Traditional risk factors for predicting of cardiovascular disease are not always effective predictors for development of cardiovascular events. This review summarizes several newly developed noninvasive imaging techniques for evaluating carotid plaques and their role in cardiovascular disease risk.
Atherosclerosis ; Cardiovascular Diseases ; Risk Factors ; Ultrasonography*

Carotid Doppler ultrasonography is a popular tool for evaluating atherosclerosis of the carotid artery. Its two-dimensional gray scale can be used for measuring the intima-media thickness, which is very good biomarker for atherosclerosis and can aid in plaque characterization. The plaque morphology is related to the risk of stroke. The ulceration of plaque is also known as one of the strong predictors of future embolic event risk. Color Doppler ultrasonography and pulse Doppler ultrasonography have been used for detecting carotid artery stenosis. Doppler ultrasonography has unique physical properties. The operator should be familiar with the physics and other parameters of Doppler ultrasonography to perform optimal Doppler ultrasonography studies.
Atherosclerosis ; Carotid Arteries ; Carotid Stenosis ; Plaque, Atherosclerotic ; Stroke ; Ulcer ; Ultrasonography ; Ultrasonography, Doppler* ; Ultrasonography, Doppler, Color

BACKGROUND: It has been hypothesized that early atherosclerosis may be related to the pathogenesis of coronary vasospasm. This study was designed to investigate the relationship between early atherosclersosis and coronary vasospasm or vasoconstriction in response to axetylcholine utilizing intravascular ultrasonography. METHOD: Total 43 segments were analyzed from subjects who were composed of 10 patients with and 7 patients without coronary vasospasm in response to intra coronary acetylcholine infusion. Spasm segment(Sp) was defined as total or subtotal occlusion, constriction segment(C) as diameter decrease>/=10%, and normal segment(N) as diameter decrease<10% compared to baseline coronary angiogram. Atherosclerotic plaque thickness was defined as the sum of thickness of intimal leading edge and sonolucent zone. Atherosclerosis was defined as atherosclerotic plaque thickness > 0.5mm. RESULTS: The atherosclerotic plaques of spasm segments were significantly thicker than those of normal and constriction segments(spasm segments : 1.19+/-0.21mm, constrict segments : 0.58+/-0.11mm, normal segment : 0.37+/-0.11, p<0.05). Atherosclerosis was present in 90% of spasm segments. Among normal of constriction segments, atherosclerotic plaque thickness of patients with vasospasm was thicker than that of patients without vasospasm, although it was statistically insignificant(patients with vasospasm : 0.65+/-0.51mm, patients without vasospasm 0.36+/-0.39mm, p=0.07). Frequency of atherosclerosis in normal or constriction segments was significantly higher in patients with vasospasm than patients without vasospasm(patients with vasospasm 47%, patients without vasospasm : 11%, p<0.05). CONCLUSION: Atherosclerosis is present at segments of vasospasm in response to intracoronary acetylcholine. Even among normal or constriction segments, the artherosclerotic plaque thickness of patients with vasospasm was thicker than that of patients without vasospasm which may indicates that coronary vasospasm is a diffuse early atherosclerotic disease.
Acetylcholine ; Atherosclerosis ; Constriction ; Coronary Vasospasm* ; Humans ; Plaque, Atherosclerotic ; Spasm ; Ultrasonography* ; Ultrasonography, Interventional ; Vasoconstriction*

Optical coherence tomography (OCT) has been recently applied to investigate coronary artery disease in interventional cardiology. Compared to intravascular ultrasound, OCT is able to visualize various vascular structures more clearly with higher resolution. Several validation studies have shown that OCT is more accurate in evaluating neointimal tissue after coronary stent implantation than intravascular ultrasound. Novel findings on OCT evaluation include the detection of strut coverage and the characterization of neointimal tissue in an in-vivo setting. In a previous study, neointimal healing of stent strut was pathologically the most important factor associated with stent thrombosis, a fatal complication, in patients treated with drug-eluting stent (DES). Recently, OCT-defined coverage of a stent strut was proposed to be related with clinical safety in DES-treated patients. Neoatherosclerosis is an atheromatous change of neointimal tissue within the stented segment. Clinical studies using OCT revealed neoatherosclerosis contributed to late-phase luminal narrowing after stent implantation. Like de novo native coronary lesions, the clinical presentation of OCT-derived neoatherosclerosis varied from stable angina to acute coronary syndrome including late stent thrombosis. Thus, early identification of neoatherosclerosis with OCT may predict clinical deterioration in patients treated with coronary stent. Additionally, intravascular OCT evaluation provides additive information about the performance of coronary stent. In the near future, new advances in OCT technology will help reduce complications with stent therapy and accelerating in the study of interventional cardiology.
Atherosclerosis/diagnosis/pathology/ultrasonography ; Coronary Artery Disease/*diagnosis/pathology/ultrasonography ; Humans ; Postoperative Complications/diagnosis/pathology/ultrasonography ; Stents/*adverse effects ; Tomography, Optical Coherence/*methods ; Ultrasonography, Interventional

BACKGROUND AND OBJECTIVES: This study aimed to assess the effect of simvastatin therapy on plaque regression and vascular remodeling in peristent reference segments of normocholesterolemic patients by using serial intravascular ultrasound (IVUS) observation. SUBJECTS AND METHODS: We retrospectively evaluated the poststenting and follow-up IVUS findings in 208 peristent (bare metal stent) reference segments of 108 normocholesterolemic patients (20 mg/day simvastatin group; n=62 vs. non-simvastatin group; n=46); 100 segments were proximal and 108 segments were distal to the stent. Quantitative volumetric IVUS analysis was performed for 5-mm vessel segments immediately proximal and distal to the stent. RESULTS: Follow-up IVUS was performed at a mean of 8.7 months after stenting (range: 3-19 months). For the proximal edge, a significant decrease in the mean lumen area and mean external elastic membrane (EEM) area and a significant increase in the mean plaque and media (P&M) area were observed at follow-up in both simvastatin and non-simvastatin groups. However, the changes in EEM (simvastatin: -0.4+/-0.3 mm2 vs. non-simvastatin: -0.4+/-0.4 mm2, p=0.983), lumen (simva-statin: -0.7+/-0.3 mm2 vs. non-simvastatin: -1.0+/-0.5 mm2, p=0.114), and P&M area (simvastatin: 0.3+/-0.2 mm2 vs. non-simvastatin: 0.6+/-0.4 mm2, p=0.110) from poststenting to follow-up at the proximal edge were not significantly different between the 2 groups. For the distal edge, a significant decrease in the mean lumen area and a significant increase in the mean P&M area were observed at follow-up in both the groups. However, the changes in the EEM area (simvastatin: -0.1+/-0.2 mm2 vs. non-simvastatin: -0.2+/-0.3 mm2, p=0.674), lumen area (simvastatin: -0.6+/-0.2 mm2 vs. non-simvastatin: -1.0+/-0.4 mm2, p=0.087), and P&M area (simvastatin: 0.5+/-0.2 mm2 vs. non-simvastatin: 0.8+/-0.3 mm2, p=0.102) from poststenting to follow-up at the distal edge were not significantly different between the groups. CONCLUSION: A conventional dose of simvastatin does not inhibit plaque progression and lumen loss in the peristent reference segments of normocholesterolemic patients who have undergone bare-metal stent implantation.
Atherosclerosis ; Follow-Up Studies ; Humans ; Hydroxymethylglutaryl-CoA Reductase Inhibitors ; Membranes ; Retrospective Studies ; Simvastatin* ; Stents ; Ultrasonography* ; Ultrasonography, Interventional

BACKGROUND: The aim of this study is to evaluation of lower extremity with doppler ultrasonography in the thrombotic poststroke patients. METHOD: The subjects were 24 thrombotic poststroke patients. We analyzed the stenosis or obstruction in the lower extremity artery with a doppler ultrasound and the cerebral artery with a magnetic resonance angiography. RESULTS: In the lower extremity artery, 3 patients had the complete obstruction in one and more vessels, 7 patients had the luminal narrowing more than 50% in one and more vessels, 11 patients had the luminal narrowing less than 50% in one and more vessels. And in the cerebral artery, 9 patients had the Obstruction or stenosis of the artery without diffuse atherosclerosis, 15 patients had the arterial obstruction or stenosis with diffuse atherosclerosis, or multiple arterial pathology. CONCLUSION: In this study, poststroke patients with arterial obstruction or stenosis with diffuse atherosclerosis in the cerebral artery had more severe atherosclerotic change in the lower extremity(p<0.05). We recommended to the evaluation of a doppler ultrasound of lower extremity in the thrombotic poststroke patients with diffuse atherosclerotic change of the cerebral artery.
Arteries ; Atherosclerosis ; Cerebral Arteries ; Constriction, Pathologic ; Humans ; Lower Extremity* ; Magnetic Resonance Angiography ; Pathology ; Phenobarbital ; Stroke ; Ultrasonography ; Ultrasonography, Doppler*

Rupture of a vulnerable plaque and subsequent thrombus formation are important mechanisms leading to the development of an acute myocardial infarction (AMI). Typical intravascular ultrasound (IVUS) features of AMI include plaque rupture, thrombus, positive remodeling, attenuated plaque, spotty calcification, and thin-cap fibroatheroma. No-reflow phenomenon was attributable to the embolization of thrombus and plaque debris that results from mechanical fragmentation of the vulnerable plaque by percutaneous coronary intervention (PCI). Several grayscale IVUS features including plaque rupture, thrombus, positive remodeling, greater plaque burden, decreased post-PCI plaque volume, and tissue prolapse, and virtual histology-IVUS features such as large necrotic corecontaining lesion and thin-cap fibroatheroma were the independent predictors of no-reflow phenomenon in AMI patients. Non-culprit lesions associated with recurrent events were more likely than those not associated with recurrent events to be characterized by a plaque burden of > or =70%, a minimal luminal area of < or =4.0 mm2, or to be classified as thin-cap fibroatheromas.
Atherosclerosis ; Humans ; Myocardial Infarction* ; No-Reflow Phenomenon ; Percutaneous Coronary Intervention ; Phenobarbital ; Plaque, Atherosclerotic ; Prolapse ; Rupture ; Thrombosis ; Ultrasonography* ; Ultrasonography, Interventional

BACKGROUND AND OBJECTIVES: Noninvasive measurements of the coronary vasomotion are important for evaluating patients with coronary artery disease (CAD). The aim of this study was to investigate the efficacy of free-hand 3D echocardiography (3DE) with rotational geometry for assessing epicardial coronary artery vasodilation. SUBJECTS AND METHODS: Forty-five subjects were studied: 29 subjects (age 51+/-12 years, M:F=14:15, Control group) with a normal coronary angiogram and 16 patients with multivessel CAD (age 60+/-12 years, M:F=9:7, CAD group). After obtaining the tubular color flow signals of the distal left anterior descending coronary artery (LAD) using an ultra-band transducer (5-12 MHz) with a special preset program in the low velocity range, the peak (PDV), mean diastolic velocity (MDV) and velocity time integral (VTI) were measured before and after administering sublingual nitroglycerin (NTG) (0.6 mg). In all subjects, 3DE image acquisition and reconstruction of the distal LAD flow was performed before and after sublingual nitroglycerin (NTG) using a 3DE unit with a magnetic tracking system (TomTec Imaging Systems) linked to the conventional 2D ultrasound system (Sonos 7500). Quantitative analysis of coronary vasodilation was performed on cross-sectional images. RESULTS: The % change in the PDV, MDV and VTI after NTG administration was 41.3+/-14.0%, 37.9+/-13.8% and 40.3+/-18.2% in the control group and 23.0+/-13.9%, 19.1+/-11.5% and 26.1+/-12.4% in the CAD group (p<0.05, versus Control group, respectively) The distal LAD diameter on the coronary 3DE after NTG administration increased from 2.28+/-0.79 mm to 3.32+/-1.07 mm (52.3+/-28.5%) in the control group and from 2.36+/-0.65 mm to 2.89+/-0.81 mm (23.7+/-23.9%) in the CAD group (p<0.005 versus Control group). The magnitude of vasodilation correlated with the % change in the PDV (r=0.516, p<0.005), MDV (r=0.519, p<0.005) and % VTI (r=0.392, p=0.008). CONCLUSION: These results suggest that level of vasodilation after NTG administration is reduced in advanced atherosclerosis and can be measured noninvasively. A 3D reconstruction of the distal LAD flow using free-hand 3DE with rotational scanning is a promising noninvasive technique for examining the coronary vasomotor function.
Atherosclerosis ; Coronary Artery Disease ; Coronary Vessels ; Echocardiography, Three-Dimensional* ; Humans ; Nitroglycerin ; Transducers ; Ultrasonography ; Vasodilation

BACKGROUND AND OBJECTIVES: The intima-media thickness (IMT) of the common carotid artery has been widely used as a good index of atherosclerosis. The aim of this study was to test the correlation between the thickness of the high echogenicity intimal area (HELIT) on carotid ultrasound and the plaque burden of the culprit lesion on coronary intravascular ultrasound (IVUS). SUBJECTS AND METHODS: In 33 patients (M:F=20:13, mean age 63+/-8 yrs) that underwent coronary angiogram, the HELIT and IMT from carotid ultrasound were compared with the plaque burden of the culprit vessel on IVUS. The high echogenic layer of the intimal area (HELIA) on carotid ultrasound was defined as a thickened echogenic superficial layer at the far wall of the common carotid artery using 15 MHz linear array transducer. The plaque burden was defined as the maximal percent plaque area of the culprit lesion on IVUS. The HELIT and IMT ration was defined as the percent ratio of HELIT on IMT. RESULTS: The mean HELIT, carotid IMT, ratio of HELIT/IMT and maximal percent plaque area of the culprit lesion were 0.27+/-0.03 mm, 0.85+/-0.22 mm, 0.33+/-0.07 and 68.43+/-11%, respectively. The HELIT was closely related to the maximal percent plaque area on IVUS (r=0.34, p<0.05), but not to the other IVUS parameters or risk factors of CAD. CONCLUSION: Our data suggest that the high echogenic layer of the intimal area on carotid ultrasound is predictive of the plaque burden in the culprit vessel.
Atherosclerosis ; Carotid Arteries* ; Carotid Artery, Common ; Coronary Artery Disease* ; Coronary Vessels* ; Humans ; Risk Factors ; Transducers ; Ultrasonography

BACKGROUND: Endothelial dysfunction is an early event in atherogenesis. The conventional non-invasive methods, measuring flow mediated vasodilation at 1 minute after hyperemic condition, had some limitation. The purpose of this study is to evaluate the usefulness of initial reaction time(IRT) after hyperemic condtion as a new parameter of endothelial function. METHOD: Flow-mediated, endothelium-dependent vasodilation (FMD), endothelium-independent vasodilation (EID) and IRT were measured in 12 young diabetic patients(6 male and 6 female, mean age 26.3) and 12 age-matched healthy controls (6 male and 6 female, mean age 25.6), For the measurement of brachial arterial diameter, 7.5MHz ultrasound was used and for the continous monitoring of arterial diameter, specially designed fixing device was applied to the all subjects. RESULT: There were no significant difference in BMI (body mass index), mean age and blood pressure between normal control and young diabetic group. The FMD of young diabetic patients was lower than that of age-matched healthy controls (diabetic patients: 6.32.1%, healthy control: 8.92.7%, p<0.05). There was no significant difference in EID between normal control and young diabetic group. The IRT of FMD was significantly shorter in healthy control group than in young diabetic group (healthy control: 20.42.8 sec, diabetic group: 29.55.4 sec, p<0.0001). But IRT of EID showed no significant difference between normal control and young diabetic group. The IRT of FMD showed a significant negative correlation with FMD (r=-0.74, p<0.001) and HDL cholesterol level(r=-0.68, p<0.0001). CONCLUSION: These findings strongly suggest that IRT can also be used for early diagnosis of endothelial dysfunction.
Atherosclerosis ; Blood Pressure ; Cholesterol, HDL ; Early Diagnosis* ; Female ; Humans ; Male ; Ultrasonography ; Vasodilation*