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

The greatest advances in understanding and treating stroke have occurred during the past 30 years. The advantages of ultrasound for vascular diagnosis are well known: it is a fast, portable, non-invasive, repeatable and inexpensive technique. Among various clinical situations for the application of ultrasound to stroke care, the best established ones include: (1) early detection and characterization of extracranial atherosclerosis and occlusive diseases especially at the carotid bifurcation; (2) evaluation of consequences of proximal arterial occlusive disease on the distal cerebral vasculature; (3) follow-up of the natural history and response to treatment of acute arterial occlusion that causes hyperacute stroke; (4) detection of microemboli associated with cardiac and aortic pathology and carotid artery surgical manipulation; and (5) follow-up of the time course and reversibility of cerebral vasospasm after subarachnoid hemorrhage. The field of ultrasonic diagnosis also has detractors and limitations. Even now, the technique is 'operator-dependent' in terms of the accuracy and validity of its results. Newer technology has provided significant advances in this regard; however, it is necessary for each laboratory to maintain a strict quality control in order to maximize the benefits that this powerful technology can provide.
Arterial Occlusive Diseases ; Atherosclerosis ; Carotid Arteries ; Diagnosis* ; Follow-Up Studies ; Natural History ; Pathology ; Quality Control ; Stroke* ; Subarachnoid Hemorrhage ; Ultrasonography* ; Vasospasm, Intracranial