Choirul Anam

Universitas Diponegoro | UNDIP · Department of Physics

The purpose of this study is to accurately and effectively automate the calculation of the water‐equivalent diameter (DW) from 3D CT images for estimating the size‐specific dose. DW is the metric that characterizes the patient size and attenuation. In this study, DW was calculated for standard CTDI phantoms and patient images. Two types of phantom...

Purpose: The purpose of this study was to introduce a new algorithm for automated measurement of the modulation transfer function (MTF) using an edge of a readily available phantom and to evaluate the effect of reconstruction filter and field of view (FOV) on the spatial resolution in the CT images. Methods: Our automated MTF measurement consist...

This study developed a simple wire phantom and an algorithm to automatically measure the modulation transfer function (MTF) in computed tomography (CT), and implemented it to evaluate the effect of focal spot size and reconstruction filter type. The phantom consisted of a resin cylinder filled with water, with a tin wire of diameter 0.1 mm position...

IndoseCT is software to calculate and manage the radiation dose of a patient undergoing computed tomography (CT) examination. It does not only calculate the radiation output dose of CT machines (in terms of volume CT dose index, CTDIvol), but also the individual dose received by each patient (in terms of size-specific dose estimate, SSDE) either ba...

The main feature of the IndoQCT software is to evaluate CT image quality. In the CT quality control (QC) procedure, generally qualified examiners or medical staff check the CT image quality parameters manually on a phantom using available tools in the control panel. The QC procedure consists of daily, monthly, and annual tasks. To carry out thi...

The purpose of this study was to evaluate the effect of rectangular region of interest (ROI) size on modulation transfer function (MTF), to develop the radial ROI, and to compare both ROIs performances for MTF measurement using a cylindrical Polymethyl Methacrylate (PMMA) phantom. The PMMA phantom used in this study was rotated 45°. Four rectangula...

This study aims to develop an algorithm for automatically measuring CT number linearity in three different types of Catphan phantom. We used a sensitometry module image from three Catphan phantoms (types 500, 504, and 604). Each phantom and its air material were segmented. Based on the centroid of the air material, the coordinates for every object...

Background: Methods for segmentation, i.e., Full-segmentation (FS) and Segmentation-rotation (SR), are proposed for maintaining Computed Tomography (CT) number linearity. However, their effectiveness has not yet been tested against noise. Objective: This study aimed to evaluate the influence of noise on the accuracy of CT number linearity of the FS...

A method to calculate a corrected effective diameter (DMIL) to more accurately estimate the dose received by a patient in chest computed tomography (CT) examination had been previously proposed. However, the discrepancy between DMIL and water-equivalent diameter (Dw) is still relatively high (i.e. about 6%). Furthermore, the method is still perform...

Purpose: This study aims to compare the modulation transfer function (MTF) measured using IndoQCT and ImQuest software on GE CT phantom images with variations of slice thickness and reconstruction filter. Method: This study compared MTFs measured using two software (i.e., IndoQCT and ImQuest software) on GE CT phantom images. IndoQCT implemented au...

The average lifetime risk of secondary cancer after irradiating glioblastoma radiation therapy to healthy organs shows that the technique of volumetric modulated arc therapy (VMAT) has a smaller risk of developing secondary cancer compared to intensity modulated radiation therapy (IMRT) and three-dimensional radiation therapy (3DCRT). Parameters of...

This study aims to develop an algorithm for automatic measurement of distance between slices on a Siemens CT phantom with variations of slice thickness and field of view (FOV). The Siemens 64-slice Somatom Perspective CT scanner was utilized to acquire the Siemens phantom image data, with slice thickness variation (i.e., 1, 2, 3, 4, and 5 mm) and F...

Introduction Deep learning image reconstruction (DLIR) is a very recent image reconstruction method that is already available for commercial use. We evaluated the quality of DLIR images and compared it to the quality of images from the latest adaptive statistical iterative reconstruction (ASIR-V) algorithm in terms of noise-power spectrum (NPS) and...

Objective: To develop an algorithm to measure slice thickness to run on three types of Catphan phantoms with the ability to adapt to any misalignment and rotation of the phantoms. Method: Images of Catphan 500, 504, and 604 phantoms were examined. In addition, images with various slice thicknesses ranging from 1.5 to 10.0 mm, distance to the iso-ce...

The gallbladder and pancreas are the organs exposed to primary radiation on abdominal computed tomography (CT). Up to now, organ dose estimation has been carried out by measuring it on Anthropomorphic phantoms with a thermo-luminiscence detector (TLD), or using a Monte Carlo simulation. The radiation dose received by the patient is estimated using...

The liver and kidneys are organs in the abdominal cavity that are usually exposed to primary radiation on abdominal computed tomography (CT) scans. So far, organ dose estimation has been carried out using an anthropomorphic phantom and thermo-luminescence detector (TLD), or Monte Carlo simulations. The estimation of the radiation dose received by t...

Estimation of radiation dose in the gallbladder and pancreas for examination using computed tomography on the basis of size-specific dose estimate (SSDE) Abstract. In computed tomography (CT), the images of many slices are sometimes displayed unorderly. In addition, multiple series are also sometimes performed in one study and images are unorderly...

In computed tomography (CT), the noise is sometimes non-uniform, i.e. the noise magnitude may vary with the gradient CT number within the image. However, the noise fluctuations due to the magnitude of the image gradient is not considered. The purpose of this study was to quantify the noise non-uniformity in CT images using appropriate 1D and 2D com...

Purpose: This study proposes a method for automatically measuring slice thickness on image of the Neusoft CT quality assurance (QA) phantom. Method: The Neusoft CT QA phantom was scanned by a Neuviz 16-slice Neusoft CT Scanner. Automated measurement was implemented using IndoQCT software, while manual measurement was conducted using MicroDicom view...

The purpose of this study to develop software to extract the profiles of the tube current and volume computed tomography dose index (CTDIvol) along the longitudinal axis (z-axis), to investigate them in clinical computed tomography (CT) scanners, and to develop a system to adjust the CTDIvol so that it fluctuates along the fluctuation of tube curre...

Parameters for determining computed tomography (CT) image quality include noise and low-contrast detectability. Studies on low-contrast detectability using the AAPM CT performance phantom have several limitations, such as the absence of quantitative information on the effect of noise and object size on low-contrast detectability. In this study, the...

A free software for the digital imaging and communications in medicine (DICOM) image anonymization is needed to protect patient information from third parties. In this study, a software for an anonymization of DICOM scanned by computed tomography (CT) was developed. The information to be anonymized was contained in the DICOM tags as data elements....

This study aims to develop a program in Python language for automatic measurement of slice thickness in computed tomography (CT) images of a Siemens phantom with different values of slice thickness, field of view (FOV), and pitch. A Siemens phantom was scanned using a Siemens 64-slice CT scanner with various slice thicknesses (i.e. 2, 4, 6, 8, and...

This study assesses the impact of using an Adaptive Mean Filter (AMF) as a preprocessing stage for classification of breast tumor histopathological images at various magnifications. The histopathological image was converted from red-green-blue (RGB) into grayscale before AMF is applied. In this study, AMF was performed with kernel sizes of 3 × 3 an...

This study is to develop an automated method to determine the spatial resolution of computed tomography (CT) images on line-pair objects of the American College of Radiology (ACR) CT accreditation phantom. The ACR phantom was scanned using a GE Healthcare 128-slice CT scanner with seven different reconstruction filters of E1, E2, E3, LU, S1, S2, S3...

Introduction: To develop an in-house acrylic-based step-wedge phantom with several thickness configurations for calibrating computed tomography (CT) localizer radiographs in order to measure the water-equivalent diameter (D w ) and the size-specific dose estimate (SSDE). Method: We developed an in-house step-wedge phantom using 3 mm thick acrylic,...

Radiation of thoracic computed tomography (CT) involves the breast although it is not considered an organ of interest. According to the International Commission on Radiological Protection (ICRP) No. 103, the breast is an organ with a high level of sensitivity when interacting with x-rays, increasing the potential risk of breast cancer. Therefore, t...

This study aims to evaluate the automated measurement of slice sensitivity profile (SSP) on the American Association of Physicists in Medicine (AAPM) computed tomography (CT) performance phantom for variations of slice thickness and field of view (FOV). The AAPM CT performance phantom was scanned using a Philips MRC 880 CT Scanner for variations of...

We investigated the accuracy of automatic measurements of the effective diameter (Deff) using IndoseCT software with axial computed tomography (CT) images of polyester-resin (PESR) phantoms of various diameters. The phantoms used PESR as the base material mixed with Methyl Ethyl Ketone Peroxide (MEKP) as the catalyst. The phantom diameters were 8,...

The aim of this study is to measure the volumetric computed tomography dose index (CTDIvol) for different tube voltages for a polyester-resin (PESR) phantom, and to compare it to values for a standard polymethyl methacrylate (PMMA) phantom. Both phantoms are head phantoms with a diameter of 16 cm. The phantoms were scanned by a CT scanner (GE Revol...

We developed a software to automatically measure the linearity between the CT numbers and densities of objects using an ACR 464 CT phantom, and investigated the CT number linearity of 16 different CT scanners. The software included a segmentation-rotation method. After segmenting five objects within the phantom image, the software computed the mean...

Purpose: To compare the methods of automated noise measurement at the polyester resin (PESR) phantom images and clinical abdominal images. Method: The PESR phantom was scanned with a Siemens SOMATOM Emotion 6 CT scanner for various tube voltages, i.e., 80, 110, and 130 kV. Noises from images of the PESR phantom and 27 clinical abdominal scans were...

Purpose: This study aims to develop a software tool for investigating patient centering profiles of axial CT images and to implement it to evaluate practices in three hospitals in Indonesia. Methods: The evaluation of patient centering accuracy was conducted by comparing the center coordinate of the patient’s image to the center coordinates of the...

This study aims to find the optimum threshold for the automatic measurement of slice thickness using ACR CT accreditation phantom. The ACR CT accreditation phantom was scanned using Siemens Somatom Perspective CT scanner. The nominal slice thicknesses of 1.5, 3, 5, 6, 7, and 10 mm were investigated. Our automated method was developed to obtain accu...

The purpose of this study is to compare the water-equivalent diameter (Dw) and size-specific dose estimate (SSDE) obtained from CT localizer radiograph based on the step-wedge and computed tomography dose index (CTDI) phantoms. The two phantoms were scanned using a 64-slice SIEMENS Somatom CT Scanner with tube currents of 100 mA and 120 kV. The CT...

We propose a new algorithm called distance transform region of interest (DT-ROI) to deal with the irregular patient's surface. The ROIs can be placed orthogonally along the patient’s surface to get spatial resolution. The algorithm was developed using several image processing techniques. The original image was first segmented to obtain a segmented...

The use of computed tomography scanners (CT scans) for medical purposes has increased rapidly since the 1970s. The most significant increase in the use of CT scans for adults is screening patients with early-stage lung cancer, heart disease, and the rest of the body. The number of Chest CT scans has also increased during the Covid-19 pandemic in th...

The current study aims to compare the radiation doses (size-specific dose estimate, SSDE) calculated using Indo-seCT software and dose measurements obtained with a pencil ionization chamber on in-house phantoms of different sizes. In-house phantoms with different diameters (i.e. 8, 16, 24, and 32 cm) were constructed using polyester-resin (PESR) as...

A bilateral filter is a non-linear denoising algorithm that can reduce noise while preserving edges. This study explores the characteristics of a bilateral filter in changing the noise of computed tomography (CT) images and their texture in an iterative implementation. We collected images of a homogeneous Neusoft phantom scanned with tube currents...

Accurate measurement of spatial resolution in terms of modulation transfer function (MTF) is essential in computed tomography (CT) images. The purpose of this study was to developed a computational phantom that can be used to evaluate the effect of noise on the MTF in CT images. Our computational phantoms for measuring MTF in CT were developed with...

Purpose: The current study proposes a method for automatically measuring slice thickness using a non-rotational method on the middle stair object of the AAPM CT performance phantom image. Method: The AAPM CT performance phantom was scanned by a GE Healthcare 128-slice CT scanner with nominal slice thicknesses of 0.625, 1.25, 2.5, 3.75, 5, 7.5 and 1...

Noise in computed tomography (CT) images is unavoidable due to various factors such as errors from patient sources, hardware errors, and image acquisition. In order to reduce the noise, a selective median filter (SMeF) has been developed. SMeF determine the median value selectively using a threshold. For quantitative evaluation, effectiveness of th...

Background: Currently, the volume computed tomography dose index (CTDIvol), the most-used quantity to express output dose of computed tomography (CT) patient’s dose, is not related to the real sizes and attenuation properties of each patient. The size—specific dose estimates (SSDE), based on the water—equivalent diameter (DW) overcomes those issues...

Background: The effect of region of interest (ROI) size variation on producing accurate noise levels is not yet studied. Objective: This study aimed to evaluate the influence of ROI sizes on the accuracy of noise measurement in computed tomography (CT) by using images of a computational and American College of Radiology (ACR) phantoms. Material an...

Institutional diagnostic reference levels are used for quality assurance in radiology departments. The purpose of this study was to establish an institutional diagnostic reference level (DRL) and to provide a practical tool in diagnostic radiology and nuclear medicine. For each type of procedure/examination, it needs at least 20 patients. The patie...

The aim of this study was to characterize electron contamination of a flattened (FF) and an unflattened (FFF) Varian Clinac iX 6X and 15X photon beams using Monte Carlo (MC) simulation. EGSnrc MC technique was used to model the flattened and unflattened head and simulate dose distribution of 6X and 15X of FF and FFF photon beam in water phantom. Th...

The purpose of this study was to calculate the average dose of a phantom with a diameter of 16 and 32 cm, as well as the dose distribution in the center and periphery. The results were then compared to those from the IndoseCT software. In this study, a standard PMMA phantom with a diameter variation of 16 and 32 cm was used. The phantom was scanned...

Radiation can be visualized using a scintillator and a digital camera. If the amount of light emitted by the scintillator increases with dose, the dose estimation can be obtained from the amount of light emitted. In this study, the basic performance of the scintillator and digital camera system was evaluated by measuring computed tomography dose in...

A bolus is a material equivalent to soft tissue and is directly placed on the skin surface during radiotherapy. It is commonly used to increase the dose on the skin surface in electron beam radiation. A typical material for a bolus is silicone rubber (SR). We made a bolus with dimensions of 17 × 17 × 1 cm ³ by varying silicone rubber (SR) RTV 52 an...

Purpose: We have developed a software to automatically find the contrast-detail (C-D) curve based on the statistical low-contrast detectability (LCD) in images of computed tomography (CT) phantoms at multiple cell sizes and to generate minimum detectable contrast (MDC) characteristics. Methods: A simple graphical user interface was developed to...

The Association of South-East Asian Nations, ASEAN, was established on 8 August 1967 in Bangkok, Thailand, with the Bangkok Declaration signed by the Founders of ASEAN, namely Indonesia, Malaysia, Philippines, Singapore and Thailand. Brunei Darussalam, Viet Nam, Lao PDR and Myanmar, and Cambodia were later joined, making up what is today the ten Me...

There are many cases where treatment of breast cancer was performed with thin body contours, especially after the breast mastectomy. This may lead in a larger radiation dose in the lungs, so that a bolus is needed to compensate the thin body for the optimal dose distribution. This study was aimed to compare the dose distribution in the breast cance...

Introduction: The purpose of this study was to determine the best normal tissue objective (NTO) values based on the dose distribution from brain tumor radiation therapy. Material and methods: The NTO is a constraint provided by Eclipse to limit the dose to normal tissues by steepening the dose gradient. The multitude of NTO setting combinations nec...

The dose received by a patient on CT examination is expressed in size-specific dose estimates (SSDE) which is a function of the patient diameter, x-ray attenuation, and scanner output (volume computed tomography dose index, CTDIvol). Patient diameter and x-ray attenuation are represented as water equivalent diameter (Dw). We conducted the research...

Purpose: The purpose of this study is to automate the field size verification to facilitate mechanical check aspect medical linear accelerator (linac) quality assurance in a MATLAB-based algorithm on electronic portal imaging device (EPID) images. Methods: A total of 5 reference datasets (i.e. field sizes of 5 cm × 5 cm, 10 cm × 10 cm, 15 cm × 15 c...

Introduction : Over the last seven years, the development of nanoparticles as computed tomography (CT) contrast agents has increased significantly. In this present work, syntheses of colloidal silver nanoparticles (Ag NPs), platinum nanoparticles (Pt NPs), and silver-platinum nanoparticles (Ag-Pt NPs) have been successfully performed using pulsed l...

Background: Body size is an important parameter in radiology examinations. Measurements of body size may be carried out remotely using a Kinect camera. Objective: We aim to develop a Matlab-based software that can be used to automatically measure the height and area in order to estimate the weight of a human body without direct contact. Methods: Th...

This study aims to compare entrance surface dose (ESD) values measured with nanoDot Al2O3:C optically-stimulated luminescence dosimeter (OSLD) and guidance level set under the second national dose survey which utilized old-version LiF:Mg,Ti thermoluminescence dosimeter (TLD). In this study, we conducted a dosimetric assessment for posteroanterior c...

We developed in-house phantoms of various sizes from polyester resin (PR) and methyl ethyl ketone peroxide (MEKP) and investigated the CT numbers of the phantoms for various tube voltages and reconstructed fields of view (FOV). In-house phantoms with diameters of 8, 16, 24, and 32 cm were developed. The phantoms were made using 99.7% PR and 0.3% ME...

The study aims to correlate the effective diameter (Deff) and water-equivalent diameter (Dw) parameters with anterior-posterior (AP) and lateral (LAT) and AP+LAT dimensions in order to estimate the patient dose in head CT examinations. Seventy-four images of patients who underwent head CT examinations were retrospectively collected. The patient’s s...

Background: The free flattening filter (FFF) beam can affect the characteristics of the linac output such as the maximum dose depth, surface dose, dose in the fall-off area, and doses outside the field because the beam hardening effect does not occur in the FFF linac head. Therefore, the present study aimed to investigate the influence of the FFF b...

Objective: The aim of this study is to investigate image qualities filtered by a selective mean filter (SMF) and its comparison to an adaptive statistical iterative reconstruction (ASIR). Materials and Methods: A CT AAPM performance phantom was used for the assessment of basic image quality. The phantom was scanned by 128 Multiple Slices Computed T...

Background: Estimation of eye lens dose is important in head computed tomography (CT) examination, since the eye lens is very sensitive organ to ionizing radiation. Objective: The purpose of this study is to compare estimations of eye lens dose in head CT examinations using local size-specific dose estimate (SSDE) based on size-conversion factors o...

Purpose: The aim of this work was to establish the relationships of patient size in terms of effective diameter (D eff ) and water-equivalent diameter (D w ) with lateral (LAT) and anterior-posterior (AP) dimensions in order to predict the specific patient dose for thoracic, abdominal, and pelvic computed tomography (CT) examinations. Methods: A to...

IndoseCT merupakan software untuk menghitung dan mendokumentasikan dosis radiasi dari setiap pasien yang menjalani pemeriksaan computed tomography (CT). Software ini tidak hanya menghitung dosis keluaran radiasi pesawat CT (dalam besaran volume CT dose index, CTDIvol), tetapi juga dosis individual yang diterima oleh setiap pasien (dalam besaran siz...

The size-specific dose estimate (SSDE) is an estimation of patient dose in computed tomography (CT). The SSDE strongly depends on the water-equivalent diameter (DW). In abdominal CT examinations, contrast agent is sometimes used to more clearly visualize tissue lesions. The Hounsfield unit (HU) of CT images with and without the use of contrast agen...

Measurement of the slice thickness in computed tomography (CT) is usually made using a special phantom, such as the AAPM CT performance phantom. Images of the phantom are analyzed manually and subjectively. The purpose of this study is to develop an automated system for measuring the slice thickness of the CT image of the phantom using MATLAB softw...

Purpose: The aim of this study is to propose an algorithm for the automated calculation of water-equivalent diameter (Dw ) and size-specific dose estimation (SSDE) from clinical computed tomography (CT) images containing one or more substantial body part. Methods: All CT datasets were retrospectively acquired by the Toshiba Aquilion 128 CT scann...

Introduction: CTDI phantoms are used to optimize computed tomography examinations in terms of X-ray image quality and received dose. In this regard, the aim of this study is to develop low price head CTDI phantoms from the polyester-resin (PESR) materials as an alternative phantom. Material and Methods: The PESR was mixed with methyl ethyl ketone p...