Gel Based Mechanical Phantom of Stenotic Coronary Artery

Author(s):  
Valérie Pazos ◽  
Jean-Claude Tardif ◽  
Rosarie Mongrain

Intravascular ultrasound (IVUS) is currently the only commercially available clinical imaging modality providing real-time high-resolution cross-sectional images of human coronary arteries in patients. New techniques and models are being developed to derive pertinent information from IVUS images about atherosclerotic tissues properties. Their evaluation and optimization often require the use of realistic test phantoms that can be made precisely, with a known, and generally simpler, structure that is used as reference and allows for a simplification of the problem.

2012 ◽  
Vol 32 (1) ◽  
pp. E6 ◽  
Author(s):  
Peter Kan ◽  
Maxim Mokin ◽  
Adib A. Abla ◽  
Jorge L. Eller ◽  
Travis M. Dumont ◽  
...  

Intravascular ultrasound (IVUS) generates high-resolution cross-sectional images and sagittal reconstructions of the vessel wall and lumen. As a result, this imaging modality can provide accurate measurements of the degree of vessel stenosis, allow the detection of intraluminal thrombus, and analyze the plaque composition. The IVUS modality is widely used in interventional cardiology, and its use in neurointerventions has gradually increased. With case examples, the authors illustrate the utility of IVUS as an adjunct to conventional angiography for a wide range of intracranial and extracranial neurointerventions.


2003 ◽  
Vol 11 (2) ◽  
pp. 143-146
Author(s):  
Piergiorgio Tozzi ◽  
Antonio F Corno ◽  
Ludwig K von Segesser

Coronary angiography and Doppler flow measurements are most commonly used to assess the patency of anastomoses in the operating theater. Intravascular ultrasound might be another means of monitoring the surgical procedure during coronary artery bypass. Five sheep underwent off-pump bypass of the left anterior descending coronary artery using the left internal mammary artery. The running suture was evaluated by intraoperative fluoroscopy and a coronary intravascular ultrasound probe inserted into the target artery proximal to the anastomosis. Macroscopic examination of the anastomosis was performed to validate the angiographic and intravascular ultrasound images. The diameter, cross-sectional area, and compliance of each anastomosis were calculated in systole and diastole. All anastomoses were patent without signs of stenosis. In one case, intravascular ultrasound showed an intimal flap, which was confirmed by macroscopic examination. The mean major anastomotic diameter was 4.5 ± 0.5 mm on angiography and 4.0 ± 0.5 mm on intravascular ultrasound. From the ultrasound data, the mean cross-sectional anastomotic area was calculated as 6.21 ± 0.1 mm2 in systole and 5.49 ± 0.1 mm2 in diastole, and these data were used to calculate the cross-sectional anastomosis compliance. Coronary intravascular ultrasound can visualize intima-to-intima apposition and provide reliable calculations of anastomosis compliance.


2019 ◽  
Vol 40 (Supplement_1) ◽  
Author(s):  
Y Panahi ◽  
M S Ghahrodi ◽  
M S Jamshir ◽  
M A Safarpour ◽  
M Pirro ◽  
...  

Abstract Background Plasma PCSK9 levels, a novel and effective therapeutic target for CVD prevention, have been associated with CVD events irrespective of traditional risk factors. Whether PCSK9 levels predict coronary artery disease (CAD) burden and severity is a matter of dispute. Purpose To investigate the association between plasma PCSK9 levels and CAD characteristics, including number of major diseased vessels, severity of coronary stenosis, and the burden of coronary calcifications. Methods One hundred and one patients undergoing coronary angiography were recruited for this cross-sectional study. The number of major coronary diseased vessels was defined as the presence of ≥1 stenoses ≥50% in diameter of at least one major coronary artery. CAD severity was defined as either the absence of coronary stenosis (no-CAD), CAD<50% or CAD≥50% in one or more coronary arteries. The burden of coronary calcifications was estimated by angiography visual inspection and classified as absent, mild, moderate or severe. Results Coronary angiography showed single, double and triple vessel disease in 26 (25.7%), 23 (22.8%) and 21 (20.8%) patients, respectively; 20 (19.8%) and 11 (10.9%) pts had either minimal CAD (<50%) or normal angiographic findings. Also, calcifications were absent in 65 patients (64.4%), and mild, moderate and severe in 23 (22.8%), 11 (10.9%) and 2 (2%) patients, respectively. Plasma PCSK9 levels were significantly associated with age (rho=0.22, p=0.025) and SBP (rho=0.21, p=0.034), and were almost doubled in patients with chronic kidney disease (CKD) as compared to those without CKD [164.6 ng/mL (104.6–187.0) vs 94.8 ng/mL (86.8–114.9), p=0.006]. Among patients without CKD, those with CAD≥50% had higher plasma PCSK9 levels than those without [97.1 ng/mL (87.8–143.0) vs 83.2 ng/mL (73.4–102.6), p=0.04]. In the overall population, higher plasma PCSK9 levels were found in pts with triple vessel disease [165.7 ng/mL (121.3–180.5)] than in those with double/single vessel involvement [97.9 ng/mL (87.6–99.8) and 88.4 ng/mL (87.3–97.4), p<0.001 for both comparisons] or without CAD [87.5 ng/mL (74.3–114.9), p<0.001]. Also, a trend toward an increase of plasma PCSK9 levels was found with higher CAD severity [no-CAD: 87.5 ng/mL (74.3–114.9), CAD<50%: 89.1 ng/mL (78.9–105.3), CAD≥50%: 97.6 ng/mL (87.9–155.3), p=0.051], which turned significant after exclusion of CKD patients (p=0.042). Adjustment for age, sex, plasma LDL-cholesterol levels, statin use and CKD abolished the association between PCSK9 and CAD severity but not with the number of significantly diseased vessels and the burden of coronary calcifications. Conclusions Circulating PCSK9, whose plasma levels are significantly influenced by the presence of CKD, discriminates patients with significant coronary artery stenosis from those without CAD. In addition, both the number of diseased coronary vessels and total coronary calcifications are independently predicted by an elevated plasma PCSK9 level. Acknowledgement/Funding None


2012 ◽  
Vol 35 (3) ◽  
pp. 129-143 ◽  
Author(s):  
Woonggyu Jung ◽  
Stephen A. Boppart

In pathology, histological examination of the “gold standard” to diagnose various diseases. It has contributed significantly toward identifying the abnormalities in tissues and cells, but has inherent drawbacks when used for fast and accurate diagnosis. These limitations include the lack ofin vivoobservation in real time and sampling errors due to limited number and area coverage of tissue sections. Its diagnostic yield also varies depending on the ability of the physician and the effectiveness of any image guidance technique that may be used for tissue screening during excisional biopsy. In order to overcome these current limitations of histology-based diagnostics, there are significant needs for either complementary or alternative imaging techniques which perform non-destructive, high resolution, and rapid tissue screening. Optical coherence tomography (OCT) is an emerging imaging modality which allows real-time cross-sectional imaging with high resolutions that approach those of histology. OCT could be a very promising technique which has the potential to be used as an adjunct to histological tissue observation when it is not practical to take specimens for histological processing, when large areas of tissue need investigating, or when rapid microscopic imaging is needed. This review will describe the use of OCT as an image guidance tool for fast tissue screening and directed histological tissue sectioning in pathology.


2002 ◽  
Vol 124 (6) ◽  
pp. 734-741 ◽  
Author(s):  
Alexander I. Veress ◽  
Jeffrey A. Weiss ◽  
Grant T. Gullberg ◽  
D. Geoffrey Vince ◽  
Richard D. Rabbitt

Atherosclerotic plaque rupture is responsible for the majority of myocardial infarctions and acute coronary syndromes. Rupture is initiated by mechanical failure of the plaque cap, and thus study of the deformation of the plaque in the artery can elucidate the events that lead to myocardial infarction. Intravascular ultrasound (IVUS) provides high resolution in vitro and in vivo cross-sectional images of blood vessels. To extract the deformation field from sequences of IVUS images, a registration process must be performed to correlate material points between image pairs. The objective of this study was to determine the efficacy of an image registration technique termed Warping to determine strains in plaques and coronary arteries from paired IVUS images representing two different states of deformation. The Warping technique uses pointwise differences in pixel intensities between image pairs to generate a distributed body force that acts to deform a finite element model. The strain distribution estimated by image-based Warping showed excellent agreement with a known forward finite element solution, representing the gold standard, from which the displaced image was created. The Warping technique had a low sensitivity to changes in material parameters or material model and had a low dependency on the noise present in the images. The Warping analysis was also able to produce accurate strain distributions when the constitutive model used for the Warping analysis and the forward analysis was different. The results of this study demonstrate that Warping in conjunction with in vivo IVUS imaging will determine the change in the strain distribution resulting from physiological loading and may be useful as a diagnostic tool for predicting the likelihood of plaque rupture through the determination of the relative stiffness of the plaque constituents.


2020 ◽  
Author(s):  
Mengyang Cong ◽  
Xingming Xu ◽  
Jianfeng Qiu ◽  
Shun Dai ◽  
Chuanzhi Chen ◽  
...  

Abstract Background: The Anomalous origin of the Right Coronary Artery (RCA) from the Left Coronary artery sinus(AORL) is one of the abnormal origins of the coronary arteries. Most of these issues seldom have effects on human health, but some individuals may have symptoms such as myocardial ischaemia or even sudden death. Recently, researchers are studying AORL through clinical cases, but study based on computational fluid dynamics (CFD) is rarely seen. In this study, haemodynamic changes between normal origin of the RCA and AORL are compared according to numerical simulation results.Methods: Realistic three-dimensional models of 16 normal right coronary arteries and 26 abnormal origins of the right coronary arteries were reconstructed, respectively. The blood flow was numerically simulated using software ANSYS. This study involves one-way fluid-solid coupling finite element model in which the blood is assumed to be incompressible Newtonian fluid, and the vessel is assumed to be isotropic, linear elastic material.Results: The differences of the cross-sectional area at the inlet between the normal group and the abnormal group was significant ( P <0.0001). There were significant differences in the volumetric flow ( P <0.0001) and the pressure ( P =0.0001). There were positive correlations with the ratio of the cross-sectional area of the RCA to the inlet area of the ascending aorta (AAO) and the ratio of the inlet volumetric flow of the RCA to the volumetric flow of the AAO, in both the normal ( P =0.0001, r=0.8198) and abnormal ( P =0.0199, r=0.4925) group.Conclusion: This study shows that the cross-sectional area of the inlet of AORL may cause ischaemia symptoms, and the results may contribute to the further understanding of the clinical symptoms of AORL based on the haemodynamics.


e-CliniC ◽  
2016 ◽  
Vol 4 (1) ◽  
Author(s):  
Lucky A. Tulung ◽  
A. Lucia Panda ◽  
Starry H. Rampengan

Abstract: Acute Coronary Syndrome (ACS) is a set of manifestations or symptoms of coronary artery disease and thrombosis which can threaten the patien’s life due to interfering the blood supply of heart muscle. The infarct size is determined by assessing the coronary arteries lesion, stenosis. This study was aimed to determine the relationship between levels of leukocytes and the severity of coronary arteries lesions in patients with ACS. This was a descriptive analytical study with a cross-sectional retrospective design. The modified Gensini score was used to assess the severity of coronary artery lesion. The first leukocyte count examined when the patients was admitted to the hospital was obtained from the medical records period July to September 2015. Data were analyzed by using SPSS 20.0. The Pearson correlation test showed no significant relationship between the levels of leukocytes and the severity of coronary arteries lesions in patients with ACS (p >0.05). Conclusion: There was no significant correlation between the levels of leukocytes and the severity of coronary arteries lesions in patients with ACS.Keywords: leukocyte, severity of lesion, acute coronary syndrome, modified Gensini score Abstrak: Sindrom koroner akut (SKA) merupakan sekumpulan manifestasi atau gejala akibat penyakit arteri koroner dan trombosis yang dapat mengancam kehidupan pasien karena mengganggu pasokan darah ke otot jantung. Penilaian luas infark dilakukan dengan menilai lesi pembuluh darah koroner yang mengalami stenosis. Penelitian ini bertujuan untuk mengetahui hubungan antara kadar leukosit dengan severitas lesi pembuluh darah koroner pada pasien SKA. Jenis penelitian ialah deskriptif analitik retrospektif dengan desain potong lintang. Penilaian severitas pembuluh darah yang mengalami lesi menggunakan skor modifikasi Gensini. Hitung leukosit yang digunakan ialah saat pasien pertama kali masuk Rumah Sakit yang diperoleh dari rekam medis periode Juli-September 2015. Data dianalisis menggunakan SPSS 20.0. Hasil uji korelasi Pearson memperlihatkan tidak terdapat hubungan bermakna antara kadar leukosit dan severitas lesi pembuluh darah koroner pada pasien SKA (p >0,05). Simpulan: Tidak terdapat hubungan bermakna antara kadar leukosit dan severitas lesi pembuluh darah koroner pada pasien Sindrom Koroner Akut. Kata kunci: leukosit, severitas lesi, sindrom koroner akut, skor modifikasi Gensini


2019 ◽  
Vol 9 (4) ◽  
pp. 24-27
Author(s):  
Anusmriti Pal ◽  
Manoj Kumar Yadav ◽  
Chiranjibi Pant ◽  
Bishow Kumar Shrestha

Background: Interstitial lung disease (ILD) is a heterogeneous group of diffuse parenchymal lung diseases, characterized by restrictive physiology, impaired gas exchange, pulmonary inflammation and fibrosis. Chest radiograph (CXR) may appear normal during initial course of the disease and may show few abnormalities. High resolution computed tomography (HRCT) chest is a most ac­curate non-invasive, high spatial resolution descriptive imaging modality for evaluation of lung parenchyma. It assesses presence, location, type and characterization of ILD in appropriate clinical setting. Our aim was to study radiological patterns and its distribution in CXR and HRCT chest of ILD patients. Methods: This was an observational, single centered, cross-sectional study conducted at author’s place over the period of 6 months starting from January 2018 using convenient sampling method. Data analysis was done using students t-test for comparison of means and chi-square test for proportions. Results: A total of 30 suspected or diagnosed patients of ILD were enrolled in our study and pat­terns found on CXR were correlated with that on HRCT chest. The number of findings in HRCT chest for a patient was significantly higher than CXR (Median number: 4 verses 2, P<0.001), commonest reticular opacity 50% in CXR and 56.6% HRCT. One subject had normal CXR. Conclusion: HRCT was superior to CXR in detection of all basic patterns and their distribution as­sociated with ILD as higher numbers of findings were detected by HRCT chest as compared to CXR. HRCT chest could characterize the abnormality and specify its location much more accurately.


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