospital, Department of Radiology and Nuclear Medicine, Oslo (Norway); University of Oslo, Institute of Clinical Medicine, Faculty of Medicine, Oslo (Norway); Owren Nygaard, Gro [Oslo University Hospital, Department of Neurology, Oslo (Norway); Bjoernerud, Atle [Intervention Center, Oslo University Hospital, Oslo (Norway); University of Oslo, Department of Physics, Oslo (Norway); Gulowsen Celius, Elisabeth [Oslo University Hospital, Department of Neurology, Oslo (Norway); University of Oslo, Institute of Health and Society, Faculty of Medicine, Oslo (Norway); Flinstad Harbo, Hanne [University of Oslo, Institute of Clinical Medicine, Faculty of Medicine, Oslo (Norway); Oslo University Hospital, Department of Neurology, Oslo (Norway); Kristiansen Beyer, Mona [Oslo University Hospital, Department of Radiology and Nuclear Medicine, Oslo (Norway); Oslo and Akershus University College of Applied Sciences, Department of Life Sciences and Health, Oslo (Norway)

2017-07-15

The utility of perfusion-weighted imaging in multiple sclerosis (MS) is not well investigated. The purpose of this study was to compare baseline normalized perfusion measures in subgroups of newly diagnosed MS patients. We wanted to test the hypothesis that this method can differentiate between groups defined according to disease severity and disease activity at 1 year follow-up. Baseline magnetic resonance imaging (MRI) including a dynamic susceptibility contrast perfusion sequence was performed on a 1.5-T scanner in 66 patients newly diagnosed with relapsing-remitting MS. From the baseline MRI, cerebral blood flow (CBF), cerebral blood volume (CBV), and mean transit time (MTT) maps were generated. Normalized (n) perfusion values were calculated by dividing each perfusion parameter obtained in white matter lesions by the same parameter obtained in normal-appearing white matter. Neurological examination was performed at baseline and at follow-up approximately 1 year later to establish the multiple sclerosis severity score (MSSS) and evidence of disease activity (EDA). Baseline normalized mean transit time (nMTT) was lower in patients with MSSS >3.79 (p = 0.016), in patients with EDA (p = 0.041), and in patients with both MSSS >3.79 and EDA (p = 0.032) at 1-year follow-up. Baseline normalized cerebral blood flow and normalized cerebral blood volume did not differ between these groups. Lower baseline nMTT was associated with higher disease severity and with presence of disease activity 1 year later in newly diagnosed MS patients. Further longitudinal studies are needed to confirm whether baseline-normalized perfusion measures can differentiate between disease severity and disease activity subgroups over time. (orig.)

Magnetic resonance imaging perfusion is associated with disease severity and activity in multiple sclerosis

International Nuclear Information System (INIS)

Sowa, Piotr; Owren Nygaard, Gro; Bjoernerud, Atle; Gulowsen Celius, Elisabeth; Flinstad Harbo, Hanne; Kristiansen Beyer, Mona

2017-01-01

The utility of perfusion-weighted imaging in multiple sclerosis (MS) is not well investigated. The purpose of this study was to compare baseline normalized perfusion measures in subgroups of newly diagnosed MS patients. We wanted to test the hypothesis that this method can differentiate between groups defined according to disease severity and disease activity at 1 year follow-up. Baseline magnetic resonance imaging (MRI) including a dynamic susceptibility contrast perfusion sequence was performed on a 1.5-T scanner in 66 patients newly diagnosed with relapsing-remitting MS. From the baseline MRI, cerebral blood flow (CBF), cerebral blood volume (CBV), and mean transit time (MTT) maps were generated. Normalized (n) perfusion values were calculated by dividing each perfusion parameter obtained in white matter lesions by the same parameter obtained in normal-appearing white matter. Neurological examination was performed at baseline and at follow-up approximately 1 year later to establish the multiple sclerosis severity score (MSSS) and evidence of disease activity (EDA). Baseline normalized mean transit time (nMTT) was lower in patients with MSSS >3.79 (p = 0.016), in patients with EDA (p = 0.041), and in patients with both MSSS >3.79 and EDA (p = 0.032) at 1-year follow-up. Baseline normalized cerebral blood flow and normalized cerebral blood volume did not differ between these groups. Lower baseline nMTT was associated with higher disease severity and with presence of disease activity 1 year later in newly diagnosed MS patients. Further longitudinal studies are needed to confirm whether baseline-normalized perfusion measures can differentiate between disease severity and disease activity subgroups over time. (orig.)

A novel MR contrast agent for angiography and perfusion: Hyperpolarized water

DEFF Research Database (Denmark)

Lipsø, Hans Kasper Wigh

, hyperpolarized by dissolution Dynamic Nuclear Polarization (d-DNP), can be applied as an MRI contrast agent for angiography and perfusion. The first part of the project focuses on development of a protocol for production of large samples of hyperpolarized protons in D2O. The samples are polarized and dissolved...

Evaluation of renal transplant perfusion by functional imaging

International Nuclear Information System (INIS)

Nicoletti, R.

1990-01-01

Radionuclide angiography (RNA) is used as a noninvasive method for the evaluation of renal transplant perfusion. The computer processing method generally used, based on regions of interest, is unsatisfactory because it does not permit the regional differentiation of perfusion defects. Furthermore, the subjective delineation of the regions of interest introduces considerable inter-observer variation of results. We developed a processing method which is less operator-dependent and permits the evaluation of local defects; it is based on the concept of functional imaging. The method was evaluated in 62 patient examinations, which were subdivided into four groups: Normal transplant perfusion (23 examinations), acute tubular necrose (ATN) (16), cellular rejection (13), and vascular rejection (10). Quantitative results derived from profile curves were combined with visual estimation of the functional images and yielded a synoptic graph which allowed differentiation into three groups: Normal transplant perfusion (sensitivity 0.78, specificity 0.97), ATN or cellular rejection (sens. 0.83, spec. 0.82), and vascular rejection (sens. 0.90, spec. 0.92). (orig.)

Dissociation of brain edema induced by cold injury in rat model. MR imaging and perfusion studies with 14C-iodo-antipyrine

International Nuclear Information System (INIS)

Itabashi, Yoko; Prado, G.L.M.; Abo, Mitsuru; Miura, Hiroyuki; Abe, Yoshinao

2001-01-01

The purpose of this study is to confirm whether T2-weighted imaging and perfusion imaging, i.e. autoradiogram of 14 C-iodoantipyrine, on the course of brain edema correspond to each other or not. Cold injured rat brains were used as a model and were sequentially examined by both methods and compared with each other and with histological specimens. Special focus relies on the time changes in the lesions. High SI of T2-weighted images were observed and the percentages in the high SI area to the total brain area in the same slice were 4.7±0.31, 5.6±0.46 and 3.4±0.42 for 6, 24 and 48 hours, respectively. By contrast, low perfusion areas were indicated in the perfusion study and their percentages were 4.6±0.55, 5.6±0.86 and 2.4±0.35 for 6, 24 and 48 hours, respectively. At 48 hours after cold injury, low perfusion areas were smaller than high SI areas. Moreover, high accumulation areas consisting of macrophages were observed surrounding necrosis. It is concluded that there is dissociation between perfusion and T2-weighted MR imaging, where the collection of macrophages surrounding edema lesions and necrosis had the same appearance on MRI and different accumulations on perfusion studies. (author)

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

DEFF Research Database (Denmark)

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

2009-01-01

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

k-t SENSE-accelerated Myocardial Perfusion MR Imaging at 3.0 Tesla - comparison with 1.5 Tesla

Science.gov (United States)

Plein, Sven; Schwitter, Juerg; Suerder, Daniel; Greenwood, John P.; Boesiger, Peter; Kozerke, Sebastian

2008-01-01

Purpose To determine the feasibility and diagnostic accuracy of high spatial resolution myocardial perfusion MR at 3.0 Tesla using k-space and time domain undersampling with sensitivity encoding (k-t SENSE). Materials and Methods The study was reviewed and approved by the local ethic review board. k-t SENSE perfusion MR was performed at 1.5 Tesla and 3.0 Tesla (saturation recovery gradient echo pulse sequence, repetition time/echo time 3.0ms/1.0ms, flip angle 15°, 5x k-t SENSE acceleration, spatial resolution 1.3×1.3×10mm3). Fourteen volunteers were studied at rest and 37 patients during adenosine stress. In volunteers, comparison was also made with standard-resolution (2.5×2.5×10mm3) 2x SENSE perfusion MR at 3.0 Tesla. Image quality, artifact scores, signal-to-noise ratios (SNR) and contrast-enhancement ratios (CER) were derived. In patients, diagnostic accuracy of visual analysis to detect >50% diameter stenosis on quantitative coronary angiography was determined by receiver-operator-characteristics (ROC). Results In volunteers, image quality and artifact scores were similar for 3.0 Tesla and 1.5 Tesla, while SNR was higher (11.6 vs. 5.6) and CER lower (1.1 vs. 1.5, p=0.012) at 3.0 Tesla. Compared with standard-resolution perfusion MR, image quality was higher for k-t SENSE (3.6 vs. 3.1, p=0.04), endocardial dark rim artifacts were reduced (artifact thickness 1.6mm vs. 2.4mm, pTesla and 1.5 Tesla, respectively. Conclusions k-t SENSE accelerated high-resolution perfusion MR at 3.0 Tesla is feasible with similar artifacts and diagnostic accuracy as at 1.5 Tesla. Compared with standard-resolution perfusion MR, image quality is improved and artifacts are reduced. PMID:18936311

Pediatric hemiplegic migraine: susceptibility weighted and MR perfusion imaging abnormality

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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.)

Pediatric hemiplegic migraine: susceptibility weighted and MR perfusion imaging abnormality

International Nuclear Information System (INIS)

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

2010-01-01

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. (orig.)

Safety of adenosine in stress cerebral perfusion imaging

International Nuclear Information System (INIS)

Hu Pengcheng; Gu Yushen; Liu Wenguan; Xiu Yan; Zhu Weimin; Chen Shuguang; Shi Hongcheng

2009-01-01

Objective: To evaluate the safety of adenosine as pharmacological stress agents in stress cerebral perfusion imaging. Methods: Eighty patients under investigation for suspected cerebral vessel disease were recruited. Each had a resting scan and a stress scan on different days. The adenosine stress protocol was as same as the protocol used in adenosine stress myocardial perfusion imaging. Subjective and objective side-effects were investigated during pharmacological stress procedure. Results: All patients completed the 6 min infusion protocol without premature termination on safety criteria or due to intolerable symptoms. 46 patients had mild side effects. 20 patients (25%) had dizziness, 12 patients (15%) had palpitation, 1 patient (1%) was hypotensive, 7 patients (9%) had dyspnoea, 4 patients (5%) felt hot, 3 patients (4%) had sweat, 4 patients (5%) had nausea, 6 patients (8%) had flushing, 19 patients (24%) had chest pain, 6 patients (8%) had abdomen pain, 3 patients (4%) had abnormal taste and 1 patient (1%) were thirsty. Transient ST change occurred in only 1 patient. Conclusion: Adenosine stress cerebral perfusion imaging is a safe diagnostic method with mild side effects. (authors)

Real-time contrast imaging: a new method to monitor capillary recruitment in human forearm skeletal muscle.

NARCIS (Netherlands)

Mulder, A.H.; Dijk, A.P.J. van; Smits, P.; Tack, C.J.J.

2008-01-01

OBJECTIVE: Muscle capillary perfusion can be measured by contrast-enhanced ultrasound. We examined whether a less time-consuming ultrasound technique, called "real-time imaging," could be used to measure capillary recruitment in human forearm skeletal muscle. METHODS: We measured microvascular blood

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 knife therapy. Therefore, CTP imaging would play an important role for liver cancer management followed argon-helium knife therapy. © The Author(s) 2014.

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

International Nuclear Information System (INIS)

Nakagawa, Tatsuya; Sugihara, Hiroki; Inagaki, Suetsugu

1989-01-01

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

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

Directory of Open Access Journals (Sweden)

Alex Förster

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

Thallium-201 exercise myocardial imaging to evaluate myocardial perfusion after coronary artery bypass surgery

International Nuclear Information System (INIS)

Hirzel, H.O.; Nuesch, K.; Sialer, G.; Horst, W.; Krayenbuehl, H.P.

1980-01-01

To assess the usefulness of thallium-201 exercise scintigraphy in evaluating myocardial perfusion after coronary artery bypass surgery, imaging was performed after submaximal bicycle ergometry and at rest in 54 patients before and within 24 +- 10 (SD) weeks after operation. Scintigraphy identified 8 out of 20 patients who were symptom free after operation and showed normal exercise electrocardiograms as still having exercise-induced ischaemia and thus as having not truly benefited from the surgical intervention. In contrast, improvement in perfusion was documented in 17 out of 31 patients despite further complaints of chest pain and persistence of a pathological exercise electrocardiogram in 6 of them. Bypass graft patency rate paralleled the scintigraphic findings in the 35 patients who were restudied arteriographically. It was concluded that thallium-201 exercise scintigraphy is a useful technique to document changes in regional perfusion after surgery and is definitely superior to the clinical evaluation of patients including the exercise electrocardiogram. (author)

Post-operative monitoring of tissue transfers: advantages using contrast enhanced ultrasound (CEUS) and contrast enhanced MRI (ceMRI) with dynamic perfusion analysis?

Science.gov (United States)

Lamby, P; Prantl, L; Fellner, C; Geis, S; Jung, E M

2011-01-01

The immediate evaluation of microvascular tissue flaps with respect to microcirculation after transplantation is crucial for optimal monitoring and outcome. The purpose of our investigation was to evaluate the clinical value of contrast-enhanced ultrasound (CEUS) and contrast-enhanced MRI (ceMRI) for monitoring the integrity of tissue flaps in plastic surgery. To this end, we investigated 10 patients (47 ± 16 a) between postoperative day 7 and 14 who underwent flap surgery in order to cover tissue defects in various body regions. For CEUS we utilized the GE LOGIQ E9 equipped with a linear transducer (6-9 MHz). After application of 2.4 ml SonoVue, the tissue perfusion was detected in Low MI-Technique (MI present, both technologies provide an optimal assessment of perfusion in cutaneous, subcutaneous and muscle tissue layers, whereby the detection of fatty tissue perfusion is currently more easily detected using CEUS compared to ceMRI.

Evaluation of liver parenchyma and perfusion using dynamic contrast-enhanced computed tomography and contrast-enhanced ultrasonography in captive green iguanas (Iguana iguana) under general anesthesia.

Science.gov (United States)

Nardini, Giordano; Di Girolamo, Nicola; Leopardi, Stefania; Paganelli, Irene; Zaghini, Anna; Origgi, Francesco C; Vignoli, Massimo

2014-05-13

Contrast-enhanced diagnostic imaging techniques are considered useful in veterinary and human medicine to evaluate liver perfusion and focal hepatic lesions. Although hepatic diseases are a common occurrence in reptile medicine, there is no reference to the use of contrast-enhanced ultrasound (CEUS) and contrast-enhanced computed tomography (CECT) to evaluate the liver in lizards. Therefore, the aim of this study was to evaluate the pattern of change in echogenicity and attenuation of the liver in green iguanas (Iguana iguana) after administration of specific contrast media. An increase in liver echogenicity and density was evident during CEUS and CECT, respectively. In CEUS, the mean ± SD (median; range) peak enhancement was 19.9% ± 7.5 (18.3; 11.7-34.6). Time to peak enhancement was 134.0 ± 125.1 (68.4; 59.6-364.5) seconds. During CECT, first visualization of the contrast medium was at 3.6 ± 0.5 (4; 3-4) seconds in the aorta, 10.7 ± 2.2 (10.5; 7-14) seconds in the hepatic arteries, and 15 ± 4.5 (14.5; 10-24) seconds in the liver parenchyma. Time to peak was 14.1 ± 3.4 (13; 11-21) and 31 ± 9.6 (29; 23-45) seconds in the aorta and the liver parenchyma, respectively. CEUS and dynamic CECT are practical means to determine liver hemodynamics in green iguanas. Distribution of contrast medium in iguana differed from mammals. Specific reference ranges of hepatic perfusion for diagnostic evaluation of the liver in iguanas are necessary since the use of mammalian references may lead the clinician to formulate incorrect diagnostic suspicions.

Quantitative contrast-enhanced first-pass cardiac perfusion MRI at 3 tesla with accurate arterial input function and myocardial wall enhancement.

Science.gov (United States)

Breton, Elodie; Kim, Daniel; Chung, Sohae; Axel, Leon

2011-09-01

To develop, and validate in vivo, a robust quantitative first-pass perfusion cardiovascular MR (CMR) method with accurate arterial input function (AIF) and myocardial wall enhancement. A saturation-recovery (SR) pulse sequence was modified to sequentially acquire multiple slices after a single nonselective saturation pulse at 3 Tesla. In each heartbeat, an AIF image is acquired in the aortic root with a short time delay (TD) (50 ms), followed by the acquisition of myocardial images with longer TD values (∼150-400 ms). Longitudinal relaxation rates (R(1) = 1/T(1)) were calculated using an ideal saturation recovery equation based on the Bloch equation, and corresponding gadolinium contrast concentrations were calculated assuming fast water exchange condition. The proposed method was validated against a reference multi-point SR method by comparing their respective R(1) measurements in the blood and left ventricular myocardium, before and at multiple time-points following contrast injections, in 7 volunteers. R(1) measurements with the proposed method and reference multi-point method were strongly correlated (r > 0.88, P < 10(-5)) and in good agreement (mean difference ±1.96 standard deviation 0.131 ± 0.317/0.018 ± 0.140 s(-1) for blood/myocardium, respectively). The proposed quantitative first-pass perfusion CMR method measured accurate R(1) values for quantification of AIF and myocardial wall contrast agent concentrations in 3 cardiac short-axis slices, in a total acquisition time of 523 ms per heartbeat. Copyright © 2011 Wiley-Liss, Inc.

Diffusion, Perfusion, and Histopathologic Characteristics of Desmoplastic Infantile Ganglioglioma.

Science.gov (United States)

Ho, Chang Y; Gener, Melissa; Bonnin, Jose; Kralik, Stephen F

2016-07-01

We present a case series of a rare tumor, the desmoplastic infantile ganglioglioma (DIG) with MRI diffusion and perfusion imaging quantification as well as histopathologic characterization. Four cases with pathologically-proven DIG had diffusion weighted imaging (DWI) and two of the four had dynamic susceptibility contrast imaging. All four tumors demonstrate DWI findings compatible with low-grade pediatric tumors. For the two cases with perfusion imaging, a higher relative cerebral blood volume was associated with higher proliferation index on histopathology for one of the cases. Our results are discussed in conjunction with a literature review.

Phase correction of MR perfusion/diffusion images

International Nuclear Information System (INIS)

Chenevert, T.L.; Pipe, J.G.; Brunberg, J.A.; Yeung, H.N.

1989-01-01

Apparent diffusion coefficient (ADC) and perfusion MR sequences are exceptionally sensitive to minute motion and, therefore, are prone to bulk motions that hamper ADC/perfusion quantification. The authors have developed a phase correction algorithm to substantially reduce this error. The algorithm uses a diffusion-insensitive data set to correct data that are diffusion sensitive but phase corrupt. An assumption of the algorithm is that bulk motion phase shifts are uniform in one dimension, although they may be arbitrarily large and variable from acquisition to acquisition. This is facilitated by orthogonal section selection. The correction is applied after one Fourier transform of a two-dimensional Fourier transform reconstruction. Imaging experiments on rat and human brain demonstrate significant artifact reduction in ADC and perfusion measurements

Perfusion redistribution after a pulmonary-embolism-like event with contrast enhanced EIT.

Science.gov (United States)

Nguyen, D T; Bhaskaran, A; Chik, W; Barry, M A; Pouliopoulos, J; Kosobrodov, R; Jin, C; Oh, T I; Thiagalingam, A; McEwan, A L

2015-06-01

Recent studies showed that regional pulmonary perfusion can be reliably estimated using electrical impedance tomography (EIT) with the aid of hypertonic saline based contrast enhancement. Building on these successful studies, we studied contrast EIT for pulmonary perfusion defect caused by an artificially induced pulmonary embolism (PE) in a large ovine model (N = 8, 78 ± 7.8 kg). Furthermore, the efficacy of a less invasive contrast bolus of 0.77 ml kg(-1) of NaCl 3% was compared with a more concentrated bolus of 0.13 ml kg(-1) of NaCl 20%. Prior to the injection of each contrast bolus injection, ventilation was turned off to provide a total of 40 to 45 s of apnoea. Each bolus of impedance contrast was injected through a catheter into the right atrium. Pulmonary embolisation was performed by balloon occlusion of part of the right branch of the pulmonary trunk. Four parameters representing the kinetics of the contrast dilution in the lung were evaluated for statistical differences between baseline and PE, including peak value, maximum uptake, maximum washout and area under the curve of the averaged contrast dilution curve in each lung. Furthermore, the right lung to left lung (R2L) ratio of each the aforementioned parameters were assessed. While all of the R2L ratios yielded significantly different means between baseline and PE, it can be concluded that the R2L ratios of area under the curve and peak value of the averaged contrast dilution curve are the most promising and reliable in assessing PE. It was also found that the efficacy of the two types of impedance contrasts were not significantly different in distinguishing PE from baseline in our model.

Dynamic Contrast-Enhanced Magnetic Resonance Enterography and Dynamic Contrast-Enhanced Ultrasonography in Crohn's Disease

DEFF Research Database (Denmark)

Wilkens, Rune; Peters, David A; Nielsen, Agnete Hedemann

2017-01-01

Purpose e Cross-sectional imaging methods are important for objective evaluationof small intestinal inflammationinCrohn'sdisease(CD).The primary aim was to compare relative parameters of intestinal perfusion between contrast-enhanced ultrasonography (CEUS) and dynamic contrast-enhanced magnetic...

Application of dynamic susceptibility contrast-enhanced perfusion in temporal lobe epilepsy

International Nuclear Information System (INIS)

Xing, Wu; Wang, Xiaoyi; Xie, Fangfang; Liao, Weihua

2013-01-01

Background: Accurately locatithe epileptogenic focus in temporal lobe epilepsy (TLE) is important in clinical practice. Single-photon emission computed tomography (SPECT) and positron-emission tomography (PET) have been widely used in the lateralization of TLE, but both have limitations. Magnetic resonance perfusion imaging can accurately and reliably reflect differences in cerebral blood flow and volume. Purpose: To investigate the diagnostic value of dynamic susceptibility contrast-enhanced (DSC) perfusion magnetic resonance imaging (MRI) in the lateralization of the epileptogenic focus in TLE. Material and Methods: Conventional MRI and DSC-MRI scanning was performed in 20 interictal cases of TLE and 20 healthy volunteers. The relative cerebral blood volume (rCBV) and relative cerebral blood flow (rCBF) of the bilateral mesial temporal lobes of the TLE cases and healthy control groups were calculated. The differences in the perfusion asymmetry indices (AIs), derived from the rCBV and rCBF of the bilateral mesial temporal lobes, were pared between the two groups. Results: In the control group, there were no statistically significant differences between the left and right sides in terms of rCBV (left 1.55 ± 0.32, right 1.57 ± 0.28) or rCBF (left 99.00 ± 24.61, right 100.38 ± 23.46) of the bilateral mesial temporal lobes. However, in the case group the ipsilateral rCBV and rCBF values (1.75 ± 0.64 and 96.35 ± 22.63, respectively) were markedly lower than those of the contralateral side (2.01 ± 0.79 and 108.56 ± 26.92; P < 0.05). Both the AI of the rCBV (AIrCBV; 13.03 ± 10.33) and the AI of the rCBF (AIrCBF; 11.24 ± 8.70) of the case group were significantly higher than that of the control group (AIrCBV 5.55 ± 3.74, AIrCBF 5.12 ± 3.48; P < 0.05). The epileptogenic foci of nine patients were correctly lateralized using the 95th percentile of the AIrCBV and AIrCBF of the control group as the normal upper limits. Conclusion: In patients with TLE interictal

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

DEFF Research Database (Denmark)

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

2001-01-01

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

Quantitative lung perfusion evaluation using Fourier decomposition perfusion MRI.

Science.gov (United States)

Kjørstad, Åsmund; Corteville, Dominique M R; Fischer, Andre; Henzler, Thomas; Schmid-Bindert, Gerald; Zöllner, Frank G; Schad, Lothar R

2014-08-01

To quantitatively evaluate lung perfusion using Fourier decomposition perfusion MRI. The Fourier decomposition (FD) method is a noninvasive method for assessing ventilation- and perfusion-related information in the lungs, where the perfusion maps in particular have shown promise for clinical use. However, the perfusion maps are nonquantitative and dimensionless, making follow-ups and direct comparisons between patients difficult. We present an approach to obtain physically meaningful and quantifiable perfusion maps using the FD method. The standard FD perfusion images are quantified by comparing the partially blood-filled pixels in the lung parenchyma with the fully blood-filled pixels in the aorta. The percentage of blood in a pixel is then combined with the temporal information, yielding quantitative blood flow values. The values of 10 healthy volunteers are compared with SEEPAGE measurements which have shown high consistency with dynamic contrast enhanced-MRI. All pulmonary blood flow (PBF) values are within the expected range. The two methods are in good agreement (mean difference = 0.2 mL/min/100 mL, mean absolute difference = 11 mL/min/100 mL, mean PBF-FD = 150 mL/min/100 mL, mean PBF-SEEPAGE = 151 mL/min/100 mL). The Bland-Altman plot shows a good spread of values, indicating no systematic bias between the methods. Quantitative lung perfusion can be obtained using the Fourier Decomposition method combined with a small amount of postprocessing. Copyright © 2013 Wiley Periodicals, Inc.

Perfusion imaging with single-photon emission computed tomography

International Nuclear Information System (INIS)

Holman, B.L.; Hill, T.C.

1987-01-01

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

Paramagnetic contrast media for magnetic resonance imaging of the central nervous system

International Nuclear Information System (INIS)

McNamara, M.T.

1987-01-01

Presently, a variety of radiofrequency (RF) and magnetic field gradient pulse sequences is used to manipulate magnetic resonance (MR) image contrast. Such manipulation may be performed by altering the RF pulse sequence repetition time (TR), the spin-echo delay time (TE), the inversion-delay time (TI), and the flip angle. The detection and characterization of a lesion or structure may thus be optimized. Although such contrast manipulation is noninvasive, magnetic resonance imaging (MRI) still suffers somewhat from lack of specificity. Also, the use of multiple imaging sequences to locate and characterize a lesion may prolong the imaging time and, thus, might place an economic burden on the system. Paramagnetic pharmaceuticals offer promise in this regard. They shorten tissue relaxation times, thus permitting the use of shorter imaging parameters, and in some circumstances, may obviate additional and more time-consuming pulse sequences. Paramagnetics could expand the sensitivity and specificity of MRI and provide functional information with regard to tissue perfusion, tissue viability, and blood-brain barrier integrity

Improved perfusion quantification in FAIR imaging by offset correction

DEFF Research Database (Denmark)

Sidaros, Karam; Andersen, Irene Klærke; 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...... 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...

Measurement of extracellular volume and transit time heterogeneity using contrast-enhanced myocardial perfusion MRI in patients after acute myocardial infarction.

Science.gov (United States)

Kunze, Karl P; Rischpler, Christoph; Hayes, Carmel; Ibrahim, Tareq; Laugwitz, Karl-Ludwig; Haase, Axel; Schwaiger, Markus; Nekolla, Stephan G

2017-06-01

To assess the ability of dynamic contrast-enhanced myocardial perfusion MRI to measure extracellular volume (ECV) and to investigate the possibility of estimating capillary transit time heterogeneity (CTH) in patients after myocardial infarction and successful revascularization. Twenty-four perfusion data sets were acquired on a 3 Tesla positron emission tomography (PET)/MRI scanner. Three perfusion models of different complexity were implemented in a hierarchical fashion with an Akaike information criterion being used to determine the number of fit parameters supported by the data. Results were compared sector-wise to ECV from an equilibrium T 1 mapping method (modified look-locker inversion recovery (MOLLI)). ECV derived from the perfusion analysis correlated well with equilibrium measurements (R² = 0.76). Estimation of CTH was supported in 16% of sectors (mostly remote). Inclusion of a nonzero CTH parameter usually led to lower estimates of first-pass extraction and slightly higher estimates of blood volume and flow. Estimation of the capillary permeability-surface area product was feasible in 81% of sectors. Transit time heterogeneity has a measurable effect on the kinetic analysis of myocardial perfusion MRI data, and Gd-DTPA extravasation in the myocardium is usually not flow-limited in infarct-related pathology. Measurement of myocardial ECV using perfusion imaging could provide a scan-time efficient alternative to methods based on T 1 mapping. Magn Reson Med 77:2320-2330, 2017. © 2016 International Society for Magnetic Resonance in Medicine. © 2016 International Society for Magnetic Resonance in Medicine.

MR-based assessment of pulmonary ventilation-perfusion in animal models

International Nuclear Information System (INIS)

Yang Jian; Wan Mingxi; Guo Youmin

2003-01-01

Objective: To show the feasibility and value in the diagnosis of airway obstruction and pulmonary embolism with MR oxygen-enhanced ventilation combined with pulmonary perfusion imaging. Methods: Eight canines were implemented for peripheral pulmonary embolism by intravenous injection of gelfoam granules at pulmonary segmental arterial level, and five of them were formed airway obstruction models by inserting self-made balloon catheter at second-bronchia. The oxygen-enhanced MR ventilation imaging was introduced by subtracting the images of pre- and post- inhaled pure oxygen. The MR pulmonary perfusion imaging was achieved by the first-pass contrast agent method. Moreover, the manifestation of MR ventilation and perfusion imaging was observed and contradistinguished with that of general pathologic anatomy, ventilation-perfusion scintigraphy, and pulmonary angiography. Results: The manifestations of airway obstruction regions in MR ventilation and perfusion imaging were matched, but those of pulmonary embolism regions were dismatched. The defect range of airway obstruction in MR ventilation image was smaller than that in ventilation scintigraphy. The abnormal perfusion regions of pulmonary embolism were divided into defect regions and reduce regions based on the time courses of signal intensity changes. The sensitivity and specificity of diagnosis on pulmonary embolism by MR ventilation combined with perfusion technique were 75.0% and 98.1%. The diagnostic results were in good coherence with ventilation-perfusion scintigraphy and pulmonary angiography (K=0.743, 0.899). Conclusion: The MR oxygen-enhanced ventilation combined with pulmonary perfusion imaging can be used to diagnose the airway and vascular abnormity in lung. This technique resembles the ventilation-perfusion scintigraphy. It can provide quantitative functional information and better spatial and temporal resolution, and possesses the value of clinical application

Dual-energy perfusion-CT of pancreatic adenocarcinoma

International Nuclear Information System (INIS)

Klauß, M.; Stiller, W.; Pahn, G.; Fritz, F.; Kieser, M.; Werner, J.; Kauczor, H.U.; Grenacher, L.

2013-01-01

Purpose: To evaluate the feasibility of dual-energy CT (DECT)-perfusion of pancreatic carcinomas for assessing the differences in perfusion, permeability and blood volume of healthy pancreatic tissue and histopathologically confirmed solid pancreatic carcinoma. Materials and methods: 24 patients with histologically proven pancreatic carcinoma were examined prospectively with a 64-slice dual source CT using a dynamic sequence of 34 dual-energy (DE) acquisitions every 1.5 s (80 ml of iodinated contrast material, 370 mg/ml, flow rate 5 ml/s). 80 kV p , 140 kV p , and weighted average (linearly blended M0.3) 120 kV p -equivalent dual-energy perfusion image data sets were evaluated with a body-perfusion CT tool (Body-PCT, Siemens Medical Solutions, Erlangen, Germany) for estimating perfusion, permeability, and blood volume values. Color-coded parameter maps were generated. Results: In all 24 patients dual-energy CT-perfusion was. All carcinomas could be identified in the color-coded perfusion maps. Calculated perfusion, permeability and blood volume values were significantly lower in pancreatic carcinomas compared to healthy pancreatic tissue. Weighted average 120 kV p -equivalent perfusion-, permeability- and blood volume-values determined from DE image data were 0.27 ± 0.04 min −1 vs. 0.91 ± 0.04 min −1 (p −1 vs. 0.67 ± 0.05 *0.5 min −1 (p = 0.06) and 0.49 ± 0.07 min −1 vs. 1.28 ± 0.11 min −1 (p p the standard deviations of the kV p 120 kV p -equivalent values were manifestly smaller. Conclusion: Dual-energy CT-perfusion of the pancreas is feasible. The use of DECT improves the accuracy of CT-perfusion of the pancreas by fully exploiting the advantages of enhanced iodine contrast at 80 kV p in combination with the noise reduction at 140 kV p . Therefore using dual-energy perfusion data could improve the delineation of pancreatic carcinomas

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

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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); 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.)

SPECT brain perfusion imaging in mild traumatic brain injury

International Nuclear Information System (INIS)

Li Juan; Liu Baojun; Zhao Feng; He Lirong; Xia Yucheng

2003-01-01

Objective: To study the clinical value of SPECT brain perfusion imaging after mild traumatic brain injury and to evaluate the mechanism of brain blood flow changes in the brain traumatic symptoms. Methods: SPECT 99 Tc m -ethylene cysteinate dimer (ECD) brain perfusion imaging was performed on 39 patients with normal consciousness and normal computed tomography. The study was performed on 23 patients within 3 months after the accidental injury and on 16 patients at more than 3 months post-injury. The cerebellum was used as the reference site (100% maximum value). Any decrease in cerebral perfusion in cortex or basal ganglia to below 70%, or even to below 50% in the medial temporal lobe, compared to the cerebellar reference was considered abnormal. Results: The results of 23 patients (59%) were abnormal. Among them, 20 patients showed 74 focal lesions with an average of 3.7 per patient (15 studies performed within 3 months and 8 studies performed more than 3 months after injury). The remaining 3 showed diffuse hypoperfusion (two at the early stage and one at more than 3 months after the injury). The 13 abnormal studies performed at the early stage showed 58 lesions (average, 4.5 per patient), whereas there was a reduction to an average of 2.3 per patient in the 7 patients (total 16 lesions) at more than 3 months post-injury. In the 20 patients with focal lesions, mainly the following regions were involved: frontal lobes 43.2% (32/74), basal ganglia 24.3% (18/74) and temporal lobes 17.6% (13/74). Conclusions: 1) SPECT brain perfusion imaging is more sensitive than computed tomography in detecting brain lesions of mild traumatic brain injury. 2) SPECT brain perfusion imaging is more sensitive at early stage than at late stage after injury. 3) The most common complaints were headache, dizziness, memory deficit. The patients without loss of consciousness may present brain hypoperfusion, too. 4) The changes may explain a neurological component of the patient symptoms in

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

International Nuclear Information System (INIS)

Padua, Rodrigo Donizete Santana de; Oliveira, Lucas Ferrari de; Marques, Paulo Mazzoncini de Azevedo; Groote, Jean-Jacques Georges Soares de; Castro, Adelson Antonio de; Ana, Lauro Wichert; Simoes, Marcus Vinicius

2008-01-01

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)

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

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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)

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

%, respectively, for SPECT. CONCLUSION: The overall performance of myocardial CT perfusion imaging in the diagnosis of anatomic CAD (stenosis ≥50%), as demonstrated with the Az, was higher than that of SPECT and was driven in part by the higher sensitivity for left main and multivessel disease.......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....... MATERIALS AND METHODS: This study was approved by the institutional review board. Written informed consent was obtained from all patients. Sixteen centers enrolled 381 patients from November 2009 to July 2011. Patients underwent rest and adenosine stress CT perfusion imaging and rest and either exercise...

Perfusion MRI as a neurosurgical tool for improved targeting in stereotactic tumor biopsies.

Science.gov (United States)

Lefranc, M; Monet, P; Desenclos, C; Peltier, J; Fichten, A; Toussaint, P; Sevestre, H; Deramond, H; Le Gars, D

2012-01-01

Stereotactic biopsies are subject to sampling errors (essentially due to target selection). The presence of contrast enhancement is not a reliable marker of malignancy. The goal of the present study was to determine whether perfusion-weighted imaging can improve target selection in stereotactic biopsies. We studied 21 consecutive stereotactic biopsies between June 2009 and March 2010. Perfusion-weighted magnetic resonance imaging (MRI) was integrated into our neuronavigator. Perfusion-weighted imaging was used as an adjunct to conventional MRI data for target determination. Conventional MRI alone was used to determine the trajectory. We found a linear correlation between regional cerebral blood volume (rCBV) and vessel density (number of vessels per mm(2); R = 0.64; p < 0.001). Perfusion-weighted imaging facilitated target determination in 11 cases (52.4%), all of which were histopathologically diagnosed as glial tumors. For glial tumors, which presented with contrast enhancement, perfusion-weighted imaging identified a more precisely delimited target in 9 cases, a different target in 1 case, and exactly the same target in 1 other case. In all cases, perfusion-selected sampling provided information on cellular features and tumor grading. rCBV was significantly associated with grading (p < 0.01), endothelial proliferation (p < 0.01), and vessel density (p < 0.01). For lesions with rCBV values ≤1, perfusion-weighted MRI did not help to determine the target but was useful for surgical management. For stereotactic biopsies, targeting based on perfusion-weighted imaging is a feasible method for reducing the sampling error and improving target selection in the histopathological diagnosis of tumors with high rCBVs. Copyright © 2012 S. Karger AG, Basel.

In vivo MR perfusion imaging of renal artery stenosis

International Nuclear Information System (INIS)

Powers, T.; Lorenz, C.H.; Bain, R.; Holburn, G.; Price, R.R.

1989-01-01

Various techniques have been developed for noninvasive evaluation of renal blood flow. More important in the assessment of potential renal ischemia may be actual perfusion of the nephron mass. MR pulse sequences have been devised that allow perfusion imaging (PI) in a dog model of renal artery stenosis. Unilateral renal artery stenosis was created in mongrel dogs and quantitation of renal blood flow was obtained with radioactive microspheres. Perfusion imaging was performed on a 1.5-T system to obtain the apparent diffusion coefficient. During initial studies, it was found that the usual gradient factor used in brain PI was too high for renal studies; a factor of < 50 was found to be optimal. Additionally, respiratory gating with acquisition at end expiration was necessary to prevent renal motion. Recent studies have shown that PI reflects the asymmetry of flow in this model

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

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

2009-04-15

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

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

International Nuclear Information System (INIS)

Fan Li; Liu Shiyuan; Sun Fei; Xiao Xiangsheng

2009-01-01

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

Correlation between the Quantifiable Parameters of Whole Solitary Pulmonary Nodules Perfusion Imaging Derived with Dynamic CT and Nodules Size

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Shiyuan LIU

2009-05-01

Full Text Available Background and objective The solitary pulmonary nodules (SPNs is one of the most common findings on chest radiographs. The blood flow patterns of the biggest single SPNs level has been studied. This assessment may be only a limited sample of the entire region of interest (ROI and is unrepresentative of the SPNs as a volume. Ideally, SPNs volume perfusion should be measured. The aim of this study is to evaluate the correlation between the quantifiableparameters of SPNs volume perfusion imaging derived with 16-slice spiral CT and 64-slice spiral CT and nodules size. Methods Sixty-five patients with SPNs (diameter≤3 cm; 42 malignant; 12 active inflammatory; 11 benign underwent multi-location dynamic contrast material-enhanced serial CT scanning mode with stable table were performed; The mean values of valid sections were calculated, as the quantifiable parameters of volume SPNs perfusion imaging derived with16-slice spiral CT and 64-slice spiral CT. The correlation between the quantifiable parameters of SPNs volume perfusion imaging derived with 16-slice spiral CT and 64-slice spiral CT and nodules size were assessed by means of linear regression analysis. Results No significant correlations were found between the nodules size and each of the peak height (PHSPN (32.15 Hu±14.55 Hu，ratio of peak height of the SPN to that of the aorta (SPN-to-A ratio(13.20±6.18%, perfusion(PSPN (29.79±19.12 mLmin-1100 g-1 and mean transit time (12.95±6.53 s (r =0.081, P =0.419; r =0.089, P =0.487; r =0.167, P =0.077; r =0.023, P =0.880. Conclusion No significant correlations were found between the quantifiable parameters of SPNs volume perfusion imaging derived with 16-slice spiral CT and 64-slice spiral CT and nodules size.

Perfusion MR imaging for differentiation of benign and malignant meningiomas

NARCIS (Netherlands)

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

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

Functional renal perfusion imaging with colour mapping: is it a useful adjunct to spiral CT of in the assessment of abdominal aortic aneurysm (AAA)?

International Nuclear Information System (INIS)

Blomley, Martin J.K.; McBride, Alan; Mohammedtagi, Sima; Albrecht, Thomas; Harvey, Christopher J.; Jaeger, Rolf; Standfield, Nigel J.; Dawson, Peter

1999-01-01

Aim: To ensure optimal timing with pre-operative spiral CT for abdominal aortic aneurysms (AAA), an initial 'timing' single level CT is commonly performed with a small bolus of contrast. This can be exploited to obtain adjunct functional information on renal perfusion. We have investigated the potential of this to measure renal perfusion, to produce colour renal perfusion maps and to predict surgical outcome in infrarenal aortic aneurysm assessment. Methods: We studied 21 patients being assessed for repair of infrarenal AAA. Prior to the spiral CT, a single level through the renal hili and aorta was scanned after the intravenous injection of 25 ml of contrast given at 10 ml/s. Ten 1 s duration scans were performed from 8 to 30 s after injection. Optimal timing for CT angiography can then be determined. Time-density curves were then drawn for both kidneys and aorta using regions of interest (ROIs) or pixel-by-pixel analysis. Renal cortical perfusion was measured using both ROI analysis and pseudocolour perfusion images. Following previous work, perfusion was calculated as the peak upslope of the tissue time density curve divided by peak aortic enhancement. Results: Cortical mean perfusion averaged 2.48 ml/min per ml (range 0.8-3.7 ml/min per ml n=34) and the values obtained agreed with literature expectations. Follow up in the 10 patients proceeding to AAA repair suggest low mean perfusion values and predict a raised postoperative creatinine (P<0.05) Conclusions: Additional functional data and imaging can be obtained from the initial timing scan of a CT study, without requiring a dedicated study

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

Science.gov (United States)

Le Faivre, Julien; Duhamel, Alain; Khung, Suonita; Faivre, Jean-Baptiste; Lamblin, Nicolas; Remy, Jacques; Remy-Jardin, Martine

2016-11-01

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. • Dual-energy computed tomography generates standard diagnostic imaging and lung perfusion analysis. • Depiction of CPE on central arteries relies on standard diagnostic imaging. • Detection of peripheral CPE is improved by perfusion imaging.

Role of myocardial perfusion imaging in acute coronary syndrome

International Nuclear Information System (INIS)

Aleem, M.

2007-01-01

Full text: In the cardiac emergency department, a number of patients present with acute chest pain. In case of non diagnostic ECG and enzymes, accurately categorizing the patient in high and low probability is difficult. Aim of study was to evaluate the role of resting myocardial perfusion imaging (MPI) in patients with acute coronary syndrome (ACS) and then to compare the results with subsequent stress imaging. Material and Methods. A total of 34 patients were selected for the study, which were divided into three groups on the basis of respective probabilities of having ACS. This probability was decided on the basis of nature of chest pain, ECG findings, enzymes levels, and age and sex. Arbitrary score was given to patient's condition. This score ranged from 1 to 14. Patients with score between 1-6 were assigned low probability, from 7-10 were assigned intermediate probability and patients having score greater than 11 were placed in high probability groups. Patients in the low and intermediate probability groups were injected with Tc 99 m- MIBI within 6 hours of onset of chest pain and were undergone resting myocardial perfusion imaging (MPI) 3 to five hours after injection.. Imaging in high probability group was performed at discharge. Four weeks after the acute event all the patients underwent stress myocardial perfusion imaging. Results: All patients (100%) with low probability of ACS (n=10) showed negative resting scans. On stress MPI two patients (20%) showed new defects. Patient with high probability of ACS (n=12), all were positive 100% on resting MPI. On stress MPI, three showed (25%) no change from rest MPI, while nine patients (75%) showed augmentation of defects and four out of these nine patients (33%) also showed new perfusion defects. Patients with intermediate probability of ACS (n=12), three showed positive rest MPI (25%). On stress MPI out of these three cases, one showed (8%) no change from rest MPI and two showed (17%) augmentation of defect

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

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

2013-07-15

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

Development of a dynamic flow imaging phantom for dynamic contrast-enhanced CT

International Nuclear Information System (INIS)

Driscoll, B.; Keller, H.; Coolens, C.

2011-01-01

Purpose: Dynamic contrast enhanced CT (DCE-CT) studies with modeling of blood flow and tissue perfusion are becoming more prevalent in the clinic, with advances in wide volume CT scanners allowing the imaging of an entire organ with sub-second image frequency and sub-millimeter accuracy. Wide-spread implementation of perfusion DCE-CT, however, is pending fundamental validation of the quantitative parameters that result from dynamic contrast imaging and perfusion modeling. Therefore, the goal of this work was to design and construct a novel dynamic flow imaging phantom capable of producing typical clinical time-attenuation curves (TACs) with the purpose of developing a framework for the quantification and validation of DCE-CT measurements and kinetic modeling under realistic flow conditions. Methods: The phantom is based on a simple two-compartment model and was printed using a 3D printer. Initial analysis of the phantom involved simple flow measurements and progressed to DCE-CT experiments in order to test the phantoms range and reproducibility. The phantom was then utilized to generate realistic input TACs. A phantom prediction model was developed to compute the input and output TACs based on a given set of five experimental (control) parameters: pump flow rate, injection pump flow rate, injection contrast concentration, and both control valve positions. The prediction model is then inversely applied to determine the control parameters necessary to generate a set of desired input and output TACs. A protocol was developed and performed using the phantom to investigate image noise, partial volume effects and CT number accuracy under realistic flow conditionsResults: This phantom and its surrounding flow system are capable of creating a wide range of physiologically relevant TACs, which are reproducible with minimal error between experiments (σ/μ 2 ) for the input function between 0.95 and 0.98, while the maximum enhancement differed by no more than 3.3%. The

Idiopathic pulmonary fibrosis. A rare cause of scintigraphic ventilation-perfusion mismatch

International Nuclear Information System (INIS)

Pochis, W.T.; Krasnow, A.Z.; Collier, B.D.; Mewissen, M.W.; Almagro, U.A.; Hellman, R.S.; Isitman, A.T.

1990-01-01

A case of idiopathic pulmonary fibrosis with multiple areas of mismatch on ventilation-perfusion lung imaging in the absence of pulmonary embolism is presented. Idiopathic pulmonary fibrosis is one of the few nonembolic diseases producing a pulmonary ventilation-perfusion mismatch. In this condition, chest radiographs may not detect the full extent of disease, and xenon-133 ventilation imaging may be relatively insensitive to morbid changes in small airways. Thus, when examining patients with idiopathic pulmonary fibrosis, one should be aware that abnormal perfusion imaging patterns without matching ventilation abnormalities are not always due to embolism. In this setting, contrast pulmonary angiography is often needed for accurate differential diagnosis

Idiopathic pulmonary fibrosis. A rare cause of scintigraphic ventilation-perfusion mismatch

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Pochis, W.T.; Krasnow, A.Z.; Collier, B.D.; Mewissen, M.W.; Almagro, U.A.; Hellman, R.S.; Isitman, A.T. (Medical College of Wisconsin, Milwaukee (USA))

1990-05-01

A case of idiopathic pulmonary fibrosis with multiple areas of mismatch on ventilation-perfusion lung imaging in the absence of pulmonary embolism is presented. Idiopathic pulmonary fibrosis is one of the few nonembolic diseases producing a pulmonary ventilation-perfusion mismatch. In this condition, chest radiographs may not detect the full extent of disease, and xenon-133 ventilation imaging may be relatively insensitive to morbid changes in small airways. Thus, when examining patients with idiopathic pulmonary fibrosis, one should be aware that abnormal perfusion imaging patterns without matching ventilation abnormalities are not always due to embolism. In this setting, contrast pulmonary angiography is often needed for accurate differential diagnosis.

CT perfusion imaging in response assessment of pulmonary metastases undergoing stereotactic ablative radiotherapy

International Nuclear Information System (INIS)

Sawyer, Brooke; Pun, Emma; Tay, Huilee; Kron, Tomas; Bressel, Mathias; Ball, David; Siva, Shankar; Samuel, Michael

2015-01-01

Stereotactic ablative body radiotherapy (SABR) is an emerging treatment technique for pulmonary metastases in which conventional Response Evaluation Criteria in Solid Tumours (RECIST) may be inadequate. This study aims to assess the utility of CT perfusion imaging in response assessment of pulmonary metastases after SABR. In this ethics board-approved prospective study, 11 patients underwent a 26-Gy single fraction of SABR to pulmonary metastases. CT perfusion imaging occurred prior to and at 14 and 70 days post-SABR. Blood flow (mL/100 mL/min), blood volume (mL/100 mL), time to peak (seconds) and surface permeability (mL/100 mL/min), perfusion parameters of pulmonary metastases undergoing SABR, were independently assessed by two radiologists. Inter-observer variability was analysed. CT perfusion results were analysed for early response assessment comparing day 14 with baseline scans and for late response by comparing day 70 with baseline scans. The largest diameter of the pulmonary metastases undergoing SABR was recorded. Ten patients completed all three scans and one patient had baseline and early response assessment CT perfusion scans only. There was strong level of inter-observer agreement of CT perfusion interpretation with a median intraclass coefficient of 0.87 (range 0.20–0.98). Changes in all four perfusion parameters and tumour sizes were not statistically significant. CT perfusion imaging of pulmonary metastases is a highly reproducible imaging technique that may provide additional response assessment information above that of conventional RECIST, and it warrants further study in a larger cohort of patients undergoing SABR.

Renal MR angiography and perfusion in the pig using hyperpolarized water.

Science.gov (United States)

Wigh Lipsø, Kasper; Hansen, Esben Søvsø Szocska; Tougaard, Rasmus Stilling; Laustsen, Christoffer; Ardenkjaer-Larsen, Jan Henrik

2017-09-01

To study hyperpolarized water as an angiography and perfusion tracer in a large animal model. Protons dissolved in deuterium oxide (D 2 O) were hyperpolarized in a SPINlab dissolution dynamic nuclear polarization (dDNP) polarizer and subsequently investigated in vivo in a pig model at 3 Tesla (T). Approximately 15 mL of hyperpolarized water was injected in the renal artery by hand over 4-5 s. A liquid state polarization of 5.3 ± 0.9% of 3.8 M protons in 15 mL of deuterium oxide was achieved with a T 1 of 24 ± 1 s. This allowed injection through an arterial catheter into the renal artery and subsequently high-contrast imaging of the entire kidney parenchyma over several seconds. The dynamic images allow quantification of tissue perfusion, with a mean cortical perfusion of 504 ± 123 mL/100 mL/min. Hyperpolarized water MR imaging was successfully demonstrated as a renal angiography and perfusion method. Quantitative perfusion maps of the kidney were obtained in agreement with literature and control experiments with gadolinium contrast. Magn Reson Med 78:1131-1135, 2017. © 2016 International Society for Magnetic Resonance in Medicine. © 2016 International Society for Magnetic Resonance in Medicine.

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

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

2009-08-15

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

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

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Wood, R; Iacobucci, G; Khobragade, P; Ying, L; Snyder, K; Wack, D; Rudin, S; Ionita, C [University at Buffalo, Buffalo, NY (United States)

2014-06-15

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

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

International Nuclear Information System (INIS)

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

2014-01-01

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

Quantitative aspects of myocardial perfusion imaging

International Nuclear Information System (INIS)

Vogel, R.A.

1980-01-01

Myocardial perfusion measurements have traditionally been performed in a quantitative fashion using application of the Sapirstein, Fick, Kety-Schmidt, or compartmental analysis principles. Although global myocardial blood flow measurements have not proven clinically useful, regional determinations have substantially advanced our understanding of and ability to detect myocardial ischemia. With the introduction of thallium-201, such studies have become widely available, although these have generally undergone qualitative evaluation. Using computer-digitized data, several methods for the quantification of myocardial perfusion images have been introduced. These include orthogonal and polar coordinate systems and anatomically oriented region of interest segmentation. Statistical ranges of normal and time-activity analyses have been applied to these data, resulting in objective and reproducible means of data evaluation

Cerebral Hemodynamics in a Healthy Population Measured by Dynamic Susceptibility Contrast MR Imaging

International Nuclear Information System (INIS)

Helenius, J.; Soinne, L.; Tatlisumak, T.; Kaste, M.; Aronen, H.J.

2003-01-01

Purpose: To establish reference data and to study age-dependency for cerebral perfusion in various regions of the brain in a healthy population. Material and Methods: Eighty healthy subjects of both genders from 22 to 85 years of age were studied with spin echo echo-planar dynamic susceptibility contrast MR imaging (DSC MRI) at 1.5 T. Cerebral blood volume (CBV), cerebral blood flow (CBF), and contrast agent mean transit time (MTT) were calculated bilaterally for 20 distinct neuro anatomic structures. Results: In gray matter, the following values were found (mean ± SD): CBV (4.6 ± 1.0 ml/100 g), CBF (94.2 ± 23.0 ml/100 g/min), and MTT (3.0 ± 0.6 s), and in white matter: CBV (1.3 ± 0.4 ml/100 g), CBF (19.6 ± 5.8 ml/100 g/min), and MTT (4.3 ± 0.7 s). The perfusion parameters did not change with age, except for a tendency to an increase in gray matter MTT and CBV. Males exhibited higher MTT and CBV than females. No hemispheric difference was found in either gender. Conclusion: Cerebral hemodynamics can be assessed with DSC MRI. Age itself seems to have only a marginal effect on cerebral perfusion in healthy population

Cerebral Hemodynamics in a Healthy Population Measured by Dynamic Susceptibility Contrast MR Imaging

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Helenius, J.; Soinne, L.; Tatlisumak, T.; Kaste, M. [Helsinki Univ. Central Hospital (Finland). Dept. of Neurology; Perkioe, J.; Salonen, O.; Savolainen, S. [Helsinki Univ. Central Hospital (Finland). Dept. of Radiology; Oestergaard, L. [Aarhus Univ. Hospital (Denmark). Dept. of Neuroradiology; Carano, R.A.D. [Synarc Inc., San Francisco, CA (United States); Aronen, H.J. [Helsinki Brain Research Center (Finland). Functional Brain Imaging Unit

2003-09-01

Purpose: To establish reference data and to study age-dependency for cerebral perfusion in various regions of the brain in a healthy population. Material and Methods: Eighty healthy subjects of both genders from 22 to 85 years of age were studied with spin echo echo-planar dynamic susceptibility contrast MR imaging (DSC MRI) at 1.5 T. Cerebral blood volume (CBV), cerebral blood flow (CBF), and contrast agent mean transit time (MTT) were calculated bilaterally for 20 distinct neuro anatomic structures. Results: In gray matter, the following values were found (mean {+-} SD): CBV (4.6 {+-} 1.0 ml/100 g), CBF (94.2 {+-} 23.0 ml/100 g/min), and MTT (3.0 {+-} 0.6 s), and in white matter: CBV (1.3 {+-} 0.4 ml/100 g), CBF (19.6 {+-} 5.8 ml/100 g/min), and MTT (4.3 {+-} 0.7 s). The perfusion parameters did not change with age, except for a tendency to an increase in gray matter MTT and CBV. Males exhibited higher MTT and CBV than females. No hemispheric difference was found in either gender. Conclusion: Cerebral hemodynamics can be assessed with DSC MRI. Age itself seems to have only a marginal effect on cerebral perfusion in healthy population.

Ultrasound Contrast Agent Microbubble Dynamics

NARCIS (Netherlands)

Overvelde, M.L.J.; Vos, Henk; de Jong, N.; Versluis, Michel; Paradossi, Gaio; Pellegretti, Paolo; Trucco, Andrea

2010-01-01

Ultrasound contrast agents are traditionally used in ultrasound-assisted organ perfusion imaging. Recently the use of coated microbubbles has been proposed for molecular imaging applications where the bubbles are covered with a layer of targeting ligands to bind specifically to their target cells.

Ex Vivo Perfusion-Simulation Measurements of Microbubbles as a Scattering Contrast Agent for Grating-Based X-Ray Dark-Field Imaging.

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Astrid Velroyen

Full Text Available The investigation of dedicated contrast agents for x-ray dark-field imaging, which exploits small-angle scattering at microstructures for contrast generation, is of strong interest in analogy to the common clinical use of high-atomic number contrast media in conventional attenuation-based imaging, since dark-field imaging has proven to provide complementary information. Therefore, agents consisting of gas bubbles, as used in ultrasound imaging for example, are of particular interest. In this work, we investigate an experimental contrast agent based on microbubbles consisting of a polyvinyl-alcohol shell with an iron oxide coating, which was originally developed for multimodal imaging and drug delivery. Its performance as a possible contrast medium for small-animal angiography was examined using a mouse carcass to realistically consider attenuating and scattering background signal. Subtraction images of dark field, phase contrast and attenuation were acquired for a concentration series of 100%, 10% and 1.3% to mimic different stages of dilution in the contrast agent in the blood vessel system. The images were compared to the gold-standard iodine-based contrast agent Solutrast, showing a good contrast improvement by microbubbles in dark-field imaging. This study proves the feasibility of microbubble-based dark-field contrast-enhancement in presence of scattering and attenuating mouse body structures like bone and fur. Therefore, it suggests a strong potential of the use of polymer-based microbubbles for small-animal dark-field angiography.

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.

Cerebral blood volume imaging by flat detector computed tomography in comparison to conventional multislice perfusion CT

International Nuclear Information System (INIS)

Struffert, Tobias; Kloska, Stephan; Engelhorn, Tobias; Doerfler, Arnd; Deuerling-Zheng, Yu; Boese, Jan; Zellerhoff, Michael; Schwab, Stefan

2011-01-01

We tested the hypothesis that Flat Detector computed tomography (FD-CT) with intravenous contrast medium would allow the calculation of whole brain cerebral blood volume (CBV) mapping (FD-CBV) and would correlate with multislice Perfusion CT (PCT). Twenty five patients were investigated with FD-CBV and PCT. Correlation of the CBV maps of both techniques was carried out with measurements from six anatomical regions from both sides of the brain. Mean values of each region and the correlation coefficient were calculated. Bland-Altman analysis was performed to compare the two different imaging techniques. The image and data quality of both PCT and FD-CBV were suitable for evaluation in all patients. The mean CBV values of FD-CBV and PCT showed only minimal differences with overlapping standard deviation. The correlation coefficient was 0.79 (p < 0.01). Bland-Altman analysis showed a mean difference of -0.077 ± 0.48 ml/100 g between FD-CBV and PCT CBV measurements, indicating that FD-CBV values were only slightly lower than those of PCT. CBV mapping with intravenous contrast medium using Flat Detector CT compared favourably with multislice PCT. The ability to assess cerebral perfusion within the angiographic suite may improve the management of ischaemic stroke and evaluation of the efficacy of dedicated therapies. (orig.)

Fully automatic registration and segmentation of first-pass myocardial perfusion MR image sequences.

Science.gov (United States)

Gupta, Vikas; Hendriks, Emile A; Milles, Julien; van der Geest, Rob J; Jerosch-Herold, Michael; Reiber, Johan H C; Lelieveldt, Boudewijn P F

2010-11-01

Derivation of diagnostically relevant parameters from first-pass myocardial perfusion magnetic resonance images involves the tedious and time-consuming manual segmentation of the myocardium in a large number of images. To reduce the manual interaction and expedite the perfusion analysis, we propose an automatic registration and segmentation method for the derivation of perfusion linked parameters. A complete automation was accomplished by first registering misaligned images using a method based on independent component analysis, and then using the registered data to automatically segment the myocardium with active appearance models. We used 18 perfusion studies (100 images per study) for validation in which the automatically obtained (AO) contours were compared with expert drawn contours on the basis of point-to-curve error, Dice index, and relative perfusion upslope in the myocardium. Visual inspection revealed successful segmentation in 15 out of 18 studies. Comparison of the AO contours with expert drawn contours yielded 2.23 ± 0.53 mm and 0.91 ± 0.02 as point-to-curve error and Dice index, respectively. The average difference between manually and automatically obtained relative upslope parameters was found to be statistically insignificant (P = .37). Moreover, the analysis time per slice was reduced from 20 minutes (manual) to 1.5 minutes (automatic). We proposed an automatic method that significantly reduced the time required for analysis of first-pass cardiac magnetic resonance perfusion images. The robustness and accuracy of the proposed method were demonstrated by the high spatial correspondence and statistically insignificant difference in perfusion parameters, when AO contours were compared with expert drawn contours. Copyright © 2010 AUR. Published by Elsevier Inc. All rights reserved.

Combined value of susceptibility weighted imaging and dynamic susceptibility-weighted contrast-enhanced MR perfusion-weighted imaging in brain astrocytoma grading

International Nuclear Information System (INIS)

Wang Xiaochun; Zhang Hui; Qin Jiangbo; Wang Le; Wu Xiaofeng

2012-01-01

Objective: To assess the value of combination of susceptibility weighted imaging (SWI) and dynamic susceptibility-weighted contrast-enhanced (DSC) perfusion-weighted magnetic resonance imaging in astrocytoma grading. Methods: SWI and DSC scans were performed in 82 patients with pathologically confirmed astrocytoma. The patient group consisted of grade Ⅱ (15), grade Ⅲ (10), and grade Ⅳ (57). The intratumoral susceptibility signal intensity (ITSS) and relative cerebral blood volume (rCBV) max were used to determine the grade of astrocytomas by Kruskal Wallis test, Welch test, Spearman correlation coefficients, Pearson correlation coefficients, and receiver operating characteristic curve (ROC)statistic methods. Results: There were no ITSS in 14 cases of low-grade astrocytomas, the degree of ITSS were grade 1 to 3 in anaplastic astrocytomas, the degree of ITSS were grade 3 in all of the glioblastomas, the degree of ITSS were significant difference in all grades (H=71.96, P<0.01). rCBV max in grade Ⅱ, grade Ⅲ and grade Ⅳ astrocytomas were 1.26 ± 0.42, 3.59 ± 2.09 and 8.34 ± 1.16 respectively, rCBV max were significant difference in all grades (F'=681.72, P<0.01). ITSS showed significant correlation with rCBV max (r=0.72, P<0.01) and tumor grades (r=0.89, P<0.01), and rCBV and tumor grades showed significant correlation (r=0.78, P<0.01). Area under the ROC curve application SWI, DSC, SWI and DSC in differentiation of the grade Ⅱ and grade Ⅲ astrocytomas were 0.99, 0.93, 1.00, differentiate grade Ⅲ from grade Ⅳ were 0.70, 0.94, 0.94, and differentiate high-grade from low-grade astrocytomas were 1.00, 0.99, 1.00. Conclusions: ITSS is helpful to determine the grade of astrocytomas. The use of SWI in combination with DSC may improve the diagnostic accuracy of astrocytoma grading. (authors)

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

International Nuclear Information System (INIS)

Narita, Michihiro; Kurihara, Tadashi

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 99m Tc-methoxy-isobutyl isonitrile (MIBI) imaging and rest 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 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 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 123 I-BMIPP). Eighteen normotensive patients with apical defect by 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 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 123 I-BMIPP showed 3 different types of perfusion. Many patients without hypertension show a pathologic process similar to hypertrophic cardiomyopathy. Perfusion and 123 I-BMIPP imaging are useful for the identification of these patients. (author)

Relationship Between Collateral Status, Contrast Transit, and Contrast Density in Acute Ischemic Stroke.

Science.gov (United States)

Kawano, Hiroyuki; Bivard, Andrew; Lin, Longting; Spratt, Neil J; Miteff, Ferdinand; Parsons, Mark W; Levi, Christopher R

2016-03-01

Collateral circulation is recognized to influence the life expectancy of the ischemic penumbra in acute ischemic stroke. The best method to quantify collateral status on acute imaging is uncertain. We aimed to determine the relationship between visual collateral status, quantitative collateral assessments, baseline computed tomographic perfusion measures, and tissue outcomes on follow-up imaging. Sixty-six consecutive patients with acute ischemic stroke clinically eligible for recanalization therapy and with M1 or M2 middle cerebral artery occlusion were evaluated. We compared the visual collateral scoring with measures of contrast peak time delay and contrast peak density. We also compared these measures for their ability to predict perfusion lesion and infarct core volumes, final infarct, and infarct growth. Shorter contrast peak time delay (P=0.041) and higher contrast peak density (P=0.002) were associated with good collateral status. Shorter contrast peak time delay correlated with higher contrast peak density (β=-4.413; P=0.037). In logistic regression analysis after adjustment for age, sex, onset-computed tomographic time, and occlusion site, higher contrast peak density was independently associated with good collateral status (P=0.009). Multiple regression analysis showed that higher contrast peak density was an independent predictor of smaller perfusion lesion volume (P=0.029), smaller ischemic core volume (P=0.044), smaller follow-up infarct volume (P=0.005), and smaller infarct growth volume (P=0.010). Visual collateral status, contrast peak density, and contrast peak time delay were inter-related, and good collateral status was strongly associated with contrast peak density. Contrast peak density in collateral vessel may be an important factor in tissue fate in acute ischemic stroke. © 2016 American Heart Association, Inc.

Preoperative subtyping of meningiomas by perfusion MR imaging

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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.)

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

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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.)

A comparative analysis of pulmonary ventilation-perfusion imaging with pulmonary angiography in the diagnosis of pulmonary embolism

International Nuclear Information System (INIS)

Wang Jincheng; Mi Hongzhi; Wang Qian; Zhang Weijun; Lu Biao; Yang Hao; Ding Jian; Lu Yao

2001-01-01

Objective: To assess the value of ventilation-perfusion imaging in the diagnosis of pulmonary embolism (PE). Methods: Thirty consecutive patients with clinically suspected pulmonary embolism were studied, male: female 15:15, mean age was (36.2 +- 13.9) years. The chest radiograms were obtained in all 30 patients. All patients underwent radionuclide ventilation-perfusion imaging and pulmonary angiography. Results: Of the 30 patients, 22 with lobe, multiple segment or multi-subsegment perfusion defects and normal or nearly normal ventilation images were reported as PE. 20 of them were confirmed to be with PE by pulmonary angiography, 2 patients were not confirmed. Eight of 30 patients with multiple perfusion defects, ventilative abnormalities were reported as non-PE and the diagnoses were confirmed by pulmonary angiography. The sensitivity, specificity and accuracy of diagnosis of PE by ventilation-perfusion imaging was 100%, 80.0% and 93.3% respectively. Conclusions: (1) Ventilation-perfusion imaging is one of the most valuable methods in the diagnosis of PE. (2) The results suggest that pulmonary embolism can be diagnosed non-invasively in most patients on the basis of clinical manifestation, chest radiograms and ventilation-perfusion imaging findings. (3) Pulmonary angiography is required while clinical manifestation and ventilation-perfusion imaging findings are discordant with each other

A Unifying model of perfusion and motion applied to reconstruction of sparsely sampled free-breathing myocardial perfusion MRI

DEFF Research Database (Denmark)

Pedersen, Henrik; Ólafsdóttir, Hildur; Larsen, Rasmus

2010-01-01

The clinical potential of dynamic contrast-enhanced magnetic resonance imaging (DCE-MRI) is currently limited by respiratory induced motion of the heart. This paper presents a unifying model of perfusion and motion in which respiratory motion becomes an integral part of myocardial perfusion...... quantification. Hence, the need for tedious manual motion correction prior to perfusion quantification is avoided. In addition, we demonstrate that the proposed framework facilitates the process of reconstructing DCEMRI from sparsely sampled data in the presence of respiratory motion. The paper focuses primarily...... on the underlying theory of the proposed framework, but shows in vivo results of respiratory motion correction and simulation results of reconstructing sparsely sampled data....

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

International Nuclear Information System (INIS)

Server, Andres; Nakstad, Per H.; Orheim, Tone E.D.; Graff, Bjoern A.; Josefsen, Roger; Kumar, Theresa

2011-01-01

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

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

Energy Technology Data Exchange (ETDEWEB)

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

2011-05-15

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

Assessment of the zonal variation of perfusion parameters in the femoral head. A 3-T dynamic contrast-enhanced MRI pilot study

Energy Technology Data Exchange (ETDEWEB)

Budzik, Jean-Francois [Lille Catholic University, Imaging Department, Lille Catholic Hospitals, Lille (France); Littoral Cote d' Opale University, Lille University, Lille (France); Lefebvre, Guillaume [University of Lille Nord de France, Musculoskeletal Imaging Department, Centre de Consultation et d' Imagerie de l' Appareil Locomoteur, CHU Lille, Lille (France); Behal, Helene [University of Lille Nord de France, Biostatistics Department, Lille Regional University Hospital, Lille (France); Verclytte, Sebastien [Lille Catholic University, Imaging Department, Lille Catholic Hospitals, Lille (France); Hardouin, Pierre [Lille University, Littoral Cote d' Opale University, Lille (France); Teixeira, Pedro [Centre Hospitalier Universitaire de Nancy, Service d' Imagerie Guilloz, Hopital Central, Nancy (France); Cotten, Anne [Littoral Cote d' Opale University, Lille University, Lille (France); University of Lille Nord de France, Musculoskeletal Imaging Department, Centre de Consultation et d' Imagerie de l' Appareil Locomoteur, CHU Lille, Lille (France)

2018-02-15

The objective was to describe MR perfusion characteristics of the femoral head, with a focus on the subchondral bone. This prospective monocentric study was approved by our local Ethics Committee. Written informed consent was obtained from all subjects. Dynamic contrast-enhanced MRI of the right hip was performed in 59 adults with suspected spondyloarthritis (32 women, 28 men). Mean age was 37.5 (±12.5) years. Regions of interest were drawn in the femoral head epiphysis, in the subchondral areas the most exposed to mechanical load (superolateral, anterosuperior, and posterior zones) and in areas less exposed to mechanical load (inferior subchondral zone and center of the femoral head). Semi-quantitative and pharmacokinetic parameters were calculated using the Tofts model. Statistical analysis was performed with a linear mixed model to compare the perfusion parameters in the different femoral head zones. Extravascular extracellular volume and area under the curve were lower in the superolateral zone than in the inferior zone (p = 0.0135 and p < 0.0001 respectively) and the central zone (p = 0.007 and p = 0.0134 respectively). Extravascular extracellular volume and rate constant were lower in the anterosuperior zone than in the inferior zones (p = 0.011 and p = 0.029). In the anterosuperior zone, extravascular extracellular volume was lower, and time to peak was higher than in the central zones (p = 0.0056 and p = 0.0013 respectively). No significant differences were found for any values between other paired zones. The perfusion of femoral head subchondral bone assessed with dynamic contrast-enhanced magnetic resonance imaging is not homogeneous: the areas exposed to more mechanical loading are less perfused. (orig.)

Assessment of the zonal variation of perfusion parameters in the femoral head. A 3-T dynamic contrast-enhanced MRI pilot study

International Nuclear Information System (INIS)

Budzik, Jean-Francois; Lefebvre, Guillaume; Behal, Helene; Verclytte, Sebastien; Hardouin, Pierre; Teixeira, Pedro; Cotten, Anne

2018-01-01

The objective was to describe MR perfusion characteristics of the femoral head, with a focus on the subchondral bone. This prospective monocentric study was approved by our local Ethics Committee. Written informed consent was obtained from all subjects. Dynamic contrast-enhanced MRI of the right hip was performed in 59 adults with suspected spondyloarthritis (32 women, 28 men). Mean age was 37.5 (±12.5) years. Regions of interest were drawn in the femoral head epiphysis, in the subchondral areas the most exposed to mechanical load (superolateral, anterosuperior, and posterior zones) and in areas less exposed to mechanical load (inferior subchondral zone and center of the femoral head). Semi-quantitative and pharmacokinetic parameters were calculated using the Tofts model. Statistical analysis was performed with a linear mixed model to compare the perfusion parameters in the different femoral head zones. Extravascular extracellular volume and area under the curve were lower in the superolateral zone than in the inferior zone (p = 0.0135 and p < 0.0001 respectively) and the central zone (p = 0.007 and p = 0.0134 respectively). Extravascular extracellular volume and rate constant were lower in the anterosuperior zone than in the inferior zones (p = 0.011 and p = 0.029). In the anterosuperior zone, extravascular extracellular volume was lower, and time to peak was higher than in the central zones (p = 0.0056 and p = 0.0013 respectively). No significant differences were found for any values between other paired zones. The perfusion of femoral head subchondral bone assessed with dynamic contrast-enhanced magnetic resonance imaging is not homogeneous: the areas exposed to more mechanical loading are less perfused. (orig.)

MRI for the assessment of organ perfusion in patients with chronic kidney disease.

Science.gov (United States)

Odudu, Aghogho; Francis, Susan T; McIntyre, Christopher W

2012-11-01

Recent data have highlighted the importance of quantitative measures of organ perfusion and functional reserve. Magnetic resonance imaging allows the assessment of markers of perfusion without the use of contrast media. Techniques such as arterial spin labelling (ASL) and blood oxygen level-dependent (BOLD) imaging have been available for some time, but advances in the technology and concerns over the safety of contrast media in renal disease have spurred renewed interest and development. ASL measures perfusion, whereas BOLD imaging provides a marker of blood oxygenation, arising from the compound effect of a number of measures including perfusion, blood volume and oxygen consumption; thus, the techniques are complementary rather than analogous. They were initially confined to brain imaging as inherently low signal, susceptibility effects and motion limited their use in thoracic and abdominal organs. Advances in technology have led to robust sequences that can quantify clinically relevant changes and correlate well with reference standards. Novel approaches are likely to accelerate translation into clinical practice. The noninvasive and repeatable nature of ASL and BOLD imaging makes it likely that they will be increasingly used in clinical research. Using a developmental framework, we suggest that the application of these techniques to thoracic and abdominal organs requires validation before they are suitable for generalized clinical use. The demand for these techniques is likely to be driven by the incentive to avoid the use of contrast media.

Added Value of 3D Cardiac SPECT/CTA Fusion Imaging in Patients with Reversible Perfusion Defect on Myocardial Perfusion SPECT

Energy Technology Data Exchange (ETDEWEB)

Kong, Eun Jung; Cho, Ihn Ho [Yeungnam University Hospital, Daegu (Korea, Republic of); Kang, Won Jun [Yonsei University Hospital, Seoul (Korea, Republic of); Kim, Seong Min [Chungnam National University Medical School and Hospital, Daejeon (Korea, Republic of); Won, Kyoung Sook [Keomyung University Dongsan Hospital, Daegu (Korea, Republic of); Lim, Seok Tae [Chonbuk National University Medical School and Hospital, Jeonju (Korea, Republic of); Hwang, Kyung Hoon [Gachon University Gil Hospital, Incheon (Korea, Republic of); Lee, Byeong Il; Bom, Hee Seung [Chonnam National University Medical School and Hospital, Gwangju (Korea, Republic of)

2009-12-15

Integration of the functional information of myocardial perfusion SPECT (MPS) and the morphoanatomical information of coronary CT angiography (CTA) may provide useful additional diagnostic information of the spatial relationship between perfusion defects and coronary stenosis. We studied to know the added value of three dimensional cardiac SPECT/CTA fusion imaging (fusion image) by comparing between fusion image and MPS. Forty-eight patients (M:F=26:22, Age: 63.3{+-}10.4 years) with a reversible perfusion defect on MPS (adenosine stress/rest SPECT with Tc-99m sestamibi or tetrofosmin) and CTA were included. Fusion images were molded and compared with the findings from the MPS. Invasive coronary angiography served as a reference standard for fusion image and MPS. Total 144 coronary arteries in 48 patients were analyzed; Fusion image yielded the sensitivity, specificity, negative and positive predictive value for the detection of hemodynamically significant stenosis per coronary artery 82.5%, 79.3%, 76.7% and 84.6%, respectively. Respective values for the MPS were 68.8%, 70.7%, 62.1% and 76.4%. And fusion image also could detect more multi-vessel disease. Fused three dimensional volume-rendered SPECT/CTA imaging provides intuitive convincing information about hemodynamic relevant lesion and could improved diagnostic accuracy.

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.

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

Science.gov (United States)

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

2011-02-01

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 cirrhotic liver disease by this fast imaging method. 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. 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 value of HBF at the tumor

Pre-clinical evaluation of a nanoparticle-based blood-pool contrast agent for MR imaging of the placenta.

Science.gov (United States)

Ghaghada, Ketan B; Starosolski, Zbigniew A; Bhayana, Saakshi; Stupin, Igor; Patel, Chandreshkumar V; Bhavane, Rohan C; Gao, Haijun; Bednov, Andrey; Yallampalli, Chandrasekhar; Belfort, Michael; George, Verghese; Annapragada, Ananth V

2017-09-01

Non-invasive 3D imaging that enables clear visualization of placental margins is of interest in the accurate diagnosis of placental pathologies. This study investigated if contrast-enhanced MRI performed using a liposomal gadolinium blood-pool contrast agent (liposomal-Gd) enables clear visualization of the placental margins and the placental-myometrial interface (retroplacental space). Non-contrast MRI and contrast-enhanced MRI using a clinically approved conventional contrast agent were used as comparators. Studies were performed in pregnant rats under an approved protocol. MRI was performed at 1T using a permanent magnet small animal scanner. Pre-contrast and post-liposomal-Gd contrast images were acquired using T1-weighted and T2-weighted sequences. Dynamic Contrast enhanced MRI (DCE-MRI) was performed using gadoterate meglumine (Gd-DOTA, Dotarem ® ). Visualization of the retroplacental clear space, a marker of normal placentation, was judged by a trained radiologist. Signal-to-noise (SNR) and contrast-to-noise (CNR) ratios were calculated for both single and averaged acquisitions. Images were reviewed by a radiologist and scored for the visualization of placental features. Contrast-enhanced CT (CE-CT) imaging using a liposomal CT agent was performed for confirmation of the MR findings. Transplacental transport of liposomal-Gd was evaluated by post-mortem elemental analysis of tissues. Ex-vivo studies in perfused human placentae from normal, GDM, and IUGR pregnancies evaluated the transport of liposomal agent across the human placental barrier. Post-contrast T1w images acquired with liposomal-Gd demonstrated significantly higher SNR (p = 0.0002) in the placenta compared to pre-contrast images (28.0 ± 4.7 vs. 6.9 ± 1.8). No significant differences (p = 0.39) were noted between SNR in pre-contrast and post-contrast liposomal-Gd images of the amniotic fluid, indicating absence of transplacental passage of the agent. The placental margins were

Spatio-temporal analysis of blood perfusion by imaging photoplethysmography

Science.gov (United States)

Zaunseder, Sebastian; Trumpp, Alexander; Ernst, Hannes; Förster, Michael; Malberg, Hagen

2018-02-01

Imaging photoplethysmography (iPPG) has attracted much attention over the last years. The vast majority of works focuses on methods to reliably extract the heart rate from videos. Only a few works addressed iPPGs ability to exploit spatio-temporal perfusion pattern to derive further diagnostic statements. This work directs at the spatio-temporal analysis of blood perfusion from videos. We present a novel algorithm that bases on the two-dimensional representation of the blood pulsation (perfusion map). The basic idea behind the proposed algorithm consists of a pairwise estimation of time delays between photoplethysmographic signals of spatially separated regions. The probabilistic approach yields a parameter denoted as perfusion speed. We compare the perfusion speed versus two parameters, which assess the strength of blood pulsation (perfusion strength and signal to noise ratio). Preliminary results using video data with different physiological stimuli (cold pressure test, cold face test) show that all measures are influenced by those stimuli (some of them with statistical certainty). The perfusion speed turned out to be more sensitive than the other measures in some cases. However, our results also show that the intraindividual stability and interindividual comparability of all used measures remain critical points. This work proves the general feasibility of employing the perfusion speed as novel iPPG quantity. Future studies will address open points like the handling of ballistocardiographic effects and will try to deepen the understanding of the predominant physiological mechanisms and their relation to the algorithmic performance.

Isoattenuating insulinomas at biphasic contrast-enhanced CT: frequency, clinicopathologic features and perfusion characteristics

Energy Technology Data Exchange (ETDEWEB)

Zhu, Liang; Xue, Hua-dan; Sun, Hao; Wang, Xuan; He, Yong-lan; Jin, Zheng-yu [Peking Union Medical College Hospital, Department of Radiology, Beijing (China); Zhao, Yu-pei [Peking Union Medical College Hospital, Department of General Surgery, Beijing (China)

2016-10-15

We aimed to determine the frequency of isoattenuating insulinomas, to investigate their clinicopathological features and to assess their regional pancreatic perfusion characteristics. Institutional review board approval was obtained, and patient informed consent was waived. From July 2010 to June 2014, 170 patients (66 male, 104 female) with endogenous hyperinsulinemic hypoglycemia underwent biphasic contrast-enhanced CT before surgery, and 129 of those patients also received preoperative whole-pancreas CT perfusion. A total of 181 tumours were proved histopathologically after surgery. Enhancement pattern and regional pancreatic perfusion characteristics were analyzed. Clinical features, tumour size and pathological grading were investigated. The frequency of isoattenuating tumours was 24.9 %. Tumour size and WHO grading was not significantly different between isoattenuating and hyperattenuating tumours. Tumour-free regions had identical blood flow (BF) regardless of their location (p = 0.35). Isoattenuating tumour-harbouring regions had lower BF compared with hyperattenuating tumour-harbouring regions; both showed higher BF compared with tumour-free neighbourhood regions (all p < 0.01). For patients with isoattenuating tumours, the overall hospital stay was longer (p < 0.01). A substantial subset of insulinomas were isoattenuating on biphasic CT. CT perfusion showed higher BF in tumour-harbouring regions compared to tumour-free regions, providing a clue for tumour regionalization. (orig.)

Mouse myocardial first-pass perfusion MR imaging

NARCIS (Netherlands)

Coolen, Bram F.; Moonen, Rik P. M.; Paulis, Leonie E. M.; Geelen, Tessa; Nicolay, Klaas; Strijkers, Gustav J.

2010-01-01

A first-pass myocardial perfusion sequence for mouse cardiac MRI is presented. A segmented ECG-triggered acquisition combined with parallel imaging acceleration was used to capture the first pass of a Gd-DTPA bolus through the mouse heart with a temporal resolution of 300-400 msec. The method was

Noninvasive quantification of myocardial perfusion heterogeneity by Markovian analysis in SPECT nuclear imaging

International Nuclear Information System (INIS)

Pons, G.

2011-01-01

Cardiovascular diseases are the leading cause of mortality worldwide, and third of these deaths are caused by coronary artery disease and rupture of vulnerable atherosclerotic plaques. The heterogeneous alteration of the coronary microcirculation is an early phenomenon associated with many cardiovascular risk factors that can strongly predict the subsequent development of coronary artery disease, and lead to the appearance of myocardial perfusion heterogeneity. Nuclear medicine allows the study of myocardial perfusion in clinical routine through scintigraphic scans performed after injection of a radioactive tracer of coronary blood flow. Analysis of scintigraphic perfusion images currently allows the detection of myocardial ischemia, but the ability of the technique to measure the perfusion heterogeneity in apparently normally perfused areas is unknown. The first part of this thesis focuses on a retrospective clinical study to determine the feasibility of myocardial perfusion heterogeneity quantification measured by Thallium-201 single photon emission computed tomography (SPECT) in diabetic patients compared with healthy subjects. The clinical study has demonstrated the ability of routine thallium-201 SPECT imaging to quantify greater myocardial perfusion heterogeneity in diabetic patients compared with normal subjects. The second part of this thesis tests the hypothesis that the myocardial perfusion heterogeneity could be quantified in small animal SPECT imaging by Thallium-201 and/or Technetium-99m-MIBI in an experimental study using two animal models of diabetes, and is correlated with histological changes. The lack of difference in myocardial perfusion heterogeneity between control and diabetic animals suggests that animal models are poorly suited, or that the technology currently available does not seem satisfactory to obtain similar results as the clinical study. (author)

Development of a practical image-based scatter correction method for brain perfusion SPECT: comparison with the TEW method

International Nuclear Information System (INIS)

Shidahara, Miho; Kato, Takashi; Kawatsu, Shoji; Yoshimura, Kumiko; Ito, Kengo; Watabe, Hiroshi; Kim, Kyeong Min; Iida, Hidehiro; Kato, Rikio

2005-01-01

An image-based scatter correction (IBSC) method was developed to convert scatter-uncorrected into scatter-corrected SPECT images. The purpose of this study was to validate this method by means of phantom simulations and human studies with 99m Tc-labeled tracers, based on comparison with the conventional triple energy window (TEW) method. The IBSC method corrects scatter on the reconstructed image I AC μb with Chang's attenuation correction factor. The scatter component image is estimated by convolving I AC μb with a scatter function followed by multiplication with an image-based scatter fraction function. The IBSC method was evaluated with Monte Carlo simulations and 99m Tc-ethyl cysteinate dimer SPECT human brain perfusion studies obtained from five volunteers. The image counts and contrast of the scatter-corrected images obtained by the IBSC and TEW methods were compared. Using data obtained from the simulations, the image counts and contrast of the scatter-corrected images obtained by the IBSC and TEW methods were found to be nearly identical for both gray and white matter. In human brain images, no significant differences in image contrast were observed between the IBSC and TEW methods. The IBSC method is a simple scatter correction technique feasible for use in clinical routine. (orig.)

Development of a practical image-based scatter correction method for brain perfusion SPECT: comparison with the TEW method.

Science.gov (United States)

Shidahara, Miho; Watabe, Hiroshi; Kim, Kyeong Min; Kato, Takashi; Kawatsu, Shoji; Kato, Rikio; Yoshimura, Kumiko; Iida, Hidehiro; Ito, Kengo

2005-10-01

An image-based scatter correction (IBSC) method was developed to convert scatter-uncorrected into scatter-corrected SPECT images. The purpose of this study was to validate this method by means of phantom simulations and human studies with 99mTc-labeled tracers, based on comparison with the conventional triple energy window (TEW) method. The IBSC method corrects scatter on the reconstructed image I(mub)AC with Chang's attenuation correction factor. The scatter component image is estimated by convolving I(mub)AC with a scatter function followed by multiplication with an image-based scatter fraction function. The IBSC method was evaluated with Monte Carlo simulations and 99mTc-ethyl cysteinate dimer SPECT human brain perfusion studies obtained from five volunteers. The image counts and contrast of the scatter-corrected images obtained by the IBSC and TEW methods were compared. Using data obtained from the simulations, the image counts and contrast of the scatter-corrected images obtained by the IBSC and TEW methods were found to be nearly identical for both gray and white matter. In human brain images, no significant differences in image contrast were observed between the IBSC and TEW methods. The IBSC method is a simple scatter correction technique feasible for use in clinical routine.

Intravoxel Incoherent Motion MR Imaging in the Head and Neck: Correlation with Dynamic Contrast-Enhanced MR Imaging and Diffusion-Weighted Imaging.

Science.gov (United States)

Xu, Xiao Quan; Choi, Young Jun; Sung, Yu Sub; Yoon, Ra Gyoung; Jang, Seung Won; Park, Ji Eun; Heo, Young Jin; Baek, Jung Hwan; Lee, Jeong Hyun

2016-01-01

To investigate the correlation between perfusion- and diffusion-related parameters from intravoxel incoherent motion (IVIM) and those from dynamic contrast-enhanced MR imaging (DCE-MRI) and diffusion-weighted imaging in tumors and normal muscles of the head and neck. We retrospectively enrolled 20 consecutive patients with head and neck tumors with MR imaging performed using a 3T MR scanner. Tissue diffusivity (D), pseudo-diffusion coefficient (D(*)), and perfusion fraction (f) were derived from bi-exponential fitting of IVIM data obtained with 14 different b-values in three orthogonal directions. We investigated the correlation between D, f, and D(*) and model-free parameters from the DCE-MRI (wash-in, Tmax, Emax, initial AUC60, whole AUC) and the apparent diffusion coefficient (ADC) value in the tumor and normal masseter muscle using a whole volume-of-interest approach. Pearson's correlation test was used for statistical analysis. No correlation was found between f or D(*) and any of the parameters from the DCE-MRI in all patients or in patients with squamous cell carcinoma (p > 0.05). The ADC was significantly correlated with D values in the tumors (p correlation with f values in the tumors (p = 0.017, r = 0.528) and muscles (p = 0.003, r = 0.630), but no correlation with D(*) (p > 0.05, respectively). Intravoxel incoherent motion shows no significant correlation with model-free perfusion parameters derived from the DCE-MRI but is feasible for the analysis of diffusivity in both tumors and normal muscles of the head and neck.

Perfusion and diffusion MR imaging in enhancing malignant cerebral tumors

International Nuclear Information System (INIS)

Calli, Cem; Kitis, Omer; Yunten, Nilgun; Yurtseven, Taskin; Islekel, Sertac; Akalin, Taner

2006-01-01

Objective: Common contrast-enhancing malignant tumors of the brain are glioblastoma multiforme (GBMs), anaplastic astrocytomas (AAs), metastases, and lymphomas, all of which have sometimes similar conventional MRI findings. Our aim was to evaluate the role of perfusion MR imaging (PWI) and diffusion-weighted imaging (DWI) in the differentiation of these contrast-enhancing malignant cerebral tumors. Materials and methods: Forty-eight patients with contrast-enhancing and histologically proven brain tumors, 14 AAs, 17 GBMs, nine metastases, and eight lymphomas, were included in the study. All patients have undergone routine MR examination where DWI and PWI were performed in the same session. DWI was performed with b values of 0, 500, and 1000 mm 2 /s. Minimum ADC values (ADC min ) of each tumor was later calculated from ADC map images. PWI was applied using dynamic susceptibility contrast technique and maximum relative cerebral blood volume (rCBV max ) was calculated from each tumor, given in ratio with contralateral normal white matter. Comparisons of ADC min and rCBV max values with the histological types of the enhancing tumors were made with a one-way analysis of variance and Bonferroni test. A P value less than 0.05 indicated a statistically significant difference. Results: The ADC min values (mean ± S.D.) in GBMs, AAs, lymphomas, and metastases were 0.79 ± 0.21 (x10 -3 mm 2 /s), 0.75 ± 0.21 (x10 -3 mm 2 /s), 0.51 ± 0.09 (x10 -3 mm 2 /s), and 0.68 ± 0.11 (x10 -3 mm 2 /s), respectively. The difference in ADC min values were statistically significant between lymphomas and GBMs (P max ratio (mean ± S.D.) in GBMs were 6.33 ± 2.03, whereas it was 3.66 ± 1.79 in AAs, 2.33 ± 0.68 in lymphomas, and 4.45 ± 1.87 in metastases. These values were statistically different between GBMs and AAs (P min and rCBV max calculations, may aid routine MR imaging in the differentiation of common cerebral contrast-enhancing malignant tumors

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

International Nuclear Information System (INIS)

Leiva-Salinas, Carlos; Provenzale, James M.; Kudo, Kohsuke; Sasaki, Makoto; Wintermark, Max

2012-01-01

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

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

Energy Technology Data Exchange (ETDEWEB)

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

2012-09-15

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

Evaluation of brain perfusion SPECT imaging using 99mTc-ECD

International Nuclear Information System (INIS)

Matsuda, Hiroshi; Kinuya, Keiko; Higashi, Sotaro; Kawasaki, Yasuhiro; Sumiya, Hisashi; Shuke, Noriyuki; Hisada, Kinichi; Yamashita, Junkoh; Yamaguchi, Nariyoshi

1991-01-01

Fundamental and clinical evaluation was performed on 99m Tc-ethyl cysteinate dimer ( 99m Tc-ECD), that is a new agent for brain perfusion SPECT. Radiochemical purity reaches a plateau of approximately 98% at 30 min after reconstruction and remains stable up to 24 hours later. A biodistribution study showed approximately 5% injected dose in the brain, very slow brain washout of 5.6% per hour on the average, and rapid washout from the other organ mainly through the urinary system. Brain ECD distribution was determined within 2 min postinjection and remained stable for up to 1 hour. Three hours later, slight but significant changes in brain distribution were observed, that were relative reduction of cerebral cortical activity and gray to white matter activity ratio, and relative elevation of white matter and thalamic activities. Comparative studies of ECD images with 123 I-iodoamphetamine (IMP) and 99m Tc-d, l-hexa-methylpro-pyleneamine oxime (HMPAO) images revealed that radioactivity contrast between affected and unaffected areas was less prominent in ECD than in IMP in cerebral and cerebellar cortical lesions, more prominent in ECD than in IMP in striatal and thalamic lesions, and somewhat more prominent in ECD than in HMPAO in both lesions. Imaging around 1 hour postinjection seems to be more appropriate than immediate postinjection imaging because of the clearance of the extracranial radioactivity and somewhat better radioactivity contrast between affected and unaffected areas. (author)

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.)

Perfusion-weighted MR imaging in persistent hemiplegic migraine

International Nuclear Information System (INIS)

Mourand, Isabelle; Menjot de Champfleur, Nicolas; Carra-Dalliere, Clarisse; Le Bars, Emmanuelle; Bonafe, Alain; Thouvenot, Eric; Roubertie, Agathe

2012-01-01

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.)

Clinical evaluation of non-invasive perfusion-weighted MRI

International Nuclear Information System (INIS)

Takasu, Miyuki

2000-01-01

A spin labeling method to measure cerebral blood flow without a contrast medium was developed and applied clinically to obtain a non-invasive perfusion-weighted image. The purpose of this study is to compare the non-invasive perfusion-weighted image using FAIR with the well-established PWI using a bolus injection of Gd-DTPA. Of 41 lesions which revealed decreased perfusion, 13 were shown to be low signal intensity areas on FAIR. Therefore, detection rate of FAIR for hypoperfusion was 32%. Of 8 lesions which revealed increased perfusion, 7 demonstrated high intensity on FAIR. Therefore, detection rate of FAIR for hyperperfusion was 88%. Seven lesions were found to have a mean pixel value of zero on PWI. Of these lesions, 5 lesions could be detected as high signal intensity area on FAIR. The rCBV- and rCBF index ratios of hypoperfused lesions detected on FAIR were significantly lower than those of lesions which were not detected on FAIR (p=0.007, p=0.01). As concerns the lesions detected of FAIR, there were positive correlation between rCBV- or rCBF index ratio and FAIR signal ratio (rCBV ratio: ρ=0.873, p=0.0002, rCBF index ratio: ρ=0.858, p=0.0003). FAIR is valuable clinical tool to detect perfusion abnormality semi-quantitatively without contrast medium, although it showed relatively low detection rate for hypoperfused lesions. (author)

Mouse myocardial first-pass perfusion MR imaging

NARCIS (Netherlands)

Coolen, B.F.; Moonen, R.P.M.; Paulis, L.E.M.; Geelen, T.; Nicolay, K.; Strijkers, G.J.

2010-01-01

A first-pass myocardial perfusion sequence for mouse cardiac MRI is presented. A segmented ECG-triggered acquisition combined with parallel imaging acceleration was used to capture the first pass of a Gd-DTPA bolus through the mouse heart with a temporal resolution of 300–400 msec. The method was

Mr imaging and mr spectroscopy of brain metastases by mr perfusion

International Nuclear Information System (INIS)

Weber, Marc-Andre; Lichy, M.P.; Thilmann, C.; Guenther, M.; Bachert, P.; Delorme, S.; Schad, L.R.; Debus, J.; Schlemmer, H.P.; Maudsley, A.A.

2003-01-01

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

A comparative study of MR imaging scores and MR perfusion imaging in pre-operative grading of intracranial gliomas

International Nuclear Information System (INIS)

Wu Honglin; Chen Junkun; Zhang Zongjun; Lu Guangming; Chen Ziqian; Wang Wei; Ji Xueman; Tang Xiaojun; Li Lin

2005-01-01

Objective: To compare the accuracy of MR imaging scores with MR perfusion imaging in pre-operative grading of intracranial gliomas. Methods: Thirty patients with intracranial gliomas (8 low-grade and 22 high-grade, according to WHO criteria) were examined with MR perfusion imaging pre-operatively. The lesions were evaluated by using an MR imaging score based on nine criteria. rCBV of the lesions were calculated by comparing the CBV of the lesion and that of contralateral normal white matter. The scores and ratios in high-grade and low-grade tumours were compared. Results: The MR imaging score of low grade (grades I and II) gliomas (0.67±0.29) were significantly lower than that of grades III (1.32 ± 0.47) (t=-3.48, P=0.003) and IV (1.56 ± 0.20) (t=-7.36, P=0.000) gliomas. There was no statistical difference when MR imaging scores of grades III and IV gliomas (t=-1.39, P=0.182) were compared. The maximum rCBV ratio of low grade (grades I and II) gliomas (2.38 ± 0.66 ) were significantly lower than that of grades III (5.81 ± 3.20) (t=-3.57, P=0.003) and IV (6.99 ± 2.47) (t=-5.09, P=0.001). There was no statistical difference when rCBV ratios of grades III and IV (t =-0.93, P=0.365) gliomas were compared. The accuracy of MR imaging scores in the noninvasive grading of untreated gliomas was all most the same as that of MR perfusion imaging (90.00% vs 89.29%). Conclusion: The MR imaging scores and MR perfusion imaging are two very useful tools in the evaluation of the histopathologic grade of cerebral gliomas. The overall accuracy in the noninvasive grading of gliomas may be imp roved if MR imaging scores and MR perfusion imaging are combined. (authors)

Analysis of perfusion weighted image of CNS lymphoma

International Nuclear Information System (INIS)

Lee, In Ho; Kim, Sung Tae; Kim, Hyung-Jin; Kim, Keon Ha; Jeon, Pyoung; Byun, Hong Sik

2010-01-01

Purpose: It is difficult to differentiate CNS lymphoma from other tumors such as malignant gliomas, metastases, or meningiomas with conventional MR imaging, because the imaging findings are overlapped between these tumors. The purpose of this study is to investigate the perfusion weighted MR imaging findings of CNS lymphomas and to compare the relative cerebral blood volume ratios between CNS lymphomas and other tumors such as high grade gliomas, metastases, or meningiomas. Materials and methods: We retrospectively reviewed MRI findings and clinical records in 13 patients with pathologically proven CNS lymphoma between January 2006 and November 2008. We evaluated the relative cerebral blood volume ratios of tumor, which were obtained by dividing the values obtained from the normal white matter on MRI. Results: Total 13 patients (M:F = 8:5; age range 46-67 years, mean age 52.3 years) were included. The CNS lymphomas showed relatively low values of maximum relative CBV ratio in most patients regardless of primary or secondary CNS lymphoma. Conclusion: Perfusion weighted image may be helpful in the diagnosis of CNS lymphoma in spite of primary or secondary or B cell or T cell.

Radiation dose reduction in cerebral CT perfusion imaging using iterative reconstruction

International Nuclear Information System (INIS)

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.; Horsch, Alexander D.

2014-01-01

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.)

The role of contrast-enhanced endoscopic ultrasound in pancreatic adenocarcinoma

DEFF Research Database (Denmark)

Saftoiu, Adrian; Vilmann, Peter; Bhutani, Manoop S

2016-01-01

contrast agents for early detection, tridimensional and fusion techniques for enhanced staging and resectability assessment but also novel applications of perfusion imaging for monitoring ablative therapy, improved local detection through EUS-guided sampling of portal vein flow or enhanced drug delivery......Contrast-enhanced endoscopic ultrasound (CE-EUS) allows characterization, differentiation, and staging of focal pancreatic masses. The method has a high sensitivity and specificity for the diagnosis of pancreatic adenocarcinoma which is visualized as hypo-enhanced as compared to the rest...... of the parenchyma while chronic pancreatitis and neuroendocrine tumors are generally either iso-enhanced or hyper-enhanced. The development of contrast-enhanced low mechanical index harmonic imaging techniques used in real time during endoscopic ultrasound (EUS) allowed perfusion imaging and the quantification...

Effect of intravenous contrast agent volume on colorectal cancer vascular parameters as measured by perfusion computed tomography

International Nuclear Information System (INIS)

Goh, V.; Bartram, C.; Halligan, S.

2009-01-01

Aim: To determine the effect of two different contrast agent volumes on quantitative and semi-quantitative vascular parameters as measured by perfusion computed tomography (CT) in colorectal cancer. Materials and methods: Following ethical approval and informed consent, eight prospectively recruited patients with proven colorectal adenocarcinoma underwent two separate perfusion CT studies on the same day after (a) 100 ml and (b) 50 ml of a 340 mg/ml iodinated contrast medium, respectively. Quantitative (blood volume, blood flow, permeability surface area product) and semi-quantitative (peak enhancement, time to peak enhancement) tumour vascular parameters were determined using commercial software based on distributed parameter analysis and compared using t-testing. Results: Tumour blood volume, blood flow, and permeability surface area product were not substantially different following the injection of 100 ml and 50 ml contrast medium: 6.12 versus 6.23 ml/100 g tissue; 73.4 versus 71.3 ml/min/100 g tissue; 15.6 versus 15.3 ml/min/100 g tissue for 100 and 50 ml, respectively; p > 0.05. Tumour peak enhancement and time to peak were significantly greater following the injection of 100 ml versus 50 ml contrast medium: 41.2 versus 28.5 HU; 16.1 versus 11.8 s for 100 ml and 50 ml, respectively; p = 0.002; p = 0.0003. Conclusion: Quantitative parameters do not appear to change substantially with a higher contrast agent volume suggesting a combined diagnostic staging-perfusion CT study following a single injection is feasible for colorectal cancer

Diagnostic accuracy of unenhanced, contrast-enhanced perfusion and angiographic MRI sequences for pulmonary embolism diagnosis: results of independent sequence readings

Energy Technology Data Exchange (ETDEWEB)

Revel, Marie Pierre [Hopital Europeen Georges Pompidou, APHP, Departments of Radiology, Paris (France); Universite Paris Descartes Sorbonne Paris Cite, Paris (France); Hotel-Dieu, Service de Radiologie, Paris (France); Sanchez, Olivier; Meyer, Guy [Hopital Europeen Georges Pompidou, APHP, Respiratory and intensive care and, Paris (France); Universite Paris Descartes Sorbonne Paris Cite, Paris (France); INSERM Unite 765, Paris (France); Lefort, Catherine; Couchon, Sophie; Hernigou, Anne; Frija, Guy [Hopital Europeen Georges Pompidou, APHP, Departments of Radiology, Paris (France); Niarra, Ralph [Hopital Europeen Georges Pompidou, APHP, Clinical Epidemiology, Paris (France); Universite Paris Descartes Sorbonne Paris Cite, Paris (France); Chatellier, Gilles [Hopital Europeen Georges Pompidou, APHP, Clinical Epidemiology, Paris (France); Universite Paris Descartes Sorbonne Paris Cite, Paris (France); INSERM CIC-EC E4, Paris (France)

2013-09-15

To independently evaluate unenhanced, contrast-enhanced perfusion and angiographic MR sequences for pulmonary embolism (PE) diagnosis. Prospective investigation, including 274 patients who underwent perfusion, unenhanced 2D steady-state-free-precession (SSFP) and contrast-enhanced 3D angiographic MR sequences on a 1.5-T unit, in addition to CTA (CT angiography). Two independent readers evaluated each sequence independently in random order. Sensitivity, specificity, predictive values and inter-reader agreement were calculated for each sequence, excluding sequences judged inconclusive. Sensitivity was also calculated according to PE location. Contrast-enhanced angiographic sequences showed the highest sensitivity (82.9 and 89.7 %, reader 1 and reader 2, respectively), specificity (98.5 and 100 %) and agreement (kappa value 0.77). Unenhanced angiographic sequences, although less sensitive overall (68.7 and 76.4 %), were sensitive for the detection of proximal PE (92.7 and 100 %) and showed high specificity (96.1 and 99.1 %) and good agreement (kappa value 0.62). Perfusion sequences showed lower sensitivity (75.0 and 79.3 %), specificity (84.8 and 89.7 %) and agreement (kappa value 0.51), and a negative predictive value of 84.8 % at best. Compared with contrast-enhanced angiographic sequences, unenhanced sequences demonstrate lower sensitivity, except for proximal PE, but high specificity and agreement. The negative predictive value of perfusion sequences was insufficient to safely rule out PE. (orig.)

Simultaneous maximal exercise radionuclide angiography and thallium stress perfusion imaging

International Nuclear Information System (INIS)

Narahara, K.A.; Mena, I.; Maublant, J.C.; Brizendine, M.; Criley, J.M.

1984-01-01

Gold-195m is a new ultra-short-lived radionuclide that can be used for cardiac studies. Accurate, reproducible ejection fraction and ventricular wall motion studies can be obtained from first-transit angiography using commercially available imaging and image-processing equipment. The short half-life of gold-195m (30.5 seconds) makes simultaneous dual isotope imaging possible and substantially reduces the radiation exposure from the isotope angiography. The feasibility and possible benefits of performing dual radionuclide studies were evaluated during a single exercise stress test in 24 subjects with known coronary artery disease (CAD) and in 20 normal volunteers. High-quality first-transit angiograms were obtained in all subjects. An 83% sensitivity and 95% specificity for detecting CAD with thallium-201 imaging was noted in this investigation, suggesting that its diagnostic accuracy was not altered by simultaneous dual isotone imaging. When segmental left ventricular (LV) wall motion was compared with thallium-201 perfusion imaging, divergent results were noted in 15 of 44 subjects. An analysis of the ejection fraction (EF) results at rest and stress provided additional information that could be useful in assessing the clinical significance of such differences in segmental wall motion and perfusion. Simultaneous dual isotope imaging appears to be appropriate for situations in which both LV perfusion and function require evaluation. The use of gold-195m allows such information to be obtained from a single exercise test and can thereby reduce the cost and time required for noninvasive evaluations of patients for CAD

Repeatability of Bolus Kinetics Ultrasound Perfusion Imaging for the Quantification of Cerebral Blood Flow

NARCIS (Netherlands)

Vinke, Elisabeth J.; Eyding, Jens; de Korte, Chris L.; Slump, Cornelis H.; van der Hoeven, Johannes G.; Hoedemaekers, Cornelia W.E.

2017-01-01

Ultrasound perfusion imaging (UPI) can be used for the quantification of cerebral perfusion. In a neuro-intensive care setting, repeated measurements are required to evaluate changes in cerebral perfusion and monitor therapy. The aim of this study was to determine the repeatability of UPI in

First-pass myocardial perfusion MR imaging with gadolinium-enhanced turbo FLASH

International Nuclear Information System (INIS)

Teresi, L.M.; Smith, C.; Messenger, J.; Watanabe, A.; Herbst, M.; O'Sullivan, R.M.; Lee, R.; Remer, J.; Rappaport, A.; Bradley, W.G.

1990-01-01

This paper determines the efficacy of MR first-pass myocardial perfusion imaging using gadolinium-enhanced Turbo--fast low-angle shot (FLASH) ultrafast imaging combined with MR systolic wall thickening data for the determination of myocardial viability. Five normal volunteers and five patients with remote myocardial infarction were studied on a 1.5-T imaging system (Siemans, Ehrlangen, NJ). Turbo-FLASH imaging utilized a 180 degrees inversion pulse followed by a rapid gradient-echo sequence (TI 400 msec, TE2 msec, TR 4.9 msec, FA 8 degrees) with a complete 64 x 64 matrix image (300 mm FOV) being acquired in 300 msec. First-pass myocardial perfusion imaging was performed in the short-axis and long-axis oblique projections with a concantenated series of Turbo-FLASH images triggered to end-systole acquired immediately before and during a rapid bolus injection of 5cc gadolinium-DTPA

CT perfusion imaging in the management of posterior reversible encephalopathy

International Nuclear Information System (INIS)

Casey, S.O.; McKinney, A.; Teksam, M.; Liu, H.; Truwit, C.L.

2004-01-01

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.)

Perfusion maps of the whole liver based on high temporal and spatial resolution contrast-enhanced MRI (4D THRIVE): Feasibility and initial results in focal liver lesions

International Nuclear Information System (INIS)

Coenegrachts, Kenneth; Ghekiere, Johan; Denolin, Vincent; Gabriele, Beck; Herigault, Gwen; Haspeslagh, Marc; Daled, Peter; Bipat, Shandra; Stoker, Jaap; Rigauts, Hans

2010-01-01

Purpose: To prospectively evaluate a new imaging sequence (4D THRIVE) for whole liver perfusion in high temporal and spatial resolution. Feasibility of parametric mapping and its potential for characterizing focal liver lesions (FLLs) are investigated. Materials and methods: Fifteen patients suspected for colorectal liver metastases (LMs) were included. Parametric maps were evaluated qualitatively (ring-enhancement and lesion heterogeneity) and compared to three-phased contrast-enhanced MRI. Quantitative analysis was based on average perfusion values of entire FLLs. Reference standard comprised surgery with histopathology or follow-up imaging. Fisher's exact test was used for qualitative and Kruskal-Wallis test for quantitative analysis. Results: In total 29 LMs, 17 hemangiomas and 4 focal nodular hyperplasias were evaluated. FLLs could be differentiated by qualitative assessment of parametric maps respectively three-phased contrast-enhanced MRI (Fisher's p < 0.001 for comparisons between LMs and hemangiomas and LMs and FNHs for both ring-enhancement and lesion heterogeneity) rather than by quantitative analysis of parametric maps (Chi-square for Kep = 0.33 (p = 0.847) and Chi-square for Kel = 1.35 (p = 0.509)). Conclusion: This preliminary study shows potential of 4D THRIVE for whole liver imaging enabling calculation of parametric maps. Qualitative rather than quantitative analysis was accurate for differentiating malignant and benign FLLs.

MRI-CEST assessment of tumour perfusion using X-ray iodinated agents: comparison with a conventional Gd-based agent

Energy Technology Data Exchange (ETDEWEB)

Anemone, Annasofia; Consolino, Lorena [Universita degli Studi di Torino, Dipartimento di Biotecnologie Molecolari e Scienze per la Salute, Torino (Italy); Longo, Dario Livio [Universita degli Studi di Torino, Istituto di Biostrutture e Bioimmagini (CNR) c/o Centro di Biotecnologie Molecolari, Torino (Italy)

2017-05-15

X-ray iodinated contrast media have been shown to generate contrast in MR images when used with the chemical exchange saturation transfer (CEST) approach. The aim of this study is to compare contrast enhancement (CE) capabilities and perfusion estimates between radiographic molecules and a Gd-based contrast agent in two tumour murine models with different vascularization patterns. MRI-CEST and MRI-CE T{sub 1w} images were acquired in murine TS/A and 4 T1 breast tumours upon sequential i.v. injection of iodinated contrast media (iodixanol, iohexol, and iopamidol) and of gadoteridol. The signal enhancements observed in the two acquisition modalities were evaluated using Pearson's correlation, and the correspondence in the spatial distribution was assessed by a voxelwise comparison. A significant, positive correlation was observed between iodinated contrast media and gadoteridol for tumour contrast enhancement and perfusion values for both tumour models (r = 0.51-0.62). High spatial correlations were observed in perfusion maps between iodinated molecules and gadoteridol (r = 0.68-0.86). Tumour parametric maps derived by iodinated contrast media and gadoteridol showed high spatial similarities. A good to strong spatial correlation between tumour perfusion parameters derived from MRI-CEST and MRI-CE modalities indicates that the two procedures provide similar information. (orig.)

Imaging angiogenesis.

Science.gov (United States)

Charnley, Natalie; Donaldson, Stephanie; Price, Pat

2009-01-01

There is a need for direct imaging of effects on tumor vasculature in assessment of response to antiangiogenic drugs and vascular disrupting agents. Imaging tumor vasculature depends on differences in permeability of vasculature of tumor and normal tissue, which cause changes in penetration of contrast agents. Angiogenesis imaging may be defined in terms of measurement of tumor perfusion and direct imaging of the molecules involved in angiogenesis. In addition, assessment of tumor hypoxia will give an indication of tumor vasculature. The range of imaging techniques available for these processes includes positron emission tomography (PET), dynamic contrast-enhanced magnetic resonance imaging (DCE-MRI), perfusion computed tomography (CT), and ultrasound (US).

Microbubble responses to a similar mechanical index with different real-time perfusion imaging techniques.

Science.gov (United States)

Porter, Thomas R; Oberdorfer, Joseph; Rafter, Patrick; Lof, John; Xie, Feng

2003-08-01

The purpose of this study was to determine differences in contrast enhancement and microbubble destruction rates with current commercially available low-mechanical index (MI) real-time perfusion imaging modalities. A tissue-mimicking phantom was developed that had vessels at 3 cm (near field) and 9 cm (far field) from a real-time transducer. Perfluorocarbon-exposed sonicated dextrose albumin microbubbles (PESDA) were injected proximal to a mixing chamber, and then passed through these vessels while the region was insonified with either pulses of alternating polarity with pulse inversion Doppler (PID) or pulses of alternating amplitude by power modulation (PM) at MIs of 0.1, 0.2 and 0.3. Effluent microbubble concentration, contrast intensity and the slope of digital contrast intensity vs. time were measured. Our results demonstrated that microbubble destruction already occurs with PID at an MI of 0.1. Contrast intensity seen with PID was less than with PM. Therefore, differences in contrast enhancement and microbubble destruction rates occur at a similar MI setting when using different real-time pulse sequence schemes.

Use of Contrast-Enhanced Ultrasound to Study Relationship between Serum Uric Acid and Renal Microvascular Perfusion in Diabetic Kidney Disease

Directory of Open Access Journals (Sweden)

Ling Wang

2015-01-01

Full Text Available Purpose. To investigate the relationship between uric acid and renal microvascular perfusion in diabetic kidney disease (DKD using contrast-enhanced ultrasound (CEUS method. Materials and Methods. 79 DKD patients and 26 healthy volunteers were enrolled. Renal function and urine protein markers were tested. DKD patients were subdivided into two groups including a normal serum uric acid (SUA group and a high SUA group. Contrast-enhanced ultrasound (CEUS was performed, and low acoustic power contrast-specific imaging was used for quantitative analysis. Results. Normal controls (NCs had the highest levels of AUC, AUC1, and AUC2. Compared to the normal SUA DKD group, high SUA DKD patients had significantly higher IMAX, AUC, and AUC1 (P<0.05. DKD patients with low urinary uric acid (UUA excretion had significantly higher AUC2 compared to DKD patients with normal UUA (P<0.05. Conclusion. Hyperuricemia in DKD patients was associated with a renal ultrasound image suggestive of microvascular hyperperfusion. The CEUS parameter AUC1 holds promise as an indicator for renal microvascular hyperperfusion, while AUC2 might be a useful indicator of declining glomerular filtration rate in DKD patients with decreased excretion of uric acid.

Automatic extraction of left ventricle in SPECT myocardial perfusion imaging

International Nuclear Information System (INIS)

Liu Li; Zhao Shujun; Yao Zhiming; Wang Daoyu

1999-01-01

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

Evaluation of myocardial involvement in Duchenne's progressive muscular dystrophy with thallium-201 myocardial perfusion imaging

International Nuclear Information System (INIS)

Kawai, Naoki; Sotobata, Iwao; Okada, Mitsuhiro

1985-01-01

Myocardial involvement in progressive muscular dystrophy of the Duchenne type was evaluated in 19 patients using thallium-201 myocardial perfusion imaging. A qualitative analysis was performed from five projection images by three experienced physicians. Distinct perfusion defects were shown in 13 patients, especially in the LV posterolateral or posterior wall (11 patients). There was no significant relationship between the presence of perfusion defects and the skeletal muscle involvements or thoracic deformities assessed by transmission computed tomography. Extensive perfusion defects were shown in 2 patients who died of congestive heart failure 1 to 2 years after the scintigraphic study. Progression of the myocardial scintigraphic abnormalities were considered to be minimal in 7 of 9 patients who underwent two serial scintigraphic studies over 2 to 3 years. It was concluded that thallium myocardial perfusion imaging is a useful clinical technique to assess myocardial involvement in Duchenne's progressive muscular dystrophy. (author)

High grade gilomas and solitary metastases: differentiation using perfusion MR imaging and spectroscopic MR imaging

International Nuclear Information System (INIS)

Law, M.; Cha, S.; Knopp, E.A.; Johnson, G.; Litt, A.W.

2002-01-01

Full text: To determine whether perfusion MRI (pMRI) and spectroscopic MR imaging (sMRI) can be used to differentiate high grade primary gliomas and solitary metastases on the basis of differences in vascularity and metabolite levels in the peritumoral. Fifty-one patients with a solitary brain tumor (33 gliomas, 18 metastases) underwent conventional MRI, contrast enhanced pMRI and sMRI before surgical resection or stereotactic biopsy. The peri-tumoral region is defined as the area within the white matter, immediately adjacent to the enhancing portion of the tumor (hyperintense on T2- weighted imaging but no enhancement on post-contrast T1-weighted imaging). Relative cerebral blood volume (rCBV) measurements were made in these regions from the pMRI data. Spectra from the enhancing tumor, the peritumoral region and normal brain, were obtained from the 2D multi-voxel CSI acquisition (TE = 135ms). The measured rCBV within the abnormal peritumoral region in highgrade gliomas and metastasis were 1.31 ± 0.97 (mean ± standard deviation) and 0.39 ± 0.19, respectively. The difference was statistically significant (p<0.0001). Spectroscopic imaging demonstrated elevated choline (Cho/Cr 2.28 ± 1.24) in the peritumoral region of gliomas but not in metastasis (Cho/Cr = 0.76 ± 0.23). The difference was again statistically significant (p 0.001), with Student's t-test. Although conventional imaging characteristics of solitary metastases and primary high grade gliomas may sometimes be similar, pMRI and sMRI are able to distinguish between the two, based on the rCBV and metabolite ratios within the peri-tumoral region. Copyright (2002) Blackwell Science Pty Ltd

Quantitative assessment of local perfusion change in acute intracerebral hemorrhage areas with and without "dynamic spot sign" using CT perfusion imaging.

Science.gov (United States)

Fu, Fan; Sui, Binbin; Liu, Liping; Su, Yaping; Sun, Shengjun; Li, Yingying

2018-01-01

Background Positive "dynamic spot sign" has been proven to be a potential risk factor for acute intracerebral hemorrhage (ICH) expansion, but local perfusion change has not been quantitatively investigated. Purpose To quantitatively evaluate perfusion changes at the ICH area using computed tomography perfusion (CTP) imaging. Material and Methods Fifty-three patients with spontaneous ICH were recruited. Unenhanced computed tomography (NCCT), CTP within 6 h, and follow-up NCCT were performed for 21 patients in the "spot sign"-positive group and 32 patients in the control group. Cerebral perfusion change was quantitatively measured on regional cerebral blood flow/regional cerebral blood volume (rCBF/rCBV) maps. Regions of interest (ROIs) were set at the "spot-sign" region and the whole hematoma area for "spot-sign"-positive cases, and at one of the highest values of three interested areas and the whole hematoma area for the control group. Hematoma expansion was determined by follow-up NCCT. Results For the "spot-sign"-positive group, the average rCBF (rCBV) values at the "spot-sign" region and the whole hematoma area were 21.34 ± 15.24 mL/min/100 g (21.64 ± 21.48 mL/100g) and 5.78 ± 6.32 mL/min/100 g (6.07 ± 5.45 mL/100g); for the control group, the average rCBF (rCBV) values at the interested area and whole hematoma area were 2.50 ± 1.83 mL/min/100 g (3.13 ± 1.96 mL/100g) and 3.02 ± 1.80 mL/min/100 g (3.40 ± 1.44 mL/100g), respectively. Average rCBF and rCBV values of the "spot-sign" region were significantly different from other regions ( P spot-sign"-positive and control groups were 25.24 ± 19.38 mL and -0.41 ± 1.34 mL, respectively. Conclusion The higher perfusion change at ICH on CTP images may reflect the contrast extravasation and be associated with the hematoma expansion.

Contrast-enhanced ultrasonography depicts small tumor vessels for the evaluation of pancreatic tumors

International Nuclear Information System (INIS)

Okamoto, Yuko; Kawamoto, Hirofumi; Takaki, Akinobu; Ishida, Etsuji; Ogawa, Tsuneyoshi; Kuwaki, Kenji; Kobayashi, Yoshiyuki; Sakaguchi, Kohsaku; Shiratori, Yasushi

2007-01-01

Objective: The aim of this study is to evaluate the efficacy of contrast-enhanced ultrasonography for the diagnosis of pancreatic tumors. Materials and methods: Contrast-enhanced ultrasonography with Levovist was performed on 62 consecutive patients (53 with pancreatic cancer, 4 with islet cell tumor, 3 with inflammatory pancreatic tumor, and 2 with metastatic tumor). The vascular and perfusion image phases of the tumors were evaluated and compared with the findings of contrast-enhanced computed tomography. Results: Contrast-enhanced ultrasonography showed tumor vessels around and/or in the tumor at the vascular image phase in 79% of pancreatic cancer patients (42/53). At the perfusion image phase, 96% of pancreatic cancers (51/53) were classified as hypo-enhancement type. However, tiny spotty or irregular heterogeneous enhanced lesions were found in 84% of hypo-enhanced pancreatic cancer patients (43/51). The presence of small vessels at the vascular image phase was closely correlated with the presence of these intratumor regional enhanced lesions at the perfusion image phase (κ coefficient = 0.42). The sensitivity of contrast-enhanced ultrasonography (100%) for pancreatic cancer was superior to that of contrast-enhanced computed tomography (91%), but no significant difference was observed between the two (McNemar test: p = 0.063). Conclusion: Contrast-enhanced ultrasonography with Levovist successfully visualizes fine vessels and enhancement in pancreatic tumors, and is useful for evaluating pancreatic tumors

The clinical application of SPECT myocardial perfusion imaging with 99mTc-MIBI

International Nuclear Information System (INIS)

Dong Weiyu

1992-01-01

This paper reported 182 SPECT myocardial perfusion images with China made 99m Tc-MIBI and were compared with ECG and UCG. The sensitivity of SPECT in ischemic were 91.2% and was higher than ECG (74.9%)and UCG (61.8%) (P < 0.01). And its specificity, accuracy and positive predictive rate were 78.3%, 90% and 97% respectively. Besides 9 cases have reverse distribution after exercise and rest images. In some ICD patients had shown their SPECT images, the perfusion defects in exercise as well as in rest image

Whole-organ perfusion of the pancreas using dynamic volume CT in patients with primary pancreas carcinoma: acquisition technique, post-processing and initial results

International Nuclear Information System (INIS)

Kandel, Sonja; Kloeters, Christian; Meyer, Henning; Hein, Patrick; Rogalla, Patrik; Hilbig, Andreas

2009-01-01

The purpose of this study was to evaluate a whole-organ perfusion protocol of the pancreas in patients with primary pancreas carcinoma and to analyse perfusion differences between normal and diseased pancreatic tissue. Thirty patients with primary pancreatic malignancy were imaged on a 320-slice CT unit. Twenty-nine cancers were histologically proven. CT data acquisition was started manually after contrast-material injection (8 ml/s, 350 mg iodine/ml) and dynamic density measurements in the right ventricle. After image registration, perfusion was determined with the gradient-relationship technique and volume regions-of-interest were defined for perfusion measurements. Contrast time-density curves and perfusion maps were generated. Statistical analysis was performed using the Kolmogorov-Smirnov test for analysis of normal distribution and Kruskal-Wallis test (nonparametric ANOVA) with Bonferroni correction for multiple stacked comparisons. In all 30 patients the entire pancreas was imaged, and registration could be completed in all cases. Perfusion of pancreatic carcinomas was significantly lower than of normal pancreatic tissue (P < 0.001) and could be visualized on colored perfusion maps. The 320-slice CT allows complete dynamic visualization of the pancreas and enables calculation of whole-organ perfusion maps. Perfusion imaging carries the potential to improve detection of pancreatic cancers due to the perfusion differences. (orig.)

Contrast-enhanced MRI of the lung

International Nuclear Information System (INIS)

Kauczor, Hans-Ulrich; Kreitner, Karl-Friedrich

2000-01-01

The lung has long been neglected by MR imaging. This is due to unique intrinsic difficulties: (1) signal loss due to cardiac pulsation and respiration; (2) susceptibility artifacts caused by multiple air-tissue interfaces; (3) low proton density. There are many MR strategies to overcome these problems. They consist of breath-hold imaging, respiratory and cardiac gating procedures, use of short repetition and echo times, increase of the relaxivity of existing spins by administration of intravenous contrast agents, and enrichment of spin density by hyperpolarized noble gases or oxygen. Improvements in scanner performance and frequent use of contrast media have increased the interest in MR imaging and MR angiography of the lung. They can be used on a routine basis for the following indications: characterization of pulmonary nodules, staging of bronchogenic carcinoma, in particular assessment of chest wall invasion; evaluation of inflammatory activity in interstitial lung disease; acute pulmonary embolism, chronic thromboembolic pulmonary hypertension, vascular involvement in malignant disease; vascular abnormalities. Future perspectives include perfusion imaging using extracellular or intravascular (blood pool) contrast agents and ventilation imaging using inhalation of hyperpolarized noble gases, of paramagnetic oxygen or of aerosolized contrast agents. These techniques represent new approaches to functional lung imaging. The combination of visualization of morphology and functional assessment of ventilation and perfusion is unequalled by any other technique

Development of a practical image-based scatter correction method for brain perfusion SPECT: comparison with the TEW method

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Shidahara, Miho; Kato, Takashi; Kawatsu, Shoji; Yoshimura, Kumiko; Ito, Kengo [National Center for Geriatrics and Gerontology Research Institute, Department of Brain Science and Molecular Imaging, Obu, Aichi (Japan); Watabe, Hiroshi; Kim, Kyeong Min; Iida, Hidehiro [National Cardiovascular Center Research Institute, Department of Investigative Radiology, Suita (Japan); Kato, Rikio [National Center for Geriatrics and Gerontology, Department of Radiology, Obu (Japan)

2005-10-01

An image-based scatter correction (IBSC) method was developed to convert scatter-uncorrected into scatter-corrected SPECT images. The purpose of this study was to validate this method by means of phantom simulations and human studies with {sup 99m}Tc-labeled tracers, based on comparison with the conventional triple energy window (TEW) method. The IBSC method corrects scatter on the reconstructed image I{sub AC}{sup {mu}}{sup b} with Chang's attenuation correction factor. The scatter component image is estimated by convolving I{sub AC}{sup {mu}}{sup b} with a scatter function followed by multiplication with an image-based scatter fraction function. The IBSC method was evaluated with Monte Carlo simulations and {sup 99m}Tc-ethyl cysteinate dimer SPECT human brain perfusion studies obtained from five volunteers. The image counts and contrast of the scatter-corrected images obtained by the IBSC and TEW methods were compared. Using data obtained from the simulations, the image counts and contrast of the scatter-corrected images obtained by the IBSC and TEW methods were found to be nearly identical for both gray and white matter. In human brain images, no significant differences in image contrast were observed between the IBSC and TEW methods. The IBSC method is a simple scatter correction technique feasible for use in clinical routine. (orig.)

Renal Cell Carcinoma Perfusion before and after Radiofrequency Ablation Measured with Dynamic Contrast Enhanced MRI: A Pilot Study.

Science.gov (United States)

Wah, Tze Min; Sourbron, Steven; Wilson, Daniel Jonathan; Magee, Derek; Gregory, Walter Martin; Selby, Peter John; Buckley, David L

2018-01-08

To investigate if the early treatment effects of radiofrequency ablation (RFA) on renal cell carcinoma (RCC) can be detected with dynamic contrast enhanced (DCE)-MRI and to correlate RCC perfusion with RFA treatment time. 20 patients undergoing RFA of their 21 RCCs were evaluated with DCE-MRI before and at one month after RFA treatment. Perfusion was estimated using the maximum slope technique at two independent sittings. Total RCC blood flow was correlated with total RFA treatment time, tumour location, size and histology. DCE-MRI examinations were successfully evaluated for 21 RCCs (size from 1.3 to 4 cm). Perfusion of the RCCs decreased significantly ( p measuring RCC perfusion before and after RFA. Perfusion significantly decreases in the zone of ablation, suggesting that it may be useful for the assessment of treatment efficacy. Pre-RFA RCC blood flow may be used to predict RFA treatment time.

Spectral imaging technique for retinal perfusion detection using confocal scanning laser ophthalmoscopy

Science.gov (United States)

Rasta, Seyed Hossein; Manivannan, Ayyakkannu; Sharp, Peter F.

2012-11-01

To evaluate retinal perfusion in the human eye, a dual-wavelength confocal scanning laser ophthalmoscope (cSLO) was developed that provides spectral imaging of the fundus using a combination of red (670 nm) and near-infrared (810 nm) wavelengths. The image of the ocular fundus was analyzed to find out if quantitative measurements of the reflectivity of tissue permit assessment of the oxygen perfusion of tissue. We explored problems that affect the reproducibility of patient measurements such as non-uniformity errors on the image. For the first time, an image processing technique was designed and used to minimize the errors of oxygen saturation measurements by illumination correction in retina wide field by increasing SNR. Retinal images were taken from healthy and diabetic retinopathy eyes using the cSLO with a confocal aperture of 100 μm. The ratio image (RI) of red/IR, as oxygen saturation (SO2) index, was calculated for normal eyes. The image correction technique improved the reproducibility of the measurements. Average RI intensity variation of healthy retina tissue was determined within a range of about 5.5%. The capability of the new technique to discriminate oxygenation levels of retinal artery and vein was successfully demonstrated and showed good promise in the diagnosis of the perfused retina.

Tc99m-sestamibi dosimetry in myocardial perfusion imaging

International Nuclear Information System (INIS)

Toledo, Janine M.; Trindade, Bruno M.; Campos, Tarcisio P.R.

2015-01-01

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

Laser speckle contrast imaging identifies ischemic areas on gastric tube reconstructions following esophagectomy.

Science.gov (United States)

Milstein, Dan M J; Ince, Can; Gisbertz, Suzanne S; Boateng, Kofi B; Geerts, Bart F; Hollmann, Markus W; van Berge Henegouwen, Mark I; Veelo, Denise P

2016-06-01

Gastric tube reconstruction (GTR) is a high-risk surgical procedure with substantial perioperative morbidity. Compromised arterial blood supply and venous congestion are believed to be the main etiologic factors associated with early and late anastomotic complications. Identifying low blood perfusion areas may provide information on the risks of future anastomotic leakage and could be essential for improving surgical techniques. The aim of this study was to generate a method for gastric microvascular perfusion analysis using laser speckle contrast imaging (LSCI) and to test the hypothesis that LSCI is able to identify ischemic regions on GTRs.Patients requiring elective laparoscopy-assisted GTR participated in this single-center observational investigation. A method for intraoperative evaluation of blood perfusion and postoperative analysis was generated and validated for reproducibility. Laser speckle measurements were performed at 3 different time pointes, baseline (devascularized) stomach (T0), after GTR (T1), and GTR at 20° reverse Trendelenburg (T2).Blood perfusion analysis inter-rater reliability was high, with intraclass correlation coefficients for each time point approximating 1 (P < 0.0001). Baseline (T0) and GTR (T1) mean blood perfusion profiles were highest at the base of the stomach and then progressively declined towards significant ischemia at the most cranial point or anastomotic tip (P < 0.01). After GTR, a statistically significant improvement in mean blood perfusion was observed in the cranial gastric regions of interest (P < 0.05). A generalized significant decrease in mean blood perfusion was observed across all GTR regions of interest during 20° reverse Trendelenburg (P < 0.05).It was feasible to implement LSCI intraoperatively to produce blood perfusion assessments on intact and reconstructed whole stomachs. The analytical design presented in this study resulted in good reproducibility of gastric perfusion measurements

Quantitative imaging by pixel-based contrast-enhanced ultrasound reveals a linear relationship between synovial vascular perfusion and the recruitment of pathogenic IL-17A-F+IL-23+ CD161+ CD4+ T helper cells in psoriatic arthritis joints.

Science.gov (United States)

Fiocco, Ugo; Stramare, Roberto; Martini, Veronica; Coran, Alessandro; Caso, Francesco; Costa, Luisa; Felicetti, Mara; Rizzo, Gaia; Tonietto, Matteo; Scanu, Anna; Oliviero, Francesca; Raffeiner, Bernd; Vezzù, Maristella; Lunardi, Francesca; Scarpa, Raffaele; Sacerdoti, David; Rubaltelli, Leopoldo; Punzi, Leonardo; Doria, Andrea; Grisan, Enrico

2017-02-01

To develop quantitative imaging biomarkers of synovial tissue perfusion by pixel-based contrast-enhanced ultrasound (CEUS), we studied the relationship between CEUS synovial vascular perfusion and the frequencies of pathogenic T helper (Th)-17 cells in psoriatic arthritis (PsA) joints. Eight consecutive patients with PsA were enrolled in this study. Gray scale CEUS evaluation was performed on the same joint immediately after joint aspiration, by automatic assessment perfusion data, using a new quantification approach of pixel-based analysis and the gamma-variate model. The set of perfusional parameters considered by the time intensity curve includes the maximum value (peak) of the signal intensity curve, the blood volume index or area under the curve, (BVI, AUC) and the contrast mean transit time (MTT). The direct ex vivo analysis of the frequencies of SF IL17A-F + CD161 + IL23 + CD4 + T cells subsets were quantified by fluorescence-activated cell sorter (FACS). In cross-sectional analyses, when tested for multiple comparison setting, a false discovery rate at 10%, a common pattern of correlations between CEUS Peak, AUC (BVI) and MTT parameters with the IL17A-F + IL23 + - IL17A-F + CD161 + - and IL17A-F + CD161 + IL23 + CD4 + T cells subsets, as well as lack of correlation between both peak and AUC values and both CD4 + T and CD4 + IL23 + T cells, was observed. The pixel-based CEUS assessment is a truly measure synovial inflammation, as a useful tool to develop quantitative imaging biomarker for monitoring target therapeutics in PsA.

Quantification de la perfusion rénale par échographie de contraste, une étude pilote

OpenAIRE

Schneider, A.

2013-01-01

Mise en perspective Le rein est un organe vital dont la fonction dépend en grande partie d'une perfusion tissulaire adéquate. Les techniques actuellement utilisées pour étudier la microcirculation rénale sont soit invasives soit très dispendieuses. L'échographie de contraste est une nouvelle technologie, non invasive, facile à réaliser au lit du malade et pour laquelle certaines techniques récemment présentées semblent permettre de quantifier la perfusion d'un organe. Une telle technique p...

Myocardial perfusion imaging in hyperthrophic cardiomyopathy

International Nuclear Information System (INIS)

Moorin, B.

1998-01-01

Full text: Patients with Hyperthrophic Cardiomyopathy (HCM) frequently suffer from syncope and cardiac arrest which may lead to sudden death. This is most often caused by ventricular arrhythmia's in adults, however in young patients the mechanisms are thought to be different. Ischaemia may play a significant role even in young asymptomatic HCM patients. The mechanisms of ischaemic development in HCM differ from those in the 'normal' myocardium (Due to intramural small vessel abnormalities and abnormal myocellular architecture). In HCM the coronary microcirculation is most often affected and massive hypertrophy means more energy is required to promote contraction thus increasing oxygen demand and compounding the effects of any ischaemic changes. A case of a 12 year old HCM patient is presented who has symptoms of syncope associated with exercise whose mother died suddenly of cardiac arrest developed from HCM. A myocardial perfusion rest/stress study was undertaken to detect any underlying myocardial ischaemia. Myocardial perfusion scintigraphy demonstrates any reduction in the microcirculation in addition to that present in the macrocirculation, unlike angiography which will only detect the latter. In this case the scan clearly showed evidence of ischaemia in the lateral wall and this may be an explanation for her episodes of syncope. We suggest an algorithm or the routine work-up of young patients with HCM which makes aggressive use of myocardial perfusion imaging to detect ischaemic changes. This may identify patients who are at higher risk and will assist with treatment decisions. We feel myocardial perfusion scintigraphy is a sensitive non-invasive accurate method of detecting microcirculatory ischaemia and is thus invaluable in HCM patients

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

International Nuclear Information System (INIS)

Hartmann, M.; Heiland, S.; Sartor, K.

2002-01-01

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

Adaptive statistical iterative reconstruction improves image quality without affecting perfusion CT quantitation in primary colorectal cancer

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D. Prezzi

Full Text Available Objectives: To determine the effect of Adaptive Statistical Iterative Reconstruction (ASIR on perfusion CT (pCT parameter quantitation and image quality in primary colorectal cancer. Methods: Prospective observational study. Following institutional review board approval and informed consent, 32 patients with colorectal adenocarcinoma underwent pCT (100 kV, 150 mA, 120 s acquisition, axial mode. Tumour regional blood flow (BF, blood volume (BV, mean transit time (MTT and permeability surface area product (PS were determined using identical regions-of-interests for ASIR percentages of 0%, 20%, 40%, 60%, 80% and 100%. Image noise, contrast-to-noise ratio (CNR and pCT parameters were assessed across ASIR percentages. Coefficients of variation (CV, repeated measures analysis of variance (rANOVA and Spearman’ rank order correlation were performed with statistical significance at 5%. Results: With increasing ASIR percentages, image noise decreased by 33% while CNR increased by 61%; peak tumour CNR was greater than 1.5 with 60% ASIR and above. Mean BF, BV, MTT and PS differed by less than 1.8%, 2.9%, 2.5% and 2.6% across ASIR percentages. CV were 4.9%, 4.2%, 3.3% and 7.9%; rANOVA P values: 0.85, 0.62, 0.02 and 0.81 respectively. Conclusions: ASIR improves image noise and CNR without altering pCT parameters substantially. Keywords: Perfusion imaging, Multidetector computed tomography, Colorectal neoplasms, Computer-assisted image processing, Radiation dosage

The clinical application value of myocardial perfusion imaging in evaluating coronary artery myocardial bridge patients with symptoms

International Nuclear Information System (INIS)

Wang Yuetao; Fu Ning; Ding Xuemei; Lu Cunzhi; Zhu Feng; Wang Guanmin; Huang Yijie; Wang Linguang

2008-01-01

Objective: Myocardial bridge is a common inborn coronary artery anomaly, myocardial bridge may be associated with myocardial ischemia. Only a few patients with coronary artery myocardial bridge were evaluated with nuclear medicine techniques. The aim of this study was to investigate the role of nuclear cardiology with myocardial perfusion technique in symptomatic myocardial bridge patients. Methods Nineteen myocardial bridge patients with the symptoms of chest pain and chest distress were analyzed retrospectively. 99 Tc m -methoxyisobutylisonitrile (MIBI) myocardial perfusion images (both exercise and rest) were performed in all. Imaging results were compared with the results of movement electrocardiogram (ECG) and coronary arteriography. The t test or χ 2 test was used to statistically analyze the data with Stata 7.0 software. Results: Of the 19 patients, 18 patients had myocardial bridge locating at the left anterior descending artery, 1 patient at the left anterior descending and left circumflex artery, the mean angiographic systolic occlusion within the myocardial bridge was (65.4 ± 22.1)%. Of these 19 patients, Exercise-rest 99 Tc m -MIBI myocardial perfusion imaging defined positive myocardial ischemia in 10 and negative in 9 patients. Of the 10 patients with 99 Tc m -MIBI myocardial perfusion imaging defined myocardial ischemia, 8 had reversible radioactive defect of partial anterior wall and (or) apex, 1 had reversible defect of post lateral wall and post septal wall, and 1 had reversible defect of inferior wall. The positive predictive value of myocardial perfusion imaging was 52.6% (10/19), which was higher than movement ECG [21.1% (4/19), χ 2 = 4.07, P 99 Tc m -MIBI myocardial periusion imaging defined myocardial ischemia. Six cases with Grade II stenosis, two were 99 Tc m -MIBI myocardial perfusion imaging defined myocardial ischemia. Eight cases with Grade III stenosis, seven were 99 Tc m -MIBI myocardial perfusion imaging defined myocardial

Quality of brain perfusion single-photon emission tomography images: multicentre evaluation using an anatomically accurate three-dimensional phantom

International Nuclear Information System (INIS)

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

1998-01-01

The aim of the study was to evaluate the quality of routine brain perfusion single-photon emission tomography (SPET) images in Finnish nuclear medicine laboratories. Twelve laboratories participated in the study. A three-dimensional high resolution brain phantom (Data Spectrum's 3D Hoffman Brain Phantom) was filled with a well-mixed solution of technetium-99m (110 MBq), water and detergent. Acquisition, reconstruction and printing were performed according to the clinical routine in each centre. Three nuclear medicine specialists blindly evaluated all image sets. The results were ranked from 1 to 5 (poor quality-high quality). Also a SPET performance phantom (Nuclear Associates' PET/SPECT Performance Phantom PS 101) was filled with the same radioactivity concentration as the brain phantom. The parameters for the acquisition, the reconstruction and the printing were exactly the same as with the brain phantom. The number of detected ''hot'' (from 0 to 8) and ''cold'' lesions (from 0 to 7) was visually evaluated from hard copies. Resolution and contrast were quantified from digital images. Average score for brain phantom images was 2.7±0.8 (range 1.5-4.5). The average diameter of the ''hot'' cylinders detected was 16 mm (range 9.2-20.0 mm) and that of the ''cold'' cylinders detected, 11 mm (5.9-14.3 mm) according to visual evaluation. Quantification of digital images showed that the hard copy was one reason for low-quality images. The quality of the hard copies was good only in four laboratories and was amazingly low in the others when comparing it with the actual structure of the brain phantom. The described quantification method is suitable for optimizing resolution and contrast detectability of hard copies. This study revealed the urgent need for external quality assurance of clinical brain perfusion SPET images. (orig.)

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

Science.gov (United States)

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

2013-07-01

Non-invasive pulsed arterial spin labeling (PASL) MRI is a method to study brain perfusion that does not require the administration of a contrast agent, which makes it a valuable diagnostic tool as it reduces cost and side effects. The purpose of the present study was to establish the viability of PASL as an alternative to dynamic susceptibility contrast (DSC-MRI) and other perfusion imaging methods in characterizing changes in perfusion patterns caused by seizures in epileptic patients. We evaluated 19 patients with PASL. Of these, the 9 affected by high-frequency seizures were observed during the peri-ictal period (within 5hours since the last seizure), while the 10 patients affected by low-frequency seizures were observed in the post-ictal period. For comparison, 17/19 patients were also evaluated with DSC-MRI and CBF/CBV. PASL imaging showed focal vascular changes, which allowed the classification of patients in three categories: 8 patients characterized by increased perfusion, 4 patients with normal perfusion and 7 patients with decreased perfusion. PASL perfusion imaging findings were comparable to those obtained by DSC-MRI. Since PASL is a) sensitive to vascular alterations induced by epileptic seizures, b) comparable to DSC-MRI for detecting perfusion asymmetries, c) potentially capable of detecting time-related perfusion changes, it can be recommended for repeated evaluations, to identify the epileptic focus, and in follow-up and/or therapy-response assessment. Copyright © 2013 Elsevier Inc. All rights reserved.

Quantitative evaluation of muscle perfusion with CEUS and with MR

International Nuclear Information System (INIS)

Weber, Marc-Andre; Delorme, Stefan; Krix, Martin

2007-01-01

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.)

Quantitative evaluation of muscle perfusion with CEUS and with MR

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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.)

Effects of smoking on lung uptake of 201Tl during exercise myocardial perfusion imaging

International Nuclear Information System (INIS)

Ouyang Wei; He Guorong; Liu Jinhua

2004-01-01

Objective: To investigate the influence of smoking on lung uptake of 201 Tl during myocardial perfusion imaging. Methods: Ninety-two healthy subjects, with normal 201 Tl myocardial perfusion imaging findings but no evidence of left ventricular hypertrophy and pulmonary disease, were divided into three groups, smoker, nonsmoker and quitted smoker groups. Exercise/delay 201 Tl myocardial perfusion imaging was performed on all subjects included. Lung/heart ratio was defined on the anterior planar image obtained during exercise tomography. Results: Both the lung/heart ratios during exercise in smoker (0.40 ± 0.07, F=10.635, P 201 Tl lung/heart ratios in smokers are higher than in nonsmokers and this must be kept in mind when 201 Tl lung/heart ratios are used clinically, even in quitted smokers

Toward fully automated processing of dynamic susceptibility contrast perfusion MRI for acute ischemic cerebral stroke.

Science.gov (United States)

Kim, Jinsuh; Leira, Enrique C; Callison, Richard C; Ludwig, Bryan; Moritani, Toshio; Magnotta, Vincent A; Madsen, Mark T

2010-05-01

We developed fully automated software for dynamic susceptibility contrast (DSC) MR perfusion-weighted imaging (PWI) to efficiently and reliably derive critical hemodynamic information for acute stroke treatment decisions. Brain MR PWI was performed in 80 consecutive patients with acute nonlacunar ischemic stroke within 24h after onset of symptom from January 2008 to August 2009. These studies were automatically processed to generate hemodynamic parameters that included cerebral blood flow and cerebral blood volume, and the mean transit time (MTT). To develop reliable software for PWI analysis, we used computationally robust algorithms including the piecewise continuous regression method to determine bolus arrival time (BAT), log-linear curve fitting, arrival time independent deconvolution method and sophisticated motion correction methods. An optimal arterial input function (AIF) search algorithm using a new artery-likelihood metric was also developed. Anatomical locations of the automatically determined AIF were reviewed and validated. The automatically computed BAT values were statistically compared with estimated BAT by a single observer. In addition, gamma-variate curve-fitting errors of AIF and inter-subject variability of AIFs were analyzed. Lastly, two observes independently assessed the quality and area of hypoperfusion mismatched with restricted diffusion area from motion corrected MTT maps and compared that with time-to-peak (TTP) maps using the standard approach. The AIF was identified within an arterial branch and enhanced areas of perfusion deficit were visualized in all evaluated cases. Total processing time was 10.9+/-2.5s (mean+/-s.d.) without motion correction and 267+/-80s (mean+/-s.d.) with motion correction on a standard personal computer. The MTT map produced with our software adequately estimated brain areas with perfusion deficit and was significantly less affected by random noise of the PWI when compared with the TTP map. Results of image

Brain perfusion imaging in amyotrophic lateral sclerosis with dementia

International Nuclear Information System (INIS)

Ishikawa, Takehisa; Morita, Mitsuya; Nakano, Imaharu

2007-01-01

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

Studies on the clinical application of MR perfusion image using arterial spin labeling method

International Nuclear Information System (INIS)

Miyasaka, Kenji

1999-01-01

A new technique for imaging brain perfusion, arterial spin labeling method was applied in clinic. Brain perfusion was imaged by FAIR and EPISTAR both of which using arterial spin labeling (ASL) method. Suitable parameters for small contamination were examined using a imaging phantom. Then normal volunteers were examined for imaging timing. Suitable time between labeling pulse and imaging pulse for brain capillary and parenchyma was 1.0 sec. For clinical application study, total 48 patients with brain diseases were examined by FAIR and/or EPISTAR. A lesion/white matter signal intensity ratio was calculated in all clinical cases. Average of signal intensity ratio in infarction, tumor and arteriovenous malformation (AVM) were 0.8, 2.2 and 18.6 at FAIR, and 0.6, 2.2 and 12.8 at EPISTAR, respectively. Low perfusion diseases such as cerebral infarction have low signal intensity ratio and high perfusion diseases such as AVM have high signal intensity ratio in both FAIR and EPISTAR. Brain lesions were imaged similarly in FAIR and EPISTAR, and no remarkable difference was found between FAIR and EPISTAR. As a result of diagnostic trial by signal intensity ratio in operated tumor, hemorrhagic cases could be diagnosed by accuracies of 75% in FAIR and 100% in EPISTAR, respectively. (author)

Adenosine stress and exercise 99Tcm-MIBI myocardial perfusion imaging in the diagnosis and risk stratification of patients with unstable angina

International Nuclear Information System (INIS)

Jia Peng; Guo Wanhua; Xu Shoulin; Feng Xuefeng

2008-01-01

Objective: The aim of this study was to evaluate the clinical value of adenosine stress or exercise 99 Tc m -methoxyisobutylisonitrile (MIBI) myocardial perfusion imaging in the diagnosis and risk stratification of patients with unstable angina. Methods: Eighty-seven hospitalized patients with unstable angina [54 men and 33 women, aged of (56.5±12.5) years] underwent adenosine stress or exercise myocardial perfusion imaging and coronary angiography. Patients were followed up. Results: Fifty-seven patients had abnormal myocardial perfusion imaging and significant coronary artery stenosis. Ten patients had abnormal myocardial perfusion imaging but normal coronary angiography. Eight patients had normal myocardial perfusion imaging but significant coronary artery stenosis. Twelve patients had normal myocardial perfusion imaging and normal coronary angiography. Patients with abnormal myocardial perfusion imaging had worse prognosis. There was relationship between cardiac events and the extent and severity of myocardial ischemia. Conclusion: Adenosine stress and exercise myocardial perfusion imaging is of important clinical value in the diagnosis and risk stratification of patients with unstable angina. (authors)

Functional MRI procedures in the diagnosis of brain tumors. Perfusion- and diffusion-weighted imaging; Funktionelle MR-Verfahren in der Diagnostik intraaxialer Hirntumoren. Perfusions- und Diffusions-Bildgebung

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Hartmann, M. [Universitaetsklinikum Heidelberg (Germany). Neurologische Klinik, Abteilung Neuroradiologie; Heiland, S.; Sartor, K.

2002-08-01

Despite the increased diagnostic accuracy of contrast material enhanced MR imaging, specification and grading of brain tumors are still only approximate at best: neither morphology, nor relaxation times or contrast material enhancement reliably predict tumor histology or tumor grade. As histology and tumor grade strongly influence which therapy concept is chosen, a more precise diagnosis is mandatory. With diffusion- and perfusion-weighted MR imaging (DWI, PWI) it is now possible to obtain important information regarding the cellular matrix and the relative regional cerebral blood volume (rrCBV) of brain tumors, which cannot be obtained with standard MR techniques. These dynamic-functional imaging techniques are very useful in the preoperative diagnosis of gliomas, lymphomas, and metastases, as well as in the differentiation of these neoplastic lesions from abscesses, atypical ischemic infarctions, and tumor-like manifestations of demyelinating disease. Additionally, they appear suitable for determining glioma grade and regions of active tumor growth which should be the target of stereotactic biopsy and therapy. After therapy these techniques are helpful to better assess the tumor response to therapy, possible therapy failure and therapy complications such as radiation necrosis. (orig.) [German] Die radiologische Diagnostik intraaxialer Hirntumoren ist durch die Magnetresonanztomographie (MRT) erheblich verbessert worden, besonders nach Einfuehrung der paramagnetischen Kontrastmittel. Mit konventionellen MR-Verfahren ist aber noch keine verlaessliche Unterscheidung zwischen Gliomen, Metastasen, primaeren Lymphomen und tumorsimulierenden entzuendlichen Erkrankungen moeglich. In dieser Hinsicht vielversprechend sind neue, funktionell-dynamische MR-Verfahren, mit denen sich nicht-invasiv die zerebrale Wasserdiffusion und Mikrozirkulation erfassen lassen und die eine bessere Gewebecharakterisierung erlauben als die herkoemmlichen MR-Methoden. Die Perfusions-MRT erfasst

Possibilities of contrast-free magnetic resonance perfusion imaging for the detection of early brain damage in essential hypertension

Directory of Open Access Journals (Sweden)

T. M. Ostroumova

2018-01-01

Full Text Available Arterial spin labeling (ASL is a promising non-invasive method to assess cerebral perfusion, which identifies a decrease in cerebral blood flow (CBF.Objective: to assess cerebral perfusion in middle-aged untreated patients with uncomplicated grade 1–2 hypertension compared to same-age healthy controls.Patients and methods. 33 patients with essential hypertension and 40 healthy individuals (a control group at the age of 40–59 years were examined. 24-hour blood pressure (BP monitoring and brain magnetic resonance imaging were performed in different modes (T1 MPRAGE, T2 TSE, T2 FLAIR, DTI, and ASL.Results. White matter hyperintensive changes were found in 7.5% of the healthy individuals and in 51.5% of the hypertensive patients (p = 0.0002. In hypertensive patients, CBF in the cortical plate of anterior frontal regions was significantly (p < 0.001 lower than that in the controls: right CBF, 39.1±5.6 and 45.8±3.2 ml/100 g/min, respectively; left CBF, 39.2±6.2 and 45.2±3.6 ml/100 g/min, respectively. In hypertensive patients with white matter hyperintensive changes, CBF was significantly lower than that in the controls: right CBF, 38.5±5.9 ml/100 g/min (p = 0.0001; left CBF, 39.2±6.7 ml/100 g/min (p = 0.002, and in those without these changes, right CBF was 39.5±5.1 ml/100 g/min (p = 0.0002; left CBF was 38.9±4.3 ml/100 g/min (p = 0.00002. Correlation analysis revealed significant inverse correlations of CBF with BP and systolic BP variability.Conclusion. Lower cerebral perfusion occurs in middle-aged untreated patients with uncomplicated grade 1–2 hypertension even in the absence of white matter hyperintensity foci. 

Dynamic Contrast-Enhanced Perfusion MRI of High Grade Brain Gliomas Obtained with Arterial or Venous Waveform Input Function.

Science.gov (United States)

Filice, Silvano; Crisi, Girolamo

2016-01-01

The aim of this study was to evaluate the differences in dynamic contrast-enhanced (DCE) magnetic resonance imaging (MRI) perfusion estimates of high-grade brain gliomas (HGG) due to the use of an input function (IF) obtained respectively from arterial (AIF) and venous (VIF) approaches by two different commercially available software applications. This prospective study includes 20 patients with pathologically confirmed diagnosis of high-grade gliomas. The data source was processed by using two DCE dedicated commercial packages, both based on the extended Toft model, but the first customized to obtain input function from arterial measurement and the second from sagittal sinus sampling. The quantitative parametric perfusion maps estimated from the two software packages were compared by means of a region of interest (ROI) analysis. The resulting input functions from venous and arterial data were also compared. No significant difference has been found between the perfusion parameters obtained with the two different software packages (P-value < .05). The comparison of the VIFs and AIFs obtained by the two packages showed no statistical differences. Direct comparison of DCE-MRI measurements with IF generated by means of arterial or venous waveform led to no statistical difference in quantitative metrics for evaluating HGG. However, additional research involving DCE-MRI acquisition protocols and post-processing would be beneficial to further substantiate the effectiveness of venous approach as the IF method compared with arterial-based IF measurement. Copyright © 2015 by the American Society of Neuroimaging.

Renal perfusion scintiscan

Science.gov (United States)

... Radionuclide renal perfusion scan; Perfusion scintiscan - renal; Scintiscan - renal perfusion Images Kidney anatomy Kidney - blood and urine flow Intravenous pyelogram References Rottenberg G, Andi AC. Renal ...

Added value of amide proton transfer imaging to conventional and perfusion MR imaging for evaluating the treatment response of newly diagnosed glioblastoma

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Park, Kye Jin; Kim, Ho Sung; Park, Ji Eun; Shim, Woo Hyun; Kim, Sang Joon [University of Ulsan College of Medicine, Asan Medical Center, Department of Radiology and Research Institute of Radiology, Seoul (Korea, Republic of); Smith, Seth A. [Vanderbilt University Institute of Imaging Science, Vanderbilt University, Department of Radiology and Radiological Sciences, Nashville, TN (United States)

2016-12-15

To determine the added value of amide proton transfer (APT) imaging to conventional and perfusion MRI for differentiating tumour progression (TP) from the treatment-related effect (TE) in patients with post-treatment glioblastomas. Sixty-five consecutive patients with enlarging contrast-enhancing lesions following concurrent chemoradiotherapy were assessed using contrast-enhanced T1-weighted MRI (CE-T1WI), 90th percentile histogram parameters of normalized cerebral blood volume (nCBV90) and APT asymmetry value (APT90). Diagnostic performance was determined using the area under the receiver operating characteristic curve (AUC) and cross validations. There were statistically significant differences in the mean APT90 between the TP and the TE groups (3.87-4.01 % vs. 1.38-1.41 %; P <.001). Compared with CE-T1WI alone, the addition of APT90 to CE-T1WI significantly improved cross-validated AUC from 0.58-0.74 to 0.89-0.91 for differentiating TP from TE. The combination of CE-T1WI, nCBV90 and APT90 resulted in greater diagnostic accuracy for differentiating TP from TE than the combination of CE-T1WI and nCBV90 (cross-validated AUC, 0.95-0.97 vs. 0.84-0.91). The inter-reader agreement between the expert and trainee was excellent for the measurements of APT90 (intraclass correlation coefficient, 0.94). Adding APT imaging to conventional and perfusion MRI improves the diagnostic performance for differentiating TP from TE. (orig.)

Preoperative localization of epileptic foci with SPECT brain perfusion imaging, electrocorticography, surgery and pathology

International Nuclear Information System (INIS)

Jia Shaowei; Xu Wengui; Chen Hongyan; Weng Yongmei; Yang Pinghua

2002-01-01

Objective: The value of preoperative localization of epileptic foci with SPECT brain perfusion imaging was investigated. Methods: The study population consisted of 23 patients with intractable partial seizures which was difficult to control with anticonvulsant for long period. In order to preoperatively locate the epileptic foci, double SPECT brain perfusion imaging was performed during interictal and ictal stage. The foci were confirmed with electrocorticography (EcoG), surgery and pathology. Results: The author checked with EcoG the foci shown by SPECT, 23 patients had all typical spike discharge. The regions of radioactivity increase in ictal matched with the abnormal electrical activity areas that EcoG showed. The spike wave originated in the corresponding cerebrum cortex instead of hyperplastic and adherent arachnoid or tumor itself. Conclusions: SPECT brain perfusion imaging contributes to distinguishing location, size, perfusion and functioning of epileptogenic foci, and has some directive function on to making out a treatment programme at preoperation

Correction of Non-Linear Propagation Artifact in Contrast-Enhanced Ultrasound Imaging of Carotid Arteries: Methods and in Vitro Evaluation.

Science.gov (United States)

Yildiz, Yesna O; Eckersley, Robert J; Senior, Roxy; Lim, Adrian K P; Cosgrove, David; Tang, Meng-Xing

2015-07-01

Non-linear propagation of ultrasound creates artifacts in contrast-enhanced ultrasound images that significantly affect both qualitative and quantitative assessments of tissue perfusion. This article describes the development and evaluation of a new algorithm to correct for this artifact. The correction is a post-processing method that estimates and removes non-linear artifact in the contrast-specific image using the simultaneously acquired B-mode image data. The method is evaluated on carotid artery flow phantoms with large and small vessels containing microbubbles of various concentrations at different acoustic pressures. The algorithm significantly reduces non-linear artifacts while maintaining the contrast signal from bubbles to increase the contrast-to-tissue ratio by up to 11 dB. Contrast signal from a small vessel 600 μm in diameter buried in tissue artifacts before correction was recovered after the correction. Copyright © 2015 World Federation for Ultrasound in Medicine & Biology. Published by Elsevier Inc. All rights reserved.

Hepatic perfusion disorders: a pictorial review of CT and MR imaging

International Nuclear Information System (INIS)

Yim, Nam Yeol; Jeong, Yong Yeon; Shin, Sang Soo; Song, Sang Gook; Lim, Hyo Soon; Heo, Suk Hee; Chang, Nam Kyu; Yoon, Woong; Kang, Heoung Keun; Lan, Shen Yu

2005-01-01

The liver has a unique dual blood supply through the portal vein and the hepatic artery. There are several communications between these two vessels under various conditions such as in hepatic tumors, trauma and liver cirrhosis, vascular compromise, among others. When vascular compromise occurs, this dual blood supply system can cause changes in the volume of blood flow in individual vessels or even in the direction of blood flow. With rapid image acquisition and increased resolution available in multislice CT and MR imaging, hepatic perfusion disorders are now more frequently encountered than in the past. Familiarity with imaging findings of these perfusion disorders will be helpful in characterizing focal hepatic lesions and will also help to avoid false positive diagnoses

Hepatic perfusion disorders: a pictorial review of CT and MR imaging

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Yim, Nam Yeol; Jeong, Yong Yeon; Shin, Sang Soo; Song, Sang Gook; Lim, Hyo Soon; Heo, Suk Hee; Chang, Nam Kyu; Yoon, Woong; Kang, Heoung Keun [Chonnam National University, Gwangju (Korea, Republic of); Lan, Shen Yu [Yan Bian Cancer Hospital, Peijing (China)

2005-09-15

The liver has a unique dual blood supply through the portal vein and the hepatic artery. There are several communications between these two vessels under various conditions such as in hepatic tumors, trauma and liver cirrhosis, vascular compromise, among others. When vascular compromise occurs, this dual blood supply system can cause changes in the volume of blood flow in individual vessels or even in the direction of blood flow. With rapid image acquisition and increased resolution available in multislice CT and MR imaging, hepatic perfusion disorders are now more frequently encountered than in the past. Familiarity with imaging findings of these perfusion disorders will be helpful in characterizing focal hepatic lesions and will also help to avoid false positive diagnoses.

Clinical applications of brain perfusion imaging with 99mTc-HM-PAO

International Nuclear Information System (INIS)

Lin Xiangtong

1989-01-01

200 patients with central nervous system diseases were studied with 99m Tc-HM-PAO and SPECT, including Parkinson's disease (PD) 47, Vascular headache 69, CVD 34, Epilepsy 26, Head truma 10, Brain tumor 5 and other 9 cases. Part of them have been compared with the results of MRI, X-CT and EEG. The positivity of SPECT in PD is 61.7% with decrease perfusion in local area of cerebram and basal ganglia and only 4 cases had lower perfusion in cerebellum; in headache is 46.4%, showing variable perfusion patterns; in CVD is 79.4% with decrease perfusion, luxury perfusion and the phenomenon of 'diaschsis'. In epilepsy, the abnormal foci mostly localize in temporal lobe and have close relation to the results of EEG. In brain tumor it also denotes decreased uptake of tracer. The clinicl singnificance of brain perfusion imaging with 99m Tc-HM-PAO was discussed

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

International Nuclear Information System (INIS)

Mathews, Marlon S.; Binder, Devin K.; Smith, Wade S.; Wintermark, Max; Dillon, William P.

2008-01-01

Postictal (''Todd's'') paralysis, or ''epileptic hemiplegia,'' is a well-known complication of focal or generalized epileptic seizures. However, it is unclear whether the pathophysiology of Todd's paralysis is related to alterations in cerebral perfusion. We report CT perfusion findings in a patient presenting with postictal aphasia and right hemiparesis. A 62-year-old woman with a history of alcohol abuse, closed head injury and posttraumatic epilepsy, presented with acute onset aphasia and right hemiparesis. A non-contrast head CT scan demonstrated no acute hemorrhage. Left hemispheric ischemia was suspected, and the patient was considered for acute thrombolytic therapy. MRI revealed a subtle increase in signal intensity involving the left medial temporal, hippocampal and parahippocampal regions on both T2-weighted FLAIR and diffusion-weighted sequences. CT angiography and CT perfusion study were performed. The CT perfusion study and CT angiography demonstrated a dramatic reduction in cerebral blood flow and blood volume involving the entire left hemisphere, but with relative symmetry of mean transit time, ruling out a large vessel occlusion. Clinical resolution of the aphasia and hemiparesis occurred within a few hours, and correlated with normalization of perfusion to the left hemisphere (detected by MR perfusion). This unique case is the first in which clinical evidence of Todd's paralysis has been correlated with reversible postictal hemispheric changes on CT and MR perfusion studies. This is important because CT perfusion study is being used more and more in the diagnosis of acute stroke, and one needs to be careful to not misinterpret the data. (orig.)

Quantitative myocardial perfusion PET parametric imaging at the voxel-level

International Nuclear Information System (INIS)

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

2015-01-01

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. (paper)

Diagnosis of Alzheimer's disease using brain perfusion SPECT and MR imaging: which modality achieves better diagnostic accuracy?

International Nuclear Information System (INIS)

Kubota, Takao; Ushijima, Yo; Yamada, Kei; Okuyama, Chio; Kizu, Osamu; Nishimura, Tsunehiko

2005-01-01

The purpose of this study was to compare the accuracy of MR imaging and brain perfusion single-photon emission tomography (SPECT) in diagnosing Alzheimer's disease (AD). The transaxial section display of brain perfusion SPECT, three-dimensional stereotactic surface projection (3D-SSP) SPECT image sets, thin-section MR imaging of the hippocampus and perfusion MR imaging were evaluated in 66 subjects comprising 35 AD patients and 31 subjects without AD. SPECT and MR imaging were visually interpreted by two experts and two novices, and the diagnostic ability of each modality was evaluated by receiver operating characteristic (ROC) analysis. In the experts' interpretations, there was no significant difference in the area under the ROC curve (A z ) between 3D-SSP and thin-section MR imaging, whereas the A z of transaxial SPECT display was significantly lower than that of 3D-SSP (3D-SSP: 0.97, thin-section MR imaging: 0.96, transaxial SPECT: 0.91), and the A z of perfusion MR imaging was lowest (0.63). The sensitivity and specificity of each modality were, respectively, 80.0% and 96.8% for 3D-SSP, 77.1% and 96.8% for thin-section MR imaging, 60.0% and 93.5% for transaxial SPECT display and 34.3% and 100% for perfusion MR imaging. In the novices' interpretations, the A z , sensitivity and specificity of 3D-SSP were superior to those of thin-section MR imaging. Thin-section hippocampal MR imaging and 3D-SSP image sets had potentially equivalent value for the diagnosis of AD, and they were superior to transaxial SPECT display and perfusion MR imaging. For avoidance of the effect of interpreters' experience on image evaluation, 3D-SSP appears to be optimal. (orig.)

Myocardial perfusion imaging for detection of silent myocardial ischemia

International Nuclear Information System (INIS)

Beller, G.A.

1988-01-01

Despite the widespread use of the exercise stress test in diagnosing asymptomatic myocardial ischemia, exercise radionuclide imaging remains useful for detecting silent ischemia in numerous patient populations, including those who are totally asymptomatic, those who have chronic stable angina, those who have recovered from an episode of unstable angina or an uncomplicated myocardial infarction, and those who have undergone angioplasty or received thrombolytic therapy. Studies show that thallium scintigraphy is more sensitive than exercise electrocardiography in detecting ischemia, i.e., in part, because perfusion defects occur more frequently than ST depression and before angina in the ischemic cascade. Thallium-201 scintigraphy can be performed to differentiate a true- from a false-positive exercise electrocardiographic test in patients with exercise-induced ST depression and no angina. The development of technetium-labeled isonitriles may improve the accuracy of myocardial perfusion imaging. 11 references

Assessment of hemodynamics in a rat model of liver cirrhosis with precancerous lesions using multislice spiral CT perfusion imaging.

Science.gov (United States)

Ma, Guolin; Bai, Rongjie; Jiang, Huijie; Hao, Xuejia; Ling, Zaisheng; Li, Kefeng

2013-01-01

To develop an optimal scanning protocol for multislice spiral CT perfusion (CTP) imaging to evaluate hemodynamic changes in liver cirrhosis with diethylnitrosamine- (DEN-) induced precancerous lesions. Male Wistar rats were randomly divided into the control group (n = 80) and the precancerous liver cirrhosis group (n = 40). The control group received saline injection and the liver cirrhosis group received 50 mg/kg DEN i.p. twice a week for 12 weeks. All animals underwent plain CT scanning, CTP, and contrast-enhanced CT scanning. Scanning parameters were optimized by adjusting the diatrizoate concentration, the flow rate, and the delivery time. The hemodynamics of both groups was further compared using optimized multislice spiral CTP imaging. High-quality CTP images were obtained with following parameters: 150 kV; 150 mAs; 5 mm thickness, 5 mm interval; pitch, 1; matrix, 512 × 512; and FOV, 9.6 cm. Compared to the control group, the liver cirrhosis group had a significantly increased value of the hepatic arterial fraction and the hepatic artery perfusion (P spiral CTP imaging can be used to evaluate the hemodynamic changes in the rat model of liver cirrhosis with precancerous lesions.

An attempt of thallium-201 myocardial perfusion imaging during transient coronary arterial occlusion by PTCA

International Nuclear Information System (INIS)

Nakagawa, Tatsuya; Sugihara, Hiroki; Katahira, Toshio

1989-01-01

To evaluate the myocardial perfusion during transient coronary occlusion, we attempted to obtain the myocardial scintigraphy during percutaneous transluminal coronary angioplasty (PTCA). Tl-201 was injected at the last inflation of angioplastic balloon and occlusion was kept on for 60 sec. Planar images or SPECT were obtained immediately after PTCA. With this protocol, myocardial perfusion defects were observed during PTCA and fully redistributed 3 hours after Tl injection. Extent of ischemic lesions were almost same as that observed during exercise in two cases without collateral vessels. In a case with well visualized collateral vessels, perfusion defect was smaller in PTCA images than that in exercise stressed images. We conclude that intravenous injection of Tl-201 during PTCA is useful to assess the alteration of myocardial perfusion due to transient coronary occlusion without increasing the risk of angioplastic procedure. (author)

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

Effect of radiographic contrast media on renal perfusion - First results.

Science.gov (United States)

Lamby, P; Jung, F; Falter, J; Mrowietz, C; Graf, S; Schellenberg, L; Platz Batista da Silva, N; Prantl, L; Franke, R P; Jung, E M

2016-01-01

Intra-arterial administration of radiographic contrast media (CM) is discussed to impair renal perfusion. The pathogenesis of contrast-induced Nephropathy (CIN) is still not clarified. This trial was performed to prove the effects of two CM with different molecular structure on renal perfusion. A prospective, randomized study on 16 pigs was designed to compare the outcome after application of a low-osmolar iodinated CM (770 mOsm/kg H2O - Group1) and an iso-osmolar iodinated CM (290 mOsm/kg H2o - Group2).Color Coded Doppler Sonography (LOGIQ E9, GE, Milwaukee, USA) was applied for measuring the Renal Resistive Index (RRI) before and after the first, fifth, and tenth bolus of CM. Statistics was performed using analysis of variance for repeated measurements with the Factor "CM". All flow spectra were documented free of artifacts and Peak Systolic Velocity (PSV), Enddiastolic Velocity (EDV) and RRI respectively could be calculated. Mean PSV in Group 1 led to a decrease while in Group 2 PSV showed a significant increase after CM (p = 0,042). The course of the mean EDV in both groups deferred accordingly (p = 0,033). Mean RRI over time significantly deferred in both groups (p = 0,001). It showed a biphasic course in Group 2 and a decrease over time in Group 2. While iso-osmolar CM induced an increase of PSV and EDV together with a decrease of RRI, low-osmolar CM could not show this effect or rather led to the opposite.

Evaluation of myocardial involvement in Duchenne progressive muscular dystrophy with thallium-201 myocardial perfusion imaging

International Nuclear Information System (INIS)

Kawai, Naoki; Yamamoto, Shuhei; Okada, Mitsuhiro

1983-01-01

Myocardial involvement in progressive muscular dystrophy of the Duchenne type was evaluated in 19 patients using thallium-201 myocardial perfusion imaging. The qualitative analysis was performed in anterior, 3 left anterior oblique and left lateral projection images by three experienced physicians. Distinct perfusion defects were shown in 13 patients, especially in LV posterolateral or posterior walls (11 patients). There was no significant relationship between the presence of perfusion defects and the skeletal muscle changes or thoracic deformities assessed by transmission computed tomography. Slightly increased thallium-201 activity in RV free wall and lungs was shown in nine and one patient, respectively. The extensive perfusion defects were shown in 2 patients who died of congestive heart failure 1 to 2 years after the scintigraphic study. The myocardial scintigraphic changes were considered to be minimal in 7 of 9 patients who underwent two serial scintigraphic studies in 2 to 3 years. It was concluded that the thallium myocardial perfusion imaging was a useful clinical technique to evaluate the cardiomyopathy in Duchenne progressive muscular dystrophy. (author)

Evaluation of myocardial involvement in Duchenne progressive muscular dystrophy with thallium-201 myocardial perfusion imaging

Energy Technology Data Exchange (ETDEWEB)

Kawai, Naoki; Yamamoto, Shuhei; Okada, Mitsuhiro (Nagoya Univ. (Japan). Faculty of Medicine)

1983-12-01

Myocardial involvement in progressive muscular dystrophy of the Duchenne type was evaluated in 19 patients using thallium-201 myocardial perfusion imaging. The qualitative analysis was performed in anterior, 3 left anterior oblique and left lateral projection images by three experienced physicians. Distinct perfusion defects were shown in 13 patients, especially in LV posterolateral or posterior walls (11 patients). There was no significant relationship between the presence of perfusion defects and the skeletal muscle changes or thoracic deformities assessed by transmission computed tomography. Slightly increased thallium-201 activity in RV free wall and lungs was shown in nine and one patient, respectively. The extensive perfusion defects were shown in 2 patients who died of congestive heart failure 1 to 2 years after the scintigraphic study. The myocardial scintigraphic changes were considered to be minimal in 7 of 9 patients who underwent two serial scintigraphic studies in 2 to 3 years. It was concluded that the thallium myocardial perfusion imaging was a useful clinical technique to evaluate the cardiomyopathy in Duchenne progressive muscular dystrophy.

Application of CT perfusion imaging in radiotherapy for lung cancer

International Nuclear Information System (INIS)

Xia Guangrong; Liu Guimei; He Wen; Jin Guohua; Xie Ruming; Xu Yongxiang; Li Xiaobo; Li Xuebing

2011-01-01

Objective: To investigate the value of CT perfusion imaging in evaluation of therapeutic effect and prognosis in radiotherapy for lung cancer. Methods: Fifty-one cases of lung cancer who were unable or refused to be operated on, 36 males and 15 females, aged 37-80, underwent CT perfusion imaging, 29 of which only before radiotherapy and 22 before and after radiotherapy twice. The images were collected by cine dynamic scanning (5 mm/4 slices) and input into the GE AW4.0 workstation for data processing. The slice positions of CT imaging were determined according to the largest tumor size in CT scan. Regions of interest of tumor were drawn at the region corresponding to the original images of CT perfusion. Radiotherapy was performed after CT perfusion imaging. Relevant parameters, including blood flow (BF), blood volume (BV), mean transit time (MTT), and permeability surface (PS) were calculated. The treatment response after radiotherapy was evaluated by RECIST. At 2 -4 weeks after the treatment, CT examination was conducted once more. Results: The tests of the 51 patients showed that the BV was 13.6 ml·100 g -1 , the BF was 129.5 ml·min -1 ·100 g -1 , the MTT was 9.1 s, and the PS was 10.0 ml· min -1 · 100 g -1 before radiotherapy. The tests of the 22 of the 51 patients showed that the values of BV and BF after radiotherapy were 7.6 ml· 100 g -1 and 97.8 ml·min -1 · 100 g -1 , respectively, both lower than those before radiotherapy (11.2 and 108.7 ml·min -1 ·100 g -1 , respectively), however, both not significantly (t=1.28, 0.40, P>0.05); and the values of MTT and PS after radiotherapy were 8.9 s and 7.8 ml·min -1 · 100 g -1 , respectively, both not significantly higher than those before radiotherapy (7.2 s and 6.8 ml· min -1 · 100 g -1 , respectively, t=-1.15, -0.57, P>0.05). The mean area of tumor after radiotherapy was 1189.6 mm 2 , significantly less than that before radiotherapy (1920.3 mm 2 , t=3.98, P<0.05). The MTT of the SCLC patients was 12

TU-A-9A-10: Verification of Photoacoustic Computed Tomography Perfusion Imaging Using DCE-CT

International Nuclear Information System (INIS)

Roth, A; Krutulis, M; Verleker, A; Stantz, K

2014-01-01

Purpose: We propose to verify quantifiable perfusion information generated by a Photoacoustic Computed Tomography (PCT) scanner using Dynamic Contrast-Enhanced CT (DCE-CT), and to investigate physicsbased models of acoustic properties of tissue and photon transport to improve quantification. These corrections first necessitate a skin identifying algorithms to reduce speed-of-sound blurring and empirical photon correction methods. Methods: Xenograft mice (n=5) of breast cancer was imaged using DCE-CT which was followed by DCE-PCT. To obtain CT perfusion data, each mouse was i.v. injected (0.2mL Isovue @0.5mL/min) and subsequent radio-opaque time curves fit to a 2-compartmental model on a voxel-wise basis. For DCE-PCT, different concentrations of ICG (250, 125, and 62.5 micro-Molar) were injected at the same rate, but also acquired at different sampling rates (3, 6, and 12 seconds). The time intensity curves from PCT were fit to a 1-compartmental model on a voxel by voxel basis. The images were coregistered (Oncentra) based on the structural similarities of the tumor vasculature after which we compared both the contrastenhanced dynamics and the vascular physiology. Results: Moderate to high doses of ICG impact the washin phase of the PCT contrast due to photon losses as a function of depth. A semi-automatic algorithm has been developed to identify the skin margin, and subsequent MC and empirical models of photon transport and variations in speed-of-sound are being evaluated. Conclusion: From our results we find that there is a need to apply photon and speed-of-sound corrections to our PCT data to improve the quantifiable image data at depth in the tumor for PCT. The dose and injection rate may help in reducing large systematic effects. Our project is partially funded by a NIH SBIR grant

Intravoxel incoehrent motion MR imaging in the head and neck: Correlation with dynamic contrast-enhanced MR imaging and diffusion-weighted imaging

Energy Technology Data Exchange (ETDEWEB)

Xu, Xiao Quan; Choi, Young Jun; Sung, Yu Sub; Jang, Seung Won; Park, Ji Eun; Heo, Young Jin; Beak, Jung Hwan; Lee, Jeong Hyun [Dept. of Radiology and Research Institute of Radiology, University of Ulsan College of Medicine, Asan Medical Center, Seoul (Korea, Republic of); Yoon, Ra Gyoung [Dept. of Radiology, Catholic Kwandong University International St. Mary' s Hospital, Catholic Kwandong University College of Medicine, Incheon (Korea, Republic of)

2016-09-15

To investigate the correlation between perfusion- and diffusion-related parameters from intravoxel incoherent motion (IVIM) and those from dynamic contrast-enhanced MR imaging (DCE-MRI) and diffusion-weighted imaging in tumors and normal muscles of the head and neck. We retrospectively enrolled 20 consecutive patients with head and neck tumors with MR imaging performed using a 3T MR scanner. Tissue diffusivity (D), pseudo-diffusion coefficient (D{sup *}), and perfusion fraction (f) were derived from bi-exponential fitting of IVIM data obtained with 14 different b-values in three orthogonal directions. We investigated the correlation between D, f, and D{sup *} and model-free parameters from the DCE-MRI (wash-in, T{sub max}, E{sub max}, initial AUC{sub 60}, whole AUC) and the apparent diffusion coefficient (ADC) value in the tumor and normal masseter muscle using a whole volume-of-interest approach. Pearson's correlation test was used for statistical analysis. No correlation was found between f or D{sup *} and any of the parameters from the DCE-MRI in all patients or in patients with squamous cell carcinoma (p > 0.05). The ADC was significantly correlated with D values in the tumors (p < 0.001, r = 0.980) and muscles (p = 0.013, r = 0.542), despite its significantly higher value than D. The difference between ADC and D showed significant correlation with f values in the tumors (p = 0.017, r = 0.528) and muscles (p = 0.003, r = 0.630), but no correlation with D{sup *} (p > 0.05, respectively). Intravoxel incoherent motion shows no significant correlation with model-free perfusion parameters derived from the DCE-MRI but is feasible for the analysis of diffusivity in both tumors and normal muscles of the head and neck.

Intravoxel Incoherent Motion MR Imaging in the Head and Neck: Correlation with Dynamic Contrast-Enhanced MR Imaging and Diffusion-Weighted Imaging

Energy Technology Data Exchange (ETDEWEB)

Xu, Xiao Quan [Department of Radiology and Research Institute of Radiology, University of Ulsan College of Medicine, Asan Medical Center, Seoul 05505 (Korea, Republic of); Department of Radiology, The First Affiliated Hospital of Nanjing Medical University, Nanjing 210029 (China); Choi, Young Jun; Sung, Yu Sub [Department of Radiology and Research Institute of Radiology, University of Ulsan College of Medicine, Asan Medical Center, Seoul 05505 (Korea, Republic of); Yoon, Ra Gyoung [Department of Radiology, Catholic Kwandong University International St. Mary' s Hospital, Catholic Kwandong University College of Medicine, Incheon 22711 (Korea, Republic of); Jang, Seung Won; Park, Ji Eun [Department of Radiology and Research Institute of Radiology, University of Ulsan College of Medicine, Asan Medical Center, Seoul 05505 (Korea, Republic of); Heo, Young Jin [Department of Radiology and Research Institute of Radiology, University of Ulsan College of Medicine, Asan Medical Center, Seoul 05505 (Korea, Republic of); Department of Radiology, Busan Paik Hospital, Inje University College of Medicine, Busan 47392 (Korea, Republic of); Baek, Jung Hwan; Lee, Jeong Hyun [Department of Radiology and Research Institute of Radiology, University of Ulsan College of Medicine, Asan Medical Center, Seoul 05505 (Korea, Republic of)

2016-11-01

To investigate the correlation between perfusion- and diffusion-related parameters from intravoxel incoherent motion (IVIM) and those from dynamic contrast-enhanced MR imaging (DCE-MRI) and diffusion-weighted imaging in tumors and normal muscles of the head and neck. We retrospectively enrolled 20 consecutive patients with head and neck tumors with MR imaging performed using a 3T MR scanner. Tissue diffusivity (D), pseudo-diffusion coefficient (D{sup *}), and perfusion fraction (f) were derived from bi-exponential fitting of IVIM data obtained with 14 different b-values in three orthogonal directions. We investigated the correlation between D, f, and D{sup *} and model-free parameters from the DCE-MRI (wash-in, T{sub max}, E{sub max}, initial AUC{sub 60}, whole AUC) and the apparent diffusion coefficient (ADC) value in the tumor and normal masseter muscle using a whole volume-of-interest approach. Pearson's correlation test was used for statistical analysis. No correlation was found between f or D{sup *} and any of the parameters from the DCE-MRI in all patients or in patients with squamous cell carcinoma (p > 0.05). The ADC was significantly correlated with D values in the tumors (p < 0.001, r = 0.980) and muscles (p = 0.013, r = 0.542), despite its significantly higher value than D. The difference between ADC and D showed significant correlation with f values in the tumors (p = 0.017, r = 0.528) and muscles (p = 0.003, r = 0.630), but no correlation with D{sup *} (p > 0.05, respectively). Intravoxel incoherent motion shows no significant correlation with model-free perfusion parameters derived from the DCE-MRI but is feasible for the analysis of diffusivity in both tumors and normal muscles of the head and neck.

Intravoxel incoehrent motion MR imaging in the head and neck: Correlation with dynamic contrast-enhanced MR imaging and diffusion-weighted imaging

International Nuclear Information System (INIS)

Xu, Xiao Quan; Choi, Young Jun; Sung, Yu Sub; Jang, Seung Won; Park, Ji Eun; Heo, Young Jin; Beak, Jung Hwan; Lee, Jeong Hyun; Yoon, Ra Gyoung

2016-01-01

To investigate the correlation between perfusion- and diffusion-related parameters from intravoxel incoherent motion (IVIM) and those from dynamic contrast-enhanced MR imaging (DCE-MRI) and diffusion-weighted imaging in tumors and normal muscles of the head and neck. We retrospectively enrolled 20 consecutive patients with head and neck tumors with MR imaging performed using a 3T MR scanner. Tissue diffusivity (D), pseudo-diffusion coefficient (D * ), and perfusion fraction (f) were derived from bi-exponential fitting of IVIM data obtained with 14 different b-values in three orthogonal directions. We investigated the correlation between D, f, and D * and model-free parameters from the DCE-MRI (wash-in, T max , E max , initial AUC 60 , whole AUC) and the apparent diffusion coefficient (ADC) value in the tumor and normal masseter muscle using a whole volume-of-interest approach. Pearson's correlation test was used for statistical analysis. No correlation was found between f or D * and any of the parameters from the DCE-MRI in all patients or in patients with squamous cell carcinoma (p > 0.05). The ADC was significantly correlated with D values in the tumors (p < 0.001, r = 0.980) and muscles (p = 0.013, r = 0.542), despite its significantly higher value than D. The difference between ADC and D showed significant correlation with f values in the tumors (p = 0.017, r = 0.528) and muscles (p = 0.003, r = 0.630), but no correlation with D * (p > 0.05, respectively). Intravoxel incoherent motion shows no significant correlation with model-free perfusion parameters derived from the DCE-MRI but is feasible for the analysis of diffusivity in both tumors and normal muscles of the head and neck

Contrast-enhanced harmonic endoscopic ultrasound

DEFF Research Database (Denmark)

Săftoiu, A; Dietrich, C F; Vilmann, P

2012-01-01

Second-generation intravenous blood-pool ultrasound contrast agents are increasingly used in endoscopic ultrasound (EUS) for characterization of microvascularization, differential diagnosis of benign and malignant focal lesions, and improving staging and guidance of therapeutic procedures. Although...... initially used as Doppler signal enhancers, second-generation microbubble contrast agents are now used with specific contrast harmonic imaging techniques, which benefit from the highly nonlinear behavior of the microbubbles. Contrast-specific modes based on multi-pulse technology are used to perform...... contrast-enhanced harmonic EUS based on a very low mechanical index (0.08 - 0.12). Quantification techniques based on dynamic contrast-enhanced ultrasound have been recommended for perfusion imaging and monitoring of anti-angiogenic treatment, mainly based on time-intensity curve analysis. Most...

Assessment of femoral head perfusion by dynamic MR imaging

International Nuclear Information System (INIS)

Ochi, Ryuya; Nakano, Tetsuo; Miyazono, Kazuki; Tsurugami, Hiroshi; Fukuda, Tomohiro; Inaba, Daisuke; Takada, Koji

2004-01-01

We studied femoral head perfusion in 21 femoral neck fractures using dynamic MR imaging (MRI) between November 2001 and July 2002. MRI patterns divided into four groups when the results between the fractured side and unaffected side were compared. Femoral head perfusion at the fractured side was normal in Type A, about half in Type B, and absent in Type C. When perfusion at both the fractured side and unaffected side was absent, Exceptional Type was suspected. The Garden I group consisted of one Type B. The Garden II group consisted of one Type A, six Type B, one Type C, and two Exceptional Type. The Garden III group consisted of two Type B and one Type C, and the Garden IV group consisted of six Type C and one Exceptional Type. Post operations of by internal fixation confirmed the incidence of aseptic necrosis using MRI. (author)

Measurement of left ventricular ejection fraction using gated 99mTc-sestamibi myocardial planar images: Comparison to contrast ventriculography

International Nuclear Information System (INIS)

Parker, D.A.; Lloret, R.L.; Barilla, F.; Douthat, L.; Gheorghiade, M.

1991-01-01

Using the new myocardial perfusion agent 99mTc-sestamibi and multigated acquisition on a nuclear medicine gamma camera, the left ventricular ejection fraction (LVEF) was derived in 13 patients with coronary artery disease (CAD). Cross-sectional activity profiles were used to measure the left ventricle from end-diastolic and end-systolic images. Several different geometric methods were then utilized to derive ejection fractions from the nuclear data. Comparison of the resultant ejection fractions to those obtained from contrast ventriculography showed significant correlation for all geometric methods (P less than 0.01, Sy X x = 6.2 to 9.6). The authors conclude that in patients with CAD one or more of these simple geometric methods can provide a useful estimate of the LVEF when performing 99mTc-sestamibi multigated myocardial perfusion imaging