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MR perfusion

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https://www.readbyqxmd.com/read/28534163/differentiating-metastatic-from-nonmetastatic-lymph-nodes-in-cervical-cancer-patients-using-monoexponential-biexponential-and-stretched-exponential-diffusion-weighted-mr-imaging
#1
Qingxia Wu, Dandan Zheng, Ligang Shi, Mingbo Liu, Meiyun Wang, Dapeng Shi
OBJECTIVES: To determine the diagnostic value of monoexponential, biexponential and stretched exponential models for identifying lymph nodes (LNs) in patients with cervical cancer. MATERIALS AND METHODS: Fifty female patients with cervical cancer underwent preoperative magnetic resonance imaging. The diffusion parameters of the LNs were calculated by fitting the values to monoexponential, biexponential and stretched exponential models and were compared between the metastatic and non-metastatic LN groups...
May 22, 2017: European Radiology
https://www.readbyqxmd.com/read/28531213/perfusion-mr-imaging-detection-of-carcinoma-arising-from-preexisting-salivary-gland-pleomorphic-adenoma-by-computer-assisted-analysis-of-time-signal-intensity-maps
#2
Ikuo Katayama, Sato Eida, Shuichi Fujita, Yuka Hotokezaka, Misa Sumi, Takashi Nakamura
Tumor perfusion can be evaluated by analyzing the time-signal intensity curve (TIC) after dynamic contrast-enhanced (DCE) MR imaging. Accordingly, TIC profiles are characteristic of some benign and malignant salivary gland tumors. A carcinoma ex pleomorphic adenoma (CXPA) arises from a long-standing pleomorphic adenoma (PA) and has a distinctive prognostic risk depending on the tumor growth potential such as invasion beyond the preexisting capsule. Differentiating CXPA from PA can be very challenging. In this study, we have attempted to discriminate CXPA from PA based on a two-dimensional TIC mapping algorithm...
2017: PloS One
https://www.readbyqxmd.com/read/28523963/brain-hypoxia-mapping-in-acute-stroke-back-to-back-t2-mr-versus-18-f-fluoromisonidazole-pet-in-rodents
#3
Ulf Jensen-Kondering, Roido Mavanaki, Sohail Ejaz, Stephen J Sawiak, T Adrian Carpenter, Tim D Fryer, Franklin I Aigbirhio, David J Williamson, Jean-Claude Baron
Background Mapping the hypoxic brain in acute ischemic stroke has considerable potential for both diagnosis and treatment monitoring. PET using (18)F-fluoro-misonidazole (FMISO) is the reference method; however, it lacks clinical accessibility and involves radiation exposure. MR-based T2' mapping may identify tissue hypoxia and holds clinical potential. However, its validation against FMISO imaging is lacking. Here we implemented back-to-back FMISO-PET and T2' MR in rodents subjected to acute middle cerebral artery occlusion...
January 1, 2017: International Journal of Stroke: Official Journal of the International Stroke Society
https://www.readbyqxmd.com/read/28523351/severity-specific-alterations-in-cbf-oef-and-cmro2-in-cirrhotic-patients-with-hepatic-encephalopathy
#4
Gang Zheng, Hanzhang Lu, Wenkui Yu, Song Luo, Ya Liu, Wei Liu, Hui Liu, Long Wu, Lijuan Zheng, Xiang Kong, Long Jiang Zhang, Guang Ming Lu
OBJECTIVES: To assess how the severity of hepatic encephalopathy (HE) affects perfusion and metabolic changes in cirrhotic patients and the association between severity and liver disease and anemia. METHODS: The study groups comprised 31 healthy subjects and 33 cirrhotic patients who underwent MR examinations, and blood and neuropsychological tests. Of the cirrhotic patients, 14 were unaffected, and 11 had covert HE (CHE) and 8 overt HE (OHE). Global cerebral blood flow (CBF), oxygen extraction fraction (OEF), and metabolic rate of oxygen (CMRO2) were noninvasively measured by phase-contrast and T2-relaxation-under-spin-tagging MRI...
May 18, 2017: European Radiology
https://www.readbyqxmd.com/read/28522666/discrimination-between-glioma-grades-ii-and-iii-using-dynamic-susceptibility-perfusion-mri-a-meta-analysis
#5
Anna F Delgado, Alberto F Delgado
BACKGROUND: DSC perfusion has been evaluated in the discrimination between low-grade and high-grade glioma but the diagnostic potential to discriminate beween glioma grades II and III remains unclear. PURPOSE: Our aim was to evaluate the diagnostic accuracy of relative maximal CBV from DSC perfusion MR imaging to discriminate glioma grades II and III. DATA SOURCES: A systematic literature search was performed in PubMed/MEDLINE, Embase, Web of Science, and ClinicalTrials...
May 18, 2017: AJNR. American Journal of Neuroradiology
https://www.readbyqxmd.com/read/28516076/primary-central-nervous-system-vasculitis-mimicking-a-cortical-brain-tumor-a-case-report
#6
Joo-Seok Lee, Tae-Young Jung, Kyung-Hwa Lee, Seul-Kee Kim
We report a case of primary central nervous system vasculitis (PCNSV) mimicking a cortical brain tumor. A 25-year-old woman presented with a 2-week history of headache and transient right hemiparesis. Brain magnetic resonance imaging (MRI) revealed a cortical-involving lesion on the left frontal lobe. The 6-cm sized lesion showed low signal intensity on T1-weighted images and high signal intensity on T2-weighted images. The lesion had continual linear enhancement on the subcortical white matter and leptomeninges...
April 2017: Brain Tumor Research and Treatment
https://www.readbyqxmd.com/read/28515582/evaluation-of-mr-perfusion-abnormalities-in-organophosphorus-poisoning-and-its-correlation-with-spect
#7
K Uday Bhanu, Niranjan Khandelwal, Sameer Vyas, Paramjeet Singh, Anuj Prabhakar, B R Mittal, Ashish Bhalla
AIM: Acute organophosphate (OP) pesticide poisoning causes substantial morbidity and mortality worldwide. Many imaging modalities, such as computerized tomography (CT), magnetic resonance imaging (MRI), and single photon emission computed tomography (SPECT) of the brain, have been used for quantitative assessment of the acute brain insult caused by acute OP poisoning. Perfusion defects on SPECT in acutely poisoned patients with OPs have been described, however, MR perfusion abnormalities have not been described in the literature...
January 2017: Indian Journal of Radiology & Imaging
https://www.readbyqxmd.com/read/28515410/differentiating-between-central-nervous-system-lymphoma-and-high-grade-glioma-using-dynamic-susceptibility-contrast-and-dynamic-contrast-enhanced-mr-imaging-with-histogram-analysis
#8
Kazuhiro Murayama, Yuya Nishiyama, Yuichi Hirose, Masato Abe, Shigeharu Ohyu, Ayako Ninomiya, Takashi Fukuba, Kazuhiro Katada, Hiroshi Toyama
PURPOSE: We evaluated the diagnostic performance of histogram analysis of data from a combination of dynamic susceptibility contrast (DSC)-magnetic resonance imaging (MRI) and dynamic contrast-enhanced (DCE)-MRI for quantitative differentiation between central nervous system lymphoma (CNSL) and high-grade glioma (HGG), with the aim of identifying useful perfusion parameters as objective radiological markers for differentiating between them. METHODS: Eight lesions with CNSLs and 15 with HGGs who underwent MRI examination, including DCE and DSC-MRI, were enrolled in our retrospective study...
May 18, 2017: Magnetic Resonance in Medical Sciences: MRMS
https://www.readbyqxmd.com/read/28514733/role-of-intravoxel-incoherent-motion-mr-imaging-in-preoperative-assessing-her2-status-of-gastric-cancers
#9
Changfeng Ji, Qinglei Zhang, Wenxian Guan, Tingting Guo, Ling Chen, Song Liu, Jian He, Zhengyang Zhou
PURPOSE: To explore the role of intravoxel incoherent motion (IVIM) magnetic resonance (MR) imaging in evaluating human epidermal growth factor receptor 2 (HER2) status of gastric cancers preoperatively. RESULTS: The apparent diffusion coefficient (ADC) and pure diffusion coefficient (D) values correlated positively with HER2 scores of gastric cancers significantly (r = 0.276, P = 0.048; r = 0.481, P < 0.001, respectively). The ADC and D values of HER2 positive gastric cancers were significantly higher than those of HER2 negative tumors (P = 0...
May 2, 2017: Oncotarget
https://www.readbyqxmd.com/read/28507896/intraoperative-resection-control-using-arterial-spin-labeling-proof-of-concept-reproducibility-of-data-and-initial-results
#10
Thomas Lindner, Hajrullah Ahmeti, Isabel Lübbing, Michael Helle, Olav Jansen, Michael Synowitz, Stephan Ulmer
OBJECTIVES: Intraoperative magnetic resonance imaging is a unique tool for visualizing structures during resection and/or for updating any kind of neuronavigation that might be hampered as a result of brain shift during surgery. Advanced MRI techniques such as perfusion-weighted imaging have already proven to be important in the initial diagnosis preoperatively, but can also help to differentiate between tumor and surgically induced changes intraoperatively. Commonly used methods to visualize brain perfusion include contrast agent administration and are therefore somewhat limited...
2017: NeuroImage: Clinical
https://www.readbyqxmd.com/read/28501269/peak-enhancement-ratio-of-myocardium-to-aorta-for-identification-of-myocardial-ischemia-using-dynamic-myocardial-computed-tomography-perfusion-imaging
#11
Yuki Tanabe, Teruhito Kido, Akira Kurata, Takahiro Yokoi, Naoki Fukuyama, Teruyoshi Uetani, Hikaru Nishiyama, Naoto Kawaguchi, Enver Tahir, Masao Miyagawa, Teruhito Mochizuki
BACKGROUND: This study aimed to evaluate the feasibility of peak enhancement (PE) ratio of myocardium to aorta (PER) derived from stress dynamic computed tomography myocardial perfusion imaging (CTP) for the detection of myocardial ischemia assessed by magnetic resonance (MR) imaging. METHODS: Forty-four patients who underwent stress dynamic CTP and MR imaging were retrospectively evaluated. From the time-attenuation curve, myocardial PE, PER, and myocardial blood flow (MBF) were calculated on a segment-based analysis...
May 10, 2017: Journal of Cardiology
https://www.readbyqxmd.com/read/28500300/alterations-of-cerebral-perfusion-in-asymptomatic-internal-carotid-artery-steno-occlusive-disease
#12
Ya-Fang Chen, Sung-Chun Tang, Wen-Chau Wu, Hsien-Li Kao, Yen-Shu Kuo, Shun-Chung Yang
Patients with asymptomatic occlusion in the internal carotid arteries (ICA) have been shown to have a better preserved hemodynamic status of the brain as compared to patients with symptoms. This study was aimed to explore the cerebral perfusion alterations in asymptomatic patients using multi-parametric arterial spin-labeling (ASL) magnetic resonance (MR) imaging. Forty-two patients diagnosed with asymptomatic ICA stenosis/occlusion were prospectively included and divided into high-grade (ultrasonographic stenosis ≥70%, N = 20) and low-grade groups (N = 22)...
May 12, 2017: Scientific Reports
https://www.readbyqxmd.com/read/28500226/mr-perfusion-lesions-after-tia-or-minor-stroke-are-associated-with-new-infarction-at-7-days
#13
Jun Lee, Manabu Inoue, Michael Mlynash, Sharanpal K Mann, Carlo W Cereda, Michael Ke, Gregory W Albers, Jean M Olivot
OBJECTIVE: To investigate the relationship between acute perfusion-weighted imaging (PWI) lesions occurring within the first hours after a TIA or a minor brain infarction (BI) and the incidence of new BI detected on a systematic MRI at 1 week. METHODS: Consecutive patients who experienced a TIA or BI with a neurologic deficit that lasted <24 hours, did not receive any revascularization therapy (thrombolysis/thrombectomy), and underwent DWI/PWI at baseline and fluid-attenuated inversion recovery (FLAIR)/DWI 1 week after symptom onset were enrolled...
May 12, 2017: Neurology
https://www.readbyqxmd.com/read/28487658/early-changes-in-glutamate-metabolism-and-perfusion-in-basal-ganglia-following-hypoxia-ischemia-in-neonatal-piglets-a-multi-sequence-3-0t-mr-study
#14
Yu-Xue Dang, Kai-Ning Shi, Xiao-Ming Wang
The excitotoxicity of glutamate metabolism as well as hemodynamic disorders of the brain are both risk factors for neonatal hypoxic-ischemic brain damage (HIBD). In the present study, changes in glutamate metabolism in the basal ganglia were detected by proton magnetic resonance spectroscopy ((1)H-MRS) at 0-6, 8-12, 24-30, and 48-60 h after the induction of hypoxia-ischemia (HI) in newborn piglets. Meanwhile, correlation analysis was performed by combining the microcirculatory perfusion informations acquired by intravoxel incoherent motion (IVIM) scan to explore their possible interaction mechanism...
2017: Frontiers in Physiology
https://www.readbyqxmd.com/read/28472943/semi-automated-brain-tumor-segmentation-on-multi-parametric-mri-using-regularized-non-negative-matrix-factorization
#15
Nicolas Sauwen, Marjan Acou, Diana M Sima, Jelle Veraart, Frederik Maes, Uwe Himmelreich, Eric Achten, Sabine Van Huffel
BACKGROUND: Segmentation of gliomas in multi-parametric (MP-)MR images is challenging due to their heterogeneous nature in terms of size, appearance and location. Manual tumor segmentation is a time-consuming task and clinical practice would benefit from (semi-) automated segmentation of the different tumor compartments. METHODS: We present a semi-automated framework for brain tumor segmentation based on non-negative matrix factorization (NMF) that does not require prior training of the method...
May 4, 2017: BMC Medical Imaging
https://www.readbyqxmd.com/read/28450944/evaluation-of-optimized-magnetic-resonance-perfusion-imaging-scanning-time-window-after-contrast-agent-injection-for-differentiating-benign-and-malignant-breast-lesions
#16
Jie Dong, Dawei Wang, Zhenshen Ma, Guodong Deng, Lanhua Wang, Jiandong Zhang
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 (Ktrans), rate constant (Kep) and extravascular extracellular volume fraction (Ve)] 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...
March 2017: Experimental and Therapeutic Medicine
https://www.readbyqxmd.com/read/28441783/comparison-between-mr-perfusion-and-18f-fdg-pet-in-differentiating-tumor-recurrence-from-nonneoplastic-contrast-enhancing-tissue
#17
Yogesh Kumar, Nishant Gupta, Manisha Mangla, Kusum Hooda, Rajiv Mangla
Objective: Comparison of the accuracy of MR perfusion and 18-FDG-PET for differentiating tumor progression from nonneoplastic contrast-enhancing tissue. Methods and Materials: Retrospective review of MR perfusion and 18-FDG-PET in 23 cases of primary brain tumors (17 high grade and 6 low grade glial neoplasms) and 5 cases of metastatic lesions with enhancing lesions on post-treatment MRI was performed. The accuracy of MR perfusion versus 18-FDG-PET for distinguishing between nonneoplastic contrast-enhancing tissue and tumor recurrence was assessed...
March 1, 2017: Asian Pacific Journal of Cancer Prevention: APJCP
https://www.readbyqxmd.com/read/28439322/susceptibility-imaging-in-glial-tumor-grading-using-3-tesla-magnetic-resonance-mr-system-and-32-channel-head-coil
#18
Omer Aydin, Ramazan Buyukkaya, Bahattin Hakyemez
BACKGROUND: Susceptibility weighted imaging (SWI) is a velocity compensated, high-resolution three-dimensional (3D) spoiled gradient-echo sequence that uses magnitude and filtered-phase data. SWI seems to be a valuable tool for non-invasive evaluation of central nervous system gliomas. Relative cerebral blood volume (rCBV) ratio is one of the best noninvasive methods for glioma grading. Degree of intratumoral susceptibility signal (ITSS) on SWI correlates with rCBV ratio and histopathological grade...
2017: Polish Journal of Radiology
https://www.readbyqxmd.com/read/28428273/assessing-prostate-cancer-aggressiveness-with-hyperpolarized-dual-agent-3d-dynamic-imaging-of-metabolism-and-perfusion
#19
Hsin-Yu Chen, Peder E Z Larson, Robert A Bok, Cornelius von Morze, Renuka Sriram, Romelyn Delos Santos, Justin Delos Santos, Jeremy W Gordon, Naeim Bahrami, Marcus Ferrone, John Kurhanewicz, Daniel B Vigneron
New magnetic resonance (MR) molecular imaging techniques offer the potential for non-invasive, simultaneous quantification of metabolic and perfusion parameters in tumors. This study applied a 3D dynamic dual-agent hyperpolarized (13)C magnetic resonance spectroscopic imaging (MRSI) approach with (13)C-pyruvate and (13)C-urea to investigate differences in perfusion and metabolism between low and high grade tumors in the TRAMP transgenic mouse model of prostate cancer. Dynamic MR data were corrected for T1 relaxation and RF excitation and modeled to provide quantitative measures of pyruvate to lactate flux (kPL) and urea perfusion (urea AUC) that correlated with TRAMP tumor histologic grade...
April 20, 2017: Cancer Research
https://www.readbyqxmd.com/read/28427867/outcomes-from-anomalous-origin-of-the-left-coronary-artery-from-the-pulmonary-artery-repair-long-term-complications-in-relation-to-residual-myocardial-abnormalities
#20
Miki Kanoh, Kei Inai, Tokuko Shinohara, Hirofumi Tomimatsu, Toshio Nakanishi
BACKGROUND: Anomalous origin of the left coronary artery from the pulmonary artery (ALCAPA) is a rare congenital coronary artery irregularity. This study aimed to clarify the long-term postoperative outcomes in ALCAPA patients, and to compare the infantile and adult types. METHODS: We retrospectively analyzed the clinical data from 33 patients with ALCAPA who underwent surgical repairs after 1980. The patients were grouped based on whether presentation occurred before (infantile type: n=14) or after (adult type: n=19) 1 year of age...
April 17, 2017: Journal of Cardiology
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