Ashrani Aizzuddin Abd. Rahni

• PhD
• Senior Lecturer at National University of Malaysia

This study evaluated the radiation attenuation of different densities of polylactic acid (PLA) and tough PLA (TPLA) by measuring their Hounsfield unit (HU) with computed tomography (CT) simulator and linear accelerator Cone Beam CT (CBCT). A phantom of 10 cm diameter with nine small cylindrical inserts of 2 cm diameter was fabricated using the thre...

This study investigates the dosimetric properties of customized three-dimensional (3D) printed thermoplastic polyurethane (TPU) slab phantom for 6 MV photon beams radiotherapy. The dimension of the customized 3D-printed TPU slab phantoms is 18.5 × 18.5 cm, with the thickness ranging from 0.1 cm to 0.2 cm. Dosimetric properties of the TPU slab phant...

Purpose: Liver hepatic vessels segmentation is a crucial step for the diagnosis process in patients with hepatic diseases. Segmentation of liver vessels helps to study the liver internal segmental anatomy that helps in the preoperative planning of surgical treatment. Methods: Recently, the convolutional neural networks (CNN) have been proved to...

Radiotherapy (RT) is the use of radiation to treat diseases in particular cancer. Recent advancements of imaging in RT and improved precision in treatment delivery require extensive training among the team. A good training approach need to be applied which aims to equip healthcare practitioners with a combination of essential understanding, clinica...

Sarcopenia, an age related condition is associated with decreased in lean muscle mass and increased in muscle fat. As a result, there is a decline in muscle strength and function in older adults. Diagnosis can be performed using bio-electrical impedance analysis (BIA) though accuracy is influenced by factors such as age, gender, hydration and ethni...

4 Dimensional Magnetic Resonance Imaging (4D MRI) is currently gaining attention as an imaging modality which is able to capture inter-cycle variability of respiratory motion. Such information is beneficial for example in radiotherapy planning and delivery. In the latter case, there may be a need for organ segmentation, however 4D MRI are of low co...

The absence of a ground truth for internal motion in clinical studies has always been a challenge to evaluate developed methods to extract respiratory motion especially during a 60-second cone-beam CT (CBCT) scan in Image-Guided Radiotherapy Treatment (IGRT). The unavailability of a gold standard has led this study to present a methodology to manua...

Radiotherapy is recognized as an effective method of cancer treatment and management that employs ionizing radiation to produce lethal effects to localized malignant cells. In employing radiotherapy, it is important to verify that the dose administered to the patient during treatment delivery is the same as sought during the treatment planning phas...

Segmentation is one of the most important steps in automated medical diagnosis applications, which affects the accuracy of the overall system. In this study, we apply a semi-automated technique that combines an active contour and low-level processing techniques in lung lesion segmentation by extracting lung lesions from thoracic Positron Emission T...

Liver vasculature segmentation is a crucial step for liver surgical planning. Segmentation of liver vasculature is an important part of the 3D visualisation of the liver anatomy. The spatial relationship between vessels and other liver structures, like tumors and liver anatomic segments, helps in reducing the surgical treatment risks. However, live...

This study examined the educational effects in strengthening programming skills among university’s undergraduate engineering students via integration of a robotics project and an experiential learning approach. In this study, a robotics project was conducted to close the gap of students’ difficulty in relating the theoretical concepts of programmin...

Brain tumour segmentation is an important task in the diagnosis of brain tumours, in particular gliomas. Manual segmentation of brain tumors is a time-consuming task due to the large amount of MR images generated during imaging, and it also depends on the clinicians’ skill. Recently there has been interest in the use of deep learning, in particular...

In Cone-Beam CT (CBCT) imaging, respiratory motion needs to be considered to mitigate motion artifacts thus increasing the accuracy of reconstructed images. Data driven methods can be used to extract respiratory signal directly from projection data without requiring any additional equipment or surrogate devices. Digital phantoms provide an adequate...

Purpose For the liver to remain viable, the resection during hepatectomy procedure should proceed along the major vessels; hence, the resection planes of the anatomic segments are defined, which mark the peripheries of the self-contained segments inside the liver. Liver anatomic segments identification represents an essential step in the preoperati...

Preoperative planning for liver surgical treatments is an essential planning tool that aids in reducing the risks of surgical resection. Based on the computed tomography (CT) images, the resection can be planned before the actual tumour resection surgery. The computer-aided system provides an overview of the spatial relationships of the liver organ...

PET/CT images are commonly used for cancer detection and management. In order to obtain high accuracy of tumour interpretation as well as the following treatment planning, accurate registration of these two is highly important. The use of hybrid PET/CT scanner to physically co-register these images does not fully solve the nonlinear misregistration...

Computed Tomography (CT) image is commonly used for medical diagnosis, to monitor disease progression as well in radiotherapy planning and treatment. In basis, image registration aims to accurately align two or more monomodal or multimodal images taken at different time or places. In order to accurately register two CT images, an accurate and relia...

Respiratory motion degrades quantitative and qualitative analysis of medical images. Estimation and hence correction of motion commonly uses static correspondence models between an external surrogate signal and internal motion. This work presents a patient specific respiratory motion model with the ability to adapt in the presence of irregular moti...

Liver segmentation from CT scans is still a challenging task due to the liver characteristics in terms of shape and intensity variability. In this work, we propose an automatic segmentation method of the liver from CT data sets. The framework consists of three main steps: liver shape model localization, liver intensity range estimation and localize...

Segmentation is one of the crucial steps in applications of medical diagnosis. The accurate image segmentation method plays an important role in proper detection of disease, staging, diagnosis, radiotherapy treatment planning and monitoring. In the advances of image segmentation techniques, joint segmentation of PET-CT images has increasingly recei...

Purpose: Segmentation of liver tumours is an important part of the 3D visualisation of the liver anatomy for surgical planning. The spatial relationship between tumours and other structures inside the liver forms the basis of preoperative surgical risk assessment. However, the automatic segmentation of liver tumours from abdominal CT scans is ridd...

Reconstructing large volumetric 3D images with minimal radiation dosage exposure with reduced scanning time has been one of the main objectives in the advancement of CT development. One of its advancement is the introduction of multi-slice arc detector geometry from a cone-beam source in third generation scanners. In solving this complex geometry,...

Recently range imagers or distance camera systems have garnered interest for measuring respiratory motion without using markers, which can then be used as a surrogate in diagnosis and treatment for example in diagnostic imaging or radiotherapy. However, their use may have limitations, especially among lower cost systems, whereby their accuracy decr...

Segmentation is one of the most important steps in automated medical diagnosis applications, which affects the accuracy of the overall system. In this paper, we propose a semi-automated segmentation method for extracting lung lesions from thoracic PET/CT images by combining low level processing and active contour techniques. The lesions are first s...

Final year project (FYP) is one of the compulsory subject for all engineering students in order to pass their undergraduate program. Normally, final year project is assessed by supervisor and examiners, which is also lecturers in the department. In the Department of Electrical, Electronic and Systems Engineering (DEESE), Faculty of Engineering and...

This paper discusses the effectiveness of the industrial training from the perspective of students who have undergone 12 weeks of industrial training. A questionnaire was distributed to 47 Third Year students at the Civil and Structural Engineering Department (JKAS), Faculty of Engineering and Built Environment, Universiti Kebangsaan Malaysia (UKM)...

This paper presents the development of automatic segmentation of the inferior vena cava (IVC) in the proximity of the liver in abdominal CT scans. In our proposed framework, starting from an initial contour mask the active contour method is used to delineate the IVC by propagating an elliptical contour in each image slice sequentially in the CT sca...

Soft skills, especially communication skills, are important skills which each graduate must possess. Accordingly, several courses and approaches have been carried out in universities to train students in communication skills. The skills are normally evaluated by course lecturers. However, assessments by a third party from outside the university are...

In this paper we present preliminary results of comparison of automatic segmentations of the infarct core, between that obtained from CT perfusion (based on time to peak parameter) and diffusion weighted imaging (DWI). For each patient, the two imaging volumes were automatically co-registered to a common frame of reference based on an acquired CT a...

Positron Emission Tomography (PET) projection data or sinogram contained poor statistics and randomness that produced noisy PET images. In order to improve the PET image, we proposed an implementation of pre-reconstruction sinogram filtering based on 3D mean-median filter. The proposed filter is designed based on three aims; to minimise angular blu...

In this paper we present a pre-processing stage for an automated volumetric CT stroke image diagnosis system. It concerns the automatic intensity-based 3D image registration of dynamic CT (used for CT perfusion imaging) to CT angiography (CTA) images. The dynamic CT images were acquired with a gantry tilt and hence the correct geometry is found. Th...

This paper thus outlines the development of an online student attendance monitoring system (named SAMSTM) based on QR codes and mobile devices. This design was chosen due to its simplicity and cost-effectiveness. The only equipment required by the user (lecturers and students) is a mobile internet device such as a tablet computer or a smartphone. T...

Respiratory motion affects image acquisition and also external beam radiotherapy (EBRT) treatment planning and delivery. Existing approaches for respiratory motion management are often based on a generic view of respiratory motion such as the general movement of organ, tissue or fiducials. This paper aims to present a more in depth analysis of resp...

Respiratory motion presents a challenge in developing techniques to increase the accuracy of image acquisition or guided interventions in abdominal and thoracic organs. The use of distance cameras, such as that from Vision RT Ltd has been considered as a surrogate for respiratory motion tracking in external beam radiotherapy that does not require t...

In this paper we present a pre-processing stage for an automated volumetric CT stroke image diagnosis system. It concerns the automatic intensity-based 3D image registration of non-contrast CT (NCCT) to CT angiography (CTA) images. The NCCT were acquired with a gantry tilt and hence they are first tilt corrected. After the tilt correction process,...

Automated segmentation is a primary step in medical diagnosis applications. This paper presents an image segmentation propagation method via image registration. Therefore, segmentation propagation accuracy depends on the accuracy of image registration. Three similarity measures were considered, namely Sum of Squared (Intensity) Differences (SSD), M...

It is well known that respiratory motion affects image acquisition and also external beam radiotherapy (EBRT) treatment planning and delivery. However often the existing approaches for respiratory motion management are based on a generic view of respiratory motion such as the general movement of organ, tissue or fiducials. This paper thus aims to p...

Accurate, Respiratory Motion Modelling of the abdominal-thoracic organs serves as a pre-requisite for motion correction of Nuclear Medicine (NM) Images. Many respiratory motion models to date build a static correspondence between a parametrized external surrogate signal and internal motion. Mean drifts in respiratory motion, changes in respiratory...

To achieve high resolution nuclear medicine imaging, respiratory motion has to be compensated, due to the image acquisition process occurring over several respiratory cycles. Motion affected imaging can either be compensated indirectly by gating or directly by applying some motion correction method. All motion correction methods rely on an estimate...

Due to the increasing amount of data available from medical imaging procedures and also the increase in computing power, there has been a rise in the automation of the analysis of such data. A crucial step in the automation of such procedures is accurate segmentation of anatomy. Popular approaches include model based segmentation. However, these ap...

Compensation for respiratory motion has been identified as a crucial factor in achieving high resolution Nuclear Medicine (NM) imaging. Many motion correction approaches have been studied and they are seen to have advantages over simpler approaches such as respiratory gating. However, all motion correction approaches rely on an assumption or estima...

Nuclear Medicine (NM) imaging serves as a powerful diagnostic tool for imaging of biochemical and physiological processes in vivo. The degradation in spatial image resolution caused by the often irregular respiratory motion must be corrected to achieve high resolution imaging. In order perform motion correction more accurately, it is proposed that...

Nuclear Medicine (NM) imaging is currently the most sensitive approach for functional imaging of the human body. However, in order to achieve high-resolution imaging, one of the factors degrading the detail or apparent resolution in the reconstructed image, namely respiratory motion, has to be overcome. All respiratory motion correction approaches...

Compensation of respiratory motion has been identified as a crucial factor in achieving high resolution Nuclear Medicine (NM) imaging. Many motion correction approaches have been studied and they are seen to have advantages over simpler motion compensation approaches such as respiratory gating. However, all motion correction approaches rely on an a...

Respiratory motion correction degrades quantitatively and qualitatively Nuclear Medicine images. We propose that adaptive approaches are required to correct for the irregular breathing patterns often encountered in the clinical setting, which can be addressed within a Bayesian tracking formulation. This allows inference of the hidden organ configur...

With the continual improvement in spatial resolution of Nuclear Medicine (NM) scanners, it has become increasingly important to accurately compensate for patient motion during image acquisition. Respiratory motion produced by normal lung ventilation is a major source of artefacts in NM emission imaging that can affect large parts of the abdominal t...

The continual improvement in spatial resolution of Nuclear Medicine (NM) scanners has made accurate compensation of patient motion increasingly important. A major source of corrupting motion in NM acquisition is due to respiration. Therefore a particle filter (PF) approach has been proposed as a powerful method for motion correction in NM. The prob...

Nuclear Medicine (NM) imaging is an important diagnostic tool, used widely in the field of oncology amongst others. However, NM images suffer from significant blurring due to inevitable patient motion, such as breathing, coughing and other voluntary or involuntary movement. Advances in detector technology and reconstruction techniques have led to a...

With the continual improvement in spatial resolution of Nuclear Medicine (NM) scanners, it has become increasingly important to accurately compensate for patient motion during acquisition. Respiratory motion produced by lung ventilation is a major source of artefacts in NM that can affect large parts of the abdominal-thoracic cavity. As such, a par...

This research aims to develop a methodological framework based on a data driven approach known as particle filters, often found in computer vision methods, to correct the effect of respiratory motion on Nuclear Medicine imaging data. Particles filters are a popular class of numerical methods for solving optimal estimation problems and we wish to us...

Motion correction of the abdominal-thoracic region is one of the main research challenges in tomographic nuclear medicine imaging. We address this issue with a flexible data-driven method of motion correction. This uses marker-less stereo tracking of the anterior abdominal-chest surface and a 'virtual dissection'-based registration approach, combin...

This paper highlights the function of 'accumulation' that is featured in OXADMs. OXADMs are new optical switching devices which have an asymmetrical architecture and can perform bi-directional functions similar to existing devices such as OADMs and OXCs. OXADMs consists of 3 sections; selective ports, add/drop operations, and path routing. Selectiv...

Thermal noise is generated naturally by thermal agitation of electrons in a conductor commonly found in opto-electronic devices. The fact that the optical medium is totally immune to noise does not exclude its occurrence in receiver parts. In communication, thermal noise has a major influence to the quality of the receiver. The lower the thermal no...

OXADMs reliability and also survivability of the trunk-line optical network used for data communication. This paper describes the analytical modeling of OXADMs and studies their performance as compared to conventional OXC devices. With two restoration schemes, the OXADM prototype system focuses on providing survivability through restoration against...

This paper introduces a new optical device model named as an optical cross add and drop multiplexer (OXADM) which has potential use in CWDM metro area networks. The device uses the concepts of combination of optical add/drop multiplexing and optical cross connect between two main transmission lines in order to implement the wavelength routing opera...

Prior to export, papaya are subjected to inspection for the purpose of quality control and grading. For size grading, the fruit is weighed manually hence the practice is tedious, time consuming and labor intensive. Therefore, this paper will discuss the development of a computer vision system for papaya size grading using shape characteristic analy...

In freehand 3D Ultrasound (3D-US) Scanning one needs to track a B-mode scanner across a subject of interest to construct the 3D image. In this paper we use a compact IMU (Inertial Measurement Unit), as an alternative method that have certain advantages compared to other conventional methods. However IMUs accumulate translational errors thus we stud...

MEMS (Micro Electro-Mechanical Systems) based technology has made it possible to fabricate accelerometers and gyroscopes that are small enough to fit onto chips and thus all the components for a 6-DOF (6 degrees of freedom) IMU (Inertial Measurement Unit) can be enclosed in one compact device. Examples in the market include those from Xsens Technol...