Publications by authors named "Triadyaksa P"
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 And Methods: In this experimental study, two phantoms were used, including computational and ACR phantoms.
Cardiac cine magnetic resonance imaging (MRI) is a widely used technique for the noninvasive assessment of cardiac functions. Deep neural networks have achieved considerable progress in overcoming various challenges in cine MRI analysis. However, deep learning models cannot be used for classification because limited cine MRI data are available.
View Article and Find Full Text PDFArticle Synopsis
- The study introduces a deep learning-based technique for automatically segmenting the right ventricle (RV) from radially reconstructed long-axis (RLA) images in cardiovascular magnetic resonance (CMR) imaging, comparing its effectiveness to conventional methods used on short axis (SA) images.
- Results show that the RLA method significantly outperforms the SA approach in segmenting the RV, achieving a Dice similarity coefficient of 0.84 compared to 0.61 for SA.
- Additionally, the correlation between the automated RLA measurements of RV strain and manual measurements was higher (0.5-0.7) than that of SA methods (0.1-0.2), demonstrating the RLA method’s enhanced accuracy
Objectives: This study aimed at evaluating left ventricular myocardial pixel-wise T2* using two truncation methods for different iron deposition T2* ranges and comparison of segmental T2* in different coronary artery territories.
Material And Methods: Bright blood multi-gradient echo data of 30 patients were quantified by pixel-wise monoexponential T2* fitting with its R and SNR truncation. T2* was analyzed at different iron classifications.
Purpose: The aim of this study is to propose an algorithm for the automated calculation of water-equivalent diameter (D ) 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 scanner. The proposed algorithm consisted of a contouring stage for the D calculation, carried out by taking the six largest objects in the cross-sectional image of the patient's body, followed by the removal of the CT table depending on the center position (y-axis) of each object.
Background: The HU linearity is an essential parameter in a quantitative imaging and the treatment planning systems of radiotherapy.
Objective: This study aims to evaluate the linearity of Hounsfield unit (HU) in applying the adaptive iterative dose reduction (AIDR) on CT scanner and its comparison to the filtered back-projection (FBP).
Material And Methods: In this experimental phantom study, a TOS-phantom was scanned using a Toshiba Alexion 6 CT scanner.
Cardiac T * mapping is a noninvasive MRI method that is used to identify myocardial iron accumulation in several iron storage diseases such as hereditary hemochromatosis, sickle cell disease, and β-thalassemia major. The method has improved over the years in terms of MR acquisition, focus on relative artifact-free myocardium regions, and T * quantification. Several improvement factors involved include blood pool signal suppression, the reproducibility of T * measurement as affected by scanner hardware, and acquisition software.
View Article and Find Full Text PDFObjective: To compare the robustness of native T1 mapping using mean and median pixel-wise quantification methods.
Methods: Fifty-seven consecutive patients without overt signs of heart failure were examined in clinical routine for suspicion of cardiomyopathy. MRI included the acquisition of native T1 maps by a motion-corrected modified Look-Locker inversion recovery sequence at 1.
Objectives: Early detection of iron loading is affected by the reproducibility of myocardial contour assessment. A novel semi-automatic myocardial segmentation method is presented on contrast-optimized composite images and compared to the results of manual drawing.
Materials And Methods: Fifty-one short-axis slices at basal, mid-ventricular and apical locations from 17 patients were acquired by bright blood multi-gradient echo MRI.
Objectives: Reproducibility of myocardial contour determination in cardiac magnetic resonance imaging is important, especially when determining T2* values per myocardial segment as a prognostic factor of heart failure or thalassemia. A method creating a composite image with contrasts optimized for drawing myocardial contours is introduced and compared with the standard method on a single image.
Materials And Methods: A total of 36 short-axis slices from bright-blood multigradient echo (MGE) T2* scans of 21 patients were acquired at eight echo times.
Objectives: The aim of this study was to assess the intermodel agreement of different magnetic resonance myocardial perfusion models and evaluate their correspondence to stenosis diameter.
Materials And Methods: In total, 260 myocardial segments were analyzed from rest and adenosine stress first-pass myocardial perfusion magnetic resonance images (1.5 T, 0.
Purpose: To assess the repeatability and reproducibility of semiquantitative magnetic resonance (MR) perfusion analysis performed by using different software packages.
Materials And Methods: The study protocol was approved by the institutional ethics committee. Informed consent was obtained from each patient.