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Table Motion

N Nguyen, N Knutson, M Schmidt, M Price
PURPOSE: To verify a method used to automatically acquire jaw, MLC, collimator and couch star shots for a Varian TrueBeam linear accelerator utilizing Developer Mode and an Electronic Portal Imaging Device (EPID). METHODS: An XML script was written to automate motion of the jaws, MLC, collimator and couch in TrueBeam Developer Mode (TBDM) to acquire star shot measurements. The XML script also dictates MV imaging parameters to facilitate automatic acquisition and recording of integrated EPID images...
June 2016: Medical Physics
E Kremmel, L Doyle, Y Yu, A Harrison
PURPOSE: A Varian PerfectPitch six degrees of freedom robotic table necessitates daily quality assurance (QA). Therapists were credentialed for this QA procedure which was easily incorporated into the existing daily warmup process. This procedure adds depth to TG-142 requirements without additional morning time costs. METHODS: This PerfectPitch table QA introduces a consistent rotation of the QUASAR™ Penta-Guide phantom and requires automatic table corrections through image fusions...
June 2016: Medical Physics
J Roeske, R Patel, M Surucu
PURPOSE: Organ motion, due to swallowing, can significantly affect the PTV margins used in head and neck patients. Evaluation of swallowing motion 2016 AAPM Annual Meeting Program Medical Physics, Vol. 43, No. 6, June 2016 3412 3412 may be performed using x-ray fluoroscopy. However, regions such as the soft palette and epiglottis may be difficult to visualize due to the presence of bone (mandible, teeth). The goal of this phantom study is to determine if dual energy (DE) subtraction would improve the visualization in these regions...
June 2016: Medical Physics
G Li, D Olek, J Wei, M Kadbi, N Tyagi, K Zakian, J Mechalakos, J Deasy, M Hunt
PURPOSE: To optimize T2-based respiratory-correlated 4DMRI for motion simulation, we evaluated the image quality after 4D reconstruction based on the two respiratory surrogates acquired independently and concurrently during the same breathing period. METHODS: Both internal navigator and external bellows were employed simultaneously during a 4DMRI acquisition on seven volunteers scanned coronally and sagittally under an IRB-approved protocol. The navigator was positioned at the right diaphragm dome while the bellows was placed at the upper abdomen...
June 2016: Medical Physics
M Law, J Yuan, O Wong, S Yu
PURPOSE: To investigate the 3D geometric distortion of four potential MR sequences for radiotheraptic applications, and its dependency on sequence-type, acquisition-orientation and receiver-bandwidth from a dedicated 1.5T 700mm-wide bore MR-simulator (Magnetom-Aera, Sienmens Healthcare, Erlangen, Germany), using a large customized geometric accuracy phantom. METHODS: This work studied 3D gradient-echo (VIBE) and spin-echo (SPACE) sequences for anatomical imaging; a specific ultra-short-TE sequence (PETRA) potentially for bone imaging and MR-based dosimetry; and a motion-insensitive sequence (BLADE) for dynamic applications like 4D-MRI...
June 2016: Medical Physics
T Szczykutowicz, E Janssen-Saldivar, D Miller, A Malkus
PURPOSE: Proper patient positioning is essential in CT to ensure automatic exposure control functions properly, noise uniformity, and CT number uniformity. This work describes how table height can be used as a surrogate for proper patient positioning and motivates incorporating table height recommendations as a function of patient size into technologist training programs. METHODS: Scan data were acquired from 551 adult and pediatric patients under IRB approval. The table height, mean anterior-posterior patient dimension, and mean lateral patient dimension were calculated for each patient...
June 2016: Medical Physics
B Burgdorf, G Freedman, B Teo
PURPOSE: The current standard CTV-to-PTV expansion for whole breast radiotherapy (WBRT) is 7mm, as recommended by RTOG-1005.This expansion is derived from the uncertainty due to patient positioning (±5mm) and respiratory motion (±5mm). We evaluated the expansion needed for respiratory motion uncertainty using 4DCT. After determining the appropriate expansion margins, RT plans were generated to evaluate the reduction in heart and lung dose. METHODS: 4DCT images were acquired during treatment simulation and retrospectively analyzed for 34 WBRT patients...
June 2016: Medical Physics
H Mehrens, B Lewis, C Lujano, T Nguyen, N Hernandez, P Alvarez, A Molineu, D Followill
PURPOSE: To describe the results of IROC Houston's international and domestic end-to-end QA phantom irradiations. METHODS: IROC Houston has anthropomorphic lung, liver, head and neck, prostate, SRS and spine phantoms that are used for credentialing and quality assurance purposes. The phantoms include structures that closely mimic targets and organs at risk and are made from tissue equivalent materials: high impact polystyrene, solid water, cork and acrylic. Motion tables are used to mimic breathing motion for some lung and liver phantoms...
June 2016: Medical Physics
R He, B Morris, N Duggar, A Markovich, J Standford, J Lu, C Yang
PURPOSE: SymmetryTM 4D IGRT system of Elekta has been installed at our institution, which offers the 4D CBCT registration option. This study is to evaluate the accuracy of 4D CBCT system by using the CIRS 4D motion phantom and to perform a feasibility study on the implementation of 4D-CBCT as image guidance for SBRT treatment. METHODS: The 3D and 4D CT image data sets are acquired using the CIRS motion phantom on a Philips large bore CT simulator. The motion was set as 0...
June 2016: Medical Physics
B Sarkar, A Manikandan, K Jassal, T Ganesh, A Munshi, B Mohanti, A Pradhan
PURPOSE: Six dimensional positional shifts (translational and rotational) determined by a volumetric imaging system were mathematically combined and incorporated as simple translational shifts and the resultant impact on dose characteristics was studied. METHODS: Thirty patients who underwent either single fraction (12 Gy) or five fractions (5 Gy per fraction) stereotactic treatments were included in this study. They were immobilized using a double layered thermoplastic mask from BrainLAB...
June 2016: Medical Physics
J Zhang, M Natwa, N C Hall, M U Knopp, B Zhang, C Tung, M V Knopp
PURPOSE: The longer patient has to remain on the table during PET imaging, the higher the likelihood of motion artifacts due to patient discomfort. This study was to investigate and optimize PET acquisition overlap in 18F-FDG oncology wholebody PET/CT to speed up PET acquisition and improve patient comfort. METHODS: Wholebody 18F-FDG PET/CT of phantoms, 8 pre-clinical patients (beagles) and 5 clinical oncology patients were performed in 90s/bed on a time-of-flight Gemini TF 64 system...
June 2016: Medical Physics
I Buzurovic, R Cormack
PURPOSE: We proposed a method for collision avoidance (CA) in external beam radiation therapy (EBRT). The method encompasses the analysis of all positions of the moving components of the beam delivery system such as the treatment table and gantry, including patient specific information obtained from the CT images. This method eliminates the need for time-consuming dry-runs prior to the actual treatments. METHODS: The QA procedure for EBRT requires that the collision should be checked prior to treatment...
June 2016: Medical Physics
T Akiyama, M A Van Zeeland, R L Boivin, T N Carlstrom, J A Chavez, C M Muscatello, R C O'Neill, J Vasquez, M Watkins, W Martin, A Colio, D K Finkenthal, D L Brower, J Chen, W X Ding, M Perry
A heterodyne detection scheme is combined with a 10.59 μm CO2 laser dispersion interferometer for the first time to allow large bandwidth measurements in the 10-100 MHz range. The approach employed utilizes a 40 MHz acousto-optic cell operating on the frequency doubled CO2 beam which is obtained using a high 2nd harmonic conversion efficiency orientation patterned gallium arsenide crystal. The measured standard deviation of the line integrated electron density equivalent phase resolution obtained with digital phase demodulation technique, is 4 × 10(17) m(-2)...
December 2016: Review of Scientific Instruments
Guang Li, Jie Wei, Devin Olek, Mo Kadbi, Neelam Tyagi, Kristen Zakian, James Mechalakos, Joseph O Deasy, Margie Hunt
PURPOSE: To compare the image quality of amplitude-binned 4-dimensional magnetic resonance imaging (4DMRI) reconstructed using 2 concurrent respiratory (navigator and bellows) waveforms. METHODS AND MATERIALS: A prospective, respiratory-correlated 4DMRI scanning program was used to acquire T2-weighted single-breath 4DMRI images with internal navigator and external bellows. After a 10-second training waveform of a surrogate signal, 2-dimensional MRI acquisition was triggered at a level (bin) and anatomic location (slice) until the bin-slice table was completed for 4DMRI reconstruction...
November 9, 2016: International Journal of Radiation Oncology, Biology, Physics
Leszek R Jaroszewicz, Anna Kurzych, Zbigniew Krajewski, Paweł Marć, Jerzy K Kowalski, Piotr Bobra, Zbigniew Zembaty, Bartosz Sakowicz, Robert Jankowski
Starting with descriptions of rotational seismology, areas of interest and historical field measurements, the fundamental requirements for rotational seismometers for seismological and engineering application are formulated. On the above basis, a review of all existing rotational seismometers is presented with a description of the principles of their operation as well as possibilities to fulfill formulated requirements. This review includes mechanical, acoustical, electrochemical and optical devices and shows that the last of these types are the most promising...
December 16, 2016: Sensors
Karen Strike, Kathy Mulder, Rojer Michael
BACKGROUND: Haemophilia is a bleeding disorder associated with haemorrhaging into joints and muscles. Exercise is often used to aid recovery after bleeds, and to improve joint function in the presence of arthropathy. OBJECTIVES: Our objective was to systematically review the available evidence on the safety and effectiveness of exercise for people with haemophilia. SEARCH METHODS: We searched the Cochrane Cystic Fibrosis and Genetic Disorders Group's Coagulopathies Trials Register and electronic databases PubMed, OVID-Embase, and CINAHL...
19, 2016: Cochrane Database of Systematic Reviews
A De Groef, M Van Kampen, N Vervloesem, E Clabau, M-R Christiaens, P Neven, I Geraerts, F Struyf, N Devoogdt
OBJECTIVES: To investigate inter-rater reliability of a set of shoulder measurements including inclinometry [shoulder range of motion (ROM)], acromion-table distance and pectoralis minor muscle length (static scapular positioning), upward rotation with two inclinometers (scapular kinematics) and pain pressure thresholds (muscle tenderness) in middle-aged women. DESIGN: Observational study. PARTICIPANTS: Thirty symptom-free middle-aged women (first cohort) were measured by two raters...
July 20, 2016: Physiotherapy
Geoff Nelson, Meng Wu, Cameron Hinkel, Ganesh Krishna, Tobias Funk, Jarrett Rosenberg, Rebecca Fahrig
PURPOSE: Electromagnetic navigation bronchoscopy (ENB) provides improved targeting accuracy during transbronchial biopsies of suspicious nodules. The greatest weakness of ENB-based guidance is the registration divergence that exists between the planning CT, acquired days or weeks before the intervention, and the patient on the table on the day of the intervention. Augmenting ENB guidance with real-time tomosynthesis imaging during the intervention could mitigate the divergence and further improve the yield of ENB-guided transbronchial biopsies...
December 2016: Medical Physics
Gregory House, Grigore Burdea, Namrata Grampurohit, Kevin Polistico, Doru Roll, Frank Damiani, Jasdeep Hundal, Didier Demesmin
BACKGROUND: Persistent pain in shoulder and arm following post-surgical breast cancer treatment can lead to cognitive and physical deficits. Depression is also common in breast cancer survivors. Virtual reality therapy with integrative cognitive and physical rehabilitation has not been clinically trialed for this population. The novel BrightArm Duo technology improved cognition and upper extremity (UE) function for other diagnoses and has great potential to benefit individuals coping with post-surgical breast cancer pain...
November 2016: British Journal of Pain
M Lyon, S L Rolston
By photoionizing samples of laser-cooled atoms with laser light tuned just above the ionization limit, plasmas can be created with electron and ion temperatures below 10 K. These ultracold neutral plasmas have extended the temperature bounds of plasma physics by two orders of magnitude. Table-top experiments, using many of the tools from atomic physics, allow for the study of plasma phenomena in this new regime with independent control over the density and temperature of the plasma through the excitation process...
January 2017: Reports on Progress in Physics
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