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MR image segmentation

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https://www.readbyqxmd.com/read/28109932/accuracy-of-noncontrast-quiescent-interval-single-shot-lower-extremity-mr-angiography-versus-ct%C3%A2-angiography-for-diagnosis-of-peripheral-artery-disease-comparison-with-digital-subtraction-angiography
#1
Akos Varga-Szemes, Julian L Wichmann, U Joseph Schoepf, Pal Suranyi, Carlo N De Cecco, Giuseppe Muscogiuri, Damiano Caruso, Ricardo T Yamada, Sheldon E Litwin, Christian Tesche, Taylor M Duguay, Shivraman Giri, Rozemarijn Vliegenthart, Thomas M Todoran
OBJECTIVES: This study sought to evaluate the image quality and diagnostic accuracy of noncontrast quiescent-interval single-shot (QISS) magnetic resonance angiography (MRA) versus iodine-contrast computed tomography angiography (CTA) in patients with peripheral artery disease (PAD), with invasive digital subtraction angiography (DSA) as the reference standard. BACKGROUND: QISS is a recently introduced noncontrast MRA technique. Although the diagnostic accuracy of QISS is reportedly similar to that of contrast-enhanced MRA, its performance compared with contrast-enhanced CTA, the most frequently used noninvasive modality for evaluation of PAD, is unknown...
January 12, 2017: JACC. Cardiovascular Imaging
https://www.readbyqxmd.com/read/28107094/dynamic-volume-assessment-of-hepatocellular-carcinoma-in-rat-livers-using-a-clinical-3t-mri-and-novel-segmentation
#2
Lorenzo A Orci, Graziano Oldani, Stephanie Lacotte, Florence Slits, Iris Friedli, Wolfgang Wirth, Christian Toso, Jean-Paul Vallée, Lindsey A Crowe
PURPOSE: In vivo liver cancer research commonly uses rodent models. One of the limitations of such models is the lack of accurate and reproducible endpoints for a dynamic assessment of growing tumor nodules. The aim of this study was to validate a noninvasive, true volume segmentation method using two rat hepatocellular carcinoma (HCC) models, correlating magnetic resonance imaging (MRI) with histological volume measurement, and with blood levels of α-fetoprotein. MATERIALS AND METHODS: We used 3T clinical MRI to quantify tumor volume with follow-up over time...
January 20, 2017: Journal of Investigative Surgery: the Official Journal of the Academy of Surgical Research
https://www.readbyqxmd.com/read/28096726/diffusion-weighted-mr-enterography-to-monitor-bowel-inflammation-after-medical-therapy-in-crohn-s-disease-a-prospective-longitudinal-study
#3
Jimi Huh, Kyung Jo Kim, Seong Ho Park, So Hyun Park, Suk-Kyun Yang, Byong Duk Ye, Sang Hyoung Park, Kyunghwa Han, Ah Young Kim
OBJECTIVE: To prospectively evaluate the performance of diffusion-weighted imaging (DWI) to monitor bowel inflammation after medical therapy for Crohn's disease (CD). MATERIALS AND METHODS: Before and following 1-2 years of medical therapy, between October 2012 and May 2015, 18 randomly selected adult CD patients (male:female, 13:5; mean age ± SD, 25.8 ± 7.9 years at the time of enrollment) prospectively underwent MR enterography (MRE) including DWI (b = 900 s/mm(2)) and ileocolonoscopy...
January 2017: Korean Journal of Radiology: Official Journal of the Korean Radiological Society
https://www.readbyqxmd.com/read/28092203/machine-learning-of-three-dimensional-right-ventricular-motion-enables-outcome-prediction-in-pulmonary-hypertension-a-cardiac-mr-imaging-study
#4
Timothy J W Dawes, Antonio de Marvao, Wenzhe Shi, Tristan Fletcher, Geoffrey M J Watson, John Wharton, Christopher J Rhodes, Luke S G E Howard, J Simon R Gibbs, Daniel Rueckert, Stuart A Cook, Martin R Wilkins, Declan P O'Regan
Purpose To determine if patient survival and mechanisms of right ventricular failure in pulmonary hypertension could be predicted by using supervised machine learning of three-dimensional patterns of systolic cardiac motion. Materials and Methods The study was approved by a research ethics committee, and participants gave written informed consent. Two hundred fifty-six patients (143 women; mean age ± standard deviation, 63 years ± 17) with newly diagnosed pulmonary hypertension underwent cardiac magnetic resonance (MR) imaging, right-sided heart catheterization, and 6-minute walk testing with a median follow-up of 4...
January 16, 2017: Radiology
https://www.readbyqxmd.com/read/28090600/learning-based-3t-brain-mri-segmentation-with-guidance-from-7t-mri-labeling
#5
Renping Yu, Minghui Deng, Pew-Thian Yap, Zhihui Wei, Li Wang, Dinggang Shen
Brain magnetic resonance image segmentation is one of the most important tasks in medical image analysis and has considerable importance to the effective use of medical imagery in clinical and surgical setting. In particular, the tissue segmentation of white matter (WM), gray matter (GM), and cerebrospinal fluid (CSF) is crucial for brain measurement and disease diagnosis. A variety of studies have shown that the learning-based techniques are efficient and effective in brain tissue segmentation. However, the learning-based segmentation methods depend largely on the availability of good training labels...
October 2016: Machine Learning in Medical Imaging
https://www.readbyqxmd.com/read/28090450/quantitative-magnetic-resonance-imaging-of-the-lumbar-intervertebral-discs
#6
REVIEW
Dosik Hwang, Sewon Kim, Nirusha A Abeydeera, Sheronda Statum, Koichi Masuda, Christine B Chung, Palanan Siriwanarangsun, Won C Bae
Human lumbar spine is composed of multiple tissue components that serve to provide structural stability and proper nutrition. Conventional magnetic resonance (MR) imaging techniques have been useful for evaluation of IVD, but inadequate at imaging the discovertebral junction and ligamentous tissues due primarily to their short T2 nature. Ultrashort time to echo (UTE) MR techniques acquire sufficient MR signal from these short T2 tissues, thereby allowing direct and quantitative evaluation. This article discusses the anatomy of the lumbar spine, MR techniques available for morphologic and quantitative MR evaluation of long and short T2 tissues of the lumbar spine, considerations for T2 relaxation modeling and fitting, and existing and new techniques for spine image post-processing, focusing on segmentation...
December 2016: Quantitative Imaging in Medicine and Surgery
https://www.readbyqxmd.com/read/28078511/intra-individual-comparison-of-different-gadolinium-based-contrast-agents-in-the-quantitative-evaluation-of-c6-glioma-with-dynamic-contrast-enhanced-magnetic-resonance-imaging
#7
Ying Li, Gang Liu, Xin Lou, Zhiye Chen, Lin Ma
This experiment aimed to compare the ionic (Gadodiamide, Gd-DTPA-BMA) and non-ionic (Gadopentetate dimeglumine, Gd-DTPA) gadolinium-based contrast agents (GBCA) in the quantitative evaluation of C6 glioma with dynamic contrast-enhanced magnetic resonance imaging (DCE-MRI). A C6 glioma model was established in 12 Wistar rats, and magnetic resonance (MR) scans were performed six days after tumor implantation. Imaging was performed using a 3.0-T MR scanner with a 7-inch handmade circular coil. Pre-contrast T1 mapping and dynamic contrast-enhanced T1WI after a bolus injection (0...
January 4, 2017: Science China. Life Sciences
https://www.readbyqxmd.com/read/28063613/why-and-where-do-we-miss-significant-prostate-cancer-with-multi-parametric-magnetic-resonance-imaging-followed-by-magnetic-resonance-guided-and-transrectal-ultrasound-guided-biopsy-in-biopsy-na%C3%A3-ve-men
#8
Martijn G Schouten, Marloes van der Leest, Morgan Pokorny, Martijn Hoogenboom, Jelle O Barentsz, Les C Thompson, Jurgen J Fütterer
BACKGROUND: Knowledge of significant prostate (sPCa) locations being missed with magnetic resonance (MR)- and transrectal ultrasound (TRUS)-guided biopsy (Bx) may help to improve these techniques. OBJECTIVE: To identify the location of sPCa lesions being missed with MR- and TRUS-Bx. DESIGN, SETTING, AND PARTICIPANTS: In a referral center, 223 consecutive Bx-naive men with elevated prostate specific antigen level and/or abnormal digital rectal examination were included...
January 4, 2017: European Urology
https://www.readbyqxmd.com/read/28059711/t1-recovery-is-predominantly-found-in-black-holes-and-is-associated-with-clinical-improvement-in-patients-with-multiple-sclerosis
#9
C Thaler, T D Faizy, J Sedlacik, B Holst, K Stürner, C Heesen, J-P Stellmann, J Fiehler, S Siemonsen
BACKGROUND AND PURPOSE: Quantitative MR imaging parameters help to evaluate disease progression in multiple sclerosis and increase correlation with clinical disability. We therefore hypothesized that T1 values might be a marker for ongoing tissue damage or even remyelination and may help increase clinical correlation. MATERIALS AND METHODS: MR imaging was performed in 17 patients with relapsing-remitting MS at baseline and after 12 months of starting immunotherapy with dimethyl fumarate...
November 10, 2016: AJNR. American Journal of Neuroradiology
https://www.readbyqxmd.com/read/28059680/correlations-of-atrial-diameter-and-frontooccipital-horn-ratio-with-ventricle-size-in-fetal-ventriculomegaly
#10
Jared M Pisapia, Martin Rozycki, Hamed Akbari, Spyridon Bakas, Jayesh P Thawani, Julie S Moldenhauer, Phillip B Storm, Deborah M Zarnow, Christos Davatzikos, Gregory G Heuer
OBJECTIVE Fetal ventriculomegaly (FV), or enlarged cerebral ventricles in utero, is defined in fetal studies as an atrial diameter (AD) greater than 10 mm. In postnatal studies, the frontooccipital horn ratio (FOHR) is commonly used as a proxy for ventricle size (VS); however, its role in FV has not been assessed. Using image analysis techniques to quantify VS on fetal MR images, authors of the present study examined correlations between linear measures (AD and FOHR) and VS in patients with FV. METHODS The authors performed a cross-sectional study using fetal MR images to measure AD in the axial plane at the level of the atria of the lateral ventricles and to calculate FOHR as the average of the frontal and occipital horn diameters divided by the biparietal distance...
January 6, 2017: Journal of Neurosurgery. Pediatrics
https://www.readbyqxmd.com/read/28059651/automatic-estimation-of-extent-of-resection-and-residual-tumor-volume-of-patients-with-glioblastoma
#11
Raphael Meier, Nicole Porz, Urspeter Knecht, Tina Loosli, Philippe Schucht, Jürgen Beck, Johannes Slotboom, Roland Wiest, Mauricio Reyes
OBJECTIVE In the treatment of glioblastoma, residual tumor burden is the only prognostic factor that can be actively influenced by therapy. Therefore, an accurate, reproducible, and objective measurement of residual tumor burden is necessary. This study aimed to evaluate the use of a fully automatic segmentation method-brain tumor image analysis (BraTumIA)-for estimating the extent of resection (EOR) and residual tumor volume (RTV) of contrast-enhancing tumor after surgery. METHODS The imaging data of 19 patients who underwent primary resection of histologically confirmed supratentorial glioblastoma were retrospectively reviewed...
January 6, 2017: Journal of Neurosurgery
https://www.readbyqxmd.com/read/28058674/quantitative-myocardial-blood-flow-imaging-with-integrated-time-of-flight-pet-mr
#12
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/28055830/stratified-decision-forests-for-accurate-anatomical-landmark-localization-in-cardiac-images
#13
Ozan Oktay, Wenjia Bai, Ricardo Guerrero, Martin Rajchl, Antonio de Marvao, Declan P O'Regan, Stuart A Cook, Mattias P Heinrich, Ben Glocker, Daniel Rueckert
Accurate localization of anatomical landmarks is an important step in medical imaging, as it provides useful prior information for subsequent image analysis and acquisition methods. It is particularly useful for initialization of automatic image analysis tools (e.g. segmentation and registration) and detection of scan planes for automated image acquisition. Landmark localization has been commonly performed using learning based approaches, such as classifier and/or regressor models. However, trained models may not generalize well in heterogeneous datasets when the images contain large differences due to size, pose and shape variations of organs...
January 2017: IEEE Transactions on Medical Imaging
https://www.readbyqxmd.com/read/28054724/learning-based-3t-brain-mri-segmentation-with-guidance-from-7t-mri-labeling
#14
Minghui Deng, Renping Yu, Li Wang, Feng Shi, Pew-Thian Yap, Dinggang Shen
PURPOSE: Segmentation of brain magnetic resonance (MR) images into white matter (WM), gray matter (GM), and cerebrospinal fluid (CSF) is crucial for brain structural measurement and disease diagnosis. Learning-based segmentation methods depend largely on the availability of good training ground truth. However, the commonly used 3T MR images are of insufficient image quality and often exhibit poor intensity contrast between WM, GM, and CSF. Therefore, they are not ideal for providing good ground truth label data for training learning-based methods...
December 2016: Medical Physics
https://www.readbyqxmd.com/read/28050972/registration-of-mri-to-intraoperative-radiographs-for-target-localization-in-spinal-interventions
#15
T De Silva, A Uneri, M D Ketcha, S Reaungamornrat, J Goerres, M W Jacobson, S Vogt, G Kleinszig, A J Khanna, J-P Wolinsky, J H Siewerdsen
Decision support to assist in target vertebra localization could provide a useful aid to safe and effective spine surgery. Previous solutions have shown 3D-2D registration of preoperative CT to intraoperative radiographs to reliably annotate vertebral labels for assistance during level localization. We present an algorithm (referred to as MR-LevelCheck) to perform 3D-2D registration based on a preoperative MRI to accommodate the increasingly common clinical scenario in which MRI is used instead of CT for preoperative planning...
January 4, 2017: Physics in Medicine and Biology
https://www.readbyqxmd.com/read/28048929/su-c-207b-04-automated-segmentation-of-pectoral-muscle-in-mr-images-of-dense-breasts
#16
E Verburg, S N de Waard, W B Veldhuis, C H van Gils, Kga Gilhuijs
PURPOSE: To develop and evaluate a fully automated method for segmentation of the pectoral muscle boundary in Magnetic Resonance Imaging (MRI) of dense breasts. METHODS: Segmentation of the pectoral muscle is an important part of automatic breast image analysis methods. Current methods for segmenting the pectoral muscle in breast MRI have difficulties delineating the muscle border correctly in breasts with a large proportion of fibroglandular tissue (i.e., dense breasts)...
June 2016: Medical Physics
https://www.readbyqxmd.com/read/28048897/su-f-j-156-the-feasibility-of-mr-only-imrt-planning-for-prostate-anatomy
#17
R Vaitheeswaran, K R Sivaramakrishnan, Prashant Kumar, Raja Gattamaneni, Girish Kumar
PURPOSE: For prostate anatomy, previous investigations have shown that simulated CT (sCT) generated from MR images can be used for accurate dose computation. In this study, we demonstrate the feasibility of MR-only IMRT planning for prostate case. METHODS: Regular CT (rCT) and MR images of the same patient were acquired for prostate anatomy. Regions-of-interest (ROIs) i.e. target and risk structures are delineated on the rCT. A simulated CT (sCT) is generated from the MR image using the method described by Schadewaldt N et al...
June 2016: Medical Physics
https://www.readbyqxmd.com/read/28048895/mo-a-207b-01-radiomics-segmentation-feature-extraction-techniques
#18
H Veeraraghavan
: Image segmentation is one of the core problems for applying radiomics-based analysis to images. However, achieving repeatable and accurate segmentations for large datasets is challenging. The choice of segmentation method, the metrics used to evaluate the quality of such segmentations all depend on the specific clinical problem. This course will introduce three approaches, namely, fully automatic, interactive, and semi-automatic methods for generating segmentations. The pros and cons of each approach and when to choose a specific method will be discussed...
June 2016: Medical Physics
https://www.readbyqxmd.com/read/28048822/su-f-j-163-in-vivo-quantification-of-sequence-parameter-effect-on-geometric-distortion-caused-by-implanted-titanium-brachytherapy-applicator
#19
T Sullivan, A Diak, M Surucu, J Yacoub, M Harkenrider, S Shea
PURPOSE: The use of MR to plan and evaluate brachytherapy treatment for cervical cancer is increasing given the availability of MR conditional or safe applicators and MRI's proven superiority to CT for characterizing soft tissue lesions. The titanium applicators, however, cause geometric distortions or imaging artifacts, which reduce the utility of MRI for dosimetry. We sought to quantify the observed volume of the same applicator on a previously optimized T2 sequence in comparison to the conventional T2 sequence and CT obtained for brachytherapy planning...
June 2016: Medical Physics
https://www.readbyqxmd.com/read/28048807/su-g-iep1-02-automated-snr-analysis-of-mr-images-using-model-based-noise-determination
#20
K Krugh
PURPOSE: To develop a robust automated method of signal-to-noise (SNR) analysis from MR images using a single image acquisition approach and model-based noise determination. METHODS: Three consecutive MRI phantom scans were performed according to the SNR test procedures in the 2015 ACR MRI Quality Control Manual. This was repeated for several different RF coils and on MRI scanners from two different vendors. The three images from each RF coil were analyzed by the single-image (SNR-ACR1) and two-image (SNR-ACR2) SNR analysis methods also described in the ACR QC Manual...
June 2016: Medical Physics
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