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MR perfusion

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https://www.readbyqxmd.com/read/28077268/development-of-high-resolution-3d-hyperpolarized-carbon-13-mr-molecular-imaging-techniques
#1
Eugene Milshteyn, Cornelius von Morze, Galen D Reed, Hong Shang, Peter J Shin, Zihan Zhu, Hsin-Yu Chen, Robert Bok, Andrei Goga, John Kurhanewicz, Peder E Z Larson, Daniel B Vigneron
The goal of this project was to develop and apply techniques for T2 mapping and 3D high resolution (1.5 mm isotropic; 0.003 cm(3)) (13)C imaging of hyperpolarized (HP) probes [1-(13)C]lactate, [1-(13)C]pyruvate, [2-(13)C]pyruvate, and [(13)C,(15)N2]urea in vivo. A specialized 2D bSSFP sequence was implemented on a clinical 3T scanner and used to obtain the first high resolution T2 maps of these different hyperpolarized compounds in both rats and tumor-bearing mice. These maps were first used to optimize timings for highest SNR for single time-point 3D bSSFP acquisitions with a 1...
January 7, 2017: Magnetic Resonance Imaging
https://www.readbyqxmd.com/read/28075625/unenhanced-and-contrast-enhanced-mr-angiography-and-perfusion-imaging-for-suspected-pulmonary-thromboembolism
#2
Yoshiharu Ohno, Takeshi Yoshikawa, Yuji Kishida, Shinichiro Seki, Nevzat Karabulut
OBJECTIVE: This article discusses the basics of unenhanced MR angiography (MRA) and MR venography (MRV), time-resolved contrast-enhanced (CE) MRA and dynamic first-pass CE perfusion MRI, and unenhanced and CE MRV, in addition to assessing the clinical relevance of these techniques for evaluating patients with suspected pulmonary thromboembolism and deep venous thrombosis. CONCLUSION: Since the 1990s, the efficacy of MRA or MRV and dynamic perfusion MRI for patients with suspected pulmonary thromboembolism and deep venous thrombosis has been evaluated...
January 11, 2017: AJR. American Journal of Roentgenology
https://www.readbyqxmd.com/read/28061488/the-use-of-mr-perfusion-imaging-in-the-evaluation-of-tumor-progression-in-gliomas
#3
Brian Snelling, Ashish H Shah, Simon Buttrick, Ronald Benveniste
OBJECTIVE: Diagnosing tumor progression and pseudoprogression remains challenging for many clinicians. Accurate recognition of these findings remains paramount given necessity of prompt treatment. However, no consensus has been reached on the optimal technique to discriminate tumor progression. We sought to investigate the role of magnetic resonance perfusion (MRP) to evaluate tumor progression in glioma patients. METHODS: An institutional retrospective review of glioma patients undergoing MRP with concurrent clinical follow up visit was performed...
January 1, 2017: Journal of Korean Neurosurgical Society
https://www.readbyqxmd.com/read/28058674/quantitative-myocardial-blood-flow-imaging-with-integrated-time-of-flight-pet-mr
#4
Tanja Kero, Jonny Nordström, Hendrik J Harms, Jens Sörensen, Håkan Ahlström, Mark Lubberink
BACKGROUND: The use of integrated PET-MR offers new opportunities for comprehensive assessment of cardiac morphology and function. However, little is known on the quantitative accuracy of cardiac PET imaging with integrated time-of-flight PET-MR. The aim of the present work was to validate the GE Signa PET-MR scanner for quantitative cardiac PET perfusion imaging. Eleven patients (nine male; mean age 59 years; range 46-74 years) with known or suspected coronary artery disease underwent (15)O-water PET scans at rest and during adenosine-induced hyperaemia on a GE Discovery ST PET-CT and a GE Signa PET-MR scanner...
December 2017: EJNMMI Physics
https://www.readbyqxmd.com/read/28048079/mo-de-207b-02-assessment-and-localization-of-aggressiveness-in-prostate-cancer-using-dynamic-contrast-enhanced-mri
#5
N A Parra, F Chinea, S Punnen, M Abramowitz, A Pollack, R Stoyanova
PURPOSE: To automatically assess prostate cancer aggressiveness and to map areas of high risk based on quantitative features from Dynamic Contrast Enhanced-MRI (DCE-MRI). METHODS: Fifty-seven patients with DCE-MRI acquired on 3T Discovery MR750 GE were retrospectively analyzed. Prostate, peripheral zone (PZ) and gluteus maximus (DCEGM) were manually contoured. Unsupervised pattern recognition was used to decompose the DCE data in prostate as the product W.H of k weight maps W and k patterns H, k=3...
June 2016: Medical Physics
https://www.readbyqxmd.com/read/28047611/su-f-r-48-early-prediction-of-pathological-response-of-locally-advanced-rectal-cancer-using-perfusion-ct-a-prospective-clinical-study
#6
K Nie, L Shi, N Yue, S Jabbour, S Kim, T Mao, L Qian, X Hu, X Sun, T Niu
PURPOSE: To prospectively evaluate the tumor vascularity assessed by perfusion CT for prediction of chemo-radiation treatment (CRT) response in locally advanced rectal cancer (LARC). METHODS: Eighteen consecutive patients (61.9±8.8 years, from March-June 2015) diagnosed with LARC who underwent 6-8 weeks CRT followed by surgery were included. The pre-treatment perfusion CT was acquired after a 5s delay of contrast agent injection for 45s with 1s interval. A total of 7-cm craniocaudal range covered the tumor region with 3-mm slice thickness...
June 2016: Medical Physics
https://www.readbyqxmd.com/read/28047334/su-f-j-02-flexible-training-of-mr-guided-laser-ablation-models-via-global-optimization
#7
S J Fahrenholtz, R J Stafford, R Madankan, J D Hazle, D Fuentes
PURPOSE: MR-guided laser ablation is currying interest in neurosurgery as a minimally invasive procedure. The procedure is planned via an assumed lesion overlaid on various anatomic and functional images. Computational models of heat transfer may further inform planning the intervention, reducing surgical morbidity and ensuring therapeutic effect. These models require physical parameter data, via less relevant literature values. Using commercialized laser ablation equipment combined with MR temperature imaging (MRTI) feedback, recent work has demonstrated the use of inverse problems as a means to gain the necessary information via retrospective analysis...
June 2016: Medical Physics
https://www.readbyqxmd.com/read/28046971/th-cd-206-01-expectation-maximization-algorithm-based-tissue-mixture-quantification-for-perfusion-mri
#8
H Han, Z Liang, L Li, L Xing
PURPOSE: To investigate the feasibility of estimating the tissue mixture perfusions and quantifying cerebral blood flow change in arterial spin labeled (ASL) perfusion MR images. METHODS: The proposed perfusion MR image analysis framework consists of 5 steps: (1) Inhomogeneity correction was performed on the T1- and T2-weighted images, which are available for each studied perfusion MR dataset. (2) We used the publicly available FSL toolbox to strip off the non-brain structures from the T1- and T2-weighted MR images...
June 2016: Medical Physics
https://www.readbyqxmd.com/read/28046902/su-d-207a-03-potential-role-of-bold-mri-in-discrimination-of-aggressive-tumor-habitat-in-prostate-cancer
#9
J Ford, C Lopez, Y Tschudi, A Breto, K Padgett, A Pollack, R Stoyanova
PURPOSE: To determine whether blood oxygenation level dependent (BOLD) MRI signal measured in prostate cancer patients, in addition to quantitative diffusion and perfusion parameters from multiparametric (mp)MRI exams, can help discriminate aggressive and/or radioresistant lesions. METHODS: Several ongoing clinical trials in our institution require mpMRI exam to determine eligibility (presence of identifiable tumor lesion on mpMRI) and prostate volumes for dose escalation...
June 2016: Medical Physics
https://www.readbyqxmd.com/read/28035425/myocardial-stress-perfusion-magnetic-resonance-initial-experience-in-a-pediatric-and-young-adult-population-using-regadenoson
#10
Cory V Noel, Ramkumar Krishnamurthy, Brady Moffett, Rajesh Krishnamurthy
BACKGROUND: Dipyridamole and adenosine are traditional pharmacological stressors for myocardial perfusion. Regadenoson, a selective adenosine A2A agonist, has a lower side effect profile with lower incidence of bronchospasm and bradycardia. There is a growing need for myocardial perfusion assessment within pediatrics. There is no report on the utility of regadenoson as a stress agent in children. OBJECTIVE: To observe the safety and feasibility of regadenoson as a pharmacologic stressor for perfusion cardiac MR in a pilot cohort of pediatric patients weighing more than 40 kg who have congenital heart disease and pediatric acquired heart disease...
December 29, 2016: Pediatric Radiology
https://www.readbyqxmd.com/read/28034995/effects-of-mri-protocol-parameters-preload-injection-dose-fractionation-strategies-and-leakage-correction-algorithms-on-the-fidelity-of-dynamic-susceptibility-contrast-mri-estimates-of-relative-cerebral-blood-volume-in-gliomas
#11
K Leu, J L Boxerman, B M Ellingson
BACKGROUND AND PURPOSE: DSC perfusion MR imaging assumes that the contrast agent remains intravascular; thus, disruptions in the blood-brain barrier common in brain tumors can lead to errors in the estimation of relative CBV. Acquisition strategies, including the choice of flip angle, TE, TR, and preload dose and incubation time, along with post hoc leakage-correction algorithms, have been proposed as means for combating these leakage effects. In the current study, we used DSC-MR imaging simulations to examine the influence of these various acquisition parameters and leakage-correction strategies on the faithful estimation of CBV...
December 29, 2016: AJNR. American Journal of Neuroradiology
https://www.readbyqxmd.com/read/28030891/impact-of-slow-blood-filling-via-collaterals-on-infarct-growth-comparison-of-mismatch-and-collateral-status
#12
Jeong Pyo Son, Mi Ji Lee, Suk Jae Kim, Jong-Won Chung, Jihoon Cha, Gyeong-Moon Kim, Chin-Sang Chung, Kwang Ho Lee, Oh Young Bang
Background and Purpose: Perfusion-diffusion mismatch has been evaluated to determine whether the presence of a target mismatch helps to identify patients who respond favorably to recanalization therapies. We compared the impact on infarct growth of collateral status and the presence of a penumbra, using magnetic resonance perfusion (MRP) techniques. Methods: Consecutive patients who were candidates for recanalization therapy and underwent serial diffusion-weighted imaging (DWI) and MRP were enrolled...
December 12, 2016: Journal of Stroke
https://www.readbyqxmd.com/read/28029273/mri-based-mismatch-detection-in-acute-ischemic-stroke-optimal-pwi-maps-and-thresholds-validated-with-pet
#13
Olivier Zaro-Weber, Walter Moeller-Hartmann, Dora Siegmund, Alexandra Kandziora, Alexander Schuster, Wolf-Dieter Heiss, Jan Sobesky
Perfusion-weighted (PW) magnetic resonance imaging (MRI) is used to detect penumbral tissue in acute stroke, but the selection of optimal PW-maps and thresholds for tissue at risk detection remains a matter of debate. We validated the performance of PW-maps with 15O-water-positron emission tomography (PET) in a large comparative PET-MR cohort of acute stroke patients. In acute and subacute stroke patients with back-to-back MRI and PET imaging, PW-maps were validated with 15O-water-PET. We pooled two different cerebral blood flow (CBF) PET-maps to define the critical flow (CF) threshold, (i) quantitative (q)CBF-PET with the CF threshold <20 ml/100 g/min and (ii) normalized non-quantitative (nq)CBF-PET with a CF threshold of <70% (corresponding to <20 ml/100 g/min according to a previously published normogram)...
January 1, 2016: Journal of Cerebral Blood Flow and Metabolism
https://www.readbyqxmd.com/read/28027754/correlation-between-intravoxel-incoherent-motion-mr-parameters-and-mr-nodular-grade-of-parotid-glands-in-patients-with-sj%C3%A3-gren-s-syndrome-a-pilot-study
#14
Chen Chu, Nan Zhou, Huayong Zhang, Xin Dou, Ming Li, Song Liu, Yun Zhu, Weibo Chen, Queenie Chan, Jian He, Lingyun Sun, Zhengyang Zhou
PURPOSE: To explore the correlation between intravoxel incoherent motion (IVIM) magnetic resonance (MR) parameters and MR nodular grade of parotid glands in patients with Sjögren's syndrome (SS). MATERIALS AND METHODS: A total of 31 consecutive patients with SS and 28 gender- and age-matched healthy volunteers underwent bilateral parotid 3.0T MR examination including the IVIM sequence (9 b values, 0-800s/mm(2)). The apparent diffusion coefficient (ADC), diffusion coefficient D, pseudo-diffusion coefficient D(*), and perfusion fraction f of bilateral parotid glands were obtained, and the nodular grade of each parotid gland was evaluated according to the MR morphological appearance...
January 2017: European Journal of Radiology
https://www.readbyqxmd.com/read/28019021/multiparametric-estimation-of-brain-hemodynamics-with-mr-fingerprinting-asl
#15
Pan Su, Deng Mao, Peiying Liu, Yang Li, Marco C Pinho, Babu G Welch, Hanzhang Lu
PURPOSE: Assessment of brain hemodynamics without exogenous contrast agents is of increasing importance in clinical applications. This study aims to develop an MR perfusion technique that can provide noncontrast and multiparametric estimation of hemodynamic markers. METHODS: We devised an arterial spin labeling (ASL) method based on the principle of MR fingerprinting (MRF), referred to as MRF-ASL. By taking advantage of the rich information contained in MRF sequence, up to seven hemodynamic parameters can be estimated concomitantly...
December 26, 2016: Magnetic Resonance in Medicine: Official Journal of the Society of Magnetic Resonance in Medicine
https://www.readbyqxmd.com/read/28007759/magnetic-resonance-perfusion-image-features-uncover-an-angiogenic-subgroup-of-glioblastoma-patients-with-poor-survival-and-better-response-to-antiangiogenic-treatment
#16
Tiffany T Liu, Achal S Achrol, Lex A Mitchell, Scott A Rodriguez, Abdullah Feroze, Christine Kim, Navjot Chaudhary, Olivier Gevaert, Josh M Stuart, Griffith R Harsh, Steven D Chang, Daniel L Rubin
BACKGROUND: In previous clinical trials, antiangiogenic therapies such as bevacizumab did not show efficacy in patients with newly diagnosed glioblastoma (GBM). This may be a result of the heterogeneity of GBM, which has a variety of imaging-based phenotypes and gene expression patterns. In this study, we sought to identify a phenotypic subtype of GBM patients who have distinct tumor-image features and molecular activities and who may benefit from antiangiogenic therapies. METHODS: Quantitative image features characterizing subregions of tumors and the whole tumor were extracted from preoperative and pretherapy perfusion magnetic resonance (MR) images of 117 GBM patients in 2 independent cohorts...
December 22, 2016: Neuro-oncology
https://www.readbyqxmd.com/read/28004976/perfusion-parameters-on-breast-dynamic-contrast-enhanced-mri-are-associated-with-disease-specific-survival-in-patients-with-triple-negative-breast-cancer
#17
Vivian Youngjean Park, Eun-Kyung Kim, Min Jung Kim, Jung Hyun Yoon, Hee Jung Moon
OBJECTIVE: The aim of this study was to investigate the association between perfusion parameters on MRI performed before treatment and survival outcome (disease-free survival [DFS], disease-specific survival [DSS]) in patients with triple-negative breast cancer (TNBC). MATERIALS AND METHODS: Sixty-one patients (median age, 50 years; age range, 27-77 years) with TNBC (tumor size on MRI: median, 25.5 mm; range, 11.0-142.0 mm) were included. We analyzed clinical and pathologic variables and MRI parameters...
December 22, 2016: AJR. American Journal of Roentgenology
https://www.readbyqxmd.com/read/28003419/47-year-old-female-with-an-apical-mass
#18
Jack Andrews, Christopher Ce Lang, Marc Dweck
CLINICAL INTRODUCTION: A 47-year-old female with no medical history presented with a sudden collapse. Physical examination, chest X-ray and high-sensitivity cardiac troponin I were normal, however ECG demonstrated anterior T-wave inversion. CT pulmonary angiography was performed which ruled out pulmonary embolism but revealed a non-calcified, homogenous mass at the left ventricular (LV) apex. It was not clear whether this mass was intramyocardial or pericardial. Transthoracic echocardiography confirmed the apical mass but was unable to establish its aetiology...
December 21, 2016: Heart: Official Journal of the British Cardiac Society
https://www.readbyqxmd.com/read/28000975/hypointense-vessels-detected-by-susceptibility-weighted-imaging-identifies-tissue-at-risk-of-infarction-in-anterior-circulation-stroke
#19
Bastian Cheng, Nikolaus Schröder, Nils Daniel Forkert, Peter Ludewig, André Kemmling, Tim Magnus, Jens Fiehler, Christian Gerloff, Götz Thomalla
BACKGROUND AND PURPOSE: The diagnostic value of susceptibility-weighted magnetic resonance imaging of acute stroke patients has shown potential as a surrogate marker of impaired hemodynamics. We investigate the value of asymmetrical hypointense cerebral vessels (HV) for the identification of vessel status and tissue at risk of infarction (TaR). METHODS: Symmetry of HV was visually rated on SWI data from a well-defined population of acute anterior circulation stroke with onset <24 hours...
December 21, 2016: Journal of Neuroimaging: Official Journal of the American Society of Neuroimaging
https://www.readbyqxmd.com/read/27999986/post-treatment-changes-of-tumour-perfusion-parameters-can-help-to-predict-survival-in-patients-with-high-grade-astrocytoma
#20
Roberto Sanz-Requena, Antonio J Revert-Ventura, Gracián García-Martí, Fares Salamé-Gamarra, Alexandre Pérez-Girbés, Enrique Mollá-Olmos, Luis Martí-Bonmatí
OBJECTIVES: Vascular characteristics of tumour and peritumoral volumes of high-grade gliomas change with treatment. This work evaluates the variations of T2*-weighted perfusion parameters as overall survival (OS) predictors. METHODS: Forty-five patients with histologically confirmed high-grade astrocytoma (8 grade III and 37 grade IV) were included. All patients underwent pre- and post-treatment T2*-weighted contrast-enhanced magnetic resonance (MR) imaging. Tumour, peritumoral and control volumes were segmented...
December 20, 2016: European Radiology
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