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https://www.readbyqxmd.com/read/29232371/treatment-effect-of-mtor-inhibition-on-tissue-composition-of-renal-angiomyolipomas-in-tuberous-sclerosis-complex-tsc
#1
Susanne Brakemeier, Lars Vogt, Lisa Adams, Bianca Zukunft, Gerd Diederichs, Bernd Hamm, Klemens Budde, Marcus R Makowski
PURPOSE: Tuberous sclerosis complex (TSC)-associated renal angiomyolipoma (AML) have a high lifetime risk of acute bleeding. MTOR-inhibitors are a promising novel treatment for TSC-AML, however adequate response to therapy can be difficult to assess. Early changes in MRI signal may serve as a novel early indicator for a satisfactory response to mTOR-inhibitor therapy of AML. MATERIALS AND METHODS: Thirty-eight patients with the definite diagnosis of tuberous sclerosis receiving everolimus therapy and n = 19 patients without specific therapy were included...
2017: PloS One
https://www.readbyqxmd.com/read/29231924/the-mineralocorticoid-receptor-knockout-in-medaka-is-further-validated-by-glucocorticoid-receptor-compensation
#2
Tatsuya Sakamoto, Madoka Yoshiki, Hirotaka Sakamoto
To study the critical role of mineralocorticoid signalling, we generated a constitutive mineralocorticoid receptor (MR)-knockout (KO) medaka as the first adult-viable MR-KO animal. This KO medaka displayed abnormal behaviours affected by visual stimuli. In contrast, the loss of MR did not result in overt phenotypic changes in osmoregulation, despite the well-known osmoregulatory functions of MR in mammals. Since glucocorticoid receptor (GR) has been suggested to compensate for loss of MR, we examined expression of duplicated GRs with markedly different ligand sensitivities, in various tissues...
December 12, 2017: Scientific Data
https://www.readbyqxmd.com/read/29230805/uspio-labeling-in-m1-and-m2-polarized-macrophages-an-in-vitro-study-using-a-clinical-magnetic-resonance-scanner
#3
Chiara Zini, Mary Anna Venneri, Selenia Miglietta, Damiano Caruso, Natale Porta, Andrea Isidori, Daniela Fiore, Daniele Gianfrilli, Vincenzo Petrozza, Andrea Laghi
BACKGROUND: To evaluate USPIO labeling in different macrophage populations using a clinical 3.0T MR unit with optical and electron microscopy as the gold standard. METHODS: Human monocytic cell line were differentiated into macrophages. Afterwards M0 macrophages were incubated with IL-4 and IL-13 in order to obtain M2 polarized macrophages or with IFN-gamma and LPS for classical macrophage activation (M1). These groups were incubated with USPIO MR contrast agent (P904) for 36 hours; M0, M0+P904, M1+P904 and M2+P904 were analyzed in gel phantoms with a 3...
December 12, 2017: Journal of Cellular Physiology
https://www.readbyqxmd.com/read/29230607/the-effect-of-high-count-rates-on-cardiac-perfusion-quantification-in-a-simultaneous-pet-mr-system-using-a-cardiac-perfusion-phantom
#4
Jim O' Doherty, Zacharias Chalampalakis, Paul Schleyer, Muhummad Sohaib Nazir, Amedeo Chiribiri, Paul K Marsden
BACKGROUND: PET-MRI is under investigation as a new strategy for quantitative myocardial perfusion imaging. Consideration is required as to the maximum scanner count rate in order to limit dead-time losses resulting from administered activity in the scanner field of view during the first pass of the radiotracer. RESULTS: We performed a decaying-source experiment to investigate the high count-rate performance of a PET-MR system (Siemens mMR) over the expected range of activities during a clinical study...
December 11, 2017: EJNMMI Physics
https://www.readbyqxmd.com/read/29229307/localizing-implanted-fiducial-markers-using-undersampled-co-rasor-mr-imaging
#5
Evan McNabb, Raimond Wong, Michael D Noseworthy
The goal of this work was to use an undersampled, dual-plane centre-out radial sampling acquisition pulse sequence, with off-resonance reception, to localize fiducial markers with reduced acquisition time. Two iterative reconstruction techniques, conjugate gradient CG-SENSE and the variational penalty Total Generalized Variation (TGV), were investigated to minimize the undersampling artifacts in off-resonant radialimaging. Simulations of a field perturber were performed at sub-millimeter resolution and reconstructed to display signal pileups that can be radially compressed towards the geometric center of the perturber for high contrast visualization, but contrast is non-recoverable as the echo time increases...
December 8, 2017: Magnetic Resonance Imaging
https://www.readbyqxmd.com/read/29229179/clinical-role-of-breast-mri-now-and-going-forward
#6
REVIEW
D Leithner, G J Wengert, T H Helbich, S Thakur, R E Ochoa-Albiztegui, E A Morris, K Pinker
Magnetic resonance imaging (MRI) is a well-established method in breast imaging, with manifold clinical applications, including the non-invasive differentiation between benign and malignant breast lesions, preoperative staging, detection of scar versus recurrence, implant assessment, and the evaluation of high-risk patients. At present, dynamic contrast-enhanced MRI is the most sensitive imaging technique for breast cancer diagnosis, and provides excellent morphological and to some extent also functional information...
December 8, 2017: Clinical Radiology
https://www.readbyqxmd.com/read/29224047/magnetic-resonance-imaging-of-cardiovascular-thrombi-in-children
#7
Pablo Caro-Dominguez, Shi-Joon Yoo, Mike Seed, Lars Grosse-Wortmann
Cardiovascular thrombosis is rare in children and usually occurs in the presence of predisposing conditions, such as indwelling vascular catheters, tumors, aneurysms, ventricular dysfunction, or after surgery. Clots can occur in the cardiac chambers, arteries or veins, or inside conduits. Detection of thrombi is feasible with a variety of magnetic resonance imaging (MRI) techniques, including unenhanced methods but also contrast-enhanced MR angiography. In this essay we illustrate the MRI appearance of cardiovascular thrombosis in children and suggest an imaging protocol based on our clinical experience...
December 9, 2017: Pediatric Radiology
https://www.readbyqxmd.com/read/29219225/dce-mri-texture-analysis-with-tumor-subregion-partitioning-for-predicting-ki-67-status-of-estrogen-receptor-positive-breast-cancers
#8
Ming Fan, Hu Cheng, Peng Zhang, Xin Gao, Juan Zhang, Guoliang Shao, Lihua Li
BACKGROUND: Breast tumor heterogeneity is related to risk factors that lead to worse prognosis, yet such heterogeneity has not been well studied. PURPOSE: To predict the Ki-67 status of estrogen receptor (ER)-positive breast cancer patients via analysis of tumor heterogeneity with subgroup identification based on patterns of dynamic contrast-enhanced magnetic resonance imaging (DCE-MRI). STUDY TYPE: Retrospective study. POPULATION: Seventy-seven breast cancer patients with ER-positive breast cancer were investigated, of whom 51 had low Ki-67 expression...
December 8, 2017: Journal of Magnetic Resonance Imaging: JMRI
https://www.readbyqxmd.com/read/29218620/the-impact-of-injector-based-contrast-agent-administration-in-time-resolved-mra
#9
Johannes Budjan, Ulrike I Attenberger, Stefan O Schoenberg, Hubertus Pietsch, Gregor Jost
OBJECTIVES: Time-resolved contrast-enhanced MR angiography (4D-MRA), which allows the simultaneous visualization of the vasculature and blood-flow dynamics, is widely used in clinical routine. In this study, the impact of two different contrast agent injection methods on 4D-MRA was examined in a controlled, standardized setting in an animal model. METHODS: Six anesthetized Goettingen minipigs underwent two identical 4D-MRA examinations at 1.5 T in a single session...
December 7, 2017: European Radiology
https://www.readbyqxmd.com/read/29218420/an-improved-pathological-brain-detection-system-based-on-two-dimensional-pca-and-evolutionary-extreme-learning-machine
#10
Deepak Ranjan Nayak, Ratnakar Dash, Banshidhar Majhi
Pathological brain detection has made notable stride in the past years, as a consequence many pathological brain detection systems (PBDSs) have been proposed. But, the accuracy of these systems still needs significant improvement in order to meet the necessity of real world diagnostic situations. In this paper, an efficient PBDS based on MR images is proposed that markedly improves the recent results. The proposed system makes use of contrast limited adaptive histogram equalization (CLAHE) to enhance the quality of the input MR images...
December 7, 2017: Journal of Medical Systems
https://www.readbyqxmd.com/read/29218271/magnetic-resonance-imaging-in-precision-radiation-therapy-for-lung-cancer
#11
REVIEW
Hannah Bainbridge, Ahmed Salem, Rob H N Tijssen, Michael Dubec, Andreas Wetscherek, Corinne Van Es, Jose Belderbos, Corinne Faivre-Finn, Fiona McDonald
Radiotherapy remains the cornerstone of curative treatment for inoperable locally advanced lung cancer, given concomitantly with platinum-based chemotherapy. With poor overall survival, research efforts continue to explore whether integration of advanced radiation techniques will assist safe treatment intensification with the potential for improving outcomes. One advance is the integration of magnetic resonance imaging (MRI) in the treatment pathway, providing anatomical and functional information with excellent soft tissue contrast without exposure of the patient to radiation...
December 2017: Translational Lung Cancer Research
https://www.readbyqxmd.com/read/29217399/feasibility-of-breast-mri-after-sentinel-procedure-for-breast-cancer-with-superparamagnetic-tracers
#12
Benedict Krischer, Serafino Forte, Tilo Niemann, Rahel A Kubik-Huch, Cornelia Leo
RATIONALE: The gold standard for detection of axillary sentinel lymph nodes uses injection of a radioisotope (99Tc Nanocoll). As an alternative to this method, a magnetometer detecting the superparamagnetic tracer Sienna+® can be applied for detection of sentinel lymph nodes. The goal of this study was to determine whether interpretation of breast MRI is impaired by Sienna+® tracer residues in the operated breast and axillary lymph nodes after a sentinel procedure using this tracer...
November 26, 2017: European Journal of Surgical Oncology
https://www.readbyqxmd.com/read/29216303/three-dimensional-self-gated-cardiac-mr-imaging-for-the-evaluation-of-myocardial-infarction-in-mouse-model-on-a-3t-clinical-mr-system
#13
Xiaoyong Zhang, Bensheng Qiu, Zijun Wei, Fei Yan, Caiyun Shi, Shi Su, Xin Liu, Jim X Ji, Guoxi Xie
PURPOSE: To develop and assess a three-dimensional (3D) self-gated technique for the evaluation of myocardial infarction (MI) in mouse model without the use of external electrocardiogram (ECG) trigger and respiratory motion sensor on a 3T clinical MR system. METHODS: A 3D T1-weighted GRE sequence with stack-of-stars sampling trajectories was developed and performed on six mice with MIs that were injected with a gadolinium-based contrast agent at a 3T clinical MR system...
2017: PloS One
https://www.readbyqxmd.com/read/29214780/mismatch-between-tof-mr-angiography-and-ct-angiography-of-the-middle-cerebral-artery-may-be-a-critical-sign-in-cerebrovascular-dynamics
#14
Keiji Igase, Michiya Igase, Ichiro Matsubara, Kazuhiko Sadamoto
PURPOSE: Although time-of-flight (TOF)-magnetic resonance angiography (MRA) can clearly depict intracranial arteries, the arterial flow of middle cerebral artery (MCA) is occasionally not detected. We evaluated this phenomenon with reference to cerebrovascular dynamics. MATERIALS AND METHODS: Seventeen patients with suspected occlusion of MCA or internal carotid artery on TOF-MRA were enrolled. All patients underwent CT angiography (CTA) and quantitative cerebral blood flow (CBF) examination for measurement of resting CBF and cerebrovascular reactivity (CVR)...
January 2018: Yonsei Medical Journal
https://www.readbyqxmd.com/read/29214448/the-role-of-dynamic-post-contrast-t1-w-mri-sequence-to-characterize-lipid-rich-and-lipid-poor-adrenal-adenomas-in-comparison-to-non-adenoma-lesions-preliminary-results
#15
Valeria Romeo, Simone Maurea, Salvatore Guarino, Pier Paolo Mainenti, Raffaele Liuzzi, Mario Petretta, Immacolata Cozzolino, Michele Klain, Arturo Brunetti
PURPOSE: The purpose of the article is to compare the features of wash-out (WO) parameters between lipid-rich and lipid-poor adrenal adenomas as well as with a group of non-adenoma adrenal lesions. METHODS: 46 patients (36 F and 10 M, median age 58 years) with unilateral adrenal lesions (35 adenomas, 7 pheochromocytomas, 1 carcinoma, and 3 metastases) were prospectively evaluated; adrenal lesions were divided into adenomas (Group 1) and non-adenomas (Group 2)...
December 6, 2017: Abdominal Radiology
https://www.readbyqxmd.com/read/29212354/image-quality-assessment-of-silent-t2-propeller-sequence-for-brain-imaging-in-infants
#16
Hyun Gi Kim, Jin Wook Choi, Soo Han Yoon, Sieun Lee
OBJECTIVE: Infants are vulnerable to high acoustic noise. Acoustic noise generated by MR scanning can be reduced by a silent sequence. The purpose of this study is to compare the image quality of the conventional and silent T2 PROPELLER sequences for brain imaging in infants. METHODS: A total of 36 scans were acquired from 24 infants using a 3.0 T MR scanner. Each patient underwent both conventional and silent T2 PROPELLER sequences. Acoustic noise level was measured...
December 7, 2017: British Journal of Radiology
https://www.readbyqxmd.com/read/29208569/a-digital-3d-atlas-of-the-marmoset-brain-based-on-multi-modal-mri
#17
Cirong Liu, Frank Q Ye, Cecil Chern-Chyi Yen, John D Newman, Daniel Glen, David A Leopold, Afonso C Silva
The common marmoset (Callithrix jacchus) is a New-World monkey of growing interest in neuroscience. Magnetic resonance imaging (MRI) is an essential tool to unveil the anatomical and functional organization of the marmoset brain. To facilitate identification of regions of interest, it is desirable to register MR images to an atlas of the brain. However, currently available atlases of the marmoset brain are mainly based on 2D histological data, which are difficult to apply to 3D imaging techniques. Here, we constructed a 3D digital atlas based on high-resolution ex-vivo MRI images, including magnetization transfer ratio (a T1-like contrast), T2w images, and multi-shell diffusion MRI...
December 2, 2017: NeuroImage
https://www.readbyqxmd.com/read/29208312/gadolinium-deposition-in-the-paediatric-brain-t1-weighted-hyperintensity-within-the-dentate-nucleus-following-repeated-gadolinium-based-contrast-agent-administration
#18
J R Young, I Orosz, M A Franke, H J Kim, D Woodworth, B M Ellingson, N Salamon, W B Pope
AIM: To determine whether repeated gadolinium-based contrast agent administration (GBCA) in children is associated with the development of increased T1-weighted signal intensity within the cerebellar dentate nucleus. MATERIALS AND METHODS: With institutional review board approval for this The Health Insurance Portability and Accountability Act-compliant retrospective study, a cohort of 41 patients under the age of 18 years who underwent at least four contrast-enhanced magnetic resonance imaging (MR) examinations of the brain from 2005 to 2015 were identified...
December 2, 2017: Clinical Radiology
https://www.readbyqxmd.com/read/29205171/engineered-core-shell-magnetic-nanoparticle-for-mr-dual-modal-tracking-and-safe-magnetic-manipulation-of-ependymal-cells-in-live-rodents
#19
Yung-Kang Peng, Cathy N P Lui, Yu-Wei Chen, Shang-Wei Chou, Pi-Tai Chou, Ken K L Yung, S C Edman Tsang
Tagging recognition group(s) on superparamagnetic iron oxide is known to aid localisation (imaging), stimulation and separation of biological entities using magnetic resonance imaging (MRI) and magnetic agitation/separation (MAS) techniques. Despite the wide applicability of iron oxide nanoparticles in T 2-weighted MRI and MAS, the quality of the images and safe manipulation of the exceptionally delicate neural cells in a live brain are currently the key challenges. Here, we demonstrate the engineered manganese oxide clusters-iron oxide core-shell nanoparticle as an MR dual-modal contrast agent for neural stem cells (NSCs) imaging and magnetic manipulation in live rodents...
December 5, 2017: Nanotechnology
https://www.readbyqxmd.com/read/29202135/latest-local-adaptive-and-sequential-training-for-tissue-segmentation-of-isointense-infant-brain-mr-images
#20
Li Wang, Yaozong Gao, Gang Li, Feng Shi, Weili Lin, Dinggang Shen
Accurate segmentation of isointense infant (~6 months of age) brain MRIs is of great importance, however, a very challenging task, due to extremely low tissue contrast caused by ongoing myelination processes. In this work, we propose a novel learning method based on Local AdapTivE and Sequential Training (LATEST) for segmentation. Specifically, random forest technique is employed to train a local classifier (a single decision tree) for each voxel in the common space based on the neighboring training samples from atlases...
2017: Medical Computer Vision and Bayesian and Graphical Models for Biomedical Imaging: MICCAI 2016 International Workshops, MCV and BAMBI, Athens, Greece, October 21, 2016, Revised Selected Papers
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