• 대한자기공명의과학회:학술대회논문집
• /
• 대한자기공명의과학회 2001년도 제6차 학술대회 초록집
• /
• pp.133-133
• /
• 2001

Purpose： To determine the relationship between anatomical variation at A-com. artery area an hemodynamically induced aneurysm-mimicking findings on 3D-TOF MRA clinically a experimentally. Method： Sixty-two patients who had no aneurysm at A-com artery on DSA were evalua with MRA. MRA was performed with 1.5T MR machine(Vision, Siemens). Scan parameters o MRA included TR/TE/FA=30/6.4/25$\psi$$\circledR$˙¡, 512＊192 of matrix with MIP technique. The occurrence of signal defect at shoulder area of bifurcated A-com artery on MRA was evalua for the relationship between the symmetricity of bilateral ACA and the patency of A-c artery. DSA images were acquired at both ICA and VA. To analyze hemodynamical facto of signal defect, experimental studies of MRA and DSA were peformed with elastic silic phantom using conducting pulsatile pump. We also compared the results with those o computational fluid dynamics(CFD).

• 대한자기공명의과학회:학술대회논문집
• /
• 대한자기공명의과학회 2001년도 제6차 학술대회 초록집
• /
• pp.134-134
• /
• 2001

Purpose： To evaluate the physiologic background of poorly visualized aneurysms during DSA a contrast-enhanced MRA(CEMRA) due to hemodynamical isolation on clinical and experiment data. Method： Two cases of intracranial aneurysm which were poorly visualized on DSA a CEMRA and one case of intracranial aneurysm which had poor turnover of contrast mediu during DSA were selected for this clinical study. We evaluated the turnover of blood in t terminal aneurysm of handmade elastic silicon phantoms for comparative experiment. Flo experiments with DSA and contrast enhanced MRA were performed in elastic phantoms aneurysm with 3 different diameters (2, 5 and 10 mm) of neck mimicking basilar ti aneurysm, attached to pulsatile pump similar to that of human physiologic parameters. W compared the results with those of computational flow dynamics(CFD).

• 한국전산유체공학회:학술대회논문집
• /
• 한국전산유체공학회 2004년도 추계 학술대회논문집
• /
• pp.203-206
• /
• 2004

In this study, a numerical analysis has been performed for a three-dimensional pulsatile blood flow associated with the elastic blood vessel and curved bileaflet for multiple cycles in terms of fluid-structure interaction. Here, blood has been assumed as a Newtonian, incompressible fluid. Pressure profiles have been used as boundary conditions at the ventricle and the aorta. From this analysis, the motion of the leaflet has been observed with fluttering phenomenon and rebound, and the flow fields of blood have been obtained with recirculation and regurgitation. The results can contribute to the development of design methodology for the curved bileaflet mechanical heart valve.

• 한국가시화정보학회지
• /
• 제3권1호
• /
• pp.26-35
• /
• 2005

The combination of ultrasound echo images with digital particle image velocimetry (DPIV) method has resulted in a two-dimensional, two-component velocity field measurement technique appropriate for opaque flow conditions including blood flow in clinical applications. Advanced PIV processing algorithms including an iterative scheme and window of offsetting were used to increase spatial resolution. The optimum concentration of the ultrasound contrast agent used for seeding was explored. Velocity validation tests in fully developed laminar pipe flow and pulsatile flow showed good agreement with both optical PIV measurements and the known analytic solution. These studies indicate that echo PIV is a promising technique for the non-invasive measurement of velocity profiles and shear stress.

• Journal of Chest Surgery
• /
• 제46권3호
• /
• pp.223-225
• /
• 2013

Chest draining is a common procedure for treating pleural effusion. Perforation of the heart is a rare often fatal complication of chest drain insertion. We report a case of a 76-year-old female patient suffering from congestive heart failure. At presentation, unilateral opacity of the left chest observed on a chest X-ray was interpreted as massive pleural effusion, so an attempt was made to drain the left pleural space. Malposition of the chest drain was suspected because blood was draining in a pulsatile way from the catheter. Computed tomography revealed perforation of the left ventricle. Mini-thoracotomy was performed and the drain extracted successfully.

• Journal of Chest Surgery
• /
• 제51권3호
• /
• pp.213-215
• /
• 2018

Aneurysm and pseudoaneurysm of the dorsalis pedis artery (DPA) are rare vascular entities. Pseudoaneurysms of the DPA are commonly due to blunt trauma, sharp penetrating injury, fracture, or iatrogenic injury. Herein, we report the case of a patient with a rare iatrogenic pseudoaneurysm that occurred after blood sampling. The diagnosis was suspected based on palpitation of a pulsatile mass on the dorsal foot and confirmed by color Doppler ultrasound and computed tomography angiography. Surgical treatment was successfully performed by reconstruction with an autologous venous graft. The patient recovered well, with no ischemic complications.

• Journal of Korean Neurosurgical Society
• /
• 제47권4호
• /
• pp.310-312
• /
• 2010

A 51-year-old man presented with a pulsatile scalp mass over the right occipital region, which had increased in size over the previous 1 month. He had no previous history of head trauma. Three-dimensional computed tomography (3D-CT) angiography of the brain revealed a $3.0{\times}1.5\;cm$ occipital artery aneurysm arising from the occipital artery. The occipital artery aneurysm was removed following the ligation of the proximal and distal portion of the occipital artery aneurysm. The histological diagnosis was true aneurysm. To the best of our knowledge, this is the first reported case in the literature.

• Journal of Chest Surgery
• /
• 제24권1호
• /
• pp.106-112
• /
• 1991

A 37-year old man was admitted due to the left subauricular mass of 6 month duration which was 3 x 4cm sized, pulsatile and slowly growing He was suffered from the intermittent left facial and auricular pain radiating to the occipital area. The carotid angiography revealed 3x4cm sized saccular aneurysm of the left internal carotid artery just above the carotid bifurcation, extending to the mandibular angle level. He was planned to be operated under the direct clamp of internal carotid artery or shunting procedure. But, the back pressure of the internal carotid was 35mmHg, which suggested adequate cerebral collateral. Thereby, aneurysmectomy and restoration of cerebral blood flow with saphenous vein graft was done under the direct clamp of internal carotid artery for 25 minutes. Although mild transient neurologic sequelae such as mydriasis, tongue deviation for 10 days, he recovered completely without any complication. The aneurysmal sac had no thrombus and pathologic finding was compatible with congenital origin.

• International Journal of Precision Engineering and Manufacturing
• /
• 제4권4호
• /
• pp.5-12
• /
• 2003

This paper discusses about the thickness effects on the structural durability of a bileaflet mechanical heart valve (MHV). In the study on the design and the mechanical characteristics of a bileaflet mechanical heart valve, the fluid mechanics analysis on the blood flow passing through leaflets, the kinetodynamics analysis on the rigid body motion of the leaflet induced by the pulsatile blood flow, and the structural mechanics analysis for the deformed leaflet are required sequentially and simultaneously. Fluid forces computed in the fluid mechanics analysis on the blood flow are used in the kinetodynamics analysis for the leaflet motion. Thereafter, the structural mechanics analysis for the deformed leaflet follows to predict the structural strength variation of the leaflet as the leaflet thickness changes. Analysis results show that structural deformations and stresses increase as the fluid pressure increases and the leaflet thickness decreases. Analysis results also show that the leaflet becomes structurally weaker and weaker as the leaflet becomes thinner and thinner.

• 대한의용생체공학회:의공학회지
• /
• 제10권2호
• /
• pp.91-93
• /
• 1989

We have developed a monoleaflet polymer valve as an inexpensive and viable alternative, especially for short-term use in the ventricular assist device or total artificial heart. The frame and leaflet of the polymer valve were made from polyurethane, To evaluate the hemodynamic performance of the polymer valve a comparative study of flow dynamics past a polymer valve and a St. Jude Medical prosthetic valve under physiological pulsatile flow conditions in vitro was made. Comparisons between the valves were made on the transvalvular pressure drop, regurgitation volume and maximum valve opening area. The polymer valve showed smaller regurgitation volume and transvalvular pressure drop compared to the mechanical valve at higher heart rate. The results showed that the functional characteristics of the polymer valve compared favorably with those of the mechanical valve at higher heart rate.