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Grzegorz Bauman, Francesco Santini, Orso Pusterla, Oliver Bieri
PURPOSE: To present a technique for simultaneous mapping of T1 , T2 , and relative spin density (M0 ) in human lung using inversion recovery ultra-fast steady-state free precession (IR-ufSSFP) imaging. METHODS: Pulmonary relaxometry with IR-ufSSFP is based on an interleaved time series acquisition of 2D images acquired at 1.5T. The technique was tested in a phantom and in four healthy volunteers using breath-hold and electrocardiogram triggering. Typically, 30 transient state images were acquired in a single breath-hold within < 10 s...
October 19, 2016: Magnetic Resonance in Medicine: Official Journal of the Society of Magnetic Resonance in Medicine
Trembach Nikita, Zabolotskikh Igor
: The aim of the study was to determine the feasibility of using a breath-holding test in assessing the sensitivity of the peripheral chemoreflex compared with the single-breath carbon dioxide test. The study involved 48 healthy volunteers between the ages of 18 to 29 years. The breath-holding test was performed followed by the single-breath carbon dioxide test on the next day. A month after the first tests, these tests were repeated to evaluate their reproducibility The coefficient of variability in the single-breath carbon dioxide test ranged from 0 to 32% with a mean of 10±7%...
October 15, 2016: Respiratory Physiology & Neurobiology
Robert R Edelman, Marcos Botelho, Amit Pursnani, Shivraman Giri, Ioannis Koktzoglou
BACKGROUND: Dark blood imaging of the heart is conventionally performed using a breath-hold, dual-inversion Cartesian fast spin-echo pulse sequence. Our aim was to develop a faster, more flexible approach that would be less motion-sensitive and provide better image quality. For this purpose, we implemented a prototype radial balanced steady-state free precession (bSSFP) pulse sequence. METHODS: The study was approved by the institutional review board. Six healthy volunteers and 27 subjects undergoing clinically-indicated cardiovascular magnetic resonance (CMR) were imaged using dark blood Cartesian fast spin-echo and radial bSSFP...
October 19, 2016: Journal of Cardiovascular Magnetic Resonance
Ralf B Loeffler, M Beth McCarville, Anne W Wagstaff, Matthew P Smeltzer, Axel J Krafft, Ruitian Song, Jane S Hankins, Claudia M Hillenbrand
BACKGROUND: Liver R2* values calculated from multi-gradient echo (mGRE) magnetic resonance images (MRI) are strongly correlated with hepatic iron concentration (HIC) as shown in several independently derived biopsy calibration studies. These calibrations were established for axial single-slice breath-hold imaging at the location of the portal vein. Scanning in multi-slice mode makes the exam more efficient, since whole-liver coverage can be achieved with two breath-holds and the optimal slice can be selected afterward...
October 17, 2016: Pediatric Radiology
Shai Tejman-Yarden, Bruria Ben-Zeev, Yuval Goldshmit, Georgia Sarquella-Brugada, Assi Cicurel, Uriel Katz, David Mishali, Michael Glikson
BACKGROUND: Pacing can be a successful treatment for pallid breath-holding spells, primarily in individuals with severe bradycardia. PATIENT DESCRIPTION: We describe an 18-month-old girl experiencing severe pallid breath-holding spells in whom repeated electrocardiographic, Holter, and electroencephalographic monitoring tests were all normal. RESULTS: Using a subcutaneous insertable cardiac monitor, severe bradycardia was detected during one of this girl's episodes...
June 25, 2016: Pediatric Neurology
I G Murphy, M J Graves, S Reid, A J Patterson, I Patterson, A N Priest, D J Lomas
PURPOSE: Hepatic magnetic resonance elastography (MRE) is currently a breath-hold imaging technique. Patients with chronic liver disease can have comorbidities that limit their ability to breath-hold (BH) for the required acquisition time. Our aim was to evaluate whether stiffness measurements obtained from a navigator-triggered MRE acquisition are comparable to standard expiratory breath-hold, inspiratory breath-hold or free-breathing in healthy participants. MATERIALS AND METHODS: Twelve healthy participants were imaged using the four methods on a clinical 1...
October 13, 2016: Magnetic Resonance Imaging
Briana Welsh, Michael Chao, Farshad Foroudi
INTRODUCTION: When irradiating the left breast, a small portion of the heart and left anterior descending coronary artery (LAD) are often included in the treatment field. Deep inspiration breath-hold (DIBH) techniques reduce dose to coronary structures, but are resource intensive and may not be tolerated by all patients. The aim of this study was to evaluate a simple multi-leaf collimator (MLC) modification technique with respect to target coverage and organ-at-risk sparing. METHODS: Forty nine patients with left-sided breast cancer, planned with a simultaneous integrated boost technique were retrospectively replanned with additional shielding of the LAD...
September 9, 2016: Journal of Medical Radiation Sciences
Kady Fischer, Dominik P Guensch, Nancy Shie, Julie Lebel, Matthias G Friedrich
BACKGROUND: Breathing maneuvers can elicit a similar vascular response as vasodilatory agents like adenosine; yet, their potential diagnostic utility in the presence of coronary artery stenosis is unknown. The objective of the study is to investigate if breathing maneuvers can non-invasively detect inducible ischemia in an experimental animal model when the myocardium is imaged with oxygenation-sensitive cardiovascular magnetic resonance (OS-CMR). METHODS AND FINDINGS: In 11 anesthetised swine with experimentally induced significant stenosis (fractional flow reserve <0...
2016: PloS One
B F Kjølby, A R Khan, A Chuhutin, L Pedersen, J B Jensen, S Jakobsen, D Zeidler, R Sangill, J R Nyengaard, S N Jespersen, B Hansen
Diffusion kurtosis imaging (DKI) is sensitive to tissue microstructure and may therefore be useful in the diagnosis and monitoring of disease in brain and body organs. Generally, diffusion magnetic resonance imaging (dMRI) in the body is challenging because of the heterogeneous body composition, which can cause image artefacts as a result of chemical shifts and susceptibility differences. In addition, the abdomen possesses physiological factors (e.g. breathing, heartbeat, blood flow) which may severely reduce image quality, especially when echo planar imaging is employed, as is typical in dMRI...
October 12, 2016: NMR in Biomedicine
Felipe R Blasco, David J McKenzie, Edwin W Taylor, F Tadeu Rantin
Clarias gariepinus is a facultative air-breathing catfish that exhibits changes in heart rate (ƒH) associated with air-breaths (AB). A transient bradycardia prior to the AB is followed by sustained tachycardia during breath-hold. This study evaluated air-breathing and cardiac responses to sustained aerobic exercise in juveniles (total length ~20 cm), and how exercise influenced variations in fH associated with AB. In particular, it investigated the role of adrenergic and cholinergic control in cardiac responses, and effects of pharmacological abolition of this control on air-breathing responses...
October 5, 2016: Comparative Biochemistry and Physiology. Part A, Molecular & Integrative Physiology
Luciana Lastrucci, Simona Borghesi, Silvia Bertocci, Chiara Gasperi, Andrea Rampini, Giovanna Buonfrate, Paola Pernici, Roberta De Majo, Pietro Giovanni Gennari
PURPOSE: To compare 3D-conformal radiotherapy (3D-CRT) treatment plans based on free-breathing (FB) and deep inspiration breath hold (DIBH) and investigated whether DIBH technique enables a decrease of cardiac left anterior descending coronary artery (LADCA) and lungs dose with respect to the FB. METHODS: Twenty-three left-sided breast cancer patients referred for breast radiotherapy were included. The planning target volume (PTV) encompassed the breast and organs at risk including heart, LADCA, lungs, and contralateral breast, which were contoured in FB and DIBH CT scans...
September 27, 2016: Tumori
Suraj D Serai, Jonathan R Dillman, Andrew T Trout
Purpose To compare two-dimensional (2D) gradient-recalled echo (GRE) and 2D spin-echo (SE) echo-planar imaging (EPI) magnetic resonance (MR) elastography for measurement of hepatic stiffness in pediatric and young adult patients suspected of having liver disease. Materials and Methods In this institutional review board-approved, HIPAA-compliant study, 58 patients underwent both 2D GRE and 2D SE-EPI MR elastography at 1.5 T during separate breath holds. Liver stiffness (mean of means; in kilopascals) was measured by five blinded reviewers...
October 10, 2016: Radiology
Shirou Ishii, Takamitsu Hara, Takeyuki Nanbu, Hiroki Suenaga, Shigeyasu Sugawara, Daichi Kuroiwa, Hirofumi Sekino, Masayuki Miyajima, Hitoshi Kubo, Noboru Oriuchi, Hiroshi Ito
Although PET/MRI has the advantages of a simultaneous acquisition of PET and MRI, high soft-tissue contrast of the MRI images, and reduction of radiation exposure, its low profitability and long acquisition time are significant problems in clinical settings. Thus, MRI protocols that meet oncological purposes need to be used in order to reduce examination time while securing detectability. Currently, half-Fourier acquisition single-shot turbo spin echo and 3D-T1 volumetric interpolated breath-hold examination may be the most commonly used sequences for whole-body imaging due to their shorter acquisition time and higher diagnostic accuracy...
October 6, 2016: Japanese Journal of Radiology
Mirjana Josipovic, Gitte F Persson, Jens Peter Bangsgaard, Lena Specht, Marianne C Aznar
OBJECTIVES: We investigated the impact of deep inspiration breath-hold (DIBH) and tumour baseline shifts on image quality and registration uncertainty in image guided DIBH radiotherapy for locally advanced lung cancer. METHODS: Patients treated with daily cone beam CT (CBCT) guided free-breathing (FB) radiotherapy had an additional CBCT in DIBH at three fractions. These CBCTs were off-line rigidly registered (on tumour) to FB and DIBH CTs acquired at planning. All registrations were repeated to evaluate the intra-observer uncertainty...
October 6, 2016: British Journal of Radiology
Florian Dittmann, Heiko Tzschätzsch, Sebastian Hirsch, Eric Barnhill, Jürgen Braun, Ingolf Sack, Jing Guo
PURPOSE: To develop a compact magnetic resonance elastography (MRE) protocol for abdomen and to investigate the effect of water uptake on tissue stiffness in the liver, spleen, kidney, and pancreas. METHODS: Nine asymptomatic volunteers were investigated by MRE before and after 1 liter water uptake. Shear-wave excitation at four frequencies was transferred to the abdomen from anterior and posterior directions using pressurized air drivers. Tomographic representations of shear-wave speed were produced by analysis of multifrequency wave numbers in axial and coronal images acquired within four breath-holds or under free breathing, respectively...
October 3, 2016: Magnetic Resonance in Medicine: Official Journal of the Society of Magnetic Resonance in Medicine
Min Hee Lee, Hae Kyung Lee, Seo-Youn Choi, Boem Ha Yi
PURPOSE: The effectiveness of real-time feedback using an audible pulse in renal Doppler ultrasonography was evaluated. METHODS: This study was approved by the institutional review board of our hospital. Written informed consent was provided by all volunteers at enrollment. The 26 healthy volunteers enrolled in this study underwent Doppler ultrasound of both kidneys using audible and inaudible pulses in randomized order and at 1-week intervals. Doppler waveforms were obtained at the interlobar or arcuate arteries using a 2-mm Doppler gate...
2016: PloS One
Molham M Eyadeh, Mark A Weston, Janos Juhasz, Kevin R Diamond
Chest wall radiation therapy treatment delivery was monitored using a 5 mm thick radiochromic poly(vinyl alcohol) cryogel that also provided buildup material. The cryogels were used to detect positioning errors and measure the impact of shifts for a chest wall treatment that was delivered to a RANDO phantom. The phantom was shifted by ± 2, ± 3, and ± 5 mm from the planned position in the anterior/posterior (A/P) direction; these shifts represent setup errors and the uncertainty associated with lung filling during breath-hold...
2016: Journal of Applied Clinical Medical Physics
Hesamoddin Jahanian, Thomas Christen, Michael E Moseley, Nicholas M Pajewski, Clinton B Wright, Manjula K Tamura, Greg Zaharchuk
Measurement of the ability of blood vessels to dilate and constrict, known as vascular reactivity, is often performed with breath-holding tasks that transiently raise arterial blood carbon dioxide (PaCO2) levels. However, following the proper commands for a breath-holding experiment may be difficult or impossible for many patients. In this study, we evaluated two approaches for obtaining vascular reactivity information using blood oxygenation level-dependent signal fluctuations obtained from resting-state functional magnetic resonance imaging data: physiological fluctuation regression and coefficient of variation of the resting-state functional magnetic resonance imaging signal...
September 28, 2016: Journal of Cerebral Blood Flow and Metabolism
Choukri Mekkaoui, Timothy G Reese, Marcel P Jackowski, Stephen F Cauley, Kawin Setsompop, Himanshu Bhat, David E Sosnovik
Purpose To develop a clinically feasible whole-heart free-breathing diffusion-tensor (DT) magnetic resonance (MR) imaging approach with an imaging time of approximately 15 minutes to enable three-dimensional (3D) tractography. Materials and Methods The study was compliant with HIPAA and the institutional review board and required written consent from the participants. DT imaging was performed in seven healthy volunteers and three patients with pulmonary hypertension by using a stimulated echo sequence. Twelve contiguous short-axis sections and six four-chamber sections that covered the entire left ventricle were acquired by using simultaneous multisection (SMS) excitation with a blipped-controlled aliasing in parallel imaging readout...
September 28, 2016: Radiology
D S K Sihono, C Weiss, L Vogel, S Kegel, J Thölking, F Wenz, H Wertz, F Lohr, J Boda-Heggemann
No abstract text is available yet for this article.
October 1, 2016: International Journal of Radiation Oncology, Biology, Physics
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