Abstract：
:Linear scaling is used to convert raw computed tomography (CT) pixel values into Hounsfield units corresponding to different tissue values. Analysis of a benchmarking study, presented here, where the same CT scan was imported into and then exported from multiple radiotherapy treatment planning systems, found inconsistencies in HU scaling parameter values exported along with the images, particularly when images were exported using the Radiation Therapy Oncology Group format. Several methods of estimating conversion parameters, based on estimating pixel values corresponding to air and water within the image, for pelvic CT images from a large multi-centre trial were compared against original Digital Imaging and Communications in Medicine export parameters. In general using the mean of a sample region at the centroid of the bladder to estimate the value of water was more accurate than using the minimum or maximum or a single value at the centroid. Accuracy of methods of air estimation tested were dependent in part on features of the CT scanners and treatment planning systems, making it difficult to pick one method as superior that was independent of scanner and treatment planning system type. Based on the above analysis, methods for estimating air and water were selected for use in performing linear scaling of a set of pelvic CT images prior to their use in an interpatient image registration application. The selected methods were validated against a more recent and homogeneous dataset. Estimation error was found to be much lower within the validation set.
journal_name
Australas Phys Eng Sci Medjournal_title
Australasian physical & engineering sciences in medicineauthors
Kennedy A,Dowling J,Greer PB,Ebert MAdoi
10.1007/s13246-018-0651-xsubject
Has Abstractpub_date
2018-09-01 00:00:00pages
739-745issue
3eissn
0158-9938issn
1879-5447pii
10.1007/s13246-018-0651-xjournal_volume
41pub_type
杂志文章abstract：:Super-pixel feature extraction is a key problem to get an acceptable performance in color super-pixel classification. Given a color feature extraction problem, it is necessary to know which is the best approach to solve this problem. In the current work, we're interested in the challenge of nucleus and cytoplasm autom...
journal_title：Australasian physical & engineering sciences in medicine
pub_type： 杂志文章
doi：10.1007/s13246-019-00735-8
更新日期：2019-06-01 00:00:00
abstract：:Compression techniques are vital for efficient storage and fast transfer of medical image data. The existing compression techniques take significant amount of time for performing encoding and decoding and hence the purpose of compression is not fully satisfied. In this paper a rapid 4-D lossy compression method constr...
journal_title：Australasian physical & engineering sciences in medicine
pub_type： 杂志文章
doi：10.1007/s13246-015-0385-y
更新日期：2015-12-01 00:00:00
abstract：:Improved technology and higher fidelity are making medical simulations increasingly popular. A simulated peripheral nerve stimulator and thumb actuator has been developed for use with the SimMan Universal Patient Simulator. This device incorporates a handheld control box, a McKibben pneumatic muscle and articulated th...
journal_title：Australasian physical & engineering sciences in medicine
pub_type： 杂志文章
doi：
更新日期：2006-03-01 00:00:00
abstract：:Mitral stenosis (MS) and mitral insufficiency (MI) have different pre-operative hemodynamic characteristics. However, it is unclear if there are differences in long-term echocardiographic characteristics of MS and MI patients after mechanical mitral valve replacement. This study is to compare long-term echocardiograph...
journal_title：Australasian physical & engineering sciences in medicine
pub_type： 杂志文章
doi：10.1007/s13246-016-0521-3
更新日期：2017-03-01 00:00:00
abstract：:In recent years, the use of gold nanoparticles in radiation therapy has been introduced as a new approach in radiotherapy. The aim of this study is to investigate the effect of gold nanoparticles (GNPs) in plaque brachytherapy for choroidal melanoma using Monte Carlo (MC) simulation. MCNPX code was used for simulation...
journal_title：Australasian physical & engineering sciences in medicine
pub_type： 杂志文章
doi：10.1007/s13246-017-0555-1
更新日期：2017-09-01 00:00:00
abstract：:The reference air kerma rate from 192Ir High Dose Rate (HDR) brachytherapy sources can be measured using a suitably calibrated Farmer chamber and an appropriate in-air calibration jig. When a primary standard for 192Ir gamma rays is available, a calibration coefficient for the chamber and jig combination can be determ...
journal_title：Australasian physical & engineering sciences in medicine
pub_type： 杂志文章
doi：10.1007/BF03178603
更新日期：2008-12-01 00:00:00
abstract：:Sometimes infusion pumps are used to deliver whole blood to patients. However, in doing so there is a potential for damage to red cells from mechanical stresses in the pump, resulting in haemolysis. In order to investigate the degree of haemolysis caused by different pumps and therefore their suitability for whole blo...
journal_title：Australasian physical & engineering sciences in medicine
pub_type： 杂志文章
doi：
更新日期：1991-03-01 00:00:00
abstract：:In-phantom figures of merit of the radiobiological dose distribution are the main criteria for evaluation of the boron neutron capture therapy (BNCT) plan and neutron beam evaluation. Since in BNCT there are several reactions, which contribute to the total dose of the tissue, the calculation of the dose distribution i...
journal_title：Australasian physical & engineering sciences in medicine
pub_type： 杂志文章
doi：10.1007/s13246-011-0107-z
更新日期：2011-12-01 00:00:00
abstract：:Ischaemic stroke is a major public health issue in both developed and developing nations. Hypothermia is believed to be neuroprotective in cerebral ischaemia. Conversely, elevated brain temperature is associated with poor outcome after ischaemic stroke. Mechanisms of heat exchange in normally-perfused brain are relati...
journal_title：Australasian physical & engineering sciences in medicine
pub_type： 杂志文章
doi：10.1007/s13246-017-0595-6
更新日期：2017-12-01 00:00:00
abstract：:A group of 113 children with poor vision who had been referred to the Electrodiagnostic Clinic over a five year period were investigated for disease of the retina and optic pathway by electroretinography (ERG), electro-oculography (EOG) and visual evoked response (VER). The electrodiagnostic measurements were made usi...
journal_title：Australasian physical & engineering sciences in medicine
pub_type： 杂志文章
doi：10.1007/BF03178360
更新日期：2001-09-01 00:00:00
abstract：:The quality of phantom materials is crucial for accurate dosimetry in radiotherapy. A wide range of factors such as density, electron density and elemental composition can influence the radiation properties, and hence the absorbed dose, of materials. New materials can be tested by direct measurements which requires co...
journal_title：Australasian physical & engineering sciences in medicine
pub_type： 杂志文章
doi：
更新日期：1993-09-01 00:00:00
abstract：:A set of four 4 MV photon beam compensators were produced, one for each field of a Hodgkins Disease treatment plan. The resultant dose profiles at various depths were measured by an ion chamber in water and by Kodak X-Omat V film in a Solid Water phantom, and compared to the doses calculated by a GE RT/Plan treatment ...
journal_title：Australasian physical & engineering sciences in medicine
pub_type： 杂志文章
doi：
更新日期：1992-03-01 00:00:00
abstract：:Accuracy of dwell position and reproducibility of dwell time are critical in high dose rate (HDR) brachytherapy. A phantom was designed to verify dwell position and dwell time reproducibility for an Ir-192 HDR stepping source using Computed Radiography (CR). The central part of the phantom, incorporating thin alternat...
journal_title：Australasian physical & engineering sciences in medicine
pub_type： 杂志文章
doi：10.1007/s13246-012-0138-0
更新日期：2012-09-01 00:00:00
abstract：:The knowledge of radiation dose at all points of interest within a patient's body is essential for the evaluation of treatment plans and for the judicious selection of the best one from among a set of competing plans. This paper discusses the physical and geometric aspects of radiation dose distribution calculations n...
journal_title：Australasian physical & engineering sciences in medicine
pub_type： 杂志文章
doi：
更新日期：1989-12-01 00:00:00
abstract：:Transmission data for a fibre cement wallboard (villaboard) are determined for use in diagnostic shielding designs. Villaboard is found to be more attenuating than plasterboard e.g. 9 mm of villaboard is equivalent to 16 mm of plasterboard. ...
journal_title：Australasian physical & engineering sciences in medicine
pub_type： 杂志文章
doi：
更新日期：1998-09-01 00:00:00
abstract：:Laparoscopic ultrasound (LUS) has been widely utilized as a surgical aide in general, urological, and gynecological applications. Our study summarizes the clinical applications of laparoscopic ultrasonography in laparoscopic gynecologic surgery. Retrospective analyses were performed on 42 women subjects using laparosc...
journal_title：Australasian physical & engineering sciences in medicine
pub_type： 杂志文章
doi：10.1007/s13246-015-0363-4
更新日期：2015-12-01 00:00:00
abstract：:Volumetric modulated arc therapy (VMAT) is modern rotational intensity modulated therapy used for treatment of several sites. The study aimed to analyze partial tangential arc VMAT treatment planning and delivery, including analyzing the cardiac and contralateral breast doses resulting from this technique. A total of ...
journal_title：Australasian physical & engineering sciences in medicine
pub_type： 杂志文章
doi：10.1007/s13246-017-0558-y
更新日期：2017-09-01 00:00:00
abstract：:In recent years there has been a significant economic growth in South East Asia, along with it a concurrent development of medical physics. The status of four countries--Malaysia, Thailand, the Philippines and Indonesia are presented. Medical physicists in these countries have been experiencing the usual problems of l...
journal_title：Australasian physical & engineering sciences in medicine
pub_type： 杂志文章
doi：
更新日期：1997-03-01 00:00:00
abstract：:Orthovoltage x-ray beams exhibit the characteristic of depth dose buildup which is not well described in the literature. The principal reason for this phenomenon is the increase in dose deposited due to electrons set in motion by secondary (Compton) scattered photons within the phantom, as depth is increased until lon...
journal_title：Australasian physical & engineering sciences in medicine
pub_type： 杂志文章
doi：
更新日期：1998-06-01 00:00:00
abstract：:Surface, build-up and depth dose characteristics of a monoenergetic electron point source simulated by Monte Carlo code MCNP4c for varying field size and SSD are extensively studied in this paper. MCNP4c (Monte Carlo N-Particle Transport Code System) has been extensively used in clinical dose simulation for its versat...
journal_title：Australasian physical & engineering sciences in medicine
pub_type： 杂志文章
doi：10.1007/BF03178652
更新日期：2004-12-01 00:00:00
abstract：:Wavelet theory is emerging as one of the prevalent tool in signal and image processing applications. However, the most suitable mother wavelet for these applications is still a relative question mark amongst researchers. Selection of best mother wavelet through parameterization leads to better findings for the analysi...
journal_title：Australasian physical & engineering sciences in medicine
pub_type： 杂志文章
doi：10.1007/s13246-014-0264-y
更新日期：2014-06-01 00:00:00
abstract：:Given that there is increasing recognition of the effect that sub-millimetre changes in collimator position can have on radiotherapy beam dosimetry, this study aimed to evaluate the potential variability in small field collimation that may exist between otherwise matched linacs. Field sizes and field output factors we...
journal_title：Australasian physical & engineering sciences in medicine
pub_type： 杂志文章
doi：10.1007/s13246-015-0349-2
更新日期：2015-06-01 00:00:00
abstract：:Fibromyalgia syndrome (FMS) is a chronic muscle and skeletal system disease observed generally in women, manifesting itself with a widespread pain and impairing the individual's quality of life. FMS diagnosis is made based on the American College of Rheumatology (ACR) criteria. However, recently the employability and ...
journal_title：Australasian physical & engineering sciences in medicine
pub_type： 杂志文章
doi：10.1007/s13246-016-0452-z
更新日期：2016-06-01 00:00:00
abstract：:A new PTW advanced Markus ionization chamber has been implemented in IMRT fields, to measure surface dose at ICRU and ICRP reference depth of 0.07 mm [ICRU Report 39, Determination of dose equivalents resulting from external radiation sources, 1985; ICRP Publication 60, 1990 recommendations of the International Commis...
journal_title：Australasian physical & engineering sciences in medicine
pub_type： 杂志文章
doi：10.1007/s13246-010-0004-x
更新日期：2010-03-01 00:00:00
abstract：:Given the difficulty and potential time- or financial-costs associated with accurate small field dosimetry, this study aimed to establish the clinical necessity of obtaining accurate small field output factor measurements and to evaluate the effects on planned doses that could arise if accurate measurements are not us...
journal_title：Australasian physical & engineering sciences in medicine
pub_type： 杂志文章
doi：10.1007/s13246-016-0461-y
更新日期：2016-09-01 00:00:00
abstract：:The study developed two models of an innovative high-speed lancing device and safety lancet, where the specially designed structure causes high-speed motion of the lancet, resulting in only one puncture of the skin. The two experimental models and other lancing devices sold on market were compared in order to: (1) mea...
journal_title：Australasian physical & engineering sciences in medicine
pub_type： 杂志文章
doi：10.1007/s13246-016-0490-6
更新日期：2016-12-01 00:00:00
abstract：:The aim of this study was to determine whether there is an effect of mobile phone electromagnetic field emissions on the human electroencephalograph (EEG). EEG recordings from ten awake subjects were taken during exposure to radiofrequency (RF) emissions from a mobile phone positioned behind the head. Two experimental...
journal_title：Australasian physical & engineering sciences in medicine
pub_type： 临床试验,杂志文章,随机对照试验
doi：10.1007/BF03179176
更新日期：2003-12-01 00:00:00
abstract：:Numerical simulation is performed to demonstrate that hemodynamic factors are significant determinants for the development of a vascular pathology. Experimental measurements by particle image velocimetry are carried out to validate the credibility of the computational approach. We present a study for determining compl...
journal_title：Australasian physical & engineering sciences in medicine
pub_type： 杂志文章
doi：10.1007/s13246-010-0050-4
更新日期：2010-12-01 00:00:00
abstract：:A continuous positive airway pressure (CPAP) device is considered one of the most effective treatments for obstructive sleep apnea (OSA). However, many patients receiving this treatment complain of mask discomfort and other issues. Therefore, this study aimed to develop a customized nasal mask cushion to reduce the di...
journal_title：Australasian physical & engineering sciences in medicine
pub_type： 杂志文章
doi：10.1007/s13246-015-0383-0
更新日期：2015-12-01 00:00:00
abstract：:Radiation therapy of cancer is today going through a very dynamic development with the introduction of a large number of new treatment principles, new types of treatment units and new radiobiologically based optimization algorithms for treatment planning. All of these make use of the recent developments in three dimen...
journal_title：Australasian physical & engineering sciences in medicine
pub_type： 杂志文章,评审
doi：
更新日期：1996-06-01 00:00:00
