Effect of high- and low-energy entrance surface dose allocation ratio for two-shot dual-energy subtraction imaging on low-contrast resolution.

INTRODUCTION: Dual-energy subtraction (DES) imaging can obtain chest radiographs with high contrast between nodules and healthy lung tissue, and evaluating of chest radiography and evaluating exposure conditions is crucial to obtain a high-quality diagnostic image. This study aimed to investigate the effect of the dose allocation ratio of entrance surface dose (ESD) between high- and low-energy projection in low-contrast resolution of soft-tissue images for two-shot DES imaging in digital radiography using a contrast-detail phantom (CD phantom). METHODS: A custom-made phantom mimicking a human chest that combined a CD phantom, polymethylmethacrylate square plate, and an aluminum plate (1-3 mm) was used. The tube voltage was 120 kVp (high-energy) and 60 kVp (low-energy). The ESD was changed from 0.1 to 0.5 mGy in 0.1 mGy increments. Dose allocation ratio of ESD between 120 kVp and 60 kVp projection was set at 1:1, 1:2, 1:3, and 2:1. Inverse image quality figure (IQFinv) was calculated from the custom-made phantom images. RESULTS: When the total ESD and aluminum thickness were constant, no significant difference in IQFinv was observed under most conditions of varied dose allocation ratio. Similarly, when the total ESD and the dose allocation ratio were constant, there was no significant difference in IQFinv based on the aluminum plate thickness. CONCLUSION: Using IQFinv to evaluate the quality of the two-shot DES image suggested that dose allocation ratio did not have a significant effect on low-contrast resolution of soft-tissue images. IMPLICATIONS FOR PRACTICE: The present results provide useful information for determining exposure conditions for two-shot DES imaging.

Coronary flow velocity analysis during short term follow up after coronary reperfusion: use of transthoracic Doppler echocardiography to predict regional wall motion recovery in patients with acute myocardial infarction.

BACKGROUND: A recent study using a Doppler guide wire showed that coronary flow velocity measurements immediately after coronary reperfusion were useful in predicting recovery of regional left ventricular function. The value of coronary flow velocity analyses during follow up after reperfusion has not been established in the clinical setting. OBJECTIVE: To evaluate coronary flow velocity measurements in predicting recovery of regional left ventricular function during short term follow up after acute anterior myocardial infarction, using transthoracic Doppler echocardiography (TTDE). METHODS: 30 consecutive patients with anterior acute myocardial infarction were studied. They all underwent successful coronary angioplasty for lesions in the left anterior descending coronary artery (LAD). Using TTDE, coronary flow velocity in the LAD was recorded on days 1 and 3, and at one and two weeks after reperfusion. Regional wall motion was analysed by the wall motion score index (WMSI), calculated as an average of segmental scores in the LAD territory before reperfusion and one month after the infarction. RESULTS: Deceleration time of diastolic flow velocity (DDT) in patients with viable myocardium (WMSI in LAD territory at one month, < 2.0) was significantly longer after recanalisation than in patients without viable myocardium (WMSI in LAD territory at one month, > 2.0): 657 (226) v 271 (117) ms on day 1, p < 0.001; 732 (219) v 373 (217) ms on day 3, p < 0.01; and 903 (107) v 577 (300) ms at one week, p < 0.01. However, the difference at two weeks (991 (75) v 795 (281) ms) was not significant. For the prediction of viable myocardium, DDT > 600 ms had a sensitivity of 78% and a specificity of 92% on day 1, and a sensitivity of 78% and a specificity of 84% on day 3. At one and two weeks, DDT > 600 ms was sensitive (100% and 100%, respectively) but less specific (46% and 26%, respectively) for predicting viable myocardium. CONCLUSIONS: Non-invasive assessment of coronary flow velocity using TTDE within three days of successful coronary angioplasty in patients with anterior acute myocardial infarction is useful in predicting recovery of regional left ventricular function.

Myocardial inflammatory cell infiltrates in cases of dilated cardiomyopathy as a determinant of outcome following partial left ventriculectomy.

Partial left ventriculectomy (PLV) can be used to treat refractory congestive heart failure caused by dilated cardiomyopathy (DCM). In order to understand the relationship between the underlying myocardial injury and early clinical outcomes after PLV, histopathologic, immunohistochemical and virologic studies of the resected myocardium were performed. The posterolateral left ventricular walls from 27 patients with idiopathic DCM were examined. Cardiomyocyte diameter, degree of myocardial fibrosis, degree of cardiomyocyte degeneration, and degree of inflammatory cell infiltration were compared with mortality rates. Polymerase chain reaction was performed to detect enterovirus genome in the myocardium. Some patients had inflammatory cell infiltrates with focal accumulations of lymphocytes and macrophages, including both cytotoxic/suppressor T-cells and helper/inducer T-cells. The number of inflammatory cells (activated lymphocytes plus macrophages/mm2) was significantly greater in patients who died of cardiac insufficiency after surgery (27.8 +/- 5.7; n = 7) than in the survivors (11.1 +/- 2.5; n = 15). There was no significant difference in the degree of myocardial fibrosis, cardiomyocyte diameter or degree of cardiomyocyte degeneration between the 2 groups. Enterovirus genome was detected in the myocardium of 9 (38%) of 24 patients examined and 5 of these enterovirus-positive hearts had severe inflammatory cell infiltrates (37.9 +/- 2.5/mm2). Early survival in patients undergoing PLV for DCM is significantly affected by the degree of myocardial inflammation, so patients with more severe or ongoing inflammation may have poor clinical outcomes. Chronic myocarditis may play an important role in the etiology and pathophysiology of idiopathic DCM.

Intercalation compounds of layered materials for drug delivery use. II. Diclofenac sodium.

Intercalation compounds of ternary layered inorganic materials, synthetic mica (Na-TSM), with diclofenac sodium (DFS) and its drug release characteristics were investigated. Hygroscopic DFS was selected as a model drug to verify the anti-humidity and anti-oxidation of the intercalation compounds. Na-TSM powder was first mixed with the reduced-type phosphatidylcholine (H-PC) solution of chloroform or ethanol. DFS was then mixed with these solutions and heated at 37 degrees C to prepare the ternary Na-TSM/H-PC/DFS compound. A remarkable phenomenon was observed in the drug release study. The net amount of DFS from the DFS powder decreased apparently after 20 min arising from the decomposition of DFS in acidic medium. On the other hand, the net amount of the released DFS from the intercalation compound was invariant. Thermal analyses study indicated that DFS powder was hygroscopic and a significant endothermic peak was observed accompanied by a large weight loss due to the dehydration of adsorbed water from 40 to 90 degrees C. On the other hand, no significant dehydration reaction was observed in the intercalation compounds even in the sample stored under humid conditions. The present results indicated that the ternary intercalation compound was resistant to acid in addition to anti-humidity.

A case of cardiomyopathy showing progression from the hypertrophic to the dilated form: association of Mt8348A-->G mutation in the mitochondrial tRNA(Lys) gene with severe ultrastructural alterations of mitochondria in cardiomyocytes.

This report describes a case of cardiomyopathy with a novel point mutation of mitochondrial DNA coding lysine tRNA in association with severe ultrastructural alterations of the mitochondria in the cardiomyocytes. Abnormalities of energy production and/or abnormal protein synthesis because of the mutation of mitochondrial DNA may have played an important role in the pathogenesis of this case, which showed severe cardiomyocyte degeneration and deterioration from hypertrophic cardiomyopathy to severe dilated cardiomyopathy.

Metabolism of 2-nitrofluorene, 2-aminofluorene and 2-acylaminofluorenes in rat and dog and the role of intestinal bacteria.

1. The in vivo metabolism of 2-nitrofluorene (NF), an environmental pollutant, and 2-aminofluorene (AF) and its acylated derivatives, 2-formylaminofluorene (FAF) and 2-acetylaminofluorene (AAF), was examined in rat and dog. 2. 7-Hydroxy-2-nitrofluorene, 5-hydroxy-2-nitrofluorene, AF, AAF, FAF, 7-hydroxy-2-aminofluorene, 5-hydroxy-2-aminofluorene, 7-hydroxy-2-acetylaminofluorene, 5-hydroxy-2-acetylaminofluorene, 7-hydroxy-2-formylaminofluorene and 5-hydroxy-2-formylaminofluorene were identified as urinary and faecal metabolites of NF in rat and dog. 3. AAF and its hydroxylated derivatives were detected as major metabolites of NF in rat, but FAF and its hydroxylated metabolites were mainly excreted in dog. 4. AF, AAF, FAF and their hydroxylated metabolites were also identified as urinary and faecal metabolites of AF, AAF or FAF in rat, suggesting that AAF and FAF are interconverted via AF. 5. Treatment of rat and dog with antibiotics significantly decreased the urinary and faecal excretion of AF and its derivatives after oral administration of NF, and partly decreased the excretion of acylated metabolites after an oral dose of AF. 6. The caecal contents of untreated rats and some species of intestinal bacteria exhibited nitro-reductase activity toward NF, and acylating activity toward AF, affording AAF and FAF.

[Incidence of systolic pulmonary venous flow reversal in patients with mitral valve prolapse: influence of the prolapse site].

OBJECTIVES: Systolic pulmonary venous flow reversal identified by pulsed Doppler echocardiography is useful for the diagnosis of severe mitral regurgitation. The direction of the mitral regurgitant jet in severe mitral regurgitation significantly influences the systolic pulmonary venous flow reversal in an experimental model. This study investigated the influence of the site of mitral valve prolapse on the incidence of systolic pulmonary venous flow reversal in patients with severe mitral regurgitation using transthoracic color Doppler echocardiography. METHODS: This study included 59 consecutive patients with severe mitral regurgitation (regurgitant fraction > 50%) due to mitral valve prolapse. Exclusion criteria were left ventricular ejection fraction < 45%, non sinus rhythms, associated aortic valve disease, bileaflet prolapse, and inadequate Doppler recordings. Right upper pulmonary venous flow was recorded and regurgitant fraction of mitral regurgitation measured by transthoracic color Doppler echocardiography. The sites of mitral valve prolapse were confirmed at operation in all patients. RESULTS: The incidence of systolic pulmonary venous flow reversal was 78% (14/18) in the patients with anterior leaflet prolapse, 82% (9/11) in the patients with medial commissure prolapse, 75% (12/16) in the patients with posterior middle scallop prolapse, 20% (2/10) in the patients with posterior medial scallop prolapse, and 25% (1/4) in the patients with posterior lateral scallop prolapse. There were no significant differences in regurgitant fraction between the five groups. The incidence of systolic pulmonary venous flow reversal was significantly lower in the patients with posterior medial scallop prolapse compared to the other sites of mitral valve prolapse (p < 0.01). CONCLUSIONS: Assessment of the severity of mitral regurgitation by systolic pulmonary venous flow reversal using transthoracic color Doppler echocardiography may be underestimated in patients with prolapse of the posterior medial scallop.

Chemical states and lattice dynamics of alpha-diimine Fe2+ complexes intercalated into gamma-zirconium phosphate.

The alpha-diimine Fe2+ complexes, [Fe(phen)3]2+, [Fe(bpy)3]2+, and [Fe(terpy)2]2+, (phen: 1,10-phenanthroline, bpy: 2,2'-bipyridyl, terpy: alpha,alpha',alpha''-tripyridine) were intercalated into zirconium dihydrogenphosphate phosphate dihydrate (gamma-zirconium phosphate, gamma-ZrP), Zr(PO4)(H2PO4).2H2O. The rate of the intercalation, the molar ratio of Fe to Zr, was found to be 3.82-7.76%. Mössbauer spectra indicated that one part of [Fe(phen)3]2+ and [Fe(bpy)3]2+ changed from a low-spin Fe2+ to high-spin Fe2+ state on intercalation, but [Fe(terpy)2]2+ did not change in chemical state. The lattice dynamics of the complexes and the intercalation compounds were investigated in terms of the temperature dependence of the area intensity on the Mössbauer spectra. A linear relationship was established for all the complex salts and the intercalation compounds investigated between the ln[A(T)/A(82)] and absolute temperature, T, where A(T) and A(82) show the intensities of a doublet at T and 82 K of the Mössbauer spectra, respectively. From the slope of the linear relation, the theta2M values, which were derived based on the Debye approximation of lattice vibration, were evaluated for the complex salts and the intercalation compounds. The Fe2+ complexes showed theta2M values of 1.27 to 2.32 x 10(6), whereas the intercalation compounds showed very similar values to each other, ranging from 2.19 to 2.39 x 10(6), irrespective of different alpha-diimine ligands. The results were explained in terms of the characteristic layered structure of zirconium phosphate, and by the tight bond between the alpha-diimine Fe2+ complexes and the host gamma-ZrP.

Backscattered electron imaging: A new method for the study of cardiomyocyte architecture using scanning electron microscopy.

Scanning electron microscopy (SEM) with secondary electron emissions is useful for the study of cardiomyocyte architecture, however, the information is limited from the cell surface. Whereas backscattered electron (BSE) emission can give a high-resolution image of the specimen's intracellular structure after heavy metal staining. In this study, we applied BSE imaging analysis to the study of the arrangement of cardiomyocytes in the myocardium. The tissue specimens from a normal fresh monkey heart, normal human heart obtained at autopsy, and surgically resected tissue from a patient with old myocardial infarction in the left ventricular aneurysmectomy were used. The tissue specimens were fixed in neutral formalin, treated with NaOH and then stained with Gomori's silver methenamine reagent followed by tannic acid and osmium tetroxide. After dehydration and drying, the specimens were coated with carbon and examined by SEM with a BSE detector. In the tissue preparations, the A bands of sarcomeres were selectively stained with silver so that the arrangements of subsarcolemmal myofibrils and the intercalated discs were clearly seen in the BSE images. In the left ventricular aneurysmal walls of old myocardial infarction, atrophied cardiomyocytes with disarray of subsarcolemmal myofibrils were observed. The results strongly suggest that BSE images are further applicable to the study of the architecture of cardiac myocytes and their branches, and the arrangement of intracellular myofibrils in various diseased myocardium.

Value of acceleration flow and the prestenotic to stenotic coronary flow velocity ratio by transthoracic color Doppler echocardiography in noninvasive diagnosis of restenosis after percutaneous transluminal coronary angioplasty.

OBJECTIVES: The study evaluated the value of coronary flow velocity measurement by transthoracic color Doppler echocardiography (TTCDE) for the noninvasive diagnosis of restenosis after percutaneous transluminal coronary angioplasty (PTCA) for left anterior descending coronary artery (LAD) lesions. BACKGROUND: Recent advances in TTCDE provide coronary flow velocity measurements in the LAD under the guidance of color flow mapping. METHODS: We studied 53 patients who underwent successful PTCA for LAD lesions and follow-up coronary angiography (18 patients with restenosis [Group-R], 35 patients without restenosis [Group-N]). We searched localized color aliasing corresponding to local flow acceleration to obtain coronary flow velocity at PTCA sites in the LAD. When localized aliasing was detected, we measured coronary flow velocity at the aliasing (stenotic site) and the prestenotic site. RESULTS: Using TTCDE, it was possible to measure mean diastolic velocity (MDV) in the LAD in 41 (77%) of 53 patients (14 of 18 patients in Group-R; 27 of 35 patients in Group-N). Localized aliasing was displayed by color flow mapping in 14 (100%) of 14 patients in Group-R, and 15 (56%) of 27 patients in Group-N. Stenotic MDV in Group-R was significantly higher than that in Group-N (60.3 +/- 21.1 vs. 35.1 +/- 7.6 cm/s, p < 0.01), although prestenotic MDV did not differ between Group-R and Group-N (20.2 +/- 3.0 vs. 19.6 +/- 2.3 cm/s). There were significant differences in the prestenotic to stenotic MDV ratio between Group-R and Group-N (0.36 +/- 0.10 vs. 0.57 +/- 0.09, p < 0.001). Localized aliasing with the prestenotic to stenotic MDV ratio <0.45 as the optimal cutoff value had a sensitivity of 86% and a specificity of 93% for the presence of restenosis in LAD lesions. CONCLUSIONS: Detection of localized color aliasing and measurement of the prestenotic to stenotic MDV ratio in the LAD by TTCDE are useful in the noninvasive diagnosis of restenosis after PTCA for LAD lesions.

[Measurement of left ventricular filling by automated contour tracking method in echocardiography: comparison with radionuclide ventriculography].

Recent development of an automated contour tracking (ACT) method using the energy minimization principle provides automated edge detection and tracking of the endocardial boundary of the left ventricle, without tracing a region of interest. This study determined whether left ventricular filling indexes obtained from the ACT method provide a reliable estimate of left ventricular diastolic filling. Fourteen patients were examined by the ACT method and equilibrium radionuclide ventriculography. The volume-time wave form for ACT measurements was obtained from the 4-chamber views. Peak filling rate and time to peak filling rate measured by the ACT method were compared with those determined by radionuclide ventriculography. Peak filling rate and time to peak filling rate by the ACT method were closely correlated with those determined by radionuclide ventriculography (peak filling rate: r = 0.88, y = 0.71x + 0.36, SEE = 0.54 ml/end-diastolic volume/sec, time to peak filling rate: r = 0.89, y = 0.72x + 30.0, SEE = 0.02 msec, respectively) The ACT method is useful for the assessment of left ventricular diastolic filling.

[Evaluation of mitral valve lesions in patients with infective endocarditis by three-dimensional echocardiography].

Recognition of the involved lesions is extremely important in mitral valve repair for infective endocarditis. Transesophageal echocardiography (TEE) is more sensitive for the detection of lesions than transthoracic echocardiography, but localization of the lesions is sometimes difficult by TEE. Three-dimensional (3D) TEE provides images of the mitral valve similar to the view from the left atrium. This study evaluated the value of 3D echocardiography for the diagnosis of involved lesions in 12 patients who underwent surgery for mitral regurgitation due to infective endocarditis. The location of the lesion in the mitral valve was classified as the medial, central and lateral portions of the anterior leaflet, and the medial, middle and lateral scallops of the posterior leaflet, respectively. In all patients, the involved sites were confirmed at operation. The sensitivities of 3D TEE for detecting the lesions at the medial, central and lateral portions of the anterior leaflet, and the medial, middle and lateral scallops of the posterior leaflet were 100%, 78% and 67%, and 100%, 100% and 100%, respectively. The specificities were 90%, 100% and 78%, and 100%, 100% and 100%, respectively. The lesions diagnosed by 3D TEE coincided with lesions confirmed at operation in 23 (92%) of 25 lesions. 3D TEE is useful for the assessment of the involved lesion of the mitral valve in patients with infective endocarditis.

[Blood conservation effect and safety of shed mediastinal blood autotransfusion after cardiac surgery].

Autotransfusion of shed mediastinal blood after cardiac surgery has been used to reduce risks related to homologous blood transfusions. To document the efficacy and safety of autotransfusion, we compared clinical findings of 80 patients receiving shed mediastinal blood (autotransfusion group) with those of the control group of 52 patients. The amount of the autotransfusion was limited to 800 ml, given the potentially harmful effects of shed blood transfusion. The mean transfused shed volume was 314 +/- 236 ml (S.D.). The serum levels of FDP-E, D-dimer and TAT after autotransfusion were higher in the autotransfusion group than in the control group (p = 0.01, p = 0.0004, p = 0.001, respectively). However, postoperative blood loss and the rate of reexploration for bleeding were similar in the two groups. The patients receiving blood products were fewer in the autotransfusion group than those in the control group (21% vs 44%; p = 0.005). Autotransfusion did not increase postoperative complications, including infection. Thus, although autotransfusion of mediastinal shed blood has the potential to affect hemostasis, unless the amount of autotransfusion exceeds 800 ml, it appears that this method is clinically safe and effective as a mean of blood conservation.

[Early repair of ventricular septal rupture in patients over 80 years of age: infarction exclusion technique].

Since 1994, three patients more than 80 years of age underwent early repair of ventricular septal rupture complicating acute myocardial infarction at our hospital. The infarction exclusion technique introduced by David and Komeda was employed. Average aortic clamp time, cardiopulmonary bypass time and operation time were 83 minutes, 129 minutes and 228 minutes, respectively. No hemostatic suture were required to the left ventricular suture line. All patients survived. One patient with posterior ventricular septal rupture had residual shunt and necessitated transient hemodialysis but recovered. Thus, the infarction exclusion technique seems to be useful in the elderly with unfavorable tissue fragility.

Angioimmunoblastic lymphadenopathy-like T-cell lymphoma. A case report and immunologic study.

BACKGROUND: Angioimmunoblastic lymphadenopathy (AILD) is rare in the head and neck and its definition remains controversial. METHOD: A case of AILD with an ulcer of the lateral pharyngeal wall was studied for viral infection, immunohistologic findings and T-cell receptor (TCR) V beta rearrangement. RESULTS: We observed elevation of antibodies against herpes simplex virus and herpes zoster virus as well as Epstein-Barr virus considered closely associated with AILD. The affected neck lymph node showed a preponderance of T-cells, predominantly CD4+ over CD8+ T-cells and all V beta gene families were expressed in the T-cells without enhancement of any particular TCR gene usage. CONCLUSION: Viral infection may occur easily in patients with AILD, possibly owing to immunodeficiency. Assessment of TCR V beta gene usage indicated T-cells to non-specifically become lymphomatous in AILD-like T-cell lymphoma.

[A case of extracardiac noncoronary sinus Valsalva aneurysm associated with aortic regugitation].

A case of extracardiac noncoronary sinus Valsalva aneurysm was reported. A 11-year-old male with history of mild AR was admitted to the hospital due to severe AR. Echocardiography revealed that the severe AR and an aneurysm in the posterior part of the ascending aorta. Angiography revealed that the origin of the aneurysm was noncoronary sinus. Operative findings showed that the aneurysm sized 23 mm by 25 mm was an extracardiac type which grew posteroinferiorily at the left side of noncoronary sinus and that the dilation. Neither aortic valve nor the aortic route showed degenerative change. The ptosis of the valvular ring due to aneurysmal dilation of the noncoronary sinus caused AR. Then, valve repair composed by commissuroplasty and commissural suspension was carried out. And intraluminal patch closure technique in which the longitudinal diameter of patch was half of that of the aneurysm was effective on suspension of the valvular ring. Postoperative echocardiography showed decreasing of AR.