Echo Density Research Articles

Relations between plasma Ox-LDL and carotid plaque among Chinese Han ethnic group

<title/>Objectives: To study the relationship between plasma oxidized low-density lipoprotein (ox-LDL) and carotid plaque, including plaque stability, of patients with acute ischemic stroke among Chinese Han ethnic group.Methods: A total of 181 patients with acute ischemic stroke were recruited and enrolled. The subjects were divided into a carotid plaque group and a no-plaque group by carotid ultrasound. The stability of carotid atheromas was assessed by ultrasound echo density, and the carotid plaque group was further divided into a vulnerable plaque group and a stable plaque group based on the echo results.Results: The study showed that the correlation between age [odds ratio (OR): 1·047; 95% confidence interval (CI): 1·014-1·082; P<0·01] and carotid plaque was significant. Plasma ox-LDL (OR: 1·020; 95%CI: 1·010-1·030; P<0·001) was also found to be significantly correlated with carotid plaque. Age was irrelevant to plaque stability (P = 0·0685). The ox-LDL of the vulnerable plaque group was found to be significantly higher than that of the stable plaque group (P = 0·015). By measuring the plasma ox-LDL in patients with ischemic stroke, the proportion under the receiver operating characteristic curve of vulnerable carotid plaques was 0·690 with a 95%CI of 0·613-0·767 (P<0·001). The point of cut-off was 94·5943, the sensitivity was 0·805, and the specificity was 0·505.Conclusion: The plasma ox-LDL level and age are possible risk factors for carotid plaque among patients with ischemic stroke of the Chinese Han ethnic group. This study suggests that ox-LDL could be used as a biomarker in screening for vulnerable carotid plaque in clinical practice.

Embolization of an Intracardiac Thrombus During a Cardiovascular Magnetic Resonance Imaging Study

An active 60-year-old man presented with a 3-month history of palpitations and a sudden discomfort in the right foot with subsequent coolness and numbness of the right toes. The patient was in atrial flutter with a ventricular rate of 136 beats/min. An echocardiogram showed moderate to severe left ventricular (LV) systolic dysfunction with an ejection fraction of 30%. A spherical echo density measuring 2.2 cm was noted in the LV apex. This mass was suggestive of an LV thrombus. The patient was admitted to the hospital for anticoagulation using warfarin, enoxaparin, and aspirin. A cardiothoracic surgical consult was obtained to discuss the option of surgical removal of the thrombus or a course of anticoagulants, and a cardiovascular magnetic resonance imaging study was requested for tissue characterization of the mass. The cardiovascular magnetic resonance examination was started at 1:43 pm. Routine cine …

Incremental Value of Three-Dimensional over Two-Dimensional Transesophageal Echocardiography in the Assessment of Acute Dysfunction of Mechanical Mitral Valve Prosthesis

We describe acute dysfunction of a bileaflet mechanical mitral valve prosthesis for the first time in a 57-year-old male. Unlike two-dimensional transesophageal echocardiography, three-dimensional imaging convincingly showed a large rounded echo density consistent with a papillary muscle in contact with one of the leaflets showing only partial opening during systole.

Pericardial Fat Masquerading as Tumor

A 65-year-old woman was evaluated for fatigue, malaise, and atypical chest pain. One year prior she had undergone subtotal gastrectomy and jejunostomy in treatment of a large gastrointestinal stromal tumor. Two-dimensional echocardiography was performed, which showed a small circumferential pericardial effusion with a soft tissue echo density attached to the right atrial/right ventricular junction that extended over the right ventricle. Because of concern about possible malignant disease, thoracoscopy and biopsy of the pericardial mass were recommended. Normal fibro-adipose tissue was found with no evidence of neoplasm. Pericardial fat deposition is common in multiple conditions. It can be found in any location but is most common over the anterior portion of the heart. In this case, the concomitant presence of a small pericardial effusion and prominent fat pad at the right atrial/right ventricular junction gave the appearance of pericardial tumor.

エコートラッキング法を用いたプラーク弾性の評価法

Objective : In order to elucidate whether the elasticity of plaques evaluated using the echo tracking method is related to plaque echo density or pathological findings, we studied patients with carotid stenosis.Methods : We carried out carotid ultrasonographic examination in 21 patients with carotid stenosis exceeding 90% in area, evaluated the echo density of the plaques, and measured the β and Ep values by echo tracking. We then compared the β and Ep values in relation to echo density. Moreover, in patients undergoing carotid endarterectomy, the β and Ep values were also compared with the pathological features of the plaque.Results : There were12low-echoic plaques in12patients (low－echoic plaque group) and9iso－hyperechoic plaques in9patients (iso－hyperechoic plaque group). The β and Ep values in the low－echoic group were significantly lower than those in the iso－hyperechoic group (β, 7.3 ± 2.6 vs. 14.0 ± 6.9, p < 0.005, Ep, 101.4 ± 32 vs. 200.7 ± 101, p < 0.005, respectively). Six patients underwent carotid endarterectomy. The AHA tissue type of the plaques was type VI in4cases and V in the other 2. The β and Ep values of the type VI plaques were lower than those of the type V plaques.Conclusions : It seems that the β and Ep values evaluated by the echo tracking method are related to the echo density and tissue characteristics of plaque.

Direct Evidence for Nitrogen Ligation to the High Stability Semiquinone Intermediate in Escherichia coli Nitrate Reductase A

The membrane-bound heterotrimeric nitrate reductase A (NarGHI) catalyzes the oxidation of quinols in the cytoplasmic membrane of Escherichia coli and reduces nitrate to nitrite in the cytoplasm. The enzyme strongly stabilizes a menasemiquinone intermediate at a quinol oxidation site (Q(D)) located in the vicinity of the distal heme b(D). Here molecular details of the interaction between the semiquinone radical and the protein environment have been provided using advanced multifrequency pulsed EPR methods. (14)N and (15)N ESEEM and HYSCORE measurements carried out at X-band ( approximately 9.7 GHz) on the wild-type enzyme or the enzyme uniformly labeled with (15)N nuclei reveal an interaction between the semiquinone and a single nitrogen nucleus. The isotropic hyperfine coupling constant A(iso)((14)N) approximately 0.8 MHz shows that it occurs via an H-bond to one of the quinone carbonyl group. Using (14)N ESEEM and HYSCORE spectroscopies at a lower frequency (S-band, approximately 3.4 GHz), the (14)N nuclear quadrupolar parameters of the interacting nitrogen nucleus (kappa = 0.49, eta = 0.50) were determined and correspond to those of a histidine N(delta), assigned to the heme b(D) ligand His-66 residue. Moreover S-band (15)N ESEEM spectra enabled us to directly measure the anisotropic part of the nitrogen hyperfine interaction (T((15)N) = 0.16 MHz). A distance of approximately 2.2 Abetween the carbonyl oxygen and the nitrogen could then be calculated. Mechanistic implications of these results are discussed in the context of the peculiar properties of the menasemiquinone intermediate stabilized at the Q(D) site of NarGHI.

Recommendations for Evaluation of Prosthetic Valves With Echocardiography and Doppler Ultrasound: A Report From the American Society of Echocardiography's Guidelines and Standards Committee and the Task Force on Prosthetic Valves, Developed in Conjunction With the American College of Cardiology Cardiovascular Imaging Committee, Cardiac Imaging Committee of the American Heart Association, the European Association of Echocardiography, a registered branch of the

Recommendations for Evaluation of Prosthetic Valves With Echocardiography and Doppler Ultrasound: A Report From the American Society of Echocardiography's Guidelines and Standards Committee and the Task Force on Prosthetic Valves, Developed in Conjunction With the American College of Cardiology Cardiovascular Imaging Committee, Cardiac Imaging Committee of the American Heart Association, the European Association of Echocardiography, a registered branch of the

Real-Time Three-Dimensional Transesophageal Echocardiography and a Congenital Bilobar Left Atrial Appendage

Fig 1. (A) The 2D midesophageal view of the LAA showing SEC. The arrow points to the echo density that is questionable for thrombus. (B) Pulsed-wave Doppler of the LAA showing a velocity <20 cm/s. (C) A trimmed 3D view of the LAA showing a bilobed appendage with an arrow pointing to the endocardial fold that was originally thought to be thrombus.

Direct Detection and Characterization of Chloride in the Active Site of the Low-pH Form of Sulfite Oxidase Using Electron Spin Echo Envelope Modulation Spectroscopy, Isotopic Labeling, and Density Functional Theory Calculations

Electron spin echo envelope modulation (ESEEM) investigations were carried out on samples of the low-pH (lpH) form of vertebrate sulfite oxidase (SO) prepared with (35)Cl- and (37)Cl-enriched buffers, as well as with buffer containing the natural abundance of Cl isotopes. The isotope-related changes observed in the ESEEM spectra provide direct and unequivocal evidence that Cl(-) is located in close proximity to the Mo(V) center of lpH SO. The measured isotropic hyperfine interaction constant of about 4 MHz ((35)Cl) suggests that the Cl(-) ion is either weakly coordinated to Mo(V) at its otherwise vacant axial position, trans to the oxo ligand, or is hydrogen-bonded to the equatorial exchangeable OH ligand. Scalar relativistic all-electron density functional theory (DFT) calculations of the hyperfine and nuclear quadrupole interaction parameters, along with steric and energetic arguments, strongly support the possibility that Cl(-) is hydrogen-bonded to the equatorial OH ligand rather than being directly coordinated to the Mo(V).

A case of pancreatic carcinoma with suspected autoimmune pancreatitis.

We present a case of pancreatic carcinoma with strongly suspected coexisting autoimmune pancreatitis (AIP). The patient presented with a chief complaint of icterus and weight loss, and was referred to our institution after a pancreatic lesion was found. Blood test showed elevation of serum bilirubin, hepato-biliary enzyme, glucose and tumor markers, and also high levels of serum IgG4 (344mg/dl, normal 4.8-105mg/dl) and anti-DNA antibody (14IU/ml, normal <6.0IU/ml). Ultrasonography demonstrated an enlarged pancreas with smooth borders and low internal echo density. Enhanced computed tomography (CT) showed a sausage-shaped pancreas without definitive metastasis to the surrounding lymph nodes and liver. Imaging of the pancreatic duct, including endoscopic retrograde pancreatography (ERP) and magnetic resonance cholangiopancreatography (MRCP), showed stenosis of the main pancreatic duct at the pancreatic head as well as a long segment of narrowing at the body and no dilatation at the tail. Tissues from these stenotic sites and open biopsy from pancreatic body showed infiltrating adenocarcinoma and dense fibrosis. To date, only a small number of reports have described pancreatic carcinoma accompanied with AIP. It is important to confirm diagnosis with histology in cases of suspicious autoimmune pancreatitis, even when the clinical images are compatible with AIP.

A hybrid model of timbre perception.

Timbre is a fundamental attribute of sound. It is important in differentiating between musical sounds, speech utterances, and characterizing everyday sounds in our environment as well as novel synthetic sounds. A hybrid model of timbre perception, which integrates the concepts of color and texture of sound, is proposed. The color of sound is described in terms of an instantaneous (or ideally timeless) spectral envelope, while the texture of a sound describes the temporal structure of the sound, as the sequential changes of color with an arbitrary range of time‐scale. The computational implementation of this model represents a sound’s color as the spectral envelope of a specific window, and its texture as the granularity (or microtexture) of the corresponding window. The temporal structures across windows from both color and texture parts of the model serve as the texture of a sound in a larger time‐scale. In support of the proposed theory a series of psychoacoutic experiments was performed. The quantitative relationship between the spectral envelope and subjective perception of complex tones used Mel‐frequency cepstral coefficients as a representation. A perceptually tested quantitative representation of texture was established using normalized echo density.

MAGNETIC RESONANCE IMAGING OF THE NORMAL CANINE THYROID GLAND

The magnetic resonance (MR) imaging features of the normal canine thyroid gland were retrospectively compiled from images acquired in 44 dogs presented for a variety of diseases unrelated to the thyroid gland. The appearance of the thyroid gland on different sequences, including pre- and postcontrast T1-weighted, T2-weighted, two-dimensional gradient echo, three-dimensional T2*-weighted gradient echo and proton density weighted images, were described in different image planes. The characteristic shape, location, and intensity of thyroid lobes compared with surrounding structures made them easily detectable in all dogs. The most common location of the thyroid lobes was dorsolateral to the trachea with the maximal cross-sectional area of the lobes located ventral to C2/3 or C3 in more than 85% of the dogs. The majority of the lobes were ovoid on transverse images. An isthmus was seen in one large dog and parathyroid glands could not be seen. The mean maximal thyroid lobe diameter on transverse images was 8.1 mm, being twice the mean diameter of the common carotid artery. Considering the excellent conspicuity and characteristic appearance of the canine thyroid gland, MR imaging can be beneficial in the diagnosis of diffuse thyroid diseases, in differentiating thyroid vs. nonthyroid neck masses and in staging and treatment planning of thyroid tumors in this species.

Öffnungs- und Schließbewegungen der Herzklappen bei kardiopulmonaler Reanimation: Beweis für die Richtigkeit der »cardiac pump theory«

Cardiorespiratory arrest occurred in a 64-year-old man with severe triple-vessel coronary artery disease (status after two myocardial infarctions) and heart failure (ejection fraction of 20%). After intubation and starting resuscitation measures, transoesophageal echocardiography (TE) was performed to exclude electromechanical dissociation with ventricular tamponade. During the thoracic compression of closed-chest cardiac massage the aortic valve opened, while the mitral and tricuspid valves closed. During the relaxation phase the mitral and tricuspid valves rapidly opened, the aortic valve closed. When the cardiac massage was stopped (wide, fixed pupils) echo density increased spontaneously in all four cardiac chambers due to the cessation of blood flow. On resuming thoracic compression after about 30 sec the echo density decreased, first in the right ventricle, then right atrium, followed by left atrium and finally left ventricle. This is the first time that the wash-out of spontaneous echo-contrast has been reported in these circumstances. It makes it possible, together with the movements of the cardiac valves during thoracic compression, to state precisely the localization and direction of blood flow during closed-chest cardiac massage in man. The observations confirm the correctness of the cardiac pump theory rather than the thoracic pump one.

Reproduzierbarkeit sonographischer Kriterien zur Charakterisierung von Karotisstenosen

Comparisons with intraoperative findings suggest that Duplex scanning may be of value in predicting the morphology of carotid artery stenoses. Such studies, however, are based on the results obtained by experienced investigators. To clarify whether sonographic criteria can be standardized, 6 investigators from different hospitals each documented 30 carotid artery stenoses of greater than or equal to 40% diameter reduction which could be imaged in at least 2 planes. Three sonographic criteria (plaque surface, echo density, echo structure), each with 8 categories, were assessed from the image documentations by the 6 as well as by 2 independent further investigators. Depending on the experience and on the device used 29-81% of all stenoses greater than or equal to 40% examined in the different laboratories could be included in the study. The +/- 1 category concordance between the different investigators averaged 50-60% for all sonographic criteria independent from the degree of stenosis and from the image quality. Because of lack of sufficient reproducibility the subjective assessment of sonographic criteria is found to be not suitable for use in multicentre studies.

Evaluation of dark circles of the lower eyelid: comparison between reflectance meters and image processing and involvement of dermal thickness in appearance

Dark circles of the lower eyelid (DCLE) represent a well-known beauty problem. The pathogenesis of DCLE is obscure, although stasis and hyperpigmentation of the eyelids have been considered to be involved. One reason for the small number of studies on DCLE may be the difficulty in measuring such soft and curved skin as the eyelids using bulky reflectance meters. The purpose of this study was to quantitatively analyze DCLE using various bioengineering methods. The lower eyelid and cheek areas of 14 subjects with DCLE and 28 without DCLE were examined using two kinds of reflectance meters and image analysis to measure erythema index (EI), melanin index (MI), and oxygenation index (OX). Ultrasound echo images were also recorded to evaluate the thickness and echo density of the dermis. An in vitro model using collagen gel and hemoglobin solution was also examined as a phantom of eyelid skin. When contact-type reflectance meters were used, no significant differences in EI, MI, and OX were found between groups with and without DCLE. However, mean values of both MI and EI at eyelids were significantly higher in subjects with DCLE on image analysis, paralleling the results of inspection. Mean dermal thickness was significantly smaller in subjects with DCLE. Evaluation of EI and MI by image processing methods seems suitable for quantitative evaluation of DCLE, since inadequate contact of the measuring head with the skin is avoided. Whether stasis or hyperpigmentation is more responsible for DCLE remains uncertain. Dermal thickness of eyelid skin may be involved in the appearance of DCLE.

Difficult differential diagnosis of a right atrial intracardiac mass

We report a case of a 51 year old patient who was admitted to the cardiology department because of an undifferentiated mass in the right atrium of the heart. The patient presentedwith congestive heart failure (New York Heart Association Class II). On examination, his weight was 84 kg, height 172 cm and blood pressure was 144/108 mm Hg. Cardiac auscultation included a normal first heart sound and a widely split second heart sound with a soft systolic ejection murmur at the upper right sternal border. Physical exam of the abdomen showed hepatomegaly. Lung auscultation was unremarkable with no evidence of edema. Furthermore there were no signs of syncope or fever. Abdominal ultrasound revealed congestion of the liver. The 12-lead electrocardiogram demonstrated sinus tachycardia of 102 bpm with a right axis deviation. The main haematological and biochemical manifestations were elevated erythrocyte sedimentation rate, elevated C-reactive protein, and elevated transaminase levels. A recent routine two-dimensional transthoracic echocardiogram (TTE) detected a mass in the right atrium. Due to the location and morphology diagnosis of myxoma was considered but not with the typical appearance to be expected. The transesophageal echocardiography (TEE) revealed a cauliflower-like mass, consisting of two homogenous parts involving the right atrium. One part demonstrated low echo density, attachment to the anterior tricuspid valve, and invasion of the right ventricle. The other part was a 7.3×4.2 cm large mobile mass with no attachment to the interatrial

Clinical Significance of B-Mode Ultrasound of Common Carotid Artery for Prediction of Severity of Coronary Artery Disease: Important Parameters on Hand Measurement

Background and Objectives：As a predictor of atherosclerosis, the intima-media thickness (IMT) of the common carotid artery (CCA) shows only a weak correlation with the extent of coronary artery disease (CAD). The purpose of this study was to evaluate the hand measured IMT value of the CCA as reliable and strong predictors of the severity of coronary artery atherosclerosis. Subjects and Methods：We performed an ultrasonographic examination of the right CCA by using a 15 MHz linear array transducer in 268 patients (M: F=160: 108, mean age 61.2±10.2) who underwent coronary angiography to evaluate ischemic heart disease. The internal dimension, maximal IMT, irrespective of location and morphology (focal or diffuse), and the IMT of 6 more randomly selected points in the CCA were measured. We classified the plaques as type A (low or equal echo density compared with adventitia) or type B (higher echo density than adventitia). Modified Gensini scores were calculated, as a marker of the extent of CAD, and compared with the results of the IMT examination. Results：Carotid plaques were detected in 156/268 (58%) patients. 119 and 37 patients were types A and B, respectively. The Gensini score was significantly higher in patients with type B (40.6±23.5) than type A plaques (29.3±21.7) (p=0.01). Modified Gensini score was correlated with age (r=0.22 p<0.001), mean IMT (r=0.178, p=0.004) and maximal IMT (r=0.296, p<0.001). After adjusting for age, the maximal IMT was the sole independent variable reflecting the severity of CAD (p=0.001). Conclusion：The maximal IMT, together with the type of CCA plaque morphology, provides more reliable information about the severity of CAD than the conventional mean IMT. (Korean Circulation J 2005;35:467-473)

Quantitative analysis of endosonographic parenchymal echogenicity in patients with chronic pancreatitis.

The aim of the study was to develop a method of quantitation of endoscopic ultrasonography (EUS) changes of chronic pancreatitis (CP). Twenty-three patients with chronic pancreatitis by EUS were compared with nine normal subjects. Hyperechogenicity was evaluated as the size of the hyperechoic area that was over a threshold echogenicity level. Mean echo density was expressed using the average gray-scale value within the region of interest. The quantitative data were compared with the diagnosis using conventional EUS criteria. The size of the hyperechoic area over the threshold level was 0.86 +/- 0.67 mm2 (mean +/- SD) in the normal pancreas using EUS criteria. In chronic pancreatitis, the size of the hyperechoic area was 7.28 +/- 2.98 mm2 in patients with mild CP, 18.12 +/- 2.56 mm2 in patients with moderate CP, and 18.02 +/- 10.81 mm2 in patients with severe CP, respectively. These changes in hyperechoic size area were statistically significant in all patients having mild to severe CP when compared with normal controls. Computer analysis of EUS images may provide objective information for the diagnosis of CP and may be useful in quantitating the severity of disease and overcoming interobserver variability in analyzing individual echo features supporting the diagnosis of CP.

Echo strength and density structure of Hawaiian mesopelagic boundary community patches.

A broadband sonar system and digital camera with strobe lights were mounted on a vertically profiling frame with a depth sensor. The echo strengths and densities of animals within individual mesopelagic boundary community patches were investigated as a function of depth. Time and distance from shore were also investigated. Simultaneous surface echosounder surveys permitted comparison of density estimates from two techniques. Echo strength values suggest nearshore boundary community animals are primarily myctophid fishes, which was confirmed by preliminary photographic evidence. Echo strength varied significantly as a function of distance from the shoreline and time. These measures of echo strength are important for estimating density from a surface echosounder. Density estimates from these revised echo strengths compare well with those made with echo highlight counting, which is independent of echo strength. These density measures suggest that previous density estimates were too low but do not change the conclusions of these studies. Vertical microstructure in density was apparent but animal size and compositional structure was not evident within a patch. Patch edges were abrupt, with no differences in the density or echo strength from patch interiors. These edges were generally straight, with a sharp drop in density to the background density of zero. Estimates of animal size as a function of time provide information about the diel migration patterns of these mesopelagic animals.

How Good at Neurology are you? – Questions

1. Are these statements true or false? 90% of large cortical infarcts are visible on CT within 48 h of symptom onset. 40% of lacunar or small cortical infarcts are...