[en] Absence of spleen in its normal location on echocardiogram. Associated anomaly: Congenital heart disease of coexisting atrial and ventricular septal defect, right sided aorta, drainage of azygous vein into superior vena cava.

[en] It is difficult to determine the activity of tuberculosis radiologically. Therefore there have been efforts to assess the activity using radiopharmaceuticals such as ⁶⁷Ga, ^99mTc-tetrofosmin, and ^99mTc-MIBI. But there may be some discrepancy in difining the term 'activity' between clinicians and nuclear physicians. While negative conversion of sputum acid fast bacilli (AFB) is defined as 'disappearance of activity' by clinicians, a loss of uptake in previously positive lesion is accepted as 'disappearance of activity' by nuclear physicians. We designed a prospective study to see if the negative conversion of sputum AFB could directly match the disappearance of radioactivity of the lesion. Fifteen patients with bacteriologically confirmed active localized pulmonary tuberculosis were scanned 10 and 60 min after intravenous injection of 550 MBq ^99mTc-MIBI. In 6 patients, who showed negative conversion of sputum AFB after 3-7 months of chemotherapy, ^99mTc-MIBI scan was repeated. For the purpose of comparison, target/nontarget raitos of the lesions were determined. 12/15 (80%) patients with active pulmonary tuberculosis showed increased uptake of ^99mTc-MIBI in tuberculous lesion. After negative conversion of sputum AFB, 5/6 (83%) patients still showed increased uptake, although the intensity of uptake decreased. Uptake of radioactivity decreased but did not disappear after negative conversion of sputum AFB. ^99mTc-MIBI scan may be useful to address the degree of inflammation of pulmonary tuberculous lesion, but the uptake did not directly match the activity defined by positivity of sputum AFB. We nuclear physicians might have used the term 'activity' somewhat differently from clinicians who treat patients with tuberculosis

[en] Myocardial perfusion scintigraphy is a useful technique to diagnose and to predict prognosis in patients with suspected or known coronary artery disease. The purpose of the present study is to evaluate the prognostic value of normal exercise ^99mTc-MIBI myocardial perfusion single photon emission computed tomography (SPECT) and to analyze results with regard to those of exercise electrocardiography or coronary angiography. We evaluated 301 patients (mean age 52±10 years, 166 males and 135 females) with normal exercise ^99mTc-MIBI myocardial perfusion SPECT performed for suspected coronary artery disease. Subjects were evaluated for cardiac events and followed for 8-55 months (mean 19±10 months) after imaging. During the follow-up period, there was no cardiac death but only one non-fatal myocardial infarction (event rate 0.21% per year). In addition, only one patient underwent coronary revascularization. There was no significant difference in cardiac event rate between patinets with positive (n=3D27) and negative (n=3D235) exercise electrocardiography (p:NS). There was no cardiac event in 17 patients who underwent coronary angiography (4 patients with >50% luminal narrowing, 2 patients with vasospasm and 11 patients with no significant lesion). Patients with normal exercise ^99mTc-MIBI myocardial perfusion SPECT has a very low risk for cardiac events regardless of exercise electrocardiographic and coronary angiographic findings.=20

[en] The aim of this study is to better understand the pattern and nature of reverse redistribution (RR) in myocardial perfusion imaging. In consecutive 20 acute myocardial infarction (MI) patients, frequency of RR was correlated with that of subendocardial MI that was detected by myocardial contrast echocardiography (MCE). RR was judged to be present when there was more than one grade of worsening in perfusion at 24 hr delayed images compared with the initial rest images. MCE evaluated the significant lack of opacification in the subendocardial myocardium relative to the subepicardial myocardium to suggest the subendocardial MI. Kendall's nonparametric correlation coefficiency was calculated. Concordant cases were 15 of 20 (75%) and correlation was statistically significant (p=3D0.0285). Our results suggested that RR was correlated with MCE-detected nontransmural MI. =20

[en] Re-188-Hydroxyethylidene diphosphonate (HEDP) is a new cost-effective agent for systemic radioisotope therapy of metastatic bone pain. We investigated the influence of carrier for labeling and biodistribution of Re-188-HEDP using HEDP kit with or without carrier (KReO₄). The kits (HEDP 15 mg, gentisic acid 4 mg and SnC1₂.2H₂O 4.5 mg) with or without carrier (KReO₄ 0.1 mg) were labeled with Re-188 solution, made available from an in-house generator by boiling for 15 min. We compared the labeling efficiency and stability of carrier-added and carrier-free preparations of Re-188-HEDP. Biodistribution and imaging studies of each preparation were performed in ICR mice (1.85-3.7 MBq/0.1 ml) and SD rats (74.1-85.2 MBq/0.5 ml). The carrier-added preparation showed high labeling efficiency (95% at pH 5) and high stability in serum (88%, 3hr). However, the carrier-free preparation showed low labeling efficiency (59% at pH 5) and low stability (43%, 3 hr). The carrier-added preparation showed high uptake in bone and low uptake in stomach and kidneys. However, the carrier-free preparation showed lower uptake in bone and higher uptake in both stomach and kidneys, which is supposed to be due to released perrhenate. The carrier-added preparation also showed better images with higher skeletal accumulation, lower uptake in other organs and lower soft tissue uptake than the carrier-free preparation. The results of these studies clearly demonstrate that addition of carrier perrhenate is required for high labeling efficiency, stability, bone uptake and good image quality of Re-188-HEDP.=20

[en] We present a case in which a patient with acute hemorrhagic gastritis demonstrated abnormal gastrointestinal accumulation of radiotracer during ^99mTc-methylene diphosphonate (MDP) skeletal scintigraphy. A hemorrhagic gastritis was subsequently demonstrated by endoscopy. The mechanism for the intestinal localization of ^99mTc-MDP in this patients is not clear, but we guess that the extravasated blood containing the radiopharmaceutical cannot recirculate and stays at the bleeding site, so we can see the intestinal activity

[en] We measured pulmonary epithelial permeability by ^99mTc-DTPA radioaerosol clearance in patients with diabetes and correlated with the presence of microangiopathy to understand the pathophysiology of pulmonary microangiopathy and evaluate ^99mTc-DTPA radioaerosol clearance as a diagnostic test to assess pulmonary microangiopathy. We performed ^99mTc-DTPA radioaerosol scan in 10 normal subjects, 10 asymptomatic smokers, 20 diabetic patients without history of smoking (10 with microangiopathy, 10 without microangiopathy). ^99mTc-DTPA clearance half-time (T_1/2) was calculated, then compared with the result of chest radiography and pulmonary function test. Chest radiography and pulmonary function test were normal in all subjects. There were no significant difference of clinical or laboratory characteristics between these groups except age. The diabetic patients with microangiophaty were significantly older (p<0.05). The T_1/2 of normal subjects and asymptomatic smokers were significantly different (65.2±23.7 min vs 39.6±9.8 min, p<0.05). For diabetic patients with microangiopathy, the T_1/2 was 90.5±46.5 min and significantly delayed when compared with those of normals and asymptomatic smokers (p<0.05). However, the T_1/2 of diabetic patients without microangiopathy, 70.0±12.7 min, was not significantly different from those of normals or asymptomatic smokers (p>0.05). No significant correlation was found between the T_1/2 and spirometric parameters including DLco, FVC, FEV₁, FEV₁/FVC (%) and FEF_25-75% in all subjects, and between the T_1/2 and duration of diabetes in diabetic patients. Eventhough the influence of age can't be excluded, delayed ^99mTc-DTPA clearance half-time (T_1/2) in diabetic patients with microangiopathy indicates decreased pulmonary capillary permeability as one of the pathophysiologic results of pulmonary microangiopaththy. Further studies are needed in larger number of age matched control and diabetic patients to evaluate the diagnostic efficacy

[en] This study investigated the method to adjust acquisition time (a) and injection dose (i) to make the best basal and subtraction images in consecutive SPECT. Image quality was assumed to be mainly affected by signal to noise ratio (S/N). Basal image was subtracted from the second image consecutively acquired at the same position. We calculated S/N ratio in basal SPECT images (S₁/N₁) and subtraction SPECT images (Ss/Ns) to find a (time) and i(dose) to maximize S/N of both images at the same time. From phantom images, we drew the relation of image counts and a (time) and i(dose) in our system using fanbeam-high-resolution collimated triple head SPECT. Noise by imaging process depended on Poisson distribution. We took maximum tolerable duration of consecutive acquisition as 30 minutes and maximum injectible dose as 1,850MBq(50 mCi) (sum of two injections) per study. Counts of second acuquired image (S₂), counts(S_s) and noise(N_s) of subtraction SPECT were as follows. C₁ was the coefficient of measurement with out system. S₂=S₁·(30-a/a)+background ·(1-(30-a/a))+C₁·(30-a)·ε·(50-i) S_s=S₂-{S₁·(30-a)/a)+background ·(1-(30-a)/a)} N_s=√N₂²+N₁²·(30-a)²/a²=√S₂+S₁·(30-a)²/a² In case of rest/acetabolamide study, effect (ε) of acetazolamide to increase global brain uptake of Tc-99m-HMPAO could be 1.5 or less. Varying ε from 1 to 1.5, a(time) and i(dose)pair to maximize both S₁/N₁ and S_s/N_s was determined. 15 mCi/17 min and 35mCi/13min was the best a (time) and i(dose) pair for rest/acetazolamide study (when ε were 1.2) and came to be used for our clinical routine after this study

[en] Cancer tissues are characterized by increased glucose uptake. ¹⁸F-fluorodeoxyglucose(FDG), a glucose analogue is used for the diagnosis of cancer in PET studies. This study was aimed to compare the glucose uptake and glucose transporter 1(GLUT1) expression in various human colon cancer cells. We measured FDG uptake by cell retention study and expression of GLUT1 using Western blotting. Human colon cancer cells, SNU-C2A, SNU-C4 and SNU-C5, were used. The cells were incubated with 1μ Ci/ml of FDG in HEPES- buffered saline for one hour. The FDG uptake of SNU-C2A, SNU-C4 and SNU-C5 were 16.8±1.36, 12.3±5.55 and 61.0±2.17 cpm/μg of protein, respectively. Dose-response and time-course studies represent that FDG uptake of cancer cells were dose dependent and time dependent. The rate of FDG uptake of SNU-C2A, SNU-C4 and SNU-C5 were 0.29±0.03, 0.21±0.09 and 1.07±0.07 cpm/min/μg of protein, respectively. Western blot analysis showed that the GLUT1 expression of SNU-C5 was significantly higher than those of SNU-C2A and SNU-C4. These results represent that FDG uptake into human colon cancer cells are different from each other. In addition, FDG uptake and expression of GLUT1 are closely related in human colon cancer cells

[en] For the purpose of using Re-188 as a therapeutic radionuclide, we performed the quality control of the W-188/Re-188 generator system. Several quality control tests of the Re-188 eluate from generator were carried out for about 300 days. After elution of Re-188 with normal saline (20 ml), chromatogram and gamma-ray spectrum of Re-188 eluate were obtained. The presence of aluminum which was derived from the alumina bed of the generator was detected by using aluminum ion indicator kit. Re-188 eluate was allowed to decay for several days, and then W-188 breakthrough in the Re-188 eluate was measured by detecting gamma-ray at 227 keV and 290 keV. The pH and the pyrogenicity of the eluate were checked. The Re-188 bolus was concentrated with ion exchange columns. The radioactivity of Re-188 eluate from the generator was 67.4±7.0% of W-188 during 270 days, and it was highest at third day after previous elution. Radiochemical purity of Re-188 eluate obtained from chromatogram was higher than 99%. Gamma-ray spectrum of Re-188 eluate showed a peak at 155 keV. Aluminum ion and W-188 contamination were not detected. The pH of Re-188 eluate was 3 and the concentration yield was 85%. Our experiments and results on quality control tests of Re-188 eluate from W-188/Re-188 generator may be useful for setting W-188/Re-188 generator in hospitals