Study of the influence of normal and high blood pressure on normal and stenosed carotid bifurcation using fluid-structure interaction

Atherosclerosis (stenosis) is a common cardiovascular disease in which the blood vessel restructures by narrowing, thickening and gets hardened due to the deposition of plaque. A detailed study of narrowing of arteries applying computational aspects which leads to better findings in order to know the underlying mechanics of development and progression of such diseases. Such kind of analysis can be a useful tool for the medical professionals to study the realistic physiological conditions. They can simulate and observe the blood flow in arteries. In the present study, a case of normal and stenosed carotid bifurcation is simulated. The models are generated in CATIA based on the clinical data obtained from a patient using Ultrasound Doppler. A transient FSI analysis considering Newtonian behavior is performed to compare the significance of High Blood Pressure (HBP) and Normal Blood Pressure (NBP) on carotid bifurcation. The FSI simulation is carried out for both HBP and NBP conditions for several pulse cycles on normal and stenosed models using ANSYS13.0 to demonstrate the changes in flow behavior at various sections of the model. The computed results agree well with clinical observations and available literature as seen in case of NBP

Quantitative and qualitative bowel analysis using mannitol, water and iodine-based endoluminal contrast agent on 64-row detector CT

Objective: To assess the performance of mannitol as a luminal contrast as compared to water and positive contrast in evaluation of bowel on multidetector computed tomography (MDCT). Materials and Methods: Three hundred patients were randomly selected for this study and were divided equally into three groups. Each subject received 1500 ml of oral contrast. Group 1 received 3% mannitol in water, group 2 received diluted iodinated positive contrast, and group 3 received plain water without additives. Qualitative and quantitative analysis for distension, fold visibility, and overall image quality were analyzed by actual diameter measurement and point scale system at different bowel levels. One-way analysis of variance (ANOVA) followed by Tukey′s HSD Post-hoc test and Pearson′s Chi-square (exact test) test were applied. Results: Group 1 showed better results for small bowel distension, intraluminal homogeneity, and visibility of mucosal folds on quantitative and qualitative analysis with statistically significant P value (P<0.001). The ileo-caecal junction distension and mural feature visibility was better with mannitol (P < 0.001). No significant difference in distension of stomach and duodenum was found between the three groups. Conclusion: Mannitol as endoluminal contrast increases the diagnostic accuracy of the investigative studies in comparison to water and iodine-based contrast by producing significantly better bowel distension and visibility of mural features with improved image quality without additional adverse effects