Computing in medicine: a role-play supports diagnosis and assessment of diseases in patients

Computing is a principle of leading data visualisation, translation and findings of new information. In medicine, understanding and reading medical images are crucial to analyse and assess medical data before making a decision and treatment for patients. Computational modelling, simulation and technology enable to form the digital medicine and gain new knowledge to develop non-invasive techniques for diagnosis and assessment of diseases in patients. This talk covers the current state of the art non-invasive imaging approaches and predicts the trends of computing and machine learning in medicine and healthcare

Maritime Computing Transportation, Environment, and Development: Trends of Data Visualization and Computational Methodologies

This research aims to characterize the field of maritime computing (MC) transportation, environment, and development. It is the first report to discover how MC domain configurations support management technologies. An aspect of this research is the creation of drivers of ocean-based businesses. Systematic search and meta-analysis are employed to classify and define the MC domain. MC developments were first identified in the 1990s, representing maritime development for designing sailboats, submarines, and ship hydrodynamics. The maritime environment is simulated to predict emission reductions, coastal waste particles, renewable energy, and engineer robots to observe the ocean ecosystem. Maritime transportation focuses on optimizing ship speed, maneuvering ships, and using liquefied natural gas and submarine pipelines. Data trends with machine learning can be obtained by collecting a big data of similar computational results for implementing artificial intelligence strategies. Research findings show that modeling is an essential skill set in the 21st century

An investigation of correlation between left coronary bifurcation angle and hemodynamic changes in coronary stenosis by coronary computed tomography angiography-derived computational fluid dynamics

Background: To investigate the correlation between left coronary bifurcation angle and coronary stenosis as assessed by coronary computed tomography angiography (CCTA)-generated computational fluid dynamics (CFD) analysis when compared to the CCTA analysis of coronary lumen stenosis and plaque lesion length with invasive coronary angiography (ICA) as the reference method. Methods: Thirty patients (22 males, mean age: 59±6.9 years) with calcified plaques at the left coronary artery were included in the study with all patients undergoing CCTA and ICA examinations. CFD simulation was performed to analyze hemodynamic changes to the left coronary artery models in terms of wall shear stress, wall pressure and flow velocity, with findings correlated to the coronary stenosis and degree of bifurcation angle. Calcified plaque length was measured in the left coronary artery with diagnostic value compared to that from coronary lumen and bifurcation angle assessments. Results: Of 26 significant stenosis at left anterior descending (LAD) and 13 at left circumflex (LCx) on CCTA, only 14 and 5 of them were confirmed to be >50% stenosis at LAD and LCx respectively on ICA, resulting in sensitivity, specificity, positive predictive value (PPV) and negative predictive value (NPV) of 100%, 52%, 49% and 100%. The mean plaque length was measured 5.3±3.6 and 4.4±1.9 mm at LAD and LCx, respectively, with diagnostic sensitivity, specificity, PPV and NPV being 92.8%, 46.7%, 61.9% and 87.5% for extensively calcified plaques. The mean bifurcation angle was measured 83.9±13.6º and 83.8±13.3º on CCTA and ICA, respectively, with no significant difference (P=0.98). The corresponding sensitivity, specificity, PPV and NPV were 100%, 78.6%, 84.2% and 100% based on bifurcation angle measurement on CCTA, 100%, 73.3%, 78.9% and 100% based on bifurcation angle measurements on ICA, respectively. Wall shear stress was noted to increase in the LAD and LCx models with significant stenosis and wider angulation (>80º), but demonstrated little or no change in most of the coronary models with no significant stenosis and narrower angulation (<80º). Conclusions: This study further clarifies the relationship between left coronary bifurcation angle and significant stenosis, with angulation measurement serving as a more accurate approach than coronary lumen assessment or plaque lesion length for determining significant coronary stenosis. Left coronary bifurcation angle is suggested to be incorporated into coronary artery disease (CAD) assessment when diagnosing significant CAD

Hemodynamic impacts of left coronary stenosis : a patient-specific analysis

This study analyses the hemodynamic variations surrounding stenoses located at the left coronary bifurcation, and their influence on the wall shear stress (WSS) in realistic coronary geometries. Four patients with suspected coronary artery disease were chosen, and coronary models were reconstructed based on high-resolution CT data. The coronary stenoses were observed at the left circumflex and left anterior descending branches, resulting in a lumen narrowing of >50%. Flow analysis was performed using computational fluid dynamics, to simulate the cardiac flow conditions of the realistic individual patient geometry. Blood flow and WSS changes in the left coronary artery were calculated throughout the entire cardiac phases. Our results revealed that the recirculation regions were found at the poststenotic locations. WSS was found to increase at the stenotic positions in all four patients. There is a strong correlation between coronary stenosis and the hemodynamic changes, which are reflected in blood flow pattern and WSS, based on the realistic left coronary geometries

Computational fluid dynamics analysis of the effect of simulated plaques in the left coronary artery: A preliminary study

Background: Atherosclerosis is the most common cause of coronary artery disease which is formed by plaque presence inside the artery wall leading to blockage of the blood supply to the heart muscle. The mechanism of atherosclerotic development is dependent on the blood flow variations in the artery wall during cardiac cycles. Characterization of plaque components and investigation of the plaques with subsequent coronary artery stenosis and myocardial dysfunction has been extensively studied in the literature. However, little is known about the effect of plaques on hemodynamic changes to the coronary artery, to the best of our knowledge. Investigation of the position of plaques in the coronary artery and its corresponding regional hemodynamic effects will provide valuable information for prediction of the coronary artery disease progression. The aim of this study is to investigate the effect of simulated plaques in the left coronary artery using computational fluid dynamics. Methods: A left coronary artery model was generated based on a computed tomography data in a patient suspected of coronary artery disease. The model consists of the left main coronary artery, left anterior descending and left circumflex, together with side branches. Simulated coronary plaques were created and placed in the left main coronary artery and left anterior descending with a resultant lumen stenosis of more than 50%. The blood rheology and pulsatile velocity at the left coronary artery were applied to simulate the realistic physiological situation. A transient simulation was performed to demonstrate the hemodynamic changes during cardiac phases. The flow velocity pattern, wall shear stress and wall pressure were measured at peak systolic and middle diastolic phases in the models with and without presence of plaques. Results: Our results showed that the flow change due to the simulated coronary plaques demonstrated a large circulation region at the left coronary bifurcation, and the velocity through bifurcation was increased. In contrast, a smooth flow pattern was observed in the non-calcified regions and flow velocity was low at the bifurcation. Low wall pressure was present in the coronary artery with a simulated coronary plaque whereas there was high wall pressure in the normal coronary artery. The simulated plaques resulted in high wall shear stress when compared to the low wall shear stress present in the normal coronary artery. The simulated coronary plaques interfered with blood flow behavior which was demonstrated as a large region of disturbed flow at coronary bifurcation. Conclusion: We successfully simulated the coronary plaques in a realistic coronary model and the effect of plaques in different locations on subsequent hemodynamic changes. Our preliminary study is useful for further investigation of the development of atherosclerosis in patients with different cardiac risk factors

An investigation of correlation between left coronary bifurcation angle and hemodynamic changes in coronary stenosis by coronary computed tomography angiography-derived computational fluid dynamics

The purpose of this study was to investigate the correlation between left coronary bifurcation angle and coronary stenosis with use of coronary CT angiography (CCTA)-generated computational fluid dynamics (CFD) analysis when compared to the CCTA analysis of coronary lumen stenosis with invasive coronary angiography (ICA) as the reference method. Thirty patients with calcified plaques at the left coronary artery were included in the study with all patients undergoing CCTA and ICA examinations. CFD simulation of left coronary models was performed to analyze hemodynamic changes including wall shear stress, wall pressure and flow velocity, with findings correlated to the coronary stenosis and degree of bifurcation angle. The mean bifurcation angle was measured 83.7 ± 12.7º and 82.3 ± 11.8º on CCTA and ICA, respectively, with no significant difference (p=0.65). Of 25 significant stenosis at left anterior descending (LAD) and 13 at left circumflex (LCx) on CCTA, only 15 and 6 of them were confirmed to be >50% stenosis at LAD and LCx respectively on ICA. Wall shear stress was noted to increase in the LAD and LCx models with significant stenosis and wider angulation (>80º), but demonstrated little or no change in most of the other coronary models with no significant stenosis and narrower angulation. Wall pressured was decreased at the coronary arteries with significant stenosis, while flow velocity was increased with turbulence observed at the post-stenotic sites. This study further clarifies the relationship between left coronary bifurcation angle and significant stenosis, with angulation measurement serving as a more accurate approach than lumen assessment for determining significant coronary stenosis. Left coronary bifurcation angle is suggested to be incorporated into coronary lumen assessment when diagnosing coronary artery disease

Computational Fluid Dynamics Analysis of the Effect of Plaques in the Left Coronary Artery

This study was to investigate the hemodynamic effect of simulated plaques in left coronary artery models, which were generated from a sample patient’s data. Plaques were simulated and placed at the left main stem and the left anterior descending (LAD) to produce at least 60% coronary stenosis. Computational fluid dynamics analysis was performed to simulate realistic physiological conditions that reflect the in vivo cardiac hemodynamics, and comparison of wall shear stress (WSS) between Newtonian and non-Newtonian fluid models was performed. The pressure gradient (PSG) and flow velocities in the left coronary artery were measured and compared in the left coronary models with and without presence of plaques during cardiac cycle. Our results showed that the highest PSG was observed in stenotic regions caused by the plaques. Low flow velocity areas were found at postplaque locations in the left circumflex, LAD, and bifurcation. WSS at the stenotic locations was similar between the non-Newtonian and Newtonian models although some more details were observed with non-Newtonian model. There is a direct correlation between coronary plaques and subsequent hemodynamic changes, based on the simulation of plaques in the realistic coronary models

Investigation of the haemodynamic environment of bifurcation plaques within the left coronary artery in realistic patient models based on CT images

The aim of this study was to investigate the plaques at the left coronary artery (LCA) and their effect on the haemodynamic and wall shear stress (WSS) in realistic patient models. Three sample patients with left coronary disease were selected based on CT data. The plaques were present at the left anterior descending and left circumflex branches with more than 50 % lumen narrowing. Computational fluid dynamics analysis was used to perform simulation of patient-specific models with realistic physiological conditions that demonstrate in vivo cardiac flow. WSS and blood flow in the LCA were measured during cardiac cycles. Our results showed that WSS was found to increase at the stenotic locations and decrease at pre- and post-plaque locations, whilst the recirculation location was found at post-plaque regions. There is a strong correlation between coronary bifurcation plaques and hemodynamic and WSS changes, based on the realistic coronary disease models

Multislice CT virtual endoscopy in pre-aortic stent grafting: optimization of scanning protocals

The purpose of this study was to investigate the optimal scanning protocols of multislice CT (MSCT) angiography in pre-aortic stent grafting, visualized on virtual endoscopy (VE). A series of scans were performed on a human aorta phantom with a 16-slice multislice CT scanner with the scanning protocols as follows: section thickness of 1.0/1.5/2.0/3.0 mm, pitch value of 1.0/1.25/1.5, and reconstruction interval of 50% overlap. Signal to noise ratio and standard deviation (SD) of the signal intensity on VE images were measured to determine the image quality in relation to MSCT scanning protocols. Subjective assessment was performed by two observers evaluating the degree of artefacts and the configuration of the renal ostium visualized on VE images. Our results showed that the scanning protocol with a section thickness of 2.0 mm resulted in the highest SNR and lowest SD compared to other protocols (p<0.05). Subjective assessment demonstrated that VE image quality was determined by section thickness, but independent of pitch values. We recommended the scanning protocol of section thickness 2.0 mm, pitch 1.5 with a reconstruction interval of 1.0 mm as the optimal one since it allows optimal visualization of VE images of aortic ostia, fewer artefacts and less radiation dose

Automatic Location of Blood Vessel Bifurcations in Digital Eye Fundus Images

Retinal blood vessels are linked with hypertension and cardiovascular disease. It is generally known that vascular bifurcation is mainly involved in varying blood flow velocity as well as its pressure. This paper presents an efficient method for automatic location of blood vessel bifurcations in digital eye fundus images. The proposed algorithm comprised of three main steps: image enhancement, fuzzy clustering, and searching vascular bifurcation. The purposed algorithm revealed successful detection of bifurcations upon test images. Results showed improved diagnostic accuracy in identifying bifurcations with use of the proposed algorithm and encourage its use for further applications such as image registration, personal identification and pre-clinical scanning of retina diagnosis