The occurrence of thyroid disorders is connected with iodine deficiency, defective synthesis or releasing of thyroid hormone and endemicity. Genetic factors are known as a single gene defects, interaction of multiple genes with environmental factors, as well as chromosomal aberrations. Diofnosis thyroid disorders is enforced by I-131 uptake test, thyroid scanning with I-131 or Tc-99 m and serum radioimmunoassays of T3, T4, free T4 and TSH. They were largely classified as hypothyroidism, hyperthyroidism, simple goiter and normal. The pedigree of 58 families was drawn by propositus, and then the correlation between thyroid disorders and TSH levels was analyzed. The results are as follows: 1) The offsprings and their mothers of 15 families were hypothyroidism, THS level was 5 folds for offsprings and 4 folds for mothers in comparison with control group. 2) 13 families were hyperthyyroidism in siblings but their mothers were normal in thyroid function, TSH level of the siblings was lower than control group. 3) Though the offsprings and their mothers of 10 families were similar to TSH level of control group, they are all simple goiter, familial thyroid disorders, in other thyroid function test. The familial thyroid disorders suggested that these transmitted from mothers to offsprings with X-linked dominant or autosomal dominant inheritance.

The pain, swelling of salivary glands and dry mouth are not infrequent complication of the high dose radioiodine treatment in the patients with differentiated thyroid cancer. The purpose of this study was, by the dynamic salivary scintigraphy, to observe the change of the salivary function after the high dose $(150\sim200mci)$ radioiodine treatment. From May 1987 to April 1988, the dynamic salivary scintigraphy with 5mci of $^{99m}Tc-pertechnetate$ and gamma camera was performed before and 7 days after the radiolodine treatment in 7 patients with differentiated thyroid cancer. Just after the dynamic scintigraphy, the stimulation test with vitamin C solution of pH3.0 and poststirnulation scintigraphy were done, and the radioactivity uptake index, excretion fraction and salivary clearance after the stimulation were calculated for each gland. There was positive correlation between the radioactivity uptake index and excretion fraction after the stimulation. The salivary clearance after the stimulation was $18.96{\pm}8.95ml/min$ in the pretreatment state, and $14.37{\pm}7.7ml/min$ after the radioioine treatment. After the radioiodine treatment, the radioactivity uptake index, excretion fraction and salivary clearance after the stimulation were significantly reduced in the parotid glands, but only the excretion fraction was reduced in the submandibular glands. The more the pretreatment salivary clearance after the stimulation was, the % change after the treatment was smaller. Further studies on the relation between the radiation dose in the salivary glands and the change of their function, and the long-term observation for the recovery of function are expected.

To evaluate diagnostic accuracy of $^{99m}Tc-pyrophosphate$ (PYP) myocardial scan, we analysed 160 $^{99m}Tc-PYP$ scans (acute transmural myocardial infarction 87 cases, acute subendocardial infarction; 20 cases, unstable angina pectoris; 7 cases, other disease; 46 cases). These scans were requested by the physician in Seoul National University Hospital from Sep. 1982 to Oct. 1987. And the diagnosis was confirmed by clinical course and laboratory examinations. 1) The diagnostic sensitivity of $^{99m}Tc-PYP$ scan in acute transmural myocardial infarction was 91.2% (62/68) if scintigraphy was performed within 7 days after infarction, 57.1% (8/14) between 8th and 14th day, 20% (1/5) and after 15 days. 2) The diagnostic sensitivity of $^{99m}Tc-PYP$ scan in acute subendocardial infarction was 75% (12/16) if scintigraphy was performed within 7 days after infarction and 0% after 8 days. 3) The diagnostic specificity of $^{99m}Tc-PYP$ scan in acute myocardial infarction was 94.3% (5/53). Among 5 cases of false positive scans, 1 case was unstable angina pectoris, 2 cases were old myocardial infarction with left ventricular aneurysm, 1 case was old myocardial infarction and the remaining 1 case was cardiomyopathy.

To assess the usefulness of myocardial SPECT imaging to detect post-myocardial infarction ventricular aneurysms, we analyzed the Technetium-99m MIBI myocardial SPECT images of 16 patients with anterior and/or apical infarction, 9 had the previously reported findings of failure of convergence of the left ventricular walls toward the apex on SPECT images and 8 of them also had ventricular aneurysms. The ventriculography of the 2 patients with mixed pattern revealed 1 case of ventricular aneurysm and 1 case without aneurysm. Among the remaining 5 pateints with converging pattern, none had ventricular aneurysm. Of the other 11 pateints with inferior and/or lateral wall infarction, 1 patient had ventricular aneurysm and the SPECT image couldn't detect the aneurysm. $Department of Internal Medicine, College of Medicine, Seoul National University$ myocardial SPECT images for the detection of ventricular aneurysm had a sensitivity of 90 %, a specificity of 88%, and an accuracy of 89%. Thus we could get the information about presence of ventricular aneurysm as well as the status of the myocardial perfusion from the Tc-99m MIBI myocardial SPECT images.

The relationship between angiographic findings and those of $^{67}Ga$ scan was evaluated in 30 patients with primary hepatocellular carcinoma diagnosed by either pathological examination or laboratory, radiologic findings. Twenty-three cases revealed hot activities on $^{67}Ga$ scan and definite tumor stains on angiography. Main findings of $^{67}Ga$ scans of 7 cases were isoactivity in 5 and cold area in 2, 5 of which revealed faint or no tumor stain on angiography. Cold areas within the primary hepatocellular carcinoma were noted in 9 cases by $^{67}Ga$ scan. In 6 cases these were due to tumor necrosis. Remaining 3 cases had arterioportal shunt, portal vein thrombosis and one had necrosis as well. These results indicate that gallium uptake of primary hepatocellular carcinoma seems to be relatively correlated with tumor stains on angiography. It is well known that the necrotic portion of primary hepatocellular carcinoma does not uptake gallium and it's the main cause of cold areas on $^{67}Ga$ scan. And we suspect that the hemodynamic changes of primary hepatocellular carcinoma such as large arterioportal shunt, portal vein thromosis may cause the decreased activity on $^{67}Ga$ scan.

The "rim sign" is a rim of increased hepatic activity adjacent to the gall bladder fossa and known as an useful indicator of acute cholecystitis. Also, many reports suggested that if rim sign is positive there is an increased risk for complications such as perforation and gangrene. To evaluate the usefulness of this rim sign, we reviewed 32 cases that were pathologically confirmed. The incidence of rim sign was 47% similar to other reports but with our results, the rim sign was not specific to acute cholecystitis nor indicator of increased risk for complications.

$^{99m}Tc-Pertechnetate\;(TcO_4^-)$ is concentrated by the stomach after intravenous injection, allowing the detection of ectopic gastric mucosa. It has been used to develop a noninvasive test of gastric secretion. However the cellular site of concentration is still controversial, that is whether mucin-secreting epithelial cell or acid-secreting parietal cell. This study is planned to investigate the effects of cimetidine and gastric acidity on the retention of $TcO_4^-$ in the gastric wall of the rat. Also we further attempted to clarify the uptake and secreting cell of $TcO_4^-$ in the gastric mucosa. One hundred rats were divided into two groups, preliminary (40 rats) and main examination group (60 rats). Preliminary examination group was composed of fasting group (20 rats) for the detection of the time for reaching stable $TcO_4^-$ retention ratio in gastric wall and post-prandial group (20 rats) for the detection of the time for reaching the maximal gastric acidity. Main examination group was composed of fasting group (30 rats), which was subdivided into control group (10 rats), cimetidine group (10rats), $Mylanta^{(R)}$ group (10 rats) and post?prandial group (30 rats), which was subaivided into 90 min group (10 rats), 90 min cimetidine group (10 rats), and 120 min group (10 rats). Retention ratio (%) of $TcO_4$ in the gastric wall and the pH of the gastric contents were measured in the extracted stomach of the six groups. Gastric wall retention ratio of $TcO_4^-$ was calculated by the gastric wall radioactivity (cpm) divided by total gastric radioactivity (cpm) at 30 mins after intravenous injection of 0.4 mCi of $TcO_4^-$. The results were as follows: 1) The time required for reaching stable $TcO_4$ retention ratio and the lowest gastric PH were 30 min and 90 min, respectively. 2) In the fasting group, the gastric wall retention ratio of $TcO_4^-$ was significantly increased in the cimetidine group, compared with the control group (P < 0.01). However there was no significant difference between the control and $Mylanta^{(R)}$ group 3) The $TcO_4^-$ retention ratios of 90 min and 120 min groups were lower than that of the fasting control group (p < 0.05), either. After administration of cimetidine, the retention ratio was significantly increased in 90 min group (p < 0.01). 4) While $TcO_4^-$ retention ratio and gastric pH were well correlated in the post-prandial 120 min group (r=0.7112, p<0.05), in the post-prandial 90 min and 90 min cimetidine groups correlated poorly. However, there was no correlation in the three fasting groups at all. Referring the above results, we infer that $TcO_4^-$ is secreted into the gastric lumen by both parietal and non-parietal cells, with dominant non-parietal $TcO_4^-$ secretion in the fasting state and dominant parietal $TcO_4^-$ secretion in the stimulated state.

Many previously described nuclear medicine procedures to assess glomerular filtration rate (GFR) required numerous blood samples obtained over a period of several hours to determine plasma concentrations of the injected radiopharmaceuticals. And other indirect methods of determining renal clearance have some problems due to individual variations in volume of distribution of the radionuclides used. Rescently reported Jackson's method have the great advantages that is a direct measurement method requiring less than 40 min of imaging time and single blood sampling. And it correctly accounts for individual variations in volume of distribution of the radiopharmaceuticals and can be done with routine renal scintrgraphy. We measured $^{99m}Tc-DTPA$ renal clearance with Jackson's method during the routine $^{99m}Tc-DTPA$ renal scintigraphy in 63 patients admitted to department of internal medicine in SNUH. In 23 cases among 63 patients creatinine clearence was accounted simultaneously. The range of $Cl_{DPDA}$ was from 19.9 ml/min to 170 ml/min and the correlation of $Cl_{DPDA}$ and creatinine clearance was discribed by Y=16.2570+0.7852 X($X=Cl_{DTPA}$ Y=creatinine clearance). And the correlation coefficient r was 0.88. We concluded that $^{99m}Tc-DTPA$ renal clearance measurement with Jackson's method was clinically useful to account GFR that can be done with routine $^{99m}Tc-DTPA$ renal scintigraphy simultaneously.

While cisplatin has been widely used in the treatment of a variety of cancers, nephrotoxicity is one of the major problems which frequently limit clinical usefulness of cisplatin. This study has been conducted to investigate nephrotoxicity of cisplatin in terms of changes in glomerular filtration rate (GFR) and effective renal plasma flow (EFPF) measured by the simultaneous use of $^{99m}Tc-DTPA$ and $^{131}I-OIH$, before and after administration of cisplatin, in 12 patients with lung cancer and four patients with esophageal cancer. Cisplatin was administrated at total doses of $75\sim100mg/m^2$ with two hour hydration and diuresis method. GFR determined by the use of $^{99m}Tc-DTPA$ had a good correlation with 24-hour creatinine clearance rate (r=0.77, p<0.001). GFR and filtration fraction decreased immediately after administration of cisplatin, however, they showed a tendency to be in completely recovered four weeks after administration. ERPF was not changed immediately after and four weeks after administration of cisplatin. GFR before and immediately after administration of cisplatin were analyzed with regard to age, sex, performance status, previous adminstration of cisplatin and method of administration. None of these factors had any influence on the rate of decrease in GFR except method of administration. Administration of cisplatin as a single dose lowered GFR more compared with that as divided doses. In this study, we have also demonstrated that the simultaneous use of $^{99m}Tc-DTPA$ and $^{131}I-OIH$ was a useful tool for the measurement of GFR and ERPF respectively.

In order to develop technetium-99m-labelled human albumin microsphere (HAM) for lung scintigraphy, various experimemts such as preparation and fractionation of HAM, establishment of optimal labelling conditions, determination of radiochemical purity, stability test and biodistribution of $^{99m}Tc-HAM$ were carried out. HAM was prepared from the suspension of 1ml aqueous human serum albumin (25%) in 130 ml of olive oil at $130\sim135^{\circ}$ with vigorous stirring. The resulting HAM was fractionated with microsieve to get the desired particle size $(15\sim50\mu)$ and autoclaved for sterilizaiton. The HAM particles were treated with stannous chloride and the pH of the suspension was adjusted to $3.0\sim3.5$ with phosphate buffer. After freeze-drying the contents of single reaction vial containing 5 mg of HAM and 0.2 mg of $SnCl_2$ it was reacted with $Na^{99m}TcO_4$. The labelling yield was higher than 99.5% and the stability of $^{99m}Tc-HAM$ was high enough to maintain 99.1% of radiochemical purity up to 24 hours. Lung and liver uptake in mice was found to be 94% and 0.9%, respectively. Excellent rabbit and human lung scans were also obtained.

For the development of $^{99m}Tc-labelled$ antimony sulfide colloid and hydroxyethyl starch, various experiments such as preparation of colloid, control of the distribution of particle size, establishment of labelling conditions, determination of labelling yield and radiochemical purity, examination of stability, and organ imagings of rabbits etc. were carried out. 1) Antimony sulfide colloid was readily prepared by the reaction of aqueous solution of antimony potassium tartrate with hydrogen sulfide generated by treating ferrous sulfide with dilute sulfuric acid. The colloid could be stabilized by adding small amount of polyvinylpyrrolidone. 2) Electron microscopy analysis exhibited the distribution of colloid size in the range of $1\sim15nm$ with a major portion of 9 m. The colloid solution was sterilized by membrane filtration $(0.2{\mu}m)$ and then stored at $4^{\circ}C$. This sterilized colloid was so stable that it was usable at least for one year. 3) The antimony sulfide colloid was labelled by adding sodium $pertechnetate-^{99m}Tc$ solution to the reaction vial, followed by adding hydrochloric acid and then boiled for 30 min. The optimal pH of the reaction mixture was found to be in the range of $1.3\sim1.4$. Instant thin layer chromatography (ITLC) analysis showed high labelling yield of above 99.5%. This labelled colloid maintained high radio-chemical purity of above 99% until 10 hours after labelling. 4) Animal studies showed high uptake of $^{99m}Tc-Sb_2S_3$ colloid at lymph vessels and nodes indicating a suitable agent for lymphoscintigraphy. Satisfactory results were also abtained in other clinical studies. 5) Hydroxyethyl starch (HES $0.6\sim1.0%$) was labelled with $Na^{99m}TcO_4$ in the presence of $SnCl_2$ with high labelling yield of above 99.5%. The optimal pH of the reaction mixture was in the range of $1.8\sim2.0$. $^{99m}Tc-HES$ maintained high radiochemical purity of above 99% until 10 hours after labelling. 6) Animal studies showed that $^{99m}Tc-HES$ migrated more rapidly from the injection sites into the lymph vessels than $^{99m}Tc-Sb_2S_3$ colloid while less amount of the former was uptaken at lymph nodes than that of the latter. Similar phenomenon was also observed in other clinical studies. As a result, $^{99m}Tc-Sb_2S_3$ colloid was found to be more effective lymphoscintigraphic agent than $^{99m}Tc-HES$.

Herpes simplex encephalitis (HSE) is one of the fulminant necrotizing, often fatal sporadic form of the encephalitis caused by herpes simplex type I virus. Characteristically, there is early and almost constant involvement of one or both temporal lobes, although there are common additional areas of involvement. Appropriate early treatment following correct diagnosis by clinical findings, CSF study, EEG and several radiological studies including angiography, redionuclide studies, CT or MRI can reduce its mortality and severity of the sequelae. We report a case of HSE diagnosed by adjuvant study of $^{99m}Tc-HMPAO$ regional cerebral blood flow SPECT, which showed a marked increase in bitemporal cerebral blood flow in a 24-year-old man.

Single pass radionuclide cardiac angiography was performed in 67-year old woman due to dyspnea and chest discomfort. The study showed markedly dilated ascending aorta and collateral ciculations from left sudclavian vein, and confirmed aortic aneurysm with partial obstruction of superior vena cava.

The $^{99m}Tc-phosphate$ compounds, of which methylene diphosphonate is most widely used, were originally introduced as bone scanning agents intended primarily to detect metastatic bone deposit. They may also accumulate in extraskeletal sites including breast. Recently we had the opportunity to observe one case of cystosarcoma phyllodes that was confirmed by tissue biopsy and demonstrated diffuse extraskeletal uptake of $^{99m}Tc-MDP$ in the breast on $^{99m}Tc-MDP$ bone scan in the breast on $^{99m}Tc-MDP$ bone scan. So we present this case with the brief review of literatures.