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Segmented MRI

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https://www.readbyqxmd.com/read/29775791/an-imaging-biomarker-for-assessing-hepatic-function-in-patients-with-primary-sclerosing-cholangitis
#1
Jennifer Schulze, Henrike Lenzen, Jan B Hinrichs, Burckhardt Ringe, Michael P Manns, Frank Wacker, Kristina I Ringe
BACKGROUND & AIMS: We aimed to evaluate the potential of hepatobiliary phase magnetic resonance imaging (MRI) as parameter for assessment of hepatocellular function in patients with primary sclerosing cholangitis (PSC). METHODS: We collected data from 111 patients (83 male, 28 female; median, 44 years old), from March 2012 through March 2016, with a confirmed diagnosis of PSC who underwent MRI evaluation before and after injection (hepatobiliary phase) of a hepatocyte-specific contrast agent (gadoxetate disodium)...
May 15, 2018: Clinical Gastroenterology and Hepatology
https://www.readbyqxmd.com/read/29775663/free-breathing-ultrashort-echo-time-lung-magnetic-resonance-imaging-using-stack-of-spirals-acquisition-a-feasibility-study-in-oncology-patients
#2
Min Jae Cha, Hyun Jeong Park, Mun Young Paek, Alto Stemmer, Eun Sun Lee, Sung Bin Park, Yang Soo Kim
OBJECTIVES: To investigate the diagnostic accuracy of lung magnetic resonance imaging (MRI) with a free-breathing three-dimensional ultrashort echo time spoiled gradient echo sequence using a stack-of-spirals acquisition (spiral 3D UTE) for pulmonary nodule detection at 3 T in oncology patients. METHODS: The institutional review board approved this retrospective study. Between June and September of 2017, 32 oncology patients underwent both free-breathing spiral 3D UTE of the lungs and thin-section chest computed tomography (CT) for pulmonary metastasis workups...
May 15, 2018: Magnetic Resonance Imaging
https://www.readbyqxmd.com/read/29775280/fluorine-meets-amine-reducing-microenvironment-induced-amino-activatable-nanoprobes-for-19f-magnetic-resonance-imaging-of-bio-thiols
#3
Pingsheng Huang, Weisheng Guo, Guang Yang, Huijuan Song, Yuqing Wang, Chun Wang, Deling Kong, Weiwei Wang
19F MRI is of great significance for non-invasive imaging and detection of various diseases. However, the main obstacle in the application of 19F MRI agents stems from the unmet signal sensitivity, due to the poor water-solubility and restricted mobility of segments with high numbers of fluorine atoms. Herein, we report a kind of intracellular reducing microenvironment-induced amino-activatable 19F MRI nanoprobe, which can be used for specific imaging of bio-thiols. In principle, the nanoprobe has an initial architecture of hydrophobic core, where the trifluoromethyl-containing segments are compactly packed and 19F NMR/MRI signals are quenched ("OFF" state)...
May 18, 2018: ACS Applied Materials & Interfaces
https://www.readbyqxmd.com/read/29773823/comparison-of-conventional-sonographic-signs-and-magnetic-resonance-imaging-proton-density-fat-fraction-for-assessment-of-hepatic-steatosis
#4
Mimi Kim, Bo-Kyeong Kang, Dae Won Jun
This study correlated conventional ultrasonography (US) signs with the magnetic resonance imaging (MRI) proton density fat fraction (PDFF) to evaluate the diagnostic performance of US signs (alone or combined) to predict presence and degree of hepatic steatosis (HS). Overall, 182 subjects met the study inclusion criteria between February 2014 and October 2016. Four US signs were evaluated independently by two radiologists. MRI PDFF was defined as the average of 24 non-overlapping regions of interest (ROIs) within eight liver segments obtained by drawing three ROIs within each segment...
May 17, 2018: Scientific Reports
https://www.readbyqxmd.com/read/29772864/-analysis-of-delayed-infection-of-proximal-junctional-zone-after-posterior-spinal-internal-fixation-and-its-treatment-strategy
#5
Gong-Qun Jiang, Yong-Heng Liu, De-Yuan Chen, Yong-Ai Liu
OBJECTIVE: To explore the features and treatment strategy of delayed infection of proximal junctional zone after posterior spinal internal fixation. METHODS: The clinical data of 1325 patients underwent posterior spinal internal fixation were retrospectively analyzed. Delayed infection occurred in 10 patients, among which 4 infections occurred at the proximal junction (non-operative site). And these 4 patients were treated with combined broad-spectrum antibiotics...
April 25, 2018: Zhongguo Gu Shang, China Journal of Orthopaedics and Traumatology
https://www.readbyqxmd.com/read/29772066/3d-specific-absorption-rate-estimation-from-high-intensity-focused-ultrasound-sonications-using-the-green-s-function-heat-kernel
#6
Nicholas J Freeman, Henrik Odéen, Dennis L Parker
PURPOSE: Evaluate a numerical inverse Green's function method of deriving specific absorption rates (SARs) from high intensity focused ultrasound (HIFU) sonications given tissue parameters (thermal conductivity, specific heat capacity, and mass density) and 3-D magnetic resonance imaging (MRI) temperature measurements. METHODS: SAR estimates were evaluated using simulations and MR temperature measurements from HIFU sonications. For simulations, a "true" SAR was calculated using the hybrid angular spectrum method for ultrasound simulations...
May 17, 2018: Medical Physics
https://www.readbyqxmd.com/read/29770765/anterior-uterine-wall-normal-and-abnormal-ct-and-mri-findings-after-cesarean-section
#7
Ali Devrim Karaosmanoğlu, Altan Güneş, Mustafa Nasuh Özmen, Deniz Akata
Cesarean section is the most commonly performed surgical procedure in women. The surgical incision line in the uterus is generally located in the lower segment of the anterior uterine wall. Acquaintance with the normal and abnormal findings of the anterior uterine wall is of critical importance for imagers in this era of ever increasing cesarean sections performed worldwide.
May 2018: Diagnostic and Interventional Radiology: Official Journal of the Turkish Society of Radiology
https://www.readbyqxmd.com/read/29770503/a-novel-phase-unwrapping-method-by-using-phase-jump-detection-and-local-surface-fitting-application-to-dixon-water-fat-mri
#8
Junying Cheng, Jijing Guan, Yingjie Mei, Lin Xu, Xiaoyun Liu, Qianjin Feng, Wufan Chen, Yanqiu Feng
PURPOSE: This study aims to develop an accurate and robust phase-unwrapping method that works effectively under severe noise, rapid-varying phase, and disconnected regions for water-fat Dixon MRI. METHODS: The proposed method first segments the phase map into blocks by automatically detecting phase jumps, and then clusters the pixels near phase jumps into residual pixels. Thereafter, the proposed method sequentially performs intrablock, interblock, and residual-pixel unwrapping using the local surface fitting approach...
May 16, 2018: Magnetic Resonance in Medicine: Official Journal of the Society of Magnetic Resonance in Medicine
https://www.readbyqxmd.com/read/29770492/accelerated-3d-grase-imaging-improves-quantitative-multiple-post-labeling-delay-arterial-spin-labeling
#9
Markus Boland, Rüdiger Stirnberg, Eberhard D Pracht, Johanna Kramme, Roberto Viviani, Julia Stingl, Tony Stöcker
PURPOSE: To investigate the impact of accelerated, single-shot 3D-GRASE acquisition on quantitative arterial spin labeling (ASL) with multiple and single post-labeling delay (PLD) in terms of perfusion-weighted SNR per unit scan time (TSNRPW ) and quantification accuracy. METHODS: Five subjects were scanned on a 3T MRI scanner using the pseudo-continuous arterial spin labeling (PCASL) technique with a 3D-GRASE imaging sequence capable of parallel imaging acceleration...
May 16, 2018: Magnetic Resonance in Medicine: Official Journal of the Society of Magnetic Resonance in Medicine
https://www.readbyqxmd.com/read/29767320/post-hepatectomy-liver-failure-after-major-hepatic-surgery-not-only-size-matters
#10
Ulrika Asenbaum, Klaus Kaczirek, Ahmed Ba-Ssalamah, Helmut Ringl, Christoph Schwarz, Fredrik Waneck, Fabian Fitschek, Christian Loewe, Richard Nolz
OBJECTIVES: To compare the value of functional future liver remnant (functFLR) to established clinical and imaging variables in prediction of post-hepatectomy liver failure (PHLF) after major liver resection. METHODS: This retrospective, cross-sectional study included 62 patients, who underwent gadoxetic acid enhanced MRI and MDCT within 10 weeks prior to resection of ≥ 4 liver segments. Future liver remnant (FLR) was measured in MDCT using semi-automatic software...
May 16, 2018: European Radiology
https://www.readbyqxmd.com/read/29766373/prostate-segmentation-in-mri-using-a-convolutional-neural-network-architecture-and-training-strategy-based-on-statistical-shape-models
#11
Davood Karimi, Golnoosh Samei, Claudia Kesch, Guy Nir, Septimiu E Salcudean
PURPOSE: Most of the existing convolutional neural network (CNN)-based medical image segmentation methods are based on methods that have originally been developed for segmentation of natural images. Therefore, they largely ignore the differences between the two domains, such as the smaller degree of variability in the shape and appearance of the target volume and the smaller amounts of training data in medical applications. We propose a CNN-based method for prostate segmentation in MRI that employs statistical shape models to address these issues...
May 15, 2018: International Journal of Computer Assisted Radiology and Surgery
https://www.readbyqxmd.com/read/29764039/-long-term-efficacy-of-cervical-artificial-disc-replacement-for-cervical-degenerative-diseases
#12
Q P Song, W Tian, D He, X Han, N Zhang, J C Wang, Z C Li
Objective: To evaluate the long-term efficacy of cervical artificial disc replacement for patients with cervical disc herniation and degenerative cervical canal stenosis. Methods: Total of sixty-eight patients underwent single-level Bryan artificial disc replacement in Beijing Jishuitan Hospital from December 2003 to December 2007 with a minimum 10-year follow-up were retrospectively analyzed. There were 43 males and 25 females with a mean age of (46±8) years. According to preoperative CT and MRI, the patients were divided into two groups: 27 patients in cervical disc herniation group and 41 patients in degenerative cervical canal stenosis group...
May 8, 2018: Zhonghua Yi Xue za Zhi [Chinese medical journal]
https://www.readbyqxmd.com/read/29763764/machine-learning-based-brain-tumour-segmentation-on-limited-data-using-local-texture-and-abnormality
#13
Stijn Bonte, Ingeborg Goethals, Roel Van Holen
Brain tumour segmentation in medical images is a very challenging task due to the large variety in tumour shape, position, appearance, scanning modalities and scanning parameters. Most existing segmentation algorithms use information from four different MRI-sequences, but since this is often not available, there is need for a method able to delineate the different tumour tissues based on a minimal amount of data. We present a novel approach using a Random Forests model combining voxelwise texture and abnormality features on a contrast-enhanced T1 and FLAIR MRI...
May 7, 2018: Computers in Biology and Medicine
https://www.readbyqxmd.com/read/29761357/classifying-brain-metastases-by-their-primary-site-of-origin-using-a-radiomics-approach-based-on-texture-analysis-a-feasibility-study
#14
Rafael Ortiz-Ramón, Andrés Larroza, Silvia Ruiz-España, Estanislao Arana, David Moratal
OBJECTIVE: To examine the capability of MRI texture analysis to differentiate the primary site of origin of brain metastases following a radiomics approach. METHODS: Sixty-seven untreated brain metastases (BM) were found in 3D T1-weighted MRI of 38 patients with cancer: 27 from lung cancer, 23 from melanoma and 17 from breast cancer. These lesions were segmented in 2D and 3D to compare the discriminative power of 2D and 3D texture features. The images were quantized using different number of gray-levels to test the influence of quantization...
May 14, 2018: European Radiology
https://www.readbyqxmd.com/read/29759948/measuring-relative-positions-and-orientations-of-the-tibia-with-respect-to-the-femur-using-one-channel-3d-tracked-a-mode-ultrasound-tracking-system-a-cadaveric-study
#15
Kenan Niu, Jasper Homminga, Victor Sluiter, André Sprengers, Nico Verdonschot
The purpose of this study is to investigate the technical feasibility of measuring relative positions and orientations of the tibia with respect to the femur in an in-vitro experiment by using a 3D-tracked A-mode ultrasound system and to determine its accuracy of angular and translational measurements. As A-mode ultrasound is capable of detecting bone surface through soft tissue in a non-invasive manner, the combination of a single A-mode ultrasound transducer with an optical motion tracking system provides the possibility for digitizing the 3D locations of bony points at different anatomical regions on the thigh and the shank...
May 11, 2018: Medical Engineering & Physics
https://www.readbyqxmd.com/read/29759775/real-time-x-mri-guided-left-ventricular-lead-implantation-for-targeted-delivery-of-cardiac-resynchronization-therapy
#16
Jonathan M Behar, Peter Mountney, Daniel Toth, Sabrina Reiml, Maria Panayiotou, Alexander Brost, Bernhard Fahn, Rashed Karim, Simon Claridge, Tom Jackson, Ben Sieniewicz, Nik Patel, Mark O'Neill, Reza Razavi, Kawal Rhode, Christopher Aldo Rinaldi
OBJECTIVES: This study sought to test the feasibility of a purpose-built, integrated software platform to process, analyze, and overlay cardiac magnetic resonance (CMR) data in real time within a combined cardiac catheter laboratory and magnetic resonance imaging scanner suite (X-MRI) to guide left ventricular (LV) lead implantation. BACKGROUND: Suboptimal LV lead position is a major determinant of poor cardiac resynchronization therapy (CRT) response, and the optimal site is highly patient specific...
August 2017: JACC. Clinical Electrophysiology
https://www.readbyqxmd.com/read/29755716/automatic-semantic-segmentation-of-brain-gliomas-from-mri-images-using-a-deep-cascaded-neural-network
#17
Shaoguo Cui, Lei Mao, Jingfeng Jiang, Chang Liu, Shuyu Xiong
Brain tumors can appear anywhere in the brain and have vastly different sizes and morphology. Additionally, these tumors are often diffused and poorly contrasted. Consequently, the segmentation of brain tumor and intratumor subregions using magnetic resonance imaging (MRI) data with minimal human interventions remains a challenging task. In this paper, we present a novel fully automatic segmentation method from MRI data containing in vivo brain gliomas. This approach can not only localize the entire tumor region but can also accurately segment the intratumor structure...
2018: Journal of Healthcare Engineering
https://www.readbyqxmd.com/read/29755313/individualized-functional-parcellation-of-the-human-amygdala-using-a-semi-supervised-clustering-method-a-7t-resting-state-fmri-study
#18
Xianchang Zhang, Hewei Cheng, Zhentao Zuo, Ke Zhou, Fei Cong, Bo Wang, Yan Zhuo, Lin Chen, Rong Xue, Yong Fan
The amygdala plays an important role in emotional functions and its dysfunction is considered to be associated with multiple psychiatric disorders in humans. Cytoarchitectonic mapping has demonstrated that the human amygdala complex comprises several subregions. However, it's difficult to delineate boundaries of these subregions in vivo even if using state of the art high resolution structural MRI. Previous attempts to parcellate this small structure using unsupervised clustering methods based on resting state fMRI data suffered from the low spatial resolution of typical fMRI data, and it remains challenging for the unsupervised methods to define subregions of the amygdala in vivo ...
2018: Frontiers in Neuroscience
https://www.readbyqxmd.com/read/29754995/additive-benefit-of-radiomics-over-size-alone-in-the-distinction-between-benign-lesions-and-luminal-a-cancers-on-a-large-clinical-breast-mri-dataset
#19
Heather M Whitney, Nathan S Taylor, Karen Drukker, Alexandra V Edwards, John Papaioannou, David Schacht, Maryellen L Giger
RATIONALE AND OBJECTIVES: The objective of this study was to demonstrate improvement in distinguishing between benign lesions and luminal A breast cancers in a large clinical breast magnetic resonance imaging database by using quantitative radiomics over maximum linear size alone. MATERIALS AND METHODS: In this retrospective study, 212 benign lesions and 296 luminal A breast cancers were automatically segmented from dynamic contrast-enhanced breast magnetic resonance images...
May 10, 2018: Academic Radiology
https://www.readbyqxmd.com/read/29754940/radioguided-hepatic-resection-with-18-f-dopa-in-a-patient-with-metastatic-medullary-thyroid-carcinoma
#20
J López-Gómez, S Medina-Ornelas, M A Salazar-Álvarez, M Álvarez-Bojórquez, N Zaragoza-Cruz, J Melchor-Ruan, A Álvarez-Cano
INTRODUCTION: Medullary carcinoma accounts for 1-2% of all thyroid malignancies. 13-20% of patients present with distant metastasis, with 45% of the cases affecting the liver. CLINICAL CASE: A 50-year-old woman, diagnosed with medullary thyroid carcinoma, was treated with total thyroidectomy and a modified neck dissection in 1999. Two lymph node recurrences in the neck were treated with surgical resection; during surveillance, she developed elevated calcitonin levels, the recurrence site was identified with 18 F-DOPA PET/CT in the liver...
May 10, 2018: Revista Española de Medicina Nuclear e Imagen Molecular
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