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https://www.readbyqxmd.com/read/28441235/noninvasive-iphone-measurement-of-left-ventricular-ejection-fraction-using-intrinsic-frequency-methodology
#1
Niema M Pahlevan, Derek G Rinderknecht, Peyman Tavallali, Marianne Razavi, Thao T Tran, Michael W Fong, Robert A Kloner, Marie Csete, Morteza Gharib
OBJECTIVE: The study is based on previously reported mathematical analysis of arterial waveform that extracts hidden oscillations in the waveform that we called intrinsic frequencies. The goal of this clinical study was to compare the accuracy of left ventricular ejection fraction derived from intrinsic frequencies noninvasively versus left ventricular ejection fraction obtained with cardiac MRI, the most accurate method for left ventricular ejection fraction measurement. DESIGN: After informed consent, in one visit, subjects underwent cardiac MRI examination and noninvasive capture of a carotid waveform using an iPhone camera (The waveform is captured using a custom app that constructs the waveform from skin displacement images during the cardiac cycle...
April 22, 2017: Critical Care Medicine
https://www.readbyqxmd.com/read/28441159/application-of-high-speed-t1-sequences-for-high-quality-hepatic-arterial-phase-magnetic-resonance-imaging-intraindividual-comparison-of-single-and-multiple-arterial-phases
#2
Yang Shin Park, Chang Hee Lee, Jeong Woo Kim, Young-Sun Lee, MunYoung Paek, Kyeong Ah Kim
PURPOSE: The aim of this study was to compare intraindividual single and multiple arterial phase acquisitions and evaluate which acquisition method was more advantageous for obtaining high-quality hepatic arterial phase in gadoxetic acid-enhanced liver magnetic resonance imaging (MRI). MATERIALS AND METHODS: Sixty-seven patients who underwent gadoxetic acid-enhanced liver MRIs and had all 3 kinds of acquisitions (single, dual, and triple arterial phases) were retrospectively included...
April 24, 2017: Investigative Radiology
https://www.readbyqxmd.com/read/28440795/multimodal-chest-surface-motion-data-for-respiratory-and-cardiovascular-monitoring-applications
#3
Ghufran Shafiq, Kalyana Chakravarthy Veluvolu
Chest surface motion is of significant importance as it contains information of respiratory and cardiac systems together with the complex coupling between these two systems. Chest surface motion is not only critical in radiotherapy, but also useful in personalized systems for continuous cardiorespiratory monitoring. In this dataset, a multimodal setup is employed to simultaneously acquire cardiorespiratory signals. These signals include high-density trunk surface motion (from 16 distinct locations) with VICON motion capture system, nasal breathing from a thermal sensor, respiratory effort from a strain belt and electrocardiogram in lead-II configuration...
April 25, 2017: Scientific Data
https://www.readbyqxmd.com/read/28436094/dosimetric-validation-of-a-magnetic-resonance-image-gated-radiotherapy-system-using-a-motion-phantom-and-radiochromic-film
#4
James M Lamb, John S Ginn, Dylan P O'Connell, Nzhde Agazaryan, Minsong Cao, David H Thomas, Yingli Yang, Mircea Lazea, Percy Lee, Daniel A Low
PURPOSE: Magnetic resonance image (MRI) guided radiotherapy enables gating directly on the target position. We present an evaluation of an MRI-guided radiotherapy system's gating performance using an MRI-compatible respiratory motion phantom and radiochromic film. Our evaluation is geared toward validation of our institution's clinical gating protocol which involves planning to a target volume formed by expanding 5 mm about the gross tumor volume (GTV) and gating based on a 3 mm window about the GTV...
April 24, 2017: Journal of Applied Clinical Medical Physics
https://www.readbyqxmd.com/read/28432730/assessment-of-voluntary-deep-inspiration-breath-hold-with-cine-imaging-for-breast-radiotherapy
#5
Reuben Patrick Estoesta, Lani Attwood, Diana Naehrig, Elizabeth Claridge-Mackonis, David Odgers, Darren Martin, Melissa Pham, Joanne Toohey, Susan Carroll
Deep Inspiration Breath-Hold (DIBH) techniques for breast cancer radiation therapy (RT) have reduced cardiac dose compared to Free Breathing (FB). Recently, a voluntary deep inspiration breath-hold (vDIBH) technique was established using in-room lasers and skin tattoos to monitor breath-hold. An in-house quality assessment of positional reproducibility during RT delivery with vDIBH in patients with left-sided breast cancer was evaluated. The electronic portal imaging device (EPID) was used in cinematographic (CINE) mode to capture a sequence of images during beam delivery...
April 22, 2017: Journal of Medical Imaging and Radiation Oncology
https://www.readbyqxmd.com/read/28428470/effects-of-valsalva-maneuver-by-different-breath-holding-techniques-to-detect-pulmonary-thromboembolism-in-a-contrast-enhanced-computed-tomography-examination
#6
Chiaki Suzuki, Kenji Fujisaki, Yuusuke Atsumi, Miki Takemura, Kouichi Mizuno, Takeki Nagamine, Tomoyasu Amano, Hideo Yamamoto, Mamoru Takahashi
The purpose of this study is to measure the hemodynamics on the effect of Valsalva maneuver aiming at pulmonary thromboembolism (PTE) using 2-dimensional (2D) phase contrast imaging of magnetic resonance image (MRI), Philips Ingenia 3.0-tesla (T). The maximal inspiration reduced the blood flow rate in various degrees at all measurement positions, superior vena cava (SVC), inferior vena cava (IVC), pulmonary artery (PA), ascending aorta (AA), and descending aorta (DA). This result suggests that the contrast effect in the PA might become weak during general PA phase to give a substantial influence of Valsalva maneuver in the condition after maximum inspiration...
2017: Nihon Hoshasen Gijutsu Gakkai Zasshi
https://www.readbyqxmd.com/read/28419608/multiple-breath-hold-proton-spectroscopy-of-human-liver-at-3t-relaxation-times-and-concentrations-of-glycogen-choline-and-lipids
#7
Jan Weis, Joel Kullberg, Håkan Ahlström
PURPOSE: To evaluate the feasibility of an expiration multiple breath-hold (1) H-MRS technique to measure glycogen (Glycg), choline-containing compounds (CCC), and lipid relaxation times T1 , T2 , and their concentrations in normal human liver. MATERIALS AND METHODS: Thirty healthy volunteers were recruited. Experiments were performed at 3T. Multiple expiration breath-hold single-voxel point-resolved spectroscopy (PRESS) technique was used for localization. Water-suppressed spectra were used for the estimation of Glycg, CCC, lipid methylene (CH2 )n relaxation times and concentrations...
April 17, 2017: Journal of Magnetic Resonance Imaging: JMRI
https://www.readbyqxmd.com/read/28419591/application-of-spin-echoes-in-the-regime-of-weak-dephasing-to-t1-mapping-of-the-lung
#8
Jakob Assländer, Steffen J Glaser, Jürgen Hennig
PURPOSE: This work presents an approach to mapping the entire lung's proton density and T1 within a single breath-hold and analyzes the apparent T1 when exciting with a spin echo generating pulse in comparison to a standard gradient echo acquisition. METHODS: An inversion-recovery SNAPSHOT-FLASH sequence with a stack-of-stars k-space readout with a golden angle increment was modified to use a spin echo generating radiofrequency-pulse for excitation. Data of five volunteers were acquired on a 3T scanner and image reconstruction was performed by an iterative algorithm adopted from MR-Fingerprinting...
April 17, 2017: Magnetic Resonance in Medicine: Official Journal of the Society of Magnetic Resonance in Medicine
https://www.readbyqxmd.com/read/28419582/free-breathing-liver-fat-quantification-using-a-multiecho-3d-stack-of-radial-technique
#9
Tess Armstrong, Isabel Dregely, Alto Stemmer, Fei Han, Yutaka Natsuaki, Kyunghyun Sung, Holden H Wu
PURPOSE: The diagnostic gold standard for nonalcoholic fatty liver disease is an invasive biopsy. Noninvasive Cartesian MRI fat quantification remains limited to a breath-hold (BH). In this work, a novel free-breathing 3D stack-of-radial (FB radial) liver fat quantification technique is developed and evaluated in a preliminary study. METHODS: Phantoms and healthy subjects (n = 11) were imaged at 3 Tesla. The proton-density fat fraction (PDFF) determined using FB radial (with and without scan acceleration) was compared to BH single-voxel MR spectroscopy (SVS) and BH 3D Cartesian MRI using linear regression (correlation coefficient ρ and concordance coefficient ρc ) and Bland-Altman analysis...
April 16, 2017: Magnetic Resonance in Medicine: Official Journal of the Society of Magnetic Resonance in Medicine
https://www.readbyqxmd.com/read/28417333/immediate-tissue-expander-or-implant-based-breast-reconstruction-does-not-compromise-the-oncologic-delivery-of-post-mastectomy-radiotherapy-pmrt
#10
Krishan R Jethwa, Mohamed M Kahila, Thomas J Whitaker, William S Harmsen, Kimberly S Corbin, Sean S Park, Elizabeth S Yan, Valerie Lemaine, Judy C Boughey, Robert W Mutter
PURPOSE: Increasingly, women are choosing immediate breast reconstruction (IBR) following mastectomy. Reports have indicated IBR may compromise post-mastectomy radiotherapy (PMRT). We investigated the impact of IBR on timing of PMRT, target coverage, and doses to organs at risk in a modern radiotherapy practice using advanced planning techniques. METHODS: Between 2013 and 2015, PMRT was delivered to 116 patients (66 mastectomy alone, 50 IBR). PMRT was delivered with a median dose of 50 Gy in 25 fractions...
April 17, 2017: Breast Cancer Research and Treatment
https://www.readbyqxmd.com/read/28409251/advanced-imaging-techniques-in-pediatric-body-mri
#11
REVIEW
Jesse Courtier, Anil G Rao, Sudha A Anupindi
While there are many challenges specific to pediatric abdomino-pelvic MRI, many recent advances are addressing these challenges. It is therefore essential for radiologists to be familiar with the latest advances in MR imaging. Laudable efforts have also recently been implemented in many centers to improve the overall experience of pediatric patients, including the use of dedicated radiology child life specialists, MRI video goggles, and improved MR suite environments. These efforts have allowed a larger number of children to be scanned while awake, with fewer studies being done under sedation or anesthesia; this has resulted in additional challenges from patient motion and difficulties with breath-holding and tolerating longer scan times...
May 2017: Pediatric Radiology
https://www.readbyqxmd.com/read/28398929/comprehensive-dynamic-contrast-enhanced-3d-magnetic-resonance-imaging-of-the-breast-with-fat-water-separation-and-high-spatiotemporal-resolution-using-radial-sampling-compressed-sensing-and-parallel-imaging
#12
Thomas Benkert, Kai Tobias Block, Samantha Heller, Melanie Moccaldi, Daniel K Sodickson, Sungheon Gene Kim, Linda Moy
OBJECTIVES: The aim of this study was to assess the applicability of Dixon radial volumetric encoding (Dixon-RAVE) for comprehensive dynamic contrast-enhanced 3D magnetic resonance imaging (MRI) of the breast using a combination of radial sampling, model-based fat/water separation, compressed sensing, and parallel imaging. MATERIALS AND METHODS: In this Health Insurance Portability and Accountability Act-compliant prospective study, 24 consecutive patients underwent bilateral breast MRI, including both conventional fat-suppressed and non-fat-suppressed precontrast T1-weighted volumetric interpolated breath-hold examination (VIBE)...
April 11, 2017: Investigative Radiology
https://www.readbyqxmd.com/read/28390002/a-tool-for-validating-mri-guided-strategies-a-digital-breathing-ct-mri-phantom-of-the-abdominal-site
#13
Chiara Paganelli, Paul Summers, Chiara Gianoli, Massimo Bellomi, Guido Baroni, Marco Riboldi
Dynamic magnetic resonance imaging (MRI) is emerging as the elected image modality for organ motion quantification and management in image-guided radiotherapy. However, the lack of validation tools is an open issue for image guidance in the abdominal and thoracic organs affected by organ motion due to respiration. We therefore present an abdominal four-dimensional (4D) CT/MRI digital phantom, including the estimation of MR tissue parameters, simulation of dedicated abdominal MR sequences, modeling of radiofrequency coil response and noise, followed by k-space sampling and image reconstruction...
April 8, 2017: Medical & Biological Engineering & Computing
https://www.readbyqxmd.com/read/28389274/significance-of-breath-hold-time-in-dry-powder-aerosol-drug-therapy-of-copd-patients
#14
Alpár Horváth, Imre Balásházy, Gábor Tomisa, Árpád Farkas
Aerosol drugs are effectively used to treat chronic respiratory diseases. The efficiency of the therapy depends also on the amount and distribution of drug deposited within the airways. The objective of this study is to apply numerical techniques to analyse the effect of the duration of breath-hold after the inhalation of six different commercialized dry powder drugs on their lung deposition. For this purpose a computational airway deposition model has been adapted and validated to the special case of therapeutic aerosols...
April 4, 2017: European Journal of Pharmaceutical Sciences
https://www.readbyqxmd.com/read/28383791/breath-hold-and-free-breathing-2d-phase-contrast-mri-for-quantification-of-oxygen-induced-changes-of-pulmonary-circulation-dynamics-in-healthy-volunteers
#15
Christoph P Czerner, Hinrich B Winther, Antonia Zapf, Frank Wacker, Jens Vogel-Claussen
PURPOSE: To evaluate the effect of inhaled 100% oxygen on pulmonary circulation dynamics in healthy volunteers using 2D phase-contrast magnetic resonance imaging (2D PC MRI). MATERIALS AND METHODS: Twenty-one healthy volunteers were examined at 1.5T. Through-plane 2D PC MRI measurements were performed in the main pulmonary artery during free-breathing and breath-hold. Acceleration time and volume, maximum and minimum area, area change, average and maximum mean velocity, forward volume, heart rate, as well as blood pressure were determined...
April 6, 2017: Journal of Magnetic Resonance Imaging: JMRI
https://www.readbyqxmd.com/read/28378187/ultra-low-dose-sequential-computed-tomography-for-quantitative-lung-aeration-assessment-a-translational-study
#16
Lorenzo Ball, Anja Braune, Francesco Corradi, Claudia Brusasco, Alessandro Garlaschi, Thomas Kiss, Thomas Bluth, Francesca Simonassi, Alice Bergamaschi, Jörg Kotzerke, Marcus J Schultz, Marcelo Gama de Abreu, Paolo Pelosi
BACKGROUND: Quantitative lung computed tomography (CT) provides fundamental information about lung aeration in critically ill patients. We tested a scanning protocol combining reduced number of CT slices and tube current, comparing quantitative analysis and radiation exposure to conventional CT. METHODS: In pigs, CT scans were performed during breath hold in a model of lung injury with three different protocols: standard spiral with 180 mAs tube current-time product (Spiral180), sequential with 20-mm distance between slices and either 180 mAs (Sequential180) or 50 mAs (Sequential50)...
December 2017: Intensive Care Medicine Experimental
https://www.readbyqxmd.com/read/28377563/breath-holding-as-a-specific-type-of-breathing-training-from-the-viewpoint-of-avicenna-authors-reply
#17
Grzegorz Bilo, Gianfranco Parati, Kalina Kawecka-Jaszcz
No abstract text is available yet for this article.
March 31, 2017: Polish Archives of Internal Medicine
https://www.readbyqxmd.com/read/28377562/breath-holding-as-a-specific-type-of-breathing-training-from-the-viewpoint-of-avicenna
#18
Narjes Gorji, Reihaneh Moeini, Seyyedali Mozaffarpour, Morteza Mojahedi
No abstract text is available yet for this article.
March 31, 2017: Polish Archives of Internal Medicine
https://www.readbyqxmd.com/read/28377138/daily-ct-guidance-improves-target-coverage-during-definitive-radiation-therapy-for-gastric-malt-lymphoma
#19
He Wang, Sarah A Milgrom, Bouthaina S Dabaja, Grace L Smith, Mary Martel, Chelsea C Pinnix
PURPOSE: Radiation therapy (RT) for gastric mucosa-associated lymphoid tissue (MALT) lymphoma is challenging because of variation in the stomach's position, size, and shape. We investigated the interfractional changes in stomach location, consequent dosimetric effects, and impact of daily computed tomography image guidance RT (CT-IGRT). METHODS AND MATERIALS: Twelve patients treated for gastric MALT lymphoma with intensity modulated radiation therapy, using a breath-hold technique and restriction of oral intake, were studied retrospectively...
March 6, 2017: Practical Radiation Oncology
https://www.readbyqxmd.com/read/28377061/respiratory-gated-bilateral-pulmonary-radiotherapy-for-ewing-s-sarcoma-and-nephroblastoma-in-children-and-young-adults-dosimetric-and-clinical-feasibility-studies
#20
C Demoor-Goldschmidt, S Chiavassa, S Josset, M-A Mahé, S Supiot
PURPOSE: Bilateral pulmonary radiotherapy in children and young adults aims to reduce the recurrence of lung metastases. The radiation field includes liver tissue, which is sensitive to even low radiation doses. We investigated the feasibility of respiratory gating radiotherapy using voluntary deep inspiration breath hold and its toxicity in these patients. PATIENTS AND METHOD: A retrospective clinical review was conducted for all patients who had undergone bilateral pulmonary radiotherapy, with or without deep inspiration breath hold, treated in our institution between October 1999 and May 2012...
April 1, 2017: Cancer Radiothérapie: Journal de la Société Française de Radiothérapie Oncologique
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