[en] The complications of pancreatitis, such as pseudocyst or abscesses, are well known to radiologists. Yet formation of a pseudoaneurysm of the short gastric artery is an uncommon complication of acute pancreatitis. It is also very rare for a psuedoaneurysm of the short gastric artery to cause splenic vein occlusion and the final result is gastric varices. We report here on a case that showed the dramatic effect of embolotherapy for a pseudoaneurysm of the short gastric artery that caused gastric variceal bleeding

[en] The creep crack growth properties in 3.5NiCrMoV steel were investigated at 550 .deg. C by using CT specimen under constant C_t condition that was held during crack growth of 1mm distance. C_t lely on load line displacement rate and C^* usually increase with crack length though load is reduced in order to maintain constant C_t value as crack growth. Fully Coalesced Area(FCA) ahead of crack tip tend to increase as C_t increase to the critical value, and after that value FCA decrease. For the tertiary creep stage of crack growth test, the most of displacement is due to the steady state creep, except only small part due to the primary creep and other effects. Therefore, tests were mainly interrupted in the tertiary stage to obtain high value of C_t. At constant load and C_t region, crack growth slope was 0.900 and 0.844 each, on the other hand C^* slope was 0.480

[en] Various programs have been developed for gating of myocardial perfusion SPECT. Among the those program, the most popular program is the Quantitative Gated SPECT (QGS)? developed by Cedars-Sinai hospital and most recently released program is 4D-MSPECT? developed by university of Michigan. It is important to know the reference range of the functional data of gated myocardial perfusion SPECT because it is necessary to determine abnormality of individual patient and echocardiographic data is different from those of gated SPECT. Tc-99m MIBI gated myocardial perfusion SPECT image was reconstructed by dual head gamma camera (Siemens, BCAM, esoft) as routine procedure and analyzed using QGS? and 4D-MSPECT? program. All patients (M: F=9: 18, Age 69±9 yrs) showed normal myocardial perfusion. The patients with following characteristics were excluded: previous angina or MI history, ECG change with Q wave or ST-T change, diabetes melitius, hypercholesterolemia, typical chest pain, hypertension and cardiomyopathy. Pre-test likelihood of all patients was low. (1) In stress gated SPECT by QGS?, EDV was 73±25 ml, ESV 25±14 ml, EF 67±11 % and area of first frame of gating 106.4±21cm². In rest gated SPECT, EDV was 76±26 ml, ESV 27±15 ml, EF 66±12 and area of first frame of gating 108±20cm². (2) In stress gated SPECT by 4D-MSPECT?, EDV was 76±28 ml, ESV 23±16 ml, EF 72±11 %, mass 115±24 g and ungated volume 42±15 ml. In rest gated SPECT, EDV was 75±27 ml, ESV 23±12 ml, EF 71±9%, mass 113±25g and ungate dvolume 42±15 ml, (3) s-EDV, s-EF, r-ESV and r-EF were significantly different between QGS? and 4D-MSPECT? (each p=0.016, p<0.001. p=0.003 and p=0.001). We determined the normal reference range of functional parameters by QGS? and 4D-MSPECT? program to diagnose individually the abnormality of patients. And the reference ranges have to adopted to be patients by each specific gating program

[en] Myocardial perfusion is altered significantly in patients with rhythm disturbances such as CLBBB and right ventricular pacing rhythm. Abnormal myocardial perfusion may be caused by ventricular preexcitation, but its location, extent, severity and correlation with accessory pathway (AP) are not established. We evaluated perfusion patterns on SPECT in patients with WPW syndrome. Adenosine Tc-99m MIBI or Tl-201 myocardial SPECT with or without coronary angiography were performed in 11 patients with WPW syndrome. Perfusion defects (PD) were compared to AP location based on ECG or electrophysiologic study. Small to large extent (11.0 8.5%, range: 0 35%) and mild to moderate severity (-71.8 42.7%, range: -217 0%) of reversible (n=9) or fixed (n=1) perfusion defects were noted. One patient with right free wall AP showed normal. Other defect locations were as follows. Myocardial perfusion defect showed variable extent, severity and location in patients with WPW syndrome. It was not specifically correlated with location of accessory pathway, but most of all patients were abnormal perfusion pattern. Therefore myocardial perfusion SPECT was interpreted carefully in patients with WPW syndrome

[en] Abnormal myocardial perfusion may be caused by ventricular preexcitation, but its location, extent, severity and correlation with accessory pathway (AP) are not established. We evaluated perfusion patterns on myocardial perfusion SPECT and location of AP in patients with WPW (Wolff-Parkison-White) syndrome. Adenosine Tc-99m MIBI or Tl-201 myocardial perfusion SPECT was performed in 11 patients with WPW syndrome. Perfusion defects (PD) were compared to AP location based on ECT with Fitzpatrick's algorithm of electrophysiologic study and radiofrequency catheter ablation. Patients had atypical chest discomfort or no symptom. Risk of coronary artery disease (CAD) was below 0.1 in 11 patients using the nomogram to estimate the probability of CAD. Coronary angiography was performed in 4 patients(mid-LAD 50% in one, normal in others). In 4 patients, AP localization was done by electrophysiologic study and radiofrequency catheter ablation (RFCA). Small to large extent (11.0 ± 8.5%, range:3 ∼ 35%) and mild to moderate severity (-71 ± 42.7%, range:-217 ∼ -39%) of reversible (n=9) or fixed (n=1) perfusion defects were noted. One patients with right free wall (right lateral) AP showed normal. PD locations were variable following the location of AP. One patient with left lateral wall AP was followed 6 weeks after RFCA and showed significantly decreased PD on SPECT with successful ablation. Myocardial perfusion defect showed variable extent, severity and location in patients with WPW syndrome. Abnormal perfusion defect showed in most of all patients, but if did not seem to be correlated specifically with location of accessory pathway and coronary artery disease. Therefore myocardial perfusion SPECT should be interpreted carefully in patients with WPW syndrome

[en] Silicon nitride/silicon-rich-oxide (SiN/SRO) superlattices were fabricated by using dual ion-beam sputtering deposition. The effect of the SiN/SRO interface on the optical properties of the Si nanocrystals precipitated in the SRO layers was investigated by means of time-resolved photoluminescence measurements. The decay times of the photoluminescence for all superlattices were in the range of 20 ns - 160 ns. Such small decay times reflect the strong effect of the non-radiative recombination centers existing at the SiN/SRO interfaces. For superlattices with thinner SRO thicknesses, the decay times were smaller for all detection wavelengths due to the increasing effect of the non-radiative recombination centers.

[en] The objectives of this study were-First, to determine the normal range of left ventricular end diastolic volume (EDV), end systolic volume (ESV) and ejection fraction (EF) from gated myocardial perfusion SPECT for Quantitative Gated SPECT (QGS) and 4D-MSPECT (4DM), respectively. Second, to evaluate the relationships between values produced by both software packages. Tc-99m MIBI gated myocardial perfusion SPECT were performed for 77 patients (mean age: 49.6 ± 13.7y, n=37(M), 40(F)) with a low likelihood (<10%) of coronary artery disease (CAD) using dual head gamma camera (E.CAM, Siemens, USA). Left ventricular EDV, ESV and EF were automatically measured by means of QGS and 4DM, respectively. In QGS, the mean EDV, ESV and EF for all patients were 78.2 ± 25.2ml, 27.4 ±12.9ml and 66.6 ± 8.0% at stress test respectively, not different from rest test (ρ >0.05). In 4DM, the mean EDV, ESV and EF for all patients were 89.1 ± 26.4ml, 29.1 ± 12.8ml and 68.5 ± 6.7% at stress test. Most cases in 4DM, there was no significant difference statistically between stress and rest test (ρ >0.05). But statistically significant difference was found in EF (68.5 ± 6.7% at stress vs 70.9 ± 8.0% at rest, ρ <0.05). Correlation coefficients between the methods for EDV, ESV and EF were comparatively high (0.95, 0.93, 0.71 at stress test and 0.95, 0.90, 0.69 at rest test, respectively). However, Bland-Altman plots showed a large range of the limit value of agreement for EDV, ESV and EF between both methods (-30ml ∼ 10ml, -12ml ∼ 8ml, -14% ∼ 11% at stress test and -32ml ∼ 5ml, -13ml ∼ 13ml, -18% ∼ 12% at rest test). We found the normal ranges of EDV, ESV and EF for patients with a low likelihood of CAD in both methods. We expect these values will be a good reference to interpret gated myocardial perfusion SPECT. Although good correlation was observed between both methods, they should not be used interchangeably. Therefore, when both programs are used at the same site, it will be important to apply normal limits specific to each method

[en] Pheochromocytoma occurs at all ages but is most common in young to mid adult life. In adults 10 percent of pheochromocytoma are bilateral. And bilateral lesions are common in the familial syndromes; within Multiple Endocrine Neoplasia (MEN) kind reds over half with pheochromocytomas have bilateral lesions. We report a case of bilateral pheochromocytoma firstly detected by ultrasonogram. This 24-year-old male was normotensive and had symptoms of dilated cardiomyopathy and elevated VMA level. CT and MRI were performed to evaluate the tissue nature and associated abnormalities. ¹³¹I-MIBG scan seems to be the imaging of choice in patients with suspected multi centric/bilateral or recurrent or metastatic pheochromocytomas.

[en] Spherically symmetric static solutions of the ''purely'' quadratic Lagrangian' model which is one of the U₄-theories of gravity with dynamic torsion are studied. The arguments for quark confinement interpretation of the solutions are discussed. For the covariantized Dirac equation in the spherically symmmetric background, the separation of variables is achieved and thus the radial equations are derived. (Author)

[en] The electroluminescence (EL) properties of metal-oxide-semiconductor (MOS) devices employing nanocrystal Si/SiO₂ superlattices are investigated. The amorphous silicon-rich oxide/SiO₂ superlattices are grown by using rapid thermal chemical vapor deposition. During high-temperature annealing at 1100 .deg. C, Si nanocrystals are precipitated. Despite the simple MOS structure, the device shows conventional diode behavior in the current-voltage characteristics. We observe EL only under the forward bias condition, and the turn-on voltage is as low as 8 V. The EL intensity increases with increasing bias and is saturated over 11 V. We observe a systematic blueshift of the EL with increasing applied bias. Therefore, the observed EL is attributed to radiative recombination of carriers confined in the Si nanocrystals.