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ABFM NEWS - Radiodiagnóstico
Laboratório de Calibração para Radiodiagnóstico
Laboratório de Calibração para Radiodiagnóstico, acreditado junto ao Inmetro:
Colaborador: Secretaria Geral
Fonte: Walmoli Gerber
Coupling surface cameras with on-board fluoroscopy: A feasibility study
"Med. Phys. 38, 2937 (2011); doi:10.1118/1.3581057 (11 pages) To investigate the feasibility of using three-dimensional surface imaging cameras as an external surrogate of tumor motion through a temporal synchronization with kV imaging. " [+ leia mais]
Fonte: Medical Physics
Reducing 4D CT artifacts using optimized sorting based on anatomic similarity
"Med. Phys. 38, 2424 (2011); doi:10.1118/1.3577601 (6 pages) Four-dimensional (4D) computed tomography (CT) has been widely used as a tool to characterize respiratory motion in radiotherapy. The two most commonly used 4D CT algorithms sort images by the associated respiratory phase or displacement into a predefined number of bins, and are prone to image artifacts at transitions between bed positions. " [+ leia mais]
Fonte: Medical Physics
Analysis of Fourier-domain task-based detectability index in tomosynthesis and cone-beam CT in relation to human observer performance
"Med. Phys. 38, 1754 (2011); doi:10.1118/1.3560428 (15 pages) Design and optimization of medical imaging systems benefit from accurate theoretical modeling that identifies the physical factors governing image quality, particularly in the early stages of system development." [+ leia mais]
Fonte: Medical Physics
Mammography Quality Standards Act and Program
"MQSA National Statistics2 (4/1/11) Mammography Facility Adverse Event and Action Report - March 21, 20113 (3/28/11) FDA Safety Notification: Mammography Problems at Huntington Radiology in Huntington Park, California4 (3/10/" [+ leia mais]
Colaborador: Gisela Menegussi
Fonte: FDA
Radiation dose evaluation in multidetector-row CT imaging for acute stroke with an anthropomorphic phantom
"British Journal of Radiology (2010) 83, 1029-1041 This study evaluated radiation dose and dose reduction in CT imaging for acute stroke. Radiation doses in three types of CT imaging (i.e. non-contrast-enhanced CT, CT perfusion (CTP) and CT angiography (CTA)) were measured with an in-phantom dosimetry system for 4-, 16- and 64-detector CT scanners in 5 hospitals." [+ leia mais]
Fonte: British Journal of Radiology
Validation of SPAMM tagged MRI based measurement of 3D soft tissue deformation
"Med. Phys. 38, 1248 (2011); doi:10.1118/1.3533942 (13 pages) This study presents and validates a novel (non-ECG-triggered) MRI sequence based on spatial modulation of the magnetization (SPAMM) to noninvasively measure 3D (quasistatic) soft tissue deformations using only six acquisitions (three static and three indentations). In the current SPAMM tagged MRI approaches, data are typically constructed from many repeated motion cycles." [+ leia mais]
Fonte: Medical Physics
Open design eight-channel transmit/receive coil for high-resolution and real-time ankle imaging at 7 T
"Med. Phys. 38, 1162 (2011); doi:10.1118/1.3553399 (6 pages) At 1.5 T, real-time MRI of joint movement has been shown to be feasible. However, 7 T, provides higher SNR and thus an improved potential for parallel imaging acceleration." [+ leia mais]
Fonte: Medical Physics
Realizing perceptive virtual reality imaging applications on conventional PC hardware
In this work, we investigate the immersive presentation of three-dimensional content using real-time multi-view projection from a conventional PC hardware platform. By combining the available graphics capability of a modern workstation with an established, low-cost technique for multi-view image separation, we present a technique for real-time, interactive virtual reality content presentation. [+ leia mais]
Fonte: The Imaging Science Journal
Immediate Anatomic Results after the Endovascular Treatment of Unruptured Intracranial Aneurysms: Analysis of the ATENA Series
"American Journal of Neuroradiology 31:140-144, January 2010 A precise analysis of the immediate postoperative anatomic results in a large series of unruptured intracranial aneurysms treated by endovascular approach has not previously been presented." [+ leia mais]
Fonte: American Journal of Neuroradiology
The role of arterial embolization in blunt splenic injury
"The aim of study was to evaluate the results of our experience with transarterial embolization based on a modified algorithm in patients with splenic injury. La Radiologia Medica DOI: 10.1007/s11547-011-0624-y" [+ leia mais]
Fonte: Radiologia Médica
Functional Imaging of the Pelvic Floor
"The clinical treatment of patients with anorectal and pelvic floor dysfunction is often difficult. Dynamic cystocolpoproctography (DCP) has evolved from a method of evaluating the anorectum for functional disorders to its current status as a functional method of evaluating the global pelvic floor for defecatory disorders and pelvic organ prolapse. Radiology January 2011 258:23-39; doi:10.1148/radiol.10092367 " [+ leia mais]
Fonte: Radiology
An automatic and accurate x-ray tube focal spot/grid alignment system for mobile radiography: System description and alignment accuracy
"Med. Phys. 37, 6402 (2010); doi:10.1118/1.3518085 (9 pages) A mobile radiography automatic grid alignment system (AGAS) has been developed by modifying a commercially available mobile unit. The objectives of this article are to describe the modifications and operation and to report on the accuracy with which the focal spot is aligned to the grid and the time required to achieve the alignment. " [+ leia mais]
Colaborador: Cássio Vilela Komatsu
Fonte: Medical Physics
3D MR-Spectroscopic Imaging Assessment of Metabolic Activity in the Prostate During the PSA “Bounce” Following 125Iodine Brachytherapy
"Volume 79, Issue 2, 1 February 2011, Pages 371-378 A temporary increase in prostate-specific antigen (PSA) values is observed in 30%–40% of men following 125 I brachytherapy (BT) for prostate cancer. We present the results of a study to characterize prostate metabolic activity during the PSA “bounce” and to correlate metabolic changes with PSA levels using three-dimensional magnetic resonance spectroscopic imaging (3D-MRSI). " [+ leia mais]
Fonte: International Journal of Radiation Oncology*Biolog
Sonographic determination of fetal gender in the second and third trimesters in a private hospital in Enugu, southeast Nigeria
"Radiography Volume 16, Issue 4, November 2010, Pages 292-296 During the study, 1211 (81.8%) women requested gender information while the gender information from 269 (18.2%) women was requested for on clinical grounds. The mean GA at which the fetuses were scanned was 29+2 ± 3+6 weeks (range 14–40 weeks). Fetal gender assignment was possible in 1350 (91.2%) out of 1480 fetuses; 680 assigned male and 670 female. Of these, the fetal gender corroborated birth sex in 1325 (89.5%) and disagreed in 25 (1.7%) cases. The overall estimated sensitivity of the scan is 98.1%, while the estimated specificity for identification of the male sex (100%) was higher than the female (78.3%). Of the 130 cases where no identification of gender was possible, 50 were in the second trimester and 80 were in the third trimester. " [+ leia mais]
Fonte: Radiography
Med. Phys. 37, 6233 (2010); doi:10.1118/1.3514130 (7 pages)
"Purpose: Current on-board imaging systems commonly used by modern linear accelerators (LINACs) have a limited field of view (FOV) for a cone-beam CT (CBCT) scan, which is typically less than 50 cm. Consequently, truncation artifacts often occur for large patients. The goal of this work is to investigate a novel method to increase the FOV for current on-board CBCT systems. Methods: When a large patient is scanned with CBCT, any region outside the FOV is only partially sampled within a short range of projection angles, and at other angles no x-ray beams may pass through that region. To increase the sampling rate for the region outside the FOV, we have designed a new source trajectory by shifting the center of rotation during a CBCT scan. This resulted in a reduced sampling rate at the central area and increased sampling rate at the edges. The tradeoff led to a more balanced sampling for an enlarged FOV. An iterative algorithm was also developed to reconstruct the CT image under the new sampling scheme using a compressed sensing technique. Results: The method was validated by numerical simulations mimicking a Varian Trilogy CBCT system, and it was found that artifact-free images could be obtained with the FOV as large as 80 cm. Conclusions: The new CT scanning trajectory can be easily realized under current clinical setup with little modification of the control system, and this can be useful for treating obese patients. " [+ leia mais]
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"Purpose: The aim of this study was to evaluate radiation dose to patients undergoing computed tomography coronary angiography (CTCA) for prospectively gated axial (PGA) technique and retrospectively gated helical (RGH) technique. Methods: Radiation doses were measured for a 320-detector row CT scanner (Toshiba Aquilion ONE) using small sized silicon-photodiode dosimeters, which were implanted at various tissue and organ positions within an anthropomorphic phantom for a standard Japanese adult male. Output signals from photodiode dosimeters were read out on a personal computer, from which organ and effective doses were computed according to guidelines published in the International Commission on Radiological Protection Publication 103. Results: Organs that received high doses were breast, followed by lung, esophagus, and liver. Breast doses obtained with PGA technique and a phase window width of 16% at a simulated heart rate of 60 beats per minute were 13 mGy compared to 53 mGy with RGH technique using electrocardiographically dependent dose modulation at the same phase window width as that in PGA technique. Effective doses obtained in this case were 4.7 and 20 mSv for the PGA and RGH techniques, respectively. Conversion factors of dose length product to the effective dose in PGA and RGH were 0.022 and 0.025 mSv mGy−1 cm−1 with a scan length of 140 mm. Conclusions: CTCA performed with PGA technique provided a substantial effective dose reduction, i.e., 70%–76%, compared to RGH technique using the dose modulation at the same phase windows as those in PGA technique. Though radiation doses in CTCA with RGH technique were the same level as, or some higher than, those in conventional coronary angiography (CCA), the use of PGA technique reduced organ and effective doses to levels less than CCA except for breast dose. " [+ leia mais]
Fonte: Medical Physics
Lista de recomendações do Exame PET/CT com 18F-FDG em Oncologia. Consenso entre a Sociedade Brasileira de Cancerologia e a Sociedade Brasileira de Bio
"RESUMO Apresentamos uma lista de recomendações sobre a utilização de 18F-FDG PET em oncologia, no diagnóstico, estadiamento e detecção de recorrência ou progressão do câncer. " [+ leia mais]
Colaborador: Laura Natal Rodrigues
Fonte: Radiologia Brasileira
Dose optimization in pediatric cardiac x-ray imaging
Purpose: The aim of this research was to explore x-ray beam parameters with intent to optimize pediatric x-ray settings in the cardiac catheterization laboratory. [+ leia mais]
Colaborador: Cássio Vilela Komatsu
Fonte: Medical Physics
Prospective-gated cardiac micro-CT imaging of free-breathing mice using carbon nanotube field emission x-ray
Purpose: Carbon nanotube (CNT) based field emission x-ray source technology has recently been investigated for diagnostic imaging applications because of its attractive characteristics including electronic programmability, fast switching, distributed source, and multiplexing. [+ leia mais]
Colaborador: Cássio Vilela Komatsu
Fonte: Medical Physics
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