Silicon Photonics and Photonic Integrated Circuits II, 2010
We present an integrated optical narrowband electrically tunable filter based on the whispering g... more We present an integrated optical narrowband electrically tunable filter based on the whispering gallery modes of sapphire microspheres and double ion-exchanged channel BK7 glass waveguides. Tuning is provided by a liquid crystal infiltrated between the spheres and the ...
The purpose of this randomized clinical study was to evaluate the efficiency of erbium, chromium-... more The purpose of this randomized clinical study was to evaluate the efficiency of erbium, chromium-doped:yttrium, scandium, gallium, and garnet (Er,Cr:YSGG) laser irradiation combined with a resin-based tricalcium silicate material and calcium hydroxide in direct pulp capping for a 6-month follow-up period. A total of 60 teeth of 60 patients between the ages of 18 and 41 years were recruited for this study. Sixty permanent vital teeth without symptoms and radiographic changes were randomly assigned to the following 4 groups (n = 15): Gr CH, the exposed area was sealed with calcium hydroxide (CH) paste; Gr laser CH, the treated area was sealed with CH paste after Er,Cr:YSGG laser irradiation at an energy level of 0.5 W without water and with 45% air; Gr TheraCal, TheraCal LC (Bisco, Schaumburg, IL) was applied directly to the exposed pulp; and Gr Laser TheraCal, TheraCal LC was applied after irradiation with an Er,Cr:YSGG laser. At the 1-week and 1-, 3-, and 6-month recall examinations...
... [Medline]; ↑ Merland JJ, Marache P, Herbreteau D. Les ... Valérie Schweizer; Troubles cogniti... more ... [Medline]; ↑ Merland JJ, Marache P, Herbreteau D. Les ... Valérie Schweizer; Troubles cognitifs et comportementaux après lésion cérébrale : impact sur la reprise professionnelle.Jean-Marie Annoni, Françoise Col; Pièges en orthopédie ambulatoire : le membre supérieur. ...
We performed aneurysm embolization in seven patients using a self-expandable Neuroform stent (Bos... more We performed aneurysm embolization in seven patients using a self-expandable Neuroform stent (Boston Scientific/Target, Fremont, CA) and coils to cover the aneurysm neck and fill the aneurysm sac. Seven patients with an average age of 45 were treated in the period from October 2002 to July 2003. The aneurysm lesions involved the basilar trunk in one case, the basilar-superior cerebellar artery in one case, the internal carotid artery in four cases, and the middle cerebral artery in one case. The ruptured lesions involved the internal carotid artery in one case and the middle cerebral artery in one case. We used a Neuroform stent measuring 4.5 x 20 mm in four cases, 4.5 x 15 mm in two cases, 3.5 x 20 mm in one case, and 3.5 x 15 mm in one case. We performed aneurysm coil embolization after Neuroform stenting in all cases without development of neurological deficits caused by the interventional procedure. In performing these procedures, we investigated the efficacy and limitations of the Neuroform stent system for intracranial aneurysms. The advantages of Neuroform self-expanding stents include better flexibility and adaptability to different vessel sizes, but this stent system presents various technical difficulties during delivery.
PURPOSE We wanted to assess the efficacy and safety of a combination of intravenous and intra-art... more PURPOSE We wanted to assess the efficacy and safety of a combination of intravenous and intra-arterial (IV-IA) tissue plasminogen activator (tPA), compared to IV thrombolysis alone. METHOD AND MATERIALS Patients with middle cerebral artery occlusion underwent systemic IV thrombolysis within 3 hours of onset of symptoms. In the absence of clinical improvement and/or signs of recanalization on ultrasound after 30 minute, angiography was performed with IA thrombolysis. For the remaining patients, we continued the IV lysis. Clinical s cores (National Institutes of Health Stroke Scale -NIHSS and modified Rankin Scale) were assessed at baseline, at 24 hours and at 3 months. Outcome measures included the proportion of patients with no or minimal neurological disability at 3 months, recanalization rate, incidence of symptomatic intracranial hemorrhage and mortality rate. RESULTS : We included a total of 26 patients, 7 of whom underwent combined therapy (IV-IA) and 19 underwent IV treatment....
We demonstrate experimentally that optical wavefront shaping selectively couples light into the f... more We demonstrate experimentally that optical wavefront shaping selectively couples light into the fundamental diffusion mode of a scattering medium. The total energy density inside a scattering medium of zinc oxide (ZnO) nanoparticles was probed by measuring the emitted fluorescent power of spheres that were randomly positioned inside the medium. The fluorescent power of an optimized incident wave front is observed to be enhanced compared to a non-optimized incident front. The observed enhancement increases with sample thickness. Based on diffusion theory, we derive a model wherein the distribution of energy density of wavefront-shaped light is described by the fundamental diffusion mode. The agreement between our model and the data is striking not in the least since there are no adjustable parameters. Enhanced total energy density is crucial to increase the efficiency of white LEDs, solar cells, and of random lasers, as well as to realize controlled illumination in biomedical optics.
The aim of this study was to evaluate the palatal mucosa thickness and greater palatine foramen l... more The aim of this study was to evaluate the palatal mucosa thickness and greater palatine foramen location using cone-beam computerized tomography (CBCT). CBCT images of 345 patients were measured. The relationship between palate vault depth and angle between the alveolar bone and palatal plane (PA) was evaluated. Differences in the palatal mucosal thickness according to age, gender, and tooth site were evaluated. The mean palatal mucosal thickness from the second molar to the canine teeth were 3.7, 3.3, 3.7, 3 and 3 mm, respectively. The palatal mucosal thickness at the second molar and second premolar were statistically different from those at other zones. There was no correlation between the palatal junction angle and the palatal depth. Greater palatine foramen was observed at the level of third molar tooth, between third and second molar, second molar 63%, 31% and 6% in men and 56%, 36% and 8% in women respectively. The second premolar to second molar zone was considered a suitabl...
Interventional neuroradiology : journal of peritherapeutic neuroradiology, surgical procedures and related neurosciences, 2011
A 32-year-old woman hospitalized for subarachnoid hemorrhage showed rare arterial variation on th... more A 32-year-old woman hospitalized for subarachnoid hemorrhage showed rare arterial variation on the right side with anomalous origins of the vertebral artery, aberrant subclavian artery and persistent trigeminal artery. Angiography showed the right vertebral artery to originate from the right common carotid artery, the right subclavian artery to arise separately from the descending aorta, and persistent trigeminal artery on the right side. The possible embryonic mechanism of this previously unreported variant combination is discussed.
Interventional neuroradiology : journal of peritherapeutic neuroradiology, surgical procedures and related neurosciences, Jan 30, 2005
We present a case of a patient who received adjunct treatment with a self-expanding stent after b... more We present a case of a patient who received adjunct treatment with a self-expanding stent after balloon dilatation of a symptomatic stenosis of the carotid siphon. After predilatation, complementary angioplasty with a balloon-expandable stent was abolished due to lack of compliance of the delivery system. Since the vascular anatomy allows for the passage of balloon systems only, the stenosis was further dilated and a self-expanding stent was delivered to avoid the risk of complications related to dissection and vessel recoil. However, problem of in-stent stenosis remains at the longterm follow-up period.
Journal of neuroradiology. Journal de neuroradiologie, 2009
To evaluate the prognostic accuracy of combining perfusion CT (PCT) and thrombolysis in brain isc... more To evaluate the prognostic accuracy of combining perfusion CT (PCT) and thrombolysis in brain ischemia (TIBI) ultrasonographic grade in the triage of stroke patients who will benefit from thrombolysis and in predicting the clinical outcome. We conducted a prospective study of all consecutive stroke patients admitted to our hospital from March 2003 to July 2007, presenting with signs of acute stroke within the therapeutic window, who had undergone either intravenous or combined intravenous and intra-arterial thrombolysis. All patients were evaluated by a complete stroke CT protocol, transcranial color-coded duplex sonographic monitoring, follow-up imaging (CT or MRI) and clinical outcome at 3 months, as assessed by the modified Rankin scale (mRS). A total of 34 patients were included with a mean NIHSS on admission of 14.2. This study revealed that PCT had 95% sensitivity and 71% specificity in the evaluation of therapy benefit as well as 75% sensitivity and 39% specificity in predict...
Digital subtraction angiography (DSA) is the method of reference for imaging of dural arterioveno... more Digital subtraction angiography (DSA) is the method of reference for imaging of dural arteriovenous fistula (DAVF). The goal of this study was to analyze the value of different MR images including 3D contrast-enhanced MR angiography (MRA) with a high temporal resolution in diagnostic and follow-up imaging of DAVFs. A total of 18 MR/MRA examinations from 14 patients with untreated (n=9) and/or treated (n=9) DAVFs were evaluated. Two observers assessed all MR and MRA investigations for signs indicating the presence of a DAVF, for fistula characteristics such as fistula grading, location of fistulous point, and fistula obliteration after treatment. All results were compared with DSA findings. On time-resolved 3D contrast-enhanced (TR 3D) MRA, the side and presence of all patent fistulas (n=13) were correctly indicated, and no false-positive findings were observed in occluded DAVFs (n=5). Grading of fistulas with this imaging technique was correct in 77% and 85% of patent fistulas for b...
The existence of the vein of the foramen caecum (VFC) in humans is still controversial. We presen... more The existence of the vein of the foramen caecum (VFC) in humans is still controversial. We present 2 patients with intracranial drainage of the nasal mucosa by a frontal cortical vein into a superior sagittal sinus, demonstrated by digital subtraction angiography. In both, the position of the intracranial passage was found to be slightly paramedian. An analogy to the VFC is made.
Cerebral internal venous thrombosis are rare and diagnosis is difficult. We report three cases in... more Cerebral internal venous thrombosis are rare and diagnosis is difficult. We report three cases in male adults. Clinical data were headaches, vomiting, dizziness and coma, in relation with an intracranial hypertension, or in a case, cardiocirculatory arrest. Cerebral internal veinous thrombosis was diagnosed by a CT scan and cerebral angiography twenty four hours after the admission in neurosurgical intensive care. CT scan showed hemorrhagic and ischemic lesions of thalami in two cases, diffuse cerebral edema in two patients, early or delayed hydrocephaly in two cases. No patient survived despite intensive treatment including heparinotherapy, ventricular CSF drainage, osmotherapy, dehydration, barbiturate, other antiepileptic drugs and mechanical ventilation. In two cases, general or local illness was found, sickle cell disease or radiotherapy for pineal tumor, and in case 3 clinical signs evoked autoimmune disease, not demonstrated by biological samples.
Angiomas are heterogenous vascular abnormalities, in terms of anatomy, biology and clinical cours... more Angiomas are heterogenous vascular abnormalities, in terms of anatomy, biology and clinical course. Patients and families are often emotionally concerned. For all these reasons, a multidisciplinary approach is necessary in order to structure diagnostic and therapeutic work-up, and to ensure proper advice. The present paper summarizes contemporary classification of angiomas and presents some principles of multidisciplinary approach as it is applied for the past fifteen years at the University Hospitals of Geneva.
ABSTRACT Background and Purpose: The assessment of blood flow speed by imaging modalities is impo... more ABSTRACT Background and Purpose: The assessment of blood flow speed by imaging modalities is important for endovascular treatments, such as stent implantation, of cerebral aneurysms. The subtracted vortex centers path line method (SVC method) is one of the ways of determining flow speed quantitatively using the image sequence. And a cinematic angiography (CA) is a high speed image acquisition system using X-ray and contrast media integrated in Digital Subtraction Angiography (DSA) for endovascular therapy. The combination of SVC and CA may useful for determining the blood flow speed during the operation using DSA. In this study, we applied this combination to analyze hemodynamic changes before and after stenting. Methods: A transparent tubular model was constructed of silicone which included an aneurysm 10 mm in diameter and having a 5 mm neck on a straight parent artery with a diameter of 3.5 mm. The model was integrated into a pulsatile circulation system. A double layer stent was placed in the parent artery on the aneurysm. By CA, successive images at 25 frames per second with injection of contrast were obtained. Results and conclusion: Rotating vortexes of contrast, which advanced along the wall of the aneurysm, were observed in successive images of the aneurysm cavity. The movement distance of the vortex center was measured and the results show that the vortex speed decrease after stenting. This indicates the possibility of applying the SVC method to medical imaging equipment for analysis of the flow in aneurysms containing stent.
Journal of neurointerventional surgery, Jan 20, 2015
Validation of computational fluid dynamics (CFD) in stented intracranial aneurysms (IAs) is still... more Validation of computational fluid dynamics (CFD) in stented intracranial aneurysms (IAs) is still lacking, to reliably predict prone to occlusion hemodynamics, probing, in particular, velocity reduction, and flow pattern changes. This study compares CFD outcome with particle imaging velocimetry (PIV) for three commercial off the shelf (COTS) stents of different material densities. The recently developed uniform and high precision multi-time lag PIV method was applied to a sidewall aneurysm before and after implantation of three COTS stents with high, intermediate, and low material densities. The measured laser sheet flow patterns and velocity reductions were compared with CFD results and correlated with stent material density. Velocity reduction was in good agreement for unstented high and low porosity stented IA, while flow pattern change was fully matched for unstented and high porosity stented IA. Poor CFD-PIV matching in IA was found for intermediate porosity stents. CFD reprodu...
This study determines the Mio-Pliocene to present-day stress regime acting at the northeastern co... more This study determines the Mio-Pliocene to present-day stress regime acting at the northeastern corner of Eastern Mediterranean region involving Adana, Kahramanmaras and Hatay areas. The right-lateral North Anatolian Fault (NAF) and left-lateral East Anatolian Fault (EAF) systems, which contribute to westward extrusion of Turkey, are the two major strike-slip fault zones of Eastern Mediterranean region. These two major fault systems
Silicon Photonics and Photonic Integrated Circuits II, 2010
We present an integrated optical narrowband electrically tunable filter based on the whispering g... more We present an integrated optical narrowband electrically tunable filter based on the whispering gallery modes of sapphire microspheres and double ion-exchanged channel BK7 glass waveguides. Tuning is provided by a liquid crystal infiltrated between the spheres and the ...
The purpose of this randomized clinical study was to evaluate the efficiency of erbium, chromium-... more The purpose of this randomized clinical study was to evaluate the efficiency of erbium, chromium-doped:yttrium, scandium, gallium, and garnet (Er,Cr:YSGG) laser irradiation combined with a resin-based tricalcium silicate material and calcium hydroxide in direct pulp capping for a 6-month follow-up period. A total of 60 teeth of 60 patients between the ages of 18 and 41 years were recruited for this study. Sixty permanent vital teeth without symptoms and radiographic changes were randomly assigned to the following 4 groups (n = 15): Gr CH, the exposed area was sealed with calcium hydroxide (CH) paste; Gr laser CH, the treated area was sealed with CH paste after Er,Cr:YSGG laser irradiation at an energy level of 0.5 W without water and with 45% air; Gr TheraCal, TheraCal LC (Bisco, Schaumburg, IL) was applied directly to the exposed pulp; and Gr Laser TheraCal, TheraCal LC was applied after irradiation with an Er,Cr:YSGG laser. At the 1-week and 1-, 3-, and 6-month recall examinations...
... [Medline]; ↑ Merland JJ, Marache P, Herbreteau D. Les ... Valérie Schweizer; Troubles cogniti... more ... [Medline]; ↑ Merland JJ, Marache P, Herbreteau D. Les ... Valérie Schweizer; Troubles cognitifs et comportementaux après lésion cérébrale : impact sur la reprise professionnelle.Jean-Marie Annoni, Françoise Col; Pièges en orthopédie ambulatoire : le membre supérieur. ...
We performed aneurysm embolization in seven patients using a self-expandable Neuroform stent (Bos... more We performed aneurysm embolization in seven patients using a self-expandable Neuroform stent (Boston Scientific/Target, Fremont, CA) and coils to cover the aneurysm neck and fill the aneurysm sac. Seven patients with an average age of 45 were treated in the period from October 2002 to July 2003. The aneurysm lesions involved the basilar trunk in one case, the basilar-superior cerebellar artery in one case, the internal carotid artery in four cases, and the middle cerebral artery in one case. The ruptured lesions involved the internal carotid artery in one case and the middle cerebral artery in one case. We used a Neuroform stent measuring 4.5 x 20 mm in four cases, 4.5 x 15 mm in two cases, 3.5 x 20 mm in one case, and 3.5 x 15 mm in one case. We performed aneurysm coil embolization after Neuroform stenting in all cases without development of neurological deficits caused by the interventional procedure. In performing these procedures, we investigated the efficacy and limitations of the Neuroform stent system for intracranial aneurysms. The advantages of Neuroform self-expanding stents include better flexibility and adaptability to different vessel sizes, but this stent system presents various technical difficulties during delivery.
PURPOSE We wanted to assess the efficacy and safety of a combination of intravenous and intra-art... more PURPOSE We wanted to assess the efficacy and safety of a combination of intravenous and intra-arterial (IV-IA) tissue plasminogen activator (tPA), compared to IV thrombolysis alone. METHOD AND MATERIALS Patients with middle cerebral artery occlusion underwent systemic IV thrombolysis within 3 hours of onset of symptoms. In the absence of clinical improvement and/or signs of recanalization on ultrasound after 30 minute, angiography was performed with IA thrombolysis. For the remaining patients, we continued the IV lysis. Clinical s cores (National Institutes of Health Stroke Scale -NIHSS and modified Rankin Scale) were assessed at baseline, at 24 hours and at 3 months. Outcome measures included the proportion of patients with no or minimal neurological disability at 3 months, recanalization rate, incidence of symptomatic intracranial hemorrhage and mortality rate. RESULTS : We included a total of 26 patients, 7 of whom underwent combined therapy (IV-IA) and 19 underwent IV treatment....
We demonstrate experimentally that optical wavefront shaping selectively couples light into the f... more We demonstrate experimentally that optical wavefront shaping selectively couples light into the fundamental diffusion mode of a scattering medium. The total energy density inside a scattering medium of zinc oxide (ZnO) nanoparticles was probed by measuring the emitted fluorescent power of spheres that were randomly positioned inside the medium. The fluorescent power of an optimized incident wave front is observed to be enhanced compared to a non-optimized incident front. The observed enhancement increases with sample thickness. Based on diffusion theory, we derive a model wherein the distribution of energy density of wavefront-shaped light is described by the fundamental diffusion mode. The agreement between our model and the data is striking not in the least since there are no adjustable parameters. Enhanced total energy density is crucial to increase the efficiency of white LEDs, solar cells, and of random lasers, as well as to realize controlled illumination in biomedical optics.
The aim of this study was to evaluate the palatal mucosa thickness and greater palatine foramen l... more The aim of this study was to evaluate the palatal mucosa thickness and greater palatine foramen location using cone-beam computerized tomography (CBCT). CBCT images of 345 patients were measured. The relationship between palate vault depth and angle between the alveolar bone and palatal plane (PA) was evaluated. Differences in the palatal mucosal thickness according to age, gender, and tooth site were evaluated. The mean palatal mucosal thickness from the second molar to the canine teeth were 3.7, 3.3, 3.7, 3 and 3 mm, respectively. The palatal mucosal thickness at the second molar and second premolar were statistically different from those at other zones. There was no correlation between the palatal junction angle and the palatal depth. Greater palatine foramen was observed at the level of third molar tooth, between third and second molar, second molar 63%, 31% and 6% in men and 56%, 36% and 8% in women respectively. The second premolar to second molar zone was considered a suitabl...
Interventional neuroradiology : journal of peritherapeutic neuroradiology, surgical procedures and related neurosciences, 2011
A 32-year-old woman hospitalized for subarachnoid hemorrhage showed rare arterial variation on th... more A 32-year-old woman hospitalized for subarachnoid hemorrhage showed rare arterial variation on the right side with anomalous origins of the vertebral artery, aberrant subclavian artery and persistent trigeminal artery. Angiography showed the right vertebral artery to originate from the right common carotid artery, the right subclavian artery to arise separately from the descending aorta, and persistent trigeminal artery on the right side. The possible embryonic mechanism of this previously unreported variant combination is discussed.
Interventional neuroradiology : journal of peritherapeutic neuroradiology, surgical procedures and related neurosciences, Jan 30, 2005
We present a case of a patient who received adjunct treatment with a self-expanding stent after b... more We present a case of a patient who received adjunct treatment with a self-expanding stent after balloon dilatation of a symptomatic stenosis of the carotid siphon. After predilatation, complementary angioplasty with a balloon-expandable stent was abolished due to lack of compliance of the delivery system. Since the vascular anatomy allows for the passage of balloon systems only, the stenosis was further dilated and a self-expanding stent was delivered to avoid the risk of complications related to dissection and vessel recoil. However, problem of in-stent stenosis remains at the longterm follow-up period.
Journal of neuroradiology. Journal de neuroradiologie, 2009
To evaluate the prognostic accuracy of combining perfusion CT (PCT) and thrombolysis in brain isc... more To evaluate the prognostic accuracy of combining perfusion CT (PCT) and thrombolysis in brain ischemia (TIBI) ultrasonographic grade in the triage of stroke patients who will benefit from thrombolysis and in predicting the clinical outcome. We conducted a prospective study of all consecutive stroke patients admitted to our hospital from March 2003 to July 2007, presenting with signs of acute stroke within the therapeutic window, who had undergone either intravenous or combined intravenous and intra-arterial thrombolysis. All patients were evaluated by a complete stroke CT protocol, transcranial color-coded duplex sonographic monitoring, follow-up imaging (CT or MRI) and clinical outcome at 3 months, as assessed by the modified Rankin scale (mRS). A total of 34 patients were included with a mean NIHSS on admission of 14.2. This study revealed that PCT had 95% sensitivity and 71% specificity in the evaluation of therapy benefit as well as 75% sensitivity and 39% specificity in predict...
Digital subtraction angiography (DSA) is the method of reference for imaging of dural arterioveno... more Digital subtraction angiography (DSA) is the method of reference for imaging of dural arteriovenous fistula (DAVF). The goal of this study was to analyze the value of different MR images including 3D contrast-enhanced MR angiography (MRA) with a high temporal resolution in diagnostic and follow-up imaging of DAVFs. A total of 18 MR/MRA examinations from 14 patients with untreated (n=9) and/or treated (n=9) DAVFs were evaluated. Two observers assessed all MR and MRA investigations for signs indicating the presence of a DAVF, for fistula characteristics such as fistula grading, location of fistulous point, and fistula obliteration after treatment. All results were compared with DSA findings. On time-resolved 3D contrast-enhanced (TR 3D) MRA, the side and presence of all patent fistulas (n=13) were correctly indicated, and no false-positive findings were observed in occluded DAVFs (n=5). Grading of fistulas with this imaging technique was correct in 77% and 85% of patent fistulas for b...
The existence of the vein of the foramen caecum (VFC) in humans is still controversial. We presen... more The existence of the vein of the foramen caecum (VFC) in humans is still controversial. We present 2 patients with intracranial drainage of the nasal mucosa by a frontal cortical vein into a superior sagittal sinus, demonstrated by digital subtraction angiography. In both, the position of the intracranial passage was found to be slightly paramedian. An analogy to the VFC is made.
Cerebral internal venous thrombosis are rare and diagnosis is difficult. We report three cases in... more Cerebral internal venous thrombosis are rare and diagnosis is difficult. We report three cases in male adults. Clinical data were headaches, vomiting, dizziness and coma, in relation with an intracranial hypertension, or in a case, cardiocirculatory arrest. Cerebral internal veinous thrombosis was diagnosed by a CT scan and cerebral angiography twenty four hours after the admission in neurosurgical intensive care. CT scan showed hemorrhagic and ischemic lesions of thalami in two cases, diffuse cerebral edema in two patients, early or delayed hydrocephaly in two cases. No patient survived despite intensive treatment including heparinotherapy, ventricular CSF drainage, osmotherapy, dehydration, barbiturate, other antiepileptic drugs and mechanical ventilation. In two cases, general or local illness was found, sickle cell disease or radiotherapy for pineal tumor, and in case 3 clinical signs evoked autoimmune disease, not demonstrated by biological samples.
Angiomas are heterogenous vascular abnormalities, in terms of anatomy, biology and clinical cours... more Angiomas are heterogenous vascular abnormalities, in terms of anatomy, biology and clinical course. Patients and families are often emotionally concerned. For all these reasons, a multidisciplinary approach is necessary in order to structure diagnostic and therapeutic work-up, and to ensure proper advice. The present paper summarizes contemporary classification of angiomas and presents some principles of multidisciplinary approach as it is applied for the past fifteen years at the University Hospitals of Geneva.
ABSTRACT Background and Purpose: The assessment of blood flow speed by imaging modalities is impo... more ABSTRACT Background and Purpose: The assessment of blood flow speed by imaging modalities is important for endovascular treatments, such as stent implantation, of cerebral aneurysms. The subtracted vortex centers path line method (SVC method) is one of the ways of determining flow speed quantitatively using the image sequence. And a cinematic angiography (CA) is a high speed image acquisition system using X-ray and contrast media integrated in Digital Subtraction Angiography (DSA) for endovascular therapy. The combination of SVC and CA may useful for determining the blood flow speed during the operation using DSA. In this study, we applied this combination to analyze hemodynamic changes before and after stenting. Methods: A transparent tubular model was constructed of silicone which included an aneurysm 10 mm in diameter and having a 5 mm neck on a straight parent artery with a diameter of 3.5 mm. The model was integrated into a pulsatile circulation system. A double layer stent was placed in the parent artery on the aneurysm. By CA, successive images at 25 frames per second with injection of contrast were obtained. Results and conclusion: Rotating vortexes of contrast, which advanced along the wall of the aneurysm, were observed in successive images of the aneurysm cavity. The movement distance of the vortex center was measured and the results show that the vortex speed decrease after stenting. This indicates the possibility of applying the SVC method to medical imaging equipment for analysis of the flow in aneurysms containing stent.
Journal of neurointerventional surgery, Jan 20, 2015
Validation of computational fluid dynamics (CFD) in stented intracranial aneurysms (IAs) is still... more Validation of computational fluid dynamics (CFD) in stented intracranial aneurysms (IAs) is still lacking, to reliably predict prone to occlusion hemodynamics, probing, in particular, velocity reduction, and flow pattern changes. This study compares CFD outcome with particle imaging velocimetry (PIV) for three commercial off the shelf (COTS) stents of different material densities. The recently developed uniform and high precision multi-time lag PIV method was applied to a sidewall aneurysm before and after implantation of three COTS stents with high, intermediate, and low material densities. The measured laser sheet flow patterns and velocity reductions were compared with CFD results and correlated with stent material density. Velocity reduction was in good agreement for unstented high and low porosity stented IA, while flow pattern change was fully matched for unstented and high porosity stented IA. Poor CFD-PIV matching in IA was found for intermediate porosity stents. CFD reprodu...
This study determines the Mio-Pliocene to present-day stress regime acting at the northeastern co... more This study determines the Mio-Pliocene to present-day stress regime acting at the northeastern corner of Eastern Mediterranean region involving Adana, Kahramanmaras and Hatay areas. The right-lateral North Anatolian Fault (NAF) and left-lateral East Anatolian Fault (EAF) systems, which contribute to westward extrusion of Turkey, are the two major strike-slip fault zones of Eastern Mediterranean region. These two major fault systems
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