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...

This study evaluated impacts of dose and iterative reconstruction (IR) level on low-contrast detectability in images of AAPM CT Performance phantom using a 4-alternative forced choice (4-AFC) approach. Five medical physicists detected low-contrast and small objects having size of 3.0 mm with the 4-AFC method. The tests were conducted at three diffe...

This study aims to determine relationship between water-equivalent diameter (Dw) and low-contract detectability (LCD) for various reconstruction filters. The water phantoms were Hitachi phantoms with diameters of 16, 22.5, 30, and 38 cm. The phantoms were scanned with a 64-slice Hitachi CT Scanner and reconstructed with various reconstruction filte...

Purpose. This study aimed to develop a new method for automated contrast-to-noise ratio (CNR) measurement using the low-contrast object in the ACR computed tomography (CT) phantom. Methods. The proposed method for CNR measurement was based on statistical criteria. A region of interest (ROI) was placed in a specific radial location and was then rota...

X-ray fluoroscopy causes relatively high radiation exposure to physicians, radiation professionals , and patients. Understanding the behavior of scattered radiation is crucial for reducing occupational exposure. We developed a system for estimating radiation exposure during fluoroscopy by monitoring the position of the physician using a depth camer...

Measurement of computed tomography (CT) number linearity is important to do in routine quality control (QC). However, this measurement requires a special phantom containing objects with various materials and densities. Because many CT centers do not necessarily have such kind of the phantom, as a result many CT centers cannot measure CT number line...

This study evaluated a method for automatic slice thickness measurement on Neusoft CT phantom for CT thorax protocol. The Neusoft CT phantom was scanned by a Neusoft Neuviz 16-slice CT Scanner with 1.25 and 5.0 mm slice thicknesses. The images were scanned with CT thorax protocol, i.e., lung and mediastinum. We used these two protocols because they...

Utilization of high-quality computed tomography (CT) imaging holds great potential in assisting clinical radiologists in diagnosing patients' illnesses with great precision and accuracy. One principal parameter of CT imaging quality is noise level, quantified as noise power spectrum (NPS). In this work, we performed CT imaging quality assessment by...

Currently, there are available software for measuring edge-based modulation transfer function (MTF) curves for characterization of spatial resolution in computed tomography (CT) images, such as IndoQCT and ImQuest. However, the MTF curves from these two softwares have not been compared. This study aims to compare the edge-based MTF curves obtained...

Deep learning image reconstruction (DLIR) is a most recent computed tomography (CT) image reconstruction method for reducing image noise while maintaining the spatial resolution of the image. It is well-understood that image noise affects the low-contrast detectability (LCD) of the images. We assessed the LCD of DLIR images using parameters of CT n...

The modulation transfer function (MTF) in compted tomography (CT) images can be measured using software tools such as IndoQCT and ImQuest. However, the accuracy of the resulting MTF curves from these two softwares has not been compared. Therefore, this study aims to compare the edge MTF curves obtained using ImQuest and IndoQCT software, and the po...

Computed tomography (CT) image can be reformatted in multi-planar reformation (MPR) by selecting image fragments in the axial, sagittal, and coronal planes. Unfortunately, the existing software to reformat an oblique plane is only available in the latest CT center, hence development of an accessible software to perform this feature is needed. This...

Contrast-to-noise ratio (CNR) is a crucial parameter for assessing computed tomography (CT) image quality, as it directly impacts the overall image clarity. IndoQCT is a software that enables automatic CNR measurement. However, due to its relatively new introduction, there has been a lack of discussion regarding the evaluation of IndoQCT's ability...

This study aims to evaluate the automatic contrast-to-noise (CNR) measurement method using IndoQCT and compare the results with those from manual method using IndoQCT and MicroDicom software. The low-contrast module of the ACR CT phantom image was utilized for this evaluation. The ACR CT phantom were scanned with variations of tube currents (80, 10...

The diagnosis of diseases with computed tomography (CT) images always needs implementation of windowing technique. Nevertheless, in some clinical application, it frequently needs switching various windows (i.e., lung, soft-tissue, and bone windows) which is ineffective and tedious. This study aims to develop a windows blending for clinical CT image...

This study aims to evaluate the accuracy of edge profile shifting based on a statistical approach to improve the edge-based modulation transfer function (MTF) measurement using the slanted-edge phantom. A slanted-edge phantom was computationally developed with two materials, a water and a material of 120 HU. The spatial resolution of the phantom wa...

In this study, we devised a radiation protection tool specifically designed for healthcare professionals and students engaged in cardiac catheterization to easily monitor and evaluate scattered radiation distribution across diverse C-arm angles and arbitrary physician associated staff positions - scrub nurse, technologist positions. In this study,...

The aim of this study is to compare the dosimetric performance of two CT acquisition protocols for the petrous bone: a standard fixed mAs protocol and a protocol using tube current modulation (TCM). By analyzing the scan length, dose-length product (DLP) and effective dose (ED) obtained with each protocol, we investigate whether TCM offers an advan...

Purpose: The aim of this study was to evaluate the point doses using a distribution of the size-specific dose estimate (SSDE) from axial CT images of in-house phantoms having diameters from 8 to 40 cm. Methods: In-house phantoms made of polyester-resin (PESR) mixed with methyl ethyl ketone peroxide (MEKP) were used. The phantoms were built with dif...

This study aimed to fabricate thyroid shields made from Silicone Rubber (SR)-Cooper (Cu) material, analyze the effectiveness of SR-Cu shields in reducing radiation dose, and compare them with tube current modulation (TCM) in computed tomography (CT) examination. Thyroid shields were made from SR-Cu with Cu percentages of 0, 5, 10, 15, and 20%. The...

This study aims to determine the comparison between the radiation dose of computed tomography dose index volume (CTDIvol) and size-specific dose estimate (SSDE) in CT scan thorax for Corona Virus Disease 2019 (Covid-19) and non-Covid-19 patients. The method used in this study is a retrospective study, where the data used is obtained from images of...

This study aims to develop an automatic method for calculating slice thickness on an ACR phantom and evaluate its accuracy at variation of orientation angle and slice thickness. The phantom was scanned using Siemens SOMATOM Perspective, with variations of the slice thickness (i.e. 1.5, 3, 5, 6, 7, and 10 mm) and rotation angles (i.e. 0.0, 22.5, 45....

To investigate the effects of tube voltage and phantom diameter on noise inhomogeneity of computed tomography (CT) image. This study used a step-wedge water cylindrical phantom with four diameters (i.e., 8, 16, 24, and 32 cm). The phantom was scanned with GE 128- Slice CT scanner with tube voltage variation of 80, 100, 120, and 140 kV. Noise inhomo...

Introduction: Size-specific dose estimation (SSDE) is suggested for accurate measurement of CT dose. Various methods have been developed for SSDE calculation by both manual and automated methods. However, truncation artefact may affect the specific size determination and SSDE calculation. In this article, we evaluate how truncation affects measurem...

Purpose. To develop a method to extract statistical low-contrast detectability (LCD) and contrast-detail (C-D) curves from clinical patient images. Method. We used the region of air surrounding the patient as an alternative for a homogeneous region within a patient. A simple graphical user interface (GUI) was created to set the initial configuratio...

This study compares the CT number uniformity and homogeneity for detecting beam hardening artefact from images of the American College of Radiology (ACR) computed tomography (CT) phantom scanned with 20 CT scanners from four manufacturers, and images with and without beam hardening artefact. Software to automatically measure CT number uniformity an...

Background: The slice spacing has a crucial role in the accuracy of CT images in sagittal, and coronal planes. However, there is no practical method for measuring accuracy of the slice spacing. Purpose: This study proposes a novel method to automatically measure the slice spacing using the AAPM CT performance phantom. Method: The AAPM CT performan...

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 software for measuring the computed tomography (CT) number of multiple materials automatically and investigate the impact of tube voltage on the measured CT numbers. The software was specifically design to automatically measure CT number of multiple materials on images of an ACR 464 CT phantom (Gammex, Inc.). Automatic...

Purpose: This study proposes a method for automatically measuring the thickness of thin slices on images of the Catphan phantom. Methods: In the proposed method, the angle of the phantom's orientation was determined based on the relative coordinates of the four hole objects in the phantom. After the angle of the wires were determined, the profiles...

Assessment of the computed tomography (CT) number linearity is an important part in the Quality Control (QC) procedures of CT images. An automated method is needed for simplify the measurement process of this parameter. This study aims to develop an automated method for measuring CT number linearity on the TOS phantom images scanned with Toshiba Aq...

The quality control (QC) procedure of computed tomography (CT) is an important task to be regularly performed. It consists of daily, monthly, and annual tasks. Each procedure can be time-consuming. Manual QC can take many hours. Manual measurement of image quality parameters can also lead to a bias due to the subjectivity of examiners. IndoQCT answ...

Introduction A significant number of head computed tomography (CT) scans are performed annually. However, due to the close proximity of the thyroid gland to the radiation field, this procedure can expose the gland to ionising radiation. Consequently, this study aimed to estimate organ dose, effective dose (ED) and lifetime attributable risk (LAR) o...

This study aims to develop three sizes of breast phantoms from silicone rubber (SR) material and evaluate tube current modulation (TCM) to reduce surface doses of the developed breast phantoms. The in-house breast phantom has three sizes: small (cup 34), medium (cup 36), and large (cup 38). The cross-sectional areas of cup 34, 36, and 38 are 78.5,...

This study aims to compare the effectivity of silicone rubber-lead (SR-Pb) eye shields and TCM technique during head CT examinations. In this study, a 95-5 wt% SR-Pb eye shield was developed with dimensions of 17 cm ×17 cm ×0.6 cm. This study was carried out at three tube voltages, namely 80, 100, and 120 kV. The measurements were conducted using O...

The computed tomography scanner (CT scan) protocol used in patient examinations must be continuously reviewed and optimized. Medical physicists evaluate the quality of the resulting image using an image quality phantom and evaluate radiation dose using a dosimetry phantom separately. Procuring a dosimetry phantom and image quality phantom for CT sc...

This study aims to evaluate the modulation transfer function (MTF) from a cylindrical step-wedge phantom having diameters of 8-32 cm at various field of views (FOVs). In this study, MTF curves were measured based on the edge spread function (ESF) using IndoQCT software. In addition, noises were also measured using IndoQCT software. It was found tha...

The performance of chest computed tomography (CT) always involved the scanning of breast since it was positioned within the scan range. It makes this organ always receives an amount of radiation that potentially harms the biological system. Many attempts have been performed to reduce the radiation doses objected to breast, including the utilization...

This study aims to evaluate effect of noise on the robustness of semantic segmentation models for Magnetic Resonance Imaging (MRI) head images with tumor. We implemented the MobileNetV2+U-Net architectural model. We tested the segmentation model with Gaussian and Poisson noises in various levels. The addition of noise was performed five iterations...

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...

This study aims to investigate the correlation between abdominal diameter against the their ages in pediatric Computed Tomography (CT) examination. The retrospective images from 96 patients ranging from 0–16 years scanned by the Siemens Somatom Go Top 128 Multi-slice CT scanner were evaluated. In a total of 46 patients were scanned by tube current...

This study established an institutional DRL based on SSDE using Water equivalent diameter

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...

The purpose of this study is to evaluate the tube current profile of Siemens 128 slice CT scanner with tube current modulation (TCM) technique using the Borobudur phantom. Borobudur phantom was made from acrylic which has four different diameters of 8, 16, 24, and 32 cm. It was filled with distilled water. The phantom was scanned using a Siemens So...

Purpose: The aim of this study is to develop software to automatically assess the laser alignment on the ACR CT phantom and evaluate its accuracy on sixteen CT scanners. Methods: Software for an automated method of laser alignment assessment on the ACR CT phantom was developed. Laser alignment assessment was based on the positions of the ball-bear...

This study aimed to develop an electrometer for dose area product (DAP) measurement to monitor patient doses on X-ray radiography examinations. The electrometer was developed based on the Atmega8535 microcontroller as the processing unit. This electrometer was operated at 12 volts of direct current (DC) and controlled by buttons for navigation. The...

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...

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...

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...

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...

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...

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...

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,...

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,...

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...

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...