Choirul Anam

Choirul Anam
Universitas Diponegoro | UNDIP · Department of Physics

Doctor of Philosophy

About

146
Publications
81,243
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589
Citations
Introduction
Choirul Anam currently works at the Physics department, Universitas Diponegoro. Choirul does research in Medical Physics, Biophysics and Computational Physics. His current project is 'Design and implementation of organ dose calculation in CT scanning.'
Additional affiliations
January 2006 - present
Universitas Diponegoro
Position
  • Lecturer
Education
September 2013 - April 2018
Bandung Institute of Technology
Field of study
  • Physics
September 2008 - July 2010
University of Indonesia
Field of study
  • Physics
September 1997 - July 2001
Universitas Diponegoro
Field of study
  • Physics

Publications

Publications (146)
Article
Full-text available
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...
Article
Full-text available
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...
Article
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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...
Article
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The aim of this study is to determine the dose distribution and the correlation between central, peripheral and weighted-centre peripheral doses for various phantom sizes and tube voltages in computed tomography (CT). We used phantoms developed in-house, with various water-equivalent diameters (Dw) from 8.5 up to 42.1 cm. The phantoms had a hole in...
Article
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Background: In the tube current modulation (TCM) technique, tube current is changed dynamically during the scanning process. To quantify the effect of a dynamic tube current, a distinct calculator is needed to estimate the CT output radiation dose in terms of volume CT dose index (CTDIvol) and individual patient dose in terms of size-specific dose...
Article
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...
Article
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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...
Article
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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...
Article
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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...
Article
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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...
Article
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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...
Article
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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...
Article
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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...
Article
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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...
Article
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...
Article
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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...
Article
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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...
Article
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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...
Article
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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...
Article
Full-text available
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...
Article
Full-text available
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...
Article
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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...
Article
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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...
Article
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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...
Article
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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...
Article
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...
Article
Full-text available
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...
Article
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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...
Article
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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...
Article
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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...
Technical Report
Full-text available
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...
Technical Report
Full-text available
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...
Article
Full-text available
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...
Article
Full-text available
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...
Article
Full-text available
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...
Article
Full-text available
Purpose: The purpose of this study is to automate the slice thickness verification on the AAPM CT performance phantom and validate it for variations of slice thickness, position from iso-center, and reconstruction filter. Methods: An automatic procedure for slice thickness verification on AAPM CT performance phantom was developed using MATLAB R2015...
Article
Full-text available
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...
Article
Full-text available
Gamma cameras are used in nuclear medicine examinations involving radioisotopes; however, they do not provide real-time feedback. We propose a real-time imaging method based on a commercially available digital camera and a scintillator array to provide simple and accurate measurements of radioisotope accumulation and contamination. We evaluate the...
Article
Full-text available
To visualize the existence of micro-calcifications in mammography there are a number of ways carried out including by the magnification technique. This study evaluates the effect of magnification technique on optical density (OD) and size of the objects of the image produced on mammography. The objects used were three circular coins. Source to imag...
Book
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Buku Standar Profesi Fisikawan Medik ini telah ditetapkan oleh Menteri Kesehatan RI NOMOR HK.01.07/MENKES/322/2020
Article
Full-text available
Size-specific dose estimate (SSDE) is dose metrics of computed tomography, to calculate SSDE we first calculate the patient's body size. In CT head examination, the head size is better to use water-equivalent diameter (Dw), because Dw considers tissue attenuation. CT Head examination with contrast agent increased patient attenuation and increased D...
Article
Full-text available
Optimization of radiation dose is very important in protecting patients against the dangers of x-ray radiation. Optimization of the dose should be able to provide image quality that is acceptable to radiologists for diagnostic purposes with the lowest possible doses. The optimization tool in computed tomography scanner (CT scan) is known as the dia...
Article
Full-text available
This study aimed to compare several methods of measuring the modulation transfer function (MTF) for different reconstruction kernels, using a point phantom, a small-circular (S-circular) Teflon object, and the automated edge of a PMMA phantom. The copper wire section of a phantom was used for the point method. The small-circular (S-circular) teflon...
Article
Full-text available
Purpose: This study was aimed to investigate the impact of noise on full-width at half maximum (FWHM) of slice sensitivity profile (SSP) of computed tomography (CT) images which was automatically calculated using Matlab-based software on the AAPM CT performance phantom. Methods: The slice thickness part of AAPM CT performance phantom was scanned by...
Article
Full-text available
Background: It is necessary to have an automated noise measurement system working accurately to optimize dose in computerized tomography (CT) examinations. Objective: This study aims to develop an algorithm to automate noise measurement that can be implemented in CT images of all body regions. Materials and methods: In this retrospective study...
Article
Full-text available
The measurement of modulation transfer function (MTF) using a head polymethyl methacrylate (PMMA) phantom has been introduced previously. However, measurement is performed using a rectangular region of interest (ROI) at the upper edge of phantom. The purpose of this study is to automatically measure radial MTF using a head PMMA phantom.The head PMM...
Article
Full-text available
Body size is one of the important information in radiological examinations. In general, body size measurements are carried out in a conventional way which still relies on direct contact. Size measurements can be remotely performed using a Kinect camera. This study aims to develop a Matlab-based software that can be used to automatically measure the...
Article
Full-text available
This study implements a selective mean filter (SMF) and determines its effectiveness on computed radiography (CR) images. A phantom of the Kualitas Citra Imajing (KUCING) was used. The effectiveness of the SMF was compared to the adaptive mean filter (AMF). The assessment of image quality was based on several parameters, such as the peak signal to...
Article
Full-text available
Convolutional neutral network (CNN) is widely used in the classification of types of brain cancer and many architectures of the CNN have been developed. Comparasions of various architectures on a specific clinical task is essential. This study aims to compare a deep transfer learning model with AlexNet and GoogleNet architectures for brain tumor cl...
Article
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The purpose of this study was to develop an automatic method for validating the computed tomography gantry tilt. A head polymethyl methacrylate phantom with a diameter of 16 cm was used. Gantry tilt angles were measured both manually and automatically. Manual measurements were performed by measuring the length of the anteroposterior and lateral dia...
Article
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This study evaluates the effect of mis-positioning of patients in relation to the iso-centre in CT examinations on the dose received by phantoms with various diameters. Phantoms with water-equivalent diameters (D w) ranging from 8.5 cm to 42.1 cm were scanned using a GE Optima CT scanner with exposure factors as follows: 200 mA, 120 kVp, 1.375 Pitc...
Article
Full-text available
Background:Reading radiographic images for Covid-19 identification by an expert radiologist requires significant time, therefore the development of an automated analysis system to assisting and saving time in diagnosing Covid-19 is important. Objective: The purpose of this study is to implement the GoogleNet architecture with various epochs in hope...
Preprint
Purpose: We used an improved algorithm to automatically measure the slice sensitivity profile (SSP) and its full-width at half maximum (FWHM) from all three stair objects within an image of the AAPM CT performance phantom. Methods: The phantom was scanned with a Philips Ingenuity 128-slice CT scanner using slice thicknesses of 1 mm and 5 mm. The th...
Article
Full-text available
Medical image fusion has been carried out to obtain information benefits from multi-modalities of medical images. The purpose of this study is to improve the image contrast of fusion image with adaptive method. The median filter was implemented to the images before registration to remove noise for obtaining good image fusion. Geometric transformati...
Article
Full-text available
This study aims to evaluate the traumatic-brain-injury on head CT images using a double-windows-blending algorithm in a single color image. Blending windows allows simultaneous viewing of both windows into one color image so that users do not need to changes the window settings. The double-window-blending algorithm was used to combine two windows o...
Article
Full-text available
In this paper, we develop a Matlab-based program on a Kinect camera to automatically calculate lateral diameter (Dlat) for estimating size-specific dose estimate (SSDE). SSDE is a metric used to express the patient's dose in a CT examination. This metric depends on two other parameters, namely the volume computed tomography dose index (CTDIvol) and...