Images in cardiovascular medicine. Serial assessment of liquefaction necrosis of mitral annular calcification by echocardiography and multislice computed tomography.
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Calcinosis↗
Biomedical subjects
Shigeru Suzuki
Publications and source records attributed to Shigeru Suzuki.
Radar imaging of binary near-Earth asteroid (66391) 1999 KW4.
High-resolution radar images reveal near-Earth asteroid (66391) 1999 KW4 to be a binary system. The approximately 1.5-kilometer-diameter primary (Alpha) is an unconsolidated gravitational aggregate with a spin period approximately 2.8 hours, bulk density approximately 2 grams per cubic centimeter, porosity approximately 50%, and an oblate shape dominated by an equatorial ridge at the object's potential-energy minimum. The approximately 0.5-kilometer secondary (Beta) is elongated and probably is denser than Alpha. Its average orbit about Alpha is circular with a radius approximately 2.5 kilometers and period approximately 17.4 hours, and its average rotation is synchronous with the long axis pointed toward Alpha, but librational departures from that orientation are evident. Exotic physical and dynamical properties may be common among near-Earth binaries.
Journal Article↗
[Steroid sulphatase deficiency].
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Chromosomes, Human, X↗
Radiosensitive functional dye: clinical application for estimation of patient skin dose.
Institutional review board approval and informed patient consent were obtained. The purpose of the study was to prospectively evaluate the use of radiosensitive indicators to estimate patient entrance skin dose (ESD). Forty-six patients wore a jacket with 48 or 52 indicators adhered to the back during percutaneous coronary interventions; they had eight additional indicators on their upper arms. The patients' ESDs were calculated according to the change in color of the indicators. There were good correlations between the ESDs estimated by using color measurements performed with an optical instrument and those estimated at visual observation (P < .001) and between the ESDs estimated by using a thermoluminescent dosimeter and those estimated by using color measurements (P < .001). The radiosensitive indicator method seems to be useful for estimating ESDs and their distribution during percutaneous coronary intervention; however, visual observation is reliable for estimating doses of up to 5 Gy only. (c) RSNA, 2006.
Aged↗
Impact of 16-slice computed tomography in percutaneous coronary intervention of chronic total occlusions.
The main reason for failure of percutaneous coronary intervention (PCI) of chronic total occlusion (CTO) is because the calcified plaque prevents the guide wire crossing the occlusion. We aimed to identify the route, and characterize plaque components within CTO, using 16-slice computed tomography (MSCT). Twenty three angiographic CTO in 22 patients (mean age 69 +/- 5 years, 17 males) were included. All patients had undergone MSCT prior to PCI. Images were analyzed for lesion visibility and plaque characteristics of CTO. The presence and location of calcified plaque within the CTO were systematically assessed. Each lesion was classified as a noncalcified, moderately calcified, or exclusively calcified plaque. Procedural failure was defined as the inability to cross a guide wire through the occlusion. All coronary routes of CTO segment were visualized. MSCT revealed three markedly bent CTO segments (13.0%), which could not be identified by coronary angiography only. Calcified plaques were detected in 30 lesions of 19 CTO segments (82.6%), but were not detected in the other four. The majority of calcified plaque was located in the proximal lesion, or both proximal and distal lesions. Fifteen out of 30 calcified lesions (50.0%) were exclusively calcified plaques. Overall procedural success was obtained in 21 CTOs (91.3%). MSCT can accurately identify the route of the CTO segment and evaluate both distribution and amount of the calcified plaque within it. Even with the complicated and/or calcified lesions, PCI success rate was excellent under MSCT guidance. MSCT should become a useful tool in PCI of CTO.
Aged↗
Distinct changing profiles of hepatitis A and E virus infection among patients with acute hepatitis, patients on maintenance hemodialysis and healthy individuals in Japan.
To compare the epidemiologic profiles of hepatitis A virus (HAV) and hepatitis E virus (HEV) infections in Japan, the prevalence of clinical or subclinical HAV and HEV infections was investigated serologically and molecularly among 128 consecutive patients (age, mean +/- standard deviation, 37.5 +/- 14.7 years) who contracted acute hepatitis between 1989 and 2005 in a city hospital, and among 416 hemodialysis patients (60.1 +/- 12.6 years) and 266 medical staff members (34.6 +/- 11.4 years) at the same hospital, using stored periodic serum samples collected since the start of hemodialysis or employment, respectively. Between 1989 and 1995, among 93 patients with acute hepatitis, 51 (54.8%) were diagnosed with hepatitis A and only one patient with hepatitis E. Between 1996 and 2005, however, among 35 patients, only 3 (8.6%) were diagnosed with hepatitis A and 2 (5.7%) with hepatitis E. Although subclinical HEV infection was recognized in four hemodialysis patients (one each in 1979, 1980, 1988, and 2003) and two medical staff members (1978 and 2003) in previous studies, none of the 191 hemodialysis patients who had been negative for anti-HAV at the start of hemodialysis contracted HAV infection during the observation period of 7.6 +/- 6.4 years. Only one (0.4%) of the 246 medical staff members who had been negative for anti-HAV at the start of employment acquired hepatitis A during the observation period of 7.9 +/- 8.0 years: none had subclinical HAV infection. Clinical or subclinical HEV infection has occurred rarely during the last three decades, while HAV infection has markedly decreased at least since 1996.
Acute Disease↗
Accuracy of attenuation measurement of vascular wall in vitro on computed tomography angiography: Effect of wall thickness, density of contrast medium, and measurement point.
OBJECTIVES: We sought to assess the effects of measurement point, wall thickness, and intravascular density of contrast material on attenuation measurement of vascular wall. MATERIALS AND METHODS: We used vascular models (actual attenuation value of the wall: 83 HU) with wall thicknesses of 1.5, 1.0, or 0.5 mm, filled with contrast material of 254, 325, or 400 HU. The 9 vascular models were fixed in an oil-filled container and scanned with a 16-detector computed tomography. The wall attenuation values were measured at 1 point for 0.5-mm thickness models, 3 for 1.0-mm thickness models, and 5 for 1.5-mm thickness models with the same interval of 0.25 mm. Total 20 measurements were done for each point. RESULTS: For 1.0-mm and 1.5-mm thickness models, wall attenuation progressively increased as the measurement points approached the lumen (P < 0.0001). At all the measurement points for 0.5-mm and 1.0-mm thickness models and the 2 inner measurement points for 1.5-mm thickness models, the densities of contrast material affected the wall attenuations significantly (P < 0.0001). At the midportion for 1.5-mm thickness models, the wall attenuations were not affected by the densities of the contrast material (P = 0.6301), and were 65-68 HU. CONCLUSIONS: The effects of the intravascular density of contrast material, measurement point, and wall thickness should be considered in the attenuation measurement of the wall.
Angiography↗
Accuracy and efficiency of left ventricular ejection fraction analysis, using multidetector row computed tomography: effect of image reconstruction window within cardiac phase, slice thickness, and interval of short-axis sections.
BACKGROUND: The aim of the present study was to assess the accuracy and efficiency of left ventricular ejection fraction (LVEF) analysis by multidetector row computed tomography (CT). METHODS AND RESULTS: The CT data of 21 patients were analyzed by semi-automated software on a workstation. In analysis of LVEF using systolic volumes in the 6 phases (30-55%), systolic images of 10% interval (35, 45, 55%) were underestimated with a mean measurement error of -0.4% and the standard error of the estimate (SEE) of 0.6%, compared with the LVEF using images of 5% interval. In analysis of LVEF using 3-slice thicknesses of axial images (1, 2, and 3 mm), and 3-slice numbers of short-axis sections (10 14, and 30 slices), there was no significant difference between the SEE of the intraobserver reproducibility and that of the analysis with 30 short-axis sections using axial images of 1-, 2- and 3-mm thickness, and that with 14 short-axis sections using axial images of 1- and 2-mm thickness. The mean analysis times were 96.9 s, 119.8 s, and 227.0 s for the analysis with 10, 14, and 30 short-axis sections, respectively. CONCLUSION: The proper selection of the reconstruction interval in the cardiac phase, the slice thickness of the axial images, and the number of short-axis sections reduces the analysis time, maintaining the accuracy of LVEF analysis. This will be acceptable for practical use at present, although more accurate analysis is preferable.
Adult↗
Radiation exposure to patient's skin during percutaneous coronary intervention for various lesions, including chronic total occlusion.
BACKGROUND: Radiation skin injuries have been reported as a result of various procedures, so in the present study the patients' entrance skin dose (ESD) during percutaneous coronary intervention (PCI) was evaluated. METHODS AND RESULTS: ESDs were assessed during 97 procedures (13 for chronic total occlusion (CTO), 14 for multivessel stenoses, 22 for single-vessel multiple stenoses, and 48 for single stenosis). The patients wore jackets that had 48 or 52 radiosensitive indicators placed on the back during the PCI procedures, with 8 other indicators placed on both upper arms. After the procedure, the color of the indicators was analyzed with a color measuring instrument, and the patients' ESDs were calculated from the color difference of the indicators. The average maximum ESDs of the patients were 4.5 +/- 2.8 Gy (median: 4.6 Gy) for CTO, 2.3 +/- 0.7 Gy (median: 2.4 Gy) for multivessel stenoses, 1.8 +/- 1.0 Gy (median: 1.5 Gy) for single-vessel multiple stenoses, and 1.4 +/- 0.9 Gy (median: 1.2 Gy) for single stenosis. CONCLUSIONS: Skin injury can occur during PCI, especially for CTO, so it is important to estimate each patient's ESD and attempt to reduce it.
Aged↗
Determination of hexabromocyclododecane diastereoisomers and tetrabromobisphenol A in water and sediment by liquid chromatography/mass spectrometry.
A method to determine alpha-, beta- and gamma-hexabromocyclododecane (HBCD) and tetrabromobisphenol A (TBBPA) in water and sediments was presented using solid phase extraction (SPE) and/or solvent extraction. Recoveries from sediments were approximately 100% for all the chemicals, while recoveries of alpha-, beta- and gamma-HBCDs from water were dependent on the extraction method. In the case of dichloromethane (CH2Cl2) extraction, recoveries of alpha-, beta- and gamma-HBCD from landfill leachates were 77%, 88% and 92%, respectively. Technical difficulties in HBCD measurement are discussed in terms of the physico-chemical properties of HBCD isomers. The method was applied to landfill samples and marine sediment.
Journal Article↗
Serological and molecular studies on subclinical hepatitis E virus infection using periodic serum samples obtained from healthy individuals.
Subclinical hepatitis E virus (HEV) infection among healthy individuals was studied serologically and molecularly. Serum samples collected at screening between March and April 2004 (or just before retirement) from 266 medical staff members (35 males, 231 females) who had been working for 8.8 +/- 8.5 (mean +/- standard deviation, range, 0.3-35.1) years in a city hospital in Japan and serum samples that had been collected from these staff members at the start of employment were tested for IgA, IgM, and IgG antibodies to HEV (anti-HEV) by in-house enzyme-linked immunosorbent assays. Overall, six subjects (2.3%) tested positive for anti-HEV IgG at the screening; among them, four subjects (1.5%) had already been positive for anti-HEV IgG at the start of employment and two subjects (0.8%) seroconverted after initiation of employment. Periodic serum samples that had been collected from the two seroconverted subjects were tested for HEV antibodies and HEV RNA. The two subjects became positive for anti-HEV IgG in 1978 or 2003, respectively, with no discernible elevation in alanine aminotransferase (ALT) level, and continued to be seropositive up through the screening date. Although anti-HEV IgM was not detectable in the two subjects, one was infected transiently with Japan-indigenous HEV strain of genotype 3 and the other was positive transiently for anti-HEV IgA. The present study indicates that even an individual with subclinical HEV infection had evidence of transient viremia in the absence of ALT elevation and that anti-HEV IgA detection may be useful for serological diagnosis of recent subclinical HEV infection.
Adult↗
Method for the elucidation of the elemental composition of low molecular mass chemicals using exact masses of product ions and neutral losses: application to environmental chemicals measured by liquid chromatography with hybrid quadrupole/time-of-flight mass spectrometry.
A method for elucidating the elemental compositions of low molecular weight chemicals, based primarily on mass measurements made using liquid chromatography (LC) with time-of-flight mass spectrometry (TOFMS) and quadrupole/time-of-flight mass spectrometry (LC/QTOFMS), was developed and tested for 113 chemicals of environmental interest with molecular masses up to approximately 400 Da. As the algorithm incorporating the method is not affected by differences in the instrument used, or by the ionization method and other ionization conditions, the method is useful not only for LC/TOFMS, but also for all kinds of mass spectra measured with higher accuracy and precision (uncertainties of a few mDa) employing all ionization methods and on-line separation techniques. The method involves calculating candidate compositions for intact ionized molecules (ionized forms of the sample molecule that have lost or gained no more than a proton, i.e., [M+H](+) or [M-H](-)) as well as for fragment ions and corresponding neutral losses, and eliminating those atomic compositions for the molecules that are inconsistent with the corresponding candidate compositions of fragment ions and neutral losses. Candidate compositions were calculated for the measured masses of the intact ionized molecules and of the fragment ions and corresponding neutral losses, using mass uncertainties of 2 and 5 mDa, respectively. Compositions proposed for the ionized molecule that did not correspond to the sum of the compositions of a candidate fragment ion and its corresponding neutral loss were discarded. One, 2-5, 6-10, 11-20, and >20 candidate compositions were found for 65%, 39%, 1%, 1%, and 0%, respectively, for the 124 ionized molecules formed from the 113 chemicals tested (both positive and negative ions were obtained from 11 of the chemicals). However, no candidate composition was found for 2% of the test cases (i.e., 3 chemicals), for each of which the measured mass of one of the product ions was in error by 5-6.7 mDa.
Chromatography, Liquid↗
Clinical application of rapid assay of interleukin-6 in influenza-associated encephalopathy.
The characteristics of influenza-associated encephalopathy is the high mortality and nimble progress with coma which appears in general cases within 48 hours. Most of patients show no abnormalities in the standard blood checks on admission or in early stage. In this study we investigated if a rapid assay of interleukin (IL)-6 is useful in influenza-associated encephalopathy in early stages. The levels of IL-6 in patients with influenza-associated encephalopathy did not show any significant difference compared with those in patients with febrile convulsion and rotavirus-associated convulsion. However the levels of IL-6 in severe cases were significantly higher than those of mild cases with influenza-associated encephalopathy. Consequently the rapid assay of serum IL-6 is useful to evaluate and decide the therapies.
Biomarkers↗
Evaluation of coronary stents in vitro with CT angiography: effect of stent diameter, convolution kernel, and vessel orientation to the z-axis.
BACKGROUND: The aims of the present study were to assess the effect of the stent diameter, convolution kernel, and vessel orientation to the z-axis on the evaluation of coronary stents, in vitro with computed tomography (CT) angiography. METHODS AND RESULTS: Seven vascular models (2 models without stenosis, 2 with obstruction, and 3 with stenosis) with an approximate inner diameter of 3 or 4 mm, filled with contrast material (79 or 330 HU) were scanned with a 16-detector CT. The diameter measurement of the stent lumen and stenosis evaluation were both done in an orientation parallel to the z-axis of the scanner using 4 convolution kernels. The measured diameters of the stented lumen were 47-57% and 36-45% smaller than the actual inner diameter of the 3- and 4-mm diameter models, respectively. The diameter measurement of the stent lumen and visualization of the in-stent stenosis were improved by using convolution kernels with higher spatial resolution. The in-stent artifacts were evaluated in 4 orientations (0 degrees , 30 degrees , 60 degrees , 90 degrees ) to the z-axis. The artifact was the minimum in 0 degrees to the z-axis, and the maximum in 90 degrees . CONCLUSION: Visualization of the lumen of a stent by CT is affected by its diameter, convolution kernel, and vessel orientation to the z-axis, and these factors should be taken into consideration in the stent evaluation.
Angiography↗
Radiation dose to patients and radiologists during transcatheter arterial embolization: comparison of a digital flat-panel system and conventional unit.
OBJECTIVE: The objective of our study was to evaluate the exposure doses to patients and radiologists during transcatheter arterial embolization (TAE) for hepatocellular carcinoma (HCC) using a new angiographic unit with a digital flat-panel system. SUBJECTS AND METHODS: Doses were assessed for 24 procedures: 12 using a new unit with a digital flat-panel system and 12 using a conventional unit. Doses to patients' skin were evaluated with thermoluminescent dosimeters behind the left, middle, and right portions of the liver. The doses to the radiologists were measured by an electronic personal dosimeter placed on the chest outside a lead protector. The maximal skin doses to the patients and the dose equivalents, Hp(0.07), to the radiologists were compared between the two procedure groups with each angiographic unit. RESULTS: For procedures with the new unit, the mean maximal skin dose to the patients was 284 +/- 127 (SD) mGy (range, 130-467 mGy), and Hp(0.07) to the radiologists was 62.8 +/- 17.4 muSv. For procedures with the conventional unit, the maximal skin dose to the patients was 1,068 +/- 439 mGy (range, 510-1,882 mGy), and Hp(0.07) to the radiologists was 68.4 +/- 25.7 muSv. The maximal skin dose to the patients was significantly lower with the new unit than with the conventional unit (p < 0.0005). There was no significant difference in the Hp(0.07) to the radiologists between the two procedure groups. CONCLUSION: The new digital flat-panel system for angiographic imaging can reduce the radiation dose to patients' skin during TAE for HCC as compared with the conventional system.
Carcinoma, Hepatocellular↗
Accuracy of automated CT angiography measurement of vascular diameter in phantoms: effect of size of display field of view, density of contrast medium, and wall thickness.
OBJECTIVE: The objective of this study was to assess the effect of wall thickness, density of intravascular contrast material, and size of the display field of view on the accuracy of measurements of vascular diameter in phantoms yielded by automated software for CT angiography. MATERIALS AND METHODS: Vascular models with three wall thicknesses (1.0, 0.8, and 0.5 mm) and an inner diameter of approximately 4 mm were filled with contrast material of three different densities (198, 270, and 350 H) and scanned with helical CT. Three sizes of display field of view (10, 15, and 20 cm) were used. We evaluated the measurement error of the automated software, which was defined as the difference between the diameter measurement of the automated software and the true inner diameter of the vascular model. Statistical analysis involved three-way analysis of variance with repeated measures. RESULTS: There were significant differences in the measurement errors among the three wall thicknesses of the vascular model, three densities of intravascular contrast material, and three sizes of display field of view. The overall measurement errors progressively increased with larger sizes of display field of view (p < 0.01) and with lower densities of intravascular contrast material (p < 0.001). The measurement errors tended to progressively increase as the thickness of the wall of the vascular models increased. CONCLUSION: The accuracy of the diameter measurements by automated software for CT angiography was affected by the size of the display field of view, intravascular density of the contrast material, and wall thickness of the vessel. It is necessary to consider the effects of these factors on the diameter measurements of small arteries.
Angiography↗
[Cardiac rupture caused by myocardial infarction in the diagonal branch area: evaluation by cardiac multislice computed tomography: a case report].
A 75-year-old woman was admitted to the emergency room because of hypotension and loss of consciousness induced by cardiac tamponade. Electrocardiography revealed ST elevation and laboratory data showed elevation of serum creatine kinase and troponin I. The patient was referred to the cardiology department 5 days later. Cardiac catheterization revealed ventricular aneurysm in the anterior wall, significant stenosis (75%) in the left anterior descending coronary artery and subtotal stenosis (99%) in the diagonal branch. Cardiac multislice computed tomography suggested that the ventricular pseudoaneurysm was probably due to cardiac rupture caused by myocardial infarction in the diagonal area. Subsequently, aneurysmectomy and coronary artery bypass graft surgery were performed. Cardiac multislice computed tomography is useful for evaluating coronary artery and cardiac rupture.
Aged↗
Determination of volatile fatty acids in landfill leachates by ion-exclusion chromatography.
An ion-exclusion chromatographic method with on-line desalinization for the determination of volatile fatty acids in landfill leachates is described. Highly sensitive conductivity detection of the organic acids was achieved by using dilute p-hydroxybenzoic acid solution as an eluent. Interference with mineral acids was reduced by treatment with barium chloride solution prior to desalinization. A silver-loaded cation-exchange guard column for the desalinization was installed in series with the analytical column to avoid the contamination of organic acids. This method features detection limits of 0.01 mg L(-1) formic acid, 0.02 mg L(-1) acetic acid, 0.05 mg L(-1) propionic acid, and 0.1 mg L(-1) butyric acid, respectively, with an injection of 20 microL sample. Application of the on-line desalinization LC method is illustrated for leachate samples from a Japanese sanitary landfill.
Chromatography, Gel↗