Exploring 3D elastic-wave scattering at interfaces using high-resolution phased-array system.

The elastic-wave scattering at interfaces, such as cracks, is essential for nondestructive inspections, and hence, understanding the phenomenon is crucial. However, the elastic-wave scattering at cracks is very complex in three dimensions since microscopic asperities of crack faces can be multiple scattering sources. We propose a method for exploring 3D elastic-wave scattering based on our previously developed high-resolution 3D phased-array system, the piezoelectric and laser ultrasonic system (PLUS).

Development of Low-Frequency Phased Array for Imaging Defects in Concrete Structures.

The nondestructive inspection of concrete structures is indispensable for ensuring the safety and reliability of aging infrastructures. Ultrasonic waves having a frequency of tens of kHz are frequently used to reduce the scattering attenuation due to coarse aggregates. Such low frequencies enable the measurement of the thickness of concrete structures and detection of layer-type defects, such as delamination, whereas it causes a lack of sensitivity to crack-type defects.

Nonlinear ultrasonic phased array with fixed-voltage fundamental wave amplitude difference for high-selectivity imaging of closed cracks.

The nondestructive evaluation of closed cracks is a challenging subject in ultrasonic testing. Recently, nonlinear ultrasonic phased array with fixed-voltage fundamental wave amplitude difference (fixed-voltage FAD) has been proposed as a practical approach. In this study, the maximum incident wave amplitude, which is one of the most critical parameters in closed-crack imaging, was investigated.

Fundamental wave amplitude difference imaging for detection and characterization of embedded cracks.

An ultrasonic technique for imaging nonlinear scatterers, such as partially-closed cracks, buried in a medium has been recently proposed. The method called fundamental wave amplitude difference (FAD) consists of a sequence of acquisitions with different subsets of elements for each line of the image. An image revealing nonlinear scatterers in the medium is reconstructed line by line by subtracting the responses measured with the subsets of elements from the response obtained with all elements transmitting.

Nonlinear ultrasonic imaging method for closed cracks using subtraction of responses at different external loads.

To improve the selectivity of closed cracks for objects other than cracks in ultrasonic imaging, we propose an extension of a novel imaging method, namely, subharmonic phased array for crack evaluation (SPACE) as well as another approach using the subtraction of responses at different external loads. By applying external static or dynamic loads to closed cracks, the contact state in the cracks varies, resulting in an intensity change of responses at cracks. In contrast, objects other than cracks are independent of external load.

Successful treatment in a case of acute myocardial infarction due to spontaneous coronary artery dissection.

Spontaneous coronary dissection is a rare cause of myocardial ischemia, myocardial infarction, and sudden death. In the present case, we performed stenting only of the severe stenotic lesion of the dissection with a short bare metal stent, and left the remaining long length of dissection vessel untreated. Six months after coronary stenting, follow-up angiography revealed complete healing of the coronary dissection and no significant in-stent restenosis.

Cor triatriatum sinister disclosed after diagnosis of acute myocardial infarction.

We present a case of cor triatriatum sinister diagnosed occasionally after acute anterior myocardial infarction. For management of the acute myocardial infarction (AMI), urgent reperfusion therapy was successfully performed through the left anterior descending coronary artery. Thereafter, no complication associated with AMI occurred.

Ultrasonic strain versus coronary flow velocity pattern for predicting regional wall motion recovery after primary coronary intervention for acute myocardial infarction.

Background: Strain Doppler echocardiography can detect regional myocardial dysfunction after acute myocardial infarction (AMI). The aim of this study was to assess the utility of strain in predicting regional wall motion recovery after AMI compared with the coronary flow velocity pattern.

Methods: Thirty-three patients with anterior AMIs undergoing successful coronary intervention were included.

Relationship of admission neutrophil count to microvascular injury, left ventricular dilation, and long-term outcome in patients treated with primary angioplasty for acute myocardial infarction.

Background: The relationship of admission neutrophil count to the degree of microvascular injury, left ventricular (LV) volume, and long-term outcome after acute myocardial infarction (AMI) was examined in the present study.

Methods And Results: The study group comprised 228 consecutive patients with a first anterior wall AMI who underwent primary angioplasty within 12 h of onset. The degree of microvascular injury was evaluated by Doppler guidewire.

Usefulness of coronary flow reserve immediately after primary coronary angioplasty for acute myocardial infarction in predicting long-term adverse cardiac events.

Coronary flow reserve (CFR) evaluated immediately after reperfusion is thought to reflect the degree of microvascular injury and predict left ventricular (LV) functional recovery after acute myocardial infarction. It was hypothesized that CFR immediately after reperfusion would be predictive of the occurrence of long-term adverse cardiac events. Using a Doppler guidewire, CFR was evaluated immediately after primary coronary angioplasty in 118 consecutive patients with first anterior acute myocardial infarctions.

Effects of smoking cessation on coronary endothelial function in patients with recent myocardial infarction.

Background: Smoking is associated with an increased risk and extent of advanced atherosclerotic vascular disease, but few studies have examined the clinical effect of smoking cessation on human coronary endothelial function.

Objectives: We sought to determine the effects of smoking cessation on endothelial function in patients with recent myocardial infarction.

Methods: Infarcted-not-related coronary arteries of 53 patients with acute myocardial infarction undergoing successful angioplasty were examined in two groups: smoking cessation group (n=35, 28 males, mean age 56 years) and non-smoking group (n=18, 10 males, mean age 65 years).

Relation between neutrophil counts on admission, microvascular injury, and left ventricular functional recovery in patients with an anterior wall first acute myocardial infarction treated with primary coronary angioplasty.

Increased neutrophil counts have been associated with an increased risk of adverse clinical events after acute myocardial infarction (AMI). We examined the association of neutrophil counts on admission with degree of microvascular injury and left ventricular functional recovery after primary coronary angioplasty in AMI. We studied 116 patients with a first anterior wall AMI who underwent primary coronary angioplasty within 12 hours of onset.

Usefulness of ultrasonic strain measurements to predict regional wall motion recovery in patients with acute myocardial infarction after percutaneous coronary intervention.

Strain Doppler echocardiography can detect systolic regional myocardial dysfunction. This study assessed whether strain could predict recovery of regional left ventricular function in patients with acute myocardial infarction (AMI) after percutaneous coronary intervention. Forty-three patients with anterior AMI undergoing successful percutaneous coronary intervention of the left anterior descending coronary artery were studied.

The effects of atorvastatin on coronary endothelial function in patients with recent myocardial infarction.

Background: Endothelial dysfunction is a key early event in atherosclerosis that occurs in acute coronary syndrome. It was reported that atorvastatin improves the endothelial function of skeletal muscle vessels, but the effect on the coronary artery is unknown.

Hypothesis: The purpose of this study is to determine the effects of atorvastatin on coronary endothelial function in humans.

Impact of hydroxymethylglutaryl coenzyme A reductase inhibition on left ventricular remodeling in patients with acute anterior myocardial infarction after primary coronary angioplasty.

Hydroxymethyglutaryl coenzyme A reductase inhibition (statin) therapy has been shown to reduce cardiac hypertrophy in vitro and in vivo. We assessed the influence of short-term statin therapy on left ventricular (LV) remodeling after acute myocardial in-farction. Thirty-five patients with first anterior acute myocardial infarction, who underwent primary coronary angioplasty within 12 hours of onset, were divided into 2 groups.

Effect of adhesion force between crack planes on subharmonic and DC responses in nonlinear ultrasound.

Subharmonic and DC responses in nonlinear ultrasound have been expected as a possible means of detecting closed cracks. Recently, it has been reported that subharmonics in a closed crack markedly increases above a certain input wave amplitude. Such a phenomenon is called "threshold behavior".

Ultrasonic tissue characterization predicts left ventricular remodeling in patients with acute anterior myocardial infarction after primary coronary angioplasty.

Objectives: The aim of this study was to assess the role of cyclic variation (CV) of myocardial integrated backscatter (IBS) in the prediction of left ventricular (LV) remodeling in patients with anterior acute myocardial infarction (AMI) after primary coronary angioplasty.

Background: Some studies have shown that the CV of myocardial IBS predicts myocardial viability for patients with AMI.

Methods: We recorded short-axis IBS images within 24 hours of angioplasty in 80 patients with anterior AMI.

Acute myocardial infarction caused by simultaneous occlusion of the right coronary artery and the left anterior descending coronary artery probably due to coronary spasm: a case report.

A 56-year-old man had an attack of chest pain associated with ST-segment elevation in both the inferolateral and anteroseptal leads on electrocardiography. Emergency coronary angiography showed thrombus in the mid right coronary artery and total occlusion in the distal left anterior descending coronary artery. Intravenous heparin infusion and antiplatelet therapy were given without other coronary intervention.

Left ventricular free wall rupture in transient left ventricular apical ballooning.

A 79-year-old woman presented with chest pain. Her symptoms, combined with the results of an electrocardiogram, echocardiogram and laboratory investigations were compatible with an extensive acute anterior myocardial infarction. However, emergency coronary angiography showed no stenotic lesion in any coronary artery, but left ventriculography revealed apical ballooning akinesis and basal hyperkinesis and she was diagnosed as having transient left ventricular apical ballooning.

Efficacy of stenting after rotational atherectomy for ostial LAD and ostial LCX stenosis in patients with diabetes.

Objective: The goal of this study was to investigate the efficacy of stenting after rotational atherectomy (rotastent) for ostial LAD and ostial LCX stenosis in patients with diabetes.

Background: Previous studies have demonstrated that rotastent for non-aorto ostial stenoses can be performed safely with high clinical success rate. However, in diabetic patients, long-term results of rotastent for ostial stenoses are still unknown.

Usefulness of coronary flow reserve immediately after primary coronary stenting in predicting wall motion recovery in patients with anterior wall acute myocardial infarction.

This study examined whether coronary flow reserve (CFR) measured immediately after primary coronary stenting could predict wall motion recovery in patients who have acute myocardial infarction. CFR significantly correlated with the change of wall motion score (r = 0.68, p <0.

Primary cardiac tumor presenting as obstruction of the left ventricular outflow tract.

A transthoracic echocardiogram revealed 3 tumors in the left atrium of a 64-year-old woman, who died suddenly 8 months after resection of the tumors. Primary cardiac tumors are unusual and a case of postoperative left ventricular metastases of the atrial tumors resulting in left ventricular outflow tract obstruction is very rare occurrence.