Australasian Physical and Engineering Sciences in Medicine This is an RSS file. You can use it to subscribe to this data in your favourite RSS reader or to display this data on your own website or blog.

Physical and visual evaluations of CT image quality of large low-contrast objects with visual model-based iterative reconstruction technique: a phantom study
AbstractWe aimed to verify whether the image quality of large low-contrast objects can be improved using visual model-based iterative reconstruction (VMR) while maintaining the visibility of conventional filtered back projection (FBP) and reducing radiation dose through physical and visual evaluation. A 64-row multi-slice CT system with SCENARIA View (FUJIFILM healthcare Corp. Tokyo, Japan) was used. The noise power spectrum (NPS), task-based transfer function (TTF), and signal-to-noise ratio (SNR) were physically evaluated. A low contrast object as a substitute for a liver mass was visually ev aluated. In the noise mea...
Source: Australasian Physical and Engineering Sciences in Medicine - December 12, 2022 Category: Biomedical Engineering Source Type: research

Double enhancement effect of a surface dose with tungsten rubber bolus in photon radiotherapy for keloids and superficial tumors
AbstractTo clarify the dosimetric characteristics of a real-time variable shape rubber-containing tungsten (STR) bolus in a clinical plan and investigate the efficacy of the STR bolus in photon radiotherapy for keloids and other superficial tumors. A 5 mm gel bolus or 1 mm STR bolus was placed on a solid water phantom. Tangential irradiation was performed using a TomoTherapy Radixact-X9 and 6 MV X-ray flattening-filter-free beam, and the surface dose was measured with radiochromic film. Clinical-like plans (TomoDirect; TD and TomoHelical; TH ) were applied with the same geometry and the dose distributions were measured.�...
Source: Australasian Physical and Engineering Sciences in Medicine - December 9, 2022 Category: Biomedical Engineering Source Type: research

Can magnetic resonance imaging after cranioplasty using titanium mesh detect brain tumors?
This study determined the dependence of the concentration and position of contrast-enhanced tumors on the radio frequency (RF)-shielding effect of titanium mesh using the contrast-to-noise ratio (CNR) in magnetic resonance imaging (MRI). A phantom was constructed by filling a plastic container with manganese chloride tetrahydrate and agar. Four cellophane cylindrical containers were arranged from the end of the plastic container, and the brain tumor model was filled with gadobutrol diluted with NaCl, with molarity values of 0.2 –1.0 mmol/L. The titanium mesh board was set on the left side of the phantom. Images were acq...
Source: Australasian Physical and Engineering Sciences in Medicine - December 6, 2022 Category: Biomedical Engineering Source Type: research

Clinical validation of the Varian Truebeam intra-fraction motion review (IMR) system for prostate treatment guidance
This study quantified the performance of Intra-fraction Motion Review (IMR) during prostate Stereotactic Body Radiotherapy (SBRT) treatments. IMR was evaluated using prostate motion data from patients treated in an SBRT clinical trial (PROMETHEUS, NCT00587990).IMR measured prostate displacements were compared to those of two 3D motion management methods: Kilovoltage Intra-fraction Motion management (KIM) and MV/kV triangulation. A planning study assessing the impact of a defined prostate motion (2 –5 mm) on the PTV coverage with and without IMR was performed. A clinically relevant IMR search region for prostate cancer...
Source: Australasian Physical and Engineering Sciences in Medicine - December 6, 2022 Category: Biomedical Engineering Source Type: research

Dual segmentation models for poorly and well-differentiated hepatocellular carcinoma using two-step transfer deep learning on dynamic contrast-enhanced CT images
AbstractThe aim of this study was to develop dual segmentation models for poorly and well-differentiated hepatocellular carcinoma (HCC), using two-step transfer learning (TSTL) based on dynamic contrast-enhanced (DCE) computed tomography (CT) images. From 2013 to 2019, DCE-CT images of 128 patients with 80 poorly differentiated and 48 well-differentiated HCCs were selected at our hospital. In the first transfer learning (TL) step, a pre-trained segmentation model with 192 CT images of lung cancer patients was retrained as a poorly differentiated HCC model. In the second TL step, a well-differentiated HCC model was built fr...
Source: Australasian Physical and Engineering Sciences in Medicine - December 5, 2022 Category: Biomedical Engineering Source Type: research

Recurrence prediction with local binary pattern-based dosiomics in patients with head and neck squamous cell carcinoma
AbstractWe investigated an approach for predicting recurrence after radiation therapy using local binary pattern (LBP)-based dosiomics in patients with head and neck squamous cell carcinoma (HNSCC). Recurrence/non-recurrence data were collected from 131 patients after intensity-modulated radiation therapy. The cases were divided into training (80%) and test (20%) datasets. A total of 327 dosiomics features, including cold spot volume, first-order features, and texture features, were extracted from the original dose distribution (ODD) and LBP on gross tumor volume, clinical target volume, and planning target volume. The Cox...
Source: Australasian Physical and Engineering Sciences in Medicine - December 5, 2022 Category: Biomedical Engineering Source Type: research

The effect of arterial cannula tip position on differential hypoxemia during venoarterial extracorporeal membrane oxygenation
This study investigated the effect of arterial cannula tip position on VA ECMO blood flow to the upper extremities using computational fluid dynamics simulations. Four arterial cannula tip positions (P1. common iliac, P2. abdominal aorta, P3. descending aorta and P4. aortic arch) were compared with different degrees of cardiac dysfunction and VA ECMO support (50%, 80% and 90% support). P4 was able to supply oxygenated blood to the arch vessels at all support levels, while P1 to P3 only supplied the arch vessels during the highest level (90%) of VA ECMO support. Even during the highest level of support, P1 to P3 could only ...
Source: Australasian Physical and Engineering Sciences in Medicine - December 2, 2022 Category: Biomedical Engineering Source Type: research

Evaluation of HyperArc ™ using film and portal dosimetry quality assurance
This study aimed to assess the efficacy of two patient-specific quality assurance methods, film and the Varian Portal Dosimetry System with Varian’ s HyperArc™ technique and raise important considerations in the customisation of patient-specific quality assurance to accommodate HyperArc™ delivery. Assessment criteria included gamma analysis and mean dose at full width half maximum. The minimum metastasis size, maximum off-axis distance and suitable energy were identified and validated. Patient-specific quality assurance procedures were applied to a range of clinically relevant brain metastasis plans. Initial investig...
Source: Australasian Physical and Engineering Sciences in Medicine - December 1, 2022 Category: Biomedical Engineering Source Type: research

An effective brain connectivity technique to predict repetitive transcranial magnetic stimulation outcome for major depressive disorder patients using EEG signals
In this study, we intend to predict the rTMS treatment response in MDD patients from electroencephalogram (EEG) signals before starting the treatment using machine learning approaches. Effective brain connectivity of 19-channel EEG data of MDD patients was calculated by the direct directed transfer function (dDTF) method. Then, using three feature selection methods, the best features were selected and patients were classified as responders or non-responders to rTMS treatment by using the support vector machine (SVM). Results on the 34 MDD patients indicated that the Fp2 region in the delta and theta frequency bands has a s...
Source: Australasian Physical and Engineering Sciences in Medicine - November 29, 2022 Category: Biomedical Engineering Source Type: research

CArdiac and REspiratory adaptive Computed Tomography (CARE-CT): a proof-of-concept digital phantom study
AbstractCurrent respiratory 4DCT imaging for high-dose rate thoracic radiotherapy treatments are negatively affected by the complex interaction of cardiac and respiratory motion. We propose an imaging method to reduce artifacts caused by thoracic motion, CArdiac and REspiratory adaptive CT (CARE-CT), that monitors respiratory motion and ECG signals in real-time, triggering CT acquisition during combined cardiac and respiratory bins. Using a digital phantom, conventional 4DCT and CARE-CT acquisitions for nineteen patient-measured physiological traces were simulated. Ten respiratory bins were acquired for conventional 4DCT s...
Source: Australasian Physical and Engineering Sciences in Medicine - November 25, 2022 Category: Biomedical Engineering Source Type: research

Obituary: Professor Alun Beddoe, PhD, DSc (22-04-1945 –21-10-2022)
(Source: Australasian Physical and Engineering Sciences in Medicine)
Source: Australasian Physical and Engineering Sciences in Medicine - November 17, 2022 Category: Biomedical Engineering Source Type: research

Multi-stage classification of Alzheimer ’s disease from 18F-FDG-PET images using deep learning techniques
AbstractThe study aims to implement a convolutional neural network framework that uses the 18F-FDG PET modality of brain imaging to detect multiple stages of dementia, including Early Mild Cognitive Impairment (EMCI) and Late Mild Cognitive Impairment (LMCI), and Alzheimer’s disease (AD) from Cognitively Normal (CN), and assess the results. 18F-FDG PET imaging modality for brain were procured from Alzheimer’s disease neuroimaging initiative’s (ADNI) repository. The ResNet50V2 model layers were utilised for feature extraction, with the final convolutional layers fine-tuned for this dataset’s multi-classification o...
Source: Australasian Physical and Engineering Sciences in Medicine - November 10, 2022 Category: Biomedical Engineering Source Type: research

Lead equivalence testing using a custom-built testing kit
This study outlines the design and development of an IEC compliant broad beam lead equivalence testing setup, using an in-house custom-built testing kit (CBTK). The practicality and robustness of this kit was performance tested using lead equivalence measurements on 97% pure lead sheets. Hospital radiation protective garments are predominantly made of lead-free or lead-composite materials due to their light weight, as such, a set of lead-free (N-Pb) samples was also performance tested. These samples were tested using two different beam qualities; a total filtration of 2.5 mmAl and 0.25 mmCu added filtration, both at 102 kV...
Source: Australasian Physical and Engineering Sciences in Medicine - November 9, 2022 Category: Biomedical Engineering Source Type: research

Dosimetric evaluation of a treatment planning system using the AAPM Medical Physics Practice Guideline 5.a (MPPG 5.a) validation tests
AbstractVerifying the accuracy of the dose calculation algorithm is considered one of the most critical steps in radiotherapy treatment for delivering an accurate dose to the patient. This work aimed to evaluate the dosimetric performance of the treatment planning system (TPS) algorithms; the AAA (v. 15.6), AXB (v. 15.6) and eMC (v. 15.6) following the AAPM medical physics practice guideline 5.a (MPPG 5.a) validation tests package in a Varian iX Linear Accelerator (Linac). A series of tests were developed based on the MPPG 5.a. on a Varian's Eclipse TPS (v. 15.6) (Varian Medical Systems). First, the basic photon and electr...
Source: Australasian Physical and Engineering Sciences in Medicine - November 9, 2022 Category: Biomedical Engineering Source Type: research

Evaluating the difference in walk patterns among normal-weight and overweight/obese individuals in real-world surfaces using statistical analysis and deep learning methods with inertial measurement unit data
The objective of this study was to statistically evaluate the variations in the walk patterns of individuals belonging to two BMI groups across a wide range of walking surfaces and to investigate whether a deep learning method could classify the BMI-specific walk patterns wi th similar variations. Data collected by wearable inertial measurement unit (IMU) sensors attached to individuals with two different BMI were collected while walking on real-world surfaces. In addition to traditional statistical analysis tools, an advanced deep learning-based neural network was used to evaluate and classify the BMI-specific walk patter...
Source: Australasian Physical and Engineering Sciences in Medicine - November 9, 2022 Category: Biomedical Engineering Source Type: research