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BMC Medical Physics

Paul M Meaney, Andrew P Gregory, Neil R Epstein, Keith D Paulsen
BACKGROUND: Tissue dielectric properties are specific to physiological changes and consequently have been pursued as imaging biomarkers of cancer and other pathological disorders. However, a recent study (Phys Med Biol 52:2637-2656, 2007; Phys Med Biol 52:6093-6115, 2007), which utilized open-ended dielectric probing techniques and a previously established sensing volume, reported that the dielectric property contrast may only be 10% or less between breast cancer and normal fibroglandular tissue whereas earlier data suggested ratios of 4:1 and higher may exist...
2014: BMC Medical Physics
Signed E Prieto Bohórquez, Javier O Rodríguez Velásquez, S Catalina Correa Herrera, M Yolanda Soracipa Muñoz
BACKGROUND: Fractal geometry has been the basis for the development of a diagnosis of preneoplastic and neoplastic cells that clears up the undetermination of the atypical squamous cells of undetermined significance (ASCUS). METHODS: Pictures of 40 cervix cytology samples diagnosed with conventional parameters were taken. A blind study was developed in which the clinic diagnosis of 10 normal cells, 10 ASCUS, 10 L-SIL and 10 H-SIL was masked. Cellular nucleus and cytoplasm were evaluated in the generalized Box-Counting space, calculating the fractal dimension and number of spaces occupied by the frontier of each object...
2014: BMC Medical Physics
Avilash K Cramer, Amanu G Haile, Sanja Ognjenovic, Tulsee S Doshi, William Matthew Reilly, Katherine E Rubinstein, Nima Nabavizadeh, Thuan Nguyen, Lu Z Meng, Martin Fuss, James A Tanyi, Arthur Y Hung
BACKGROUND: The rapid adoption of image-guidance in prostate intensity-modulated radiotherapy (IMRT) results in longer treatment times, which may result in larger intrafraction motion, thereby negating the advantage of image-guidance. This study aims to qualify and quantify the contribution of image-guidance to the temporal dependence of intrafraction motion during prostate IMRT. METHODS: One-hundred and forty-three patients who underwent conventional IMRT (n=67) or intensity-modulated arc therapy (IMAT/RapidArc, n=76) for localized prostate cancer were evaluated...
September 23, 2013: BMC Medical Physics
Javier O Rodríguez, Signed E Prieto, Catalina Correa, Carlos E Pérez, Jessica T Mora, Juan Bravo, Yolanda Soracipa, Luisa F Alvarez
BACKGROUND: HIV diagnosis, prognostic and treatment requires T CD4 lymphocytes' number from flow cytometry, an expensive technique often not available to people in developing countries. The aim of this work is to apply a previous developed methodology that predicts T CD4 lymphocytes' value based on total white blood cell (WBC) count and lymphocytes count applying sets theory, from information taken from the Complete Blood Count (CBC). METHODS: Sets theory was used to classify into groups named A, B, C and D the number of leucocytes/mm3, lymphocytes/mm3, and CD4/μL3 subpopulation per flow cytometry of 800 HIV diagnosed patients...
September 14, 2013: BMC Medical Physics
David Tilly, Nina Tilly, Anders Ahnesjö
BACKGROUND: Calculation of accumulated dose in fractionated radiotherapy based on spatial mapping of the dose points generally requires deformable image registration (DIR). The accuracy of the accumulated dose thus depends heavily on the DIR quality. This motivates investigations of how the registration uncertainty influences dose planning objectives and treatment outcome predictions.A framework was developed where the dose mapping can be associated with a variable known uncertainty to simulate the DIR uncertainties in a clinical workflow...
June 14, 2013: BMC Medical Physics
Louise A Kelly, Duncan Ge McMillan, Alexandra Anderson, Morgan Fippinger, Gunnar Fillerup, Jane Rider
BACKGROUND: Few studies to date have directly compared the Actigraphs GT1M and the GT3X, it would be of tremendous value to know if these accelerometers give similar information about intensities of PA. Knowing if output is similar would have implications for cross-examination of studies. The purpose of the study was to assess the validity of the GT1M and the GT3X Actigraph accelerometers for the assessment of physical activity against oxygen consumption in laboratory conditions. METHODS: Forty-two college-aged participants aged 18-25 years wore the GT1M and the GT3X on their right hip during treadmill exercise at three different speeds, slow walking 4...
2013: BMC Medical Physics
Jan Axelsson, Jens Sörensen
BACKGROUND: In this paper we apply the principal-component analysis filter (Hotelling filter) to reduce noise from dynamic positron-emission tomography (PET) patient data, for a number of different radio-tracer molecules. We furthermore show how preprocessing images with this filter improves parametric images created from such dynamic sequence.We use zero-mean unit variance normalization, prior to performing a Hotelling filter on the slices of a dynamic time-series. The Scree-plot technique was used to determine which principal components to be rejected in the filter process...
2013: BMC Medical Physics
Patricio S La Rosa, Hari Eswaran, Hubert Preissl, Arye Nehorai
BACKGROUND: Analyzing and monitoring uterine contractions during pregnancy is relevant to the field of reproductive health assessment. Its clinical importance is grounded in the need to reliably predict the onset of labor at term and pre-term. Preterm births can cause health problems or even be fatal for the fetus. Currently, there are no objective methods for consistently predicting the onset of labor based on sensing of the mechanical or electrophysiological aspects of uterine contractions...
November 5, 2012: BMC Medical Physics
Meysam Khosravifarsani, Ali Shabestani Monfared, Haleh Akhavan-Niaki, Dariush Moslemi, Karimollah Hajian-Tilaki, Farideh Elahimanesh, Sajad Borzoueisileh, Nayer Seyfizadeh, Mehrangiz Amiri
UNLABELLED: <AbstractText Label="BACKGROUND" NlmCategory="BACKGROUND">Radiosensitivity is an inheriting trait that mainly depends on genetic factors. it is well known in similar dose of ionizing radiation and identical biological characteristics 9-10 percent of normal population have higher radiation response. Some reports indicate that distribution of breast cancer, immune diseases including autoimmune diseases as example lupus, Myasthenia Gravies and even the rate of allergy are more frequent in left handed individuals compared to right handed individuals...
August 24, 2012: BMC Medical Physics
Violaine Beneyton, Claudine Niederst, Céline Vigneron, Philippe Meyer, François Becmeur, Luc Marcellin, Patrick Lutz, Georges Noel
BACKGROUND: Intensity modulated radiotherapy is an efficient radiotherapy technique to increase dose in target volumes and decrease irradiation dose in organs at risk. This last objective is mainly relevant in children. However, previous results suggested that IMRT could increase low dose, factor of risk for secondary radiation induced cancer. This study was performed to compare dose distributions with 3D-radiotherapy (3D-RT) and IMRT with tomotherapy (HT) in children with neuroblastoma...
June 28, 2012: BMC Medical Physics
Angela Ng, Thao-Nguyen Nguyen, Joanne L Moseley, David C Hodgson, Michael B Sharpe, Kristy K Brock
BACKGROUND: Biologically-based models that utilize 3D radiation dosimetry data to estimate the risk of late cardiac effects could have significant utility for planning radiotherapy in young patients. A major challenge arises from having only 2D treatment planning data for patients with long-term follow-up. In this study, we evaluate the accuracy of an advanced deformable image registration (DIR) and navigator channels (NC) adaptation technique to reconstruct 3D heart volumes from 2D radiotherapy planning images for Hodgkin's Lymphoma (HL) patients...
January 18, 2012: BMC Medical Physics
Yongsook C Lee, Gary D Fullerton, Cristel Baiu, Margaret G Lescrenier, Beth A Goins
BACKGROUND: Evaluation of changes in tumor size from images acquired by ultrasound (US), computed tomography (CT) or magnetic resonance imaging (MRI) is a common measure of cancer chemotherapy efficacy. Tumor size measurement based on either the World Health Organization (WHO) criteria or the Response Evaluation Criteria in Solid Tumors (RECIST) is the only imaging biomarker for anti-cancer drug testing presently approved by the United States Food and Drug Administration (FDA). The aim of this paper was to design and test a quality assurance phantom with the capability of monitoring tumor size changes with multiple preclinical imaging scanners (US, CT and MRI) in order to facilitate preclinical anti-cancer drug testing...
September 30, 2011: BMC Medical Physics
Javier O Rodríguez, Signed E Prieto, Catalina Correa, Pedro A Bernal, Germán E Puerta, Sarith Vitery, Yolanda Soracipa, Diana Muñoz
BACKGROUND: Fractal geometry is employ to characterize the irregular objects and had been used in experimental and clinic applications. Starting from a previous work, here we made a theoretical research based on a geometric generalization of the experimental results, to develop a theoretical generalization of the stenotic and restenotic process, based on fractal geometry and Intrinsic Mathematical Harmony. METHODS: Starting from all the possibilities of space occupation in box-counting space, all arterial prototypes differentiating normality and disease were obtained with a computational simulation...
September 17, 2010: BMC Medical Physics
Rupak Pathak, Adarsh Ramakumar, Uma Subramanian, Pataje G S Prasanna
BACKGROUND: Radiation-induced chromosome aberrations lead to a plethora of detrimental effects at cellular level. Chromosome aberrations provide broad spectrum of information ranging from probability of malignant transformation to assessment of absorbed dose. Studies mapping differences in radiation sensitivities between human chromosomes are seldom undertaken. Consequently, health risk assessment based on radio-sensitivities of individual chromosomes may be erroneous. Our efforts in this article, attempt to demonstrate differences in radio-sensitivities of human chromosome-1 and/or -2, both in interphase and metaphase spreads...
June 16, 2009: BMC Medical Physics
Raymond Q Migrino, Richard Christenson, Aniko Szabo, Megan Bright, Seth Truran, Parameswaran Hari
BACKGROUND: Light chain amyloidosis (AL) is a rare plasma cell dyscrasia associated with poor survival especially in the setting of heart failure. Late gadolinium enhancement (LGE) on cardiac MRI was recently found to correlate with myocardial amyloid deposition but the prognostic role is not established. The aim is to determine the prognostic significance of LGE in AL by comparing long term survival of AL patients with and without LGE. METHODS: Twenty nine consecutive patients (14 females; 62 +/- 11 years) with biopsy-proven AL undergoing cardiac MRI with gadolinium as part of AL workup were included...
May 5, 2009: BMC Medical Physics
Amita Shukla-Dave, Nancy Lee, Hilda Stambuk, Ya Wang, Wei Huang, Howard T Thaler, Snehal G Patel, Jatin P Shah, Jason A Koutcher
BACKGROUND: The present study determines the feasibility of generating an average arterial input function (Avg-AIF) from a limited population of patients with neck nodal metastases to be used for pharmacokinetic modeling of dynamic contrast-enhanced MRI (DCE-MRI) data in clinical trials of larger populations. METHODS: Twenty patients (mean age 50 years [range 27-77 years]) with neck nodal metastases underwent pretreatment DCE-MRI studies with a temporal resolution of 3...
April 7, 2009: BMC Medical Physics
Janaka Lenora, Kristina Norrgren, Ola Thorsson, Per Wollmer, Karl J Obrant, Kaisa K Ivaska
BACKGROUND: Skeletal uptake of 99mTc labelled methylene diphosphonate (99mTc-MDP) is used for producing images of pathological bone uptake due to its incorporation to the sites of active bone turnover. This study was done to validate bone turnover markers using total skeletal uptake (TSU) of 99mTc-MDP. METHODS: 22 postmenopausal women (52-80 years) volunteered to participate. Scintigraphy was performed by injecting 520 MBq of 99mTc-MDP and taking whole body images after 3 minutes, and 5 hours...
March 30, 2009: BMC Medical Physics
Karin Knešaurek, Josef Machac, Zhuangyu Zhang
BACKGROUND: We evaluated the repeatability of the calculation of myocardial blood flow (MBF) at rest and pharmacological stress, and calculated the coronary flow reserve (CFR) utilizing 82Rb PET imaging. The aim of the research was to prove high repeatability for global MBF and CFR values and good repeatability for regional MBF and CFR values. The results will have significant impact on cardiac PET imaging in terms of making it more affordable and increasing its use. METHODS: 12 normal volunteers were imaged at rest and during pharmacological stress, with 2220 MBq of 82Rb each...
January 29, 2009: BMC Medical Physics
Eilon D Kirson, Rosa S Schneiderman, Vladimír Dbalý, Frantisek Tovarys, Josef Vymazal, Aviran Itzhaki, Daniel Mordechovich, Zoya Gurvich, Esther Shmueli, Dorit Goldsher, Yoram Wasserman, Yoram Palti
BACKGROUND: The present study explores the efficacy and toxicity of combining a new, non-toxic, cancer treatment modality, termed Tumor Treating Fields (TTFields), with chemotherapeutic treatment in-vitro, in-vivo and in a pilot clinical trial. METHODS: Cell proliferation in culture was studied in human breast carcinoma (MDA-MB-231) and human glioma (U-118) cell lines, exposed to TTFields, paclitaxel, doxorubicin, cyclophosphamide and dacarbazine (DTIC) separately and in combinations...
2009: BMC Medical Physics
Helmar Bergmann, Gregory Minear, Maria Raith, Peter M Schaffarich
BACKGROUND: The accuracy of multiple window spatial resolution characterises the performance of a gamma camera for dual isotope imaging. In the present study we investigate an alternative method to the standard NEMA procedure for measuring this performance parameter. METHODS: A long-lived 133Ba point source with gamma energies close to 67Ga and a single bore lead collimator were used to measure the multiple window spatial registration error. Calculation of the positions of the point source in the images used the NEMA algorithm...
December 9, 2008: BMC Medical Physics
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