Comparison of in vitro Antimicrobial Activities of Tc-99m Infecton and Ciprofloxacin / 대한핵의학회잡지

PURPOSE: There was little evidence that Tc-99m labeled ciprofloxacin (Infecton) located inside of bacteria. Antimicrobial activity of Infecton could be an indirect evidence of its location. We compared in vitro antimicrobial activities of Infecton and ciprofloxacin. MATERIALS AND METHODS: Minimum inhibitory concentration (MIC) and minimum bactericidal concentration (MBC) of Infecton and ciprofloxacin against three standard strains of bacteria, Staphylococcus aureus ATCC 29213, Escherichia coli ATCC 25922 and Pseudomonas aeruginosa ATCC 27853 were measured using modified broth macrodilution techniques and pour plate methods, respectively. Data were expressed as mean+/-SE (range). RESULTS: MICs of Infecton and ciprofloxacin were 1.12+/-0.20 (0.8~1.6) microgram/ml and 0.36+/-0.04 (0.2~0.4) microgram/ml for S. aureus, 0.03+/-0.005 (0.025~0.05) microgram/ml and 0.011+/-0.001 (0.006~0.012) microgram/ml for E. coli, and 0.96+/-0.16 (0.8~1.6) microgram/ml and 0.56+/-0.098 (0.4~0.8) microgram/ml for P. aeruginosa, respectively. MBCs of Infecton and ciprofloxacin were 2.56+/-0.39 (1.6~3.2) microgram/ml and 0.88+/-0.2 (0.4~1.6) microgram/ml for S. aureus, 0.04+/-0.06 (0.025~0.05) microgram/ml and 0.02+/-0.01 (0.025~0.05) microgram/ml for E. coli, and 2.24+/-0.39 (1.6~3.2) microgram/ml and 1.44+/-0.16 (0.8~1.6) microgram/ml for P. aeruginosa, respectively. CONCLUSION: Although both MICs and MBCs of Infecton were higher than those of ciprofloxacin, all three standard bacterial strains were sensitive to Infecton. It could be an indirect evidence that Tc-99m Infecton be a specific imaging agent for bacterial infection.

Bilateral Inguinal Hernias Detected by Peritoneal Scintigraphy during the Evaluation of Scrotal Swelling in a Patient on Continuous Ambulatory Peritoneal Dialysis / 대한핵의학회잡지

A 47-year-old man with end-stage renal disease due to diabetic nephropathy underwent a peritoneal scintigraphy to evaluate the cause of recently developed scrotal swelling. Two liters of dialysate mixed with 111 MBq of Tc-99m sulfur colloid were administered into the peritoneal cavity via the dialysis catheter. Various anterior images of the abdomen and pelvis were obtained at 15 min, 2 hr and 4 hr after the tracer instillation. At 15 min, anterior images of the abdomen and pelvis demonstrated linear tracts of activity through both inguinal canals, which were more prominent in the right side (A). Images at 2 hr revealed a passage of the radioactive fluid into the right hemiscrotum. At the same time, there was a considerable accumulation of activity in the right inguinal canal (B). In the delayed image, there was a progressive accumulation of activity in the inguinal canals and a prominent passage of the tracer into the scrotum (C). Both abdominal and inguinal hernias are commonly associated with continuous ambulatory peritoneal dialysis (CAPD). Overall incidence of CAPD-induced hernia ranges from 2.7% to 25%.1) Inguinal hernias were frequently manifested as scrotal swelling. Leakages of dialysate fluid into the scrotum has been noted in CAPD patients with scrotal swelling, with or without clinical findings of inguinal hernia.1,2) In the present case, the right side had leakage from a clinical inguinal hernia and the left side, leakage from a subclinial inguinal hernia. A subclinical inguinal hernia was easily demonstrable with peritoneal scintigraphy. Peritoneal scintigraphy is extremely helpful in the evaluation of scrotal swelling in a patient on CAPD.

Genes Associated with Radiation Adaptive Response Induced by Low Level Radiation from (99m)Tc in Human Cell Lines / 대한핵의학회잡지

No abstract available.

Preoperative Cisternoscintigraphy As a Guide to Therapeutic Decision Making for Cystic Subdural Hygroma / 대한핵의학회잡지

We report a case of a patient with cystic subdural hygroma who underwent pre-operative Tc-99m DTPA cistrenoscintigraphy to determine the course of operation. A 68-year-old female was admitted to the department of neurosurgery because of acute subarachnoid hemorrhage. After emergency ventricular drainage, the hydrocephalus and cystic subdural hygroma in the right fronto-temporal area developed. She underwent Tc-99m DTPA cisternoscintigraphy to evaluate the type of hydrocephalus, which revealed obstructive communicating hydrocephalus and the communication between the subdural hygroma and the subarachnoid space. As a result of these findings, she underwent the ventriculo-peritoneal shunt operation without removal of the subdural hygroma. Post-operative brain CT showed nearly normalized shape and size of the right ventricle and disappearance of subdural hygroma. We recommend the pre-operative cisternoscintigraphy in patients with complex hygroma to evaluate the communication between subdural hygroma and the subarachnoid space.

Comparison of Radiation Adaptive Responses in Peripheral Lymphocytes of Patients Undergoing Tc-99m MDP and Tc-99m DTPA Scintigraphies / 대한핵의학회잡지

PURPOSE: The purpose of this study was to compare the radiation adaptive response (RAR) in peripheral lymphocytes (PL) of patients induced by Tc.-99m MDP and Tc-99m DTPA scintigraphies. MATERIALS AND METHODS: Lymphocytes from 45 patients (25 males, 20 females, mean age 44+/-18 years) were collected before and after scintigraphies using 740 MBq Tc-99m MDP (n=22) or Tc-99m L)TPA (n=23). Lympho-cytes from 20 controls (12 males, 8 females, mean age 43+/-7 years) were also callected. They were exposed to challenge dose of 2 Gy gamma-rays using a Cs-137 cell irradiator, Number of ring-form (R) and dicentric (D) chromosomes was counted under the light microscope. From them a representative score, Ydr, was calculated as Ydr=(D+R)/cells. Adaptation index (AI) was defined as difference of Ydr between unconditioned and conditioned lymphocytes. Ydr was also measured after an administration of cyclohexi-mide (CHM), a protein synthesis inhibitor, before challenge dose. RESULTS: RAR was induced in both groups of patients. CHM abolished the adaptive response in both groups. AI of Tc-99m MDP group was significantly higher than that of Tc-99m DTPA group. CONCLUSION: Tc-99m MDP induced RAR was more prominent than those induced by Tc-99m DTPA.

Development of a Noble Dosimetry Using Metaphase Analysis and Micronuclei Assay of Bone Marrow Cells in Mice / 대한핵의학회잡지

PURPOSE: The purpose of this study was to develop in vivo dosimetries using both chromosomal aberrations and micronuclei in mice to assess biological effects of radiations. MATERIALS AND METHODS: Five each mice were irradiated with 0, 1, 2, 3, 4, 5, 10 Gy of Cs-137 gamma-rays. We scored numbers of chromosomal aberrations in metaphase spreads and numbers of micronuclei in bone marrow smears under light microscope, and obtained the dose-response relationships. We also examined the relationship between the two dose-response curves. RESULTS: The frequency of both chromosomal aberrations and micronuclei increased with dose, in a linear-quadratic manner. The delta, beta, and alpha coefficients were 0.0176, 0.0324, and 0.0567 for metaphase analysis (r=1.0, p<0.001) and 0.0019, 0.0073, and 0.0506 for micronuclei assay (r=1.0, p<0.001). The frequency of chromosomal aberrations and micronuclei in diffirent radiation doses was significantly correlated (r=0.99, p<0.01). CONCLUSION: In vivo dosimetry using either metaphase analysis or micronucleus assay was feasible in mice. These methods could be useful to evaluate biological effects of radiation.

Sialolithiasis Mimicking Metastatic Thyroid Cancer / 대한핵의학회잡지

We report a false positive case of I-131 scan due to a sialolithiasis in right submandibular gland. I-131 images showed not only remnant thyroid tissues and functional metastases in the anterior neck but also a hot uptake near right submandibular gland. We confirmed the sialolithiasis by radiologic studies. Sialolithiasis should be regarded as a false positive cause when I-131 scan shows a hot spot near salivary bed.

Role of Dacryoscintigraphy in the Diagnosis and Treatment of Pediatric with Epiphora / 대한핵의학회잡지

PURPOSE: We conducted this study to evaluate the role of dacryoscintigraphy in the diagnosis and treatment of pediatric patients with epiphora. MATERIALS AND METHODS: In 58 patients aged from 2 months to 15 years (mean age 2.8+/-2.3 years), dacryoscintigraphy was performed using a gamma camera with 4 mm pinhole collimator. We correlated symptoms with dacryosicntigraphic findings in all patients. In 37 patients who underwent ophthalmologic procedures, we analyzed the agreements of dacryoscintigraphic findings with the operation. RESULTS: High rates of agreements between epiphora and obstruction on dacryoscintigraphy (69/72, 95.8%), and between scintigraphic obstructive findings and operation sites (44/47, 93.6%) were noted. Nine of fourty-four (20.5%) asymptomatic eyes showed obstructive findings on dacroscintigraphy. CONCLUSION: In pediatric patients with epiphora, dacryoscintigraphy is a useful tool not only in diagnosing nasolacrimal duct obstruction but also in making a decision for therapeutic procedures.

A Comparison Study of Metaphase Analysis of Chromosomal Aberration and Flow Cytometric Assessment of Radiation- induced Apoptosis in Human Peripheral Lymphocytes / 대한핵의학회잡지

PURPOSE: Radiation-induced chromosomal damage and apoptosis were compared in human lymphocytes. MATERIALS AND METHODS: Peripheral lymphocytes from 10 normal volunteers (6 males, 4 females, age range 23~41 years) were irradiated by gamma rays from a cell irradiator. Doses of irradiation were 0 (control), 0.18, 2, 5, 10, 20 and 25 Gy. Irradiated lymphocytes were examined by metaphase analysis for chromosomal aberrations and by flow cytometry for apoptosis. RESULTS of both studies were compared according to dose. RESULTS: Number of dicentric and ring chromosomes (D+R) was 0.5+/-0.53 at baseline, which was significantly increased after radiation according to the dose. The fraction of cells showing annexin V-fluore-scein isothiocyanate uptake was 0.55+/-0.39%, which increased to 3.58+/-1.85% by 2 Gy irradiation, and then decreased. The fraction of cells showing propidium iodide (PI) uptake was 0.52+/-0.12%, which significantly increased according to dose (upto 15.64+/-5.99% by 20 Gy irradiation). D+R and PI uptake were well correlated (r=0.84, p<0.001). CONCLUSION: Radiation-induced chromosomal aberration was correlated to nuclear uptake of PI, a marker of late apoptosis.

Change of Cerebral Blood Flow Distribution and Vascular Reserve according to Age in Koreans Measured by Tc-99m HMPAO Brain SPECT / 대한핵의학회잡지

PURPOSE: The aim of this study was to evaluate the normal values of regional cerebral blood flow (rCBF) and cerebrovascular reserve (CVR) in normal children to aged volunteers using Tc-99m HMPAO. MATERIALS AND METHODS: Thirty four right-handed normal volunteers (20 males, 14 females, mean age 40.3+/-24.9 years, range 4 to 82 years) were underwent rest/acetazolamide (ACZ) brain SPECT using Tc-99m HMPAO and the sequential injection and subtraction method. rCBF was estimated on the basis of a semiquantitative approach by means of right/left ratio, region/cerebellum and region to whole brain ratios in frontal, parietal, temporal, and occipital lobes, basal ganglia, thalami, and cerebellum. CVR was measured by means of % perfusion increase calculated as % mean count change compared to rest rCBF in each regions. RESULTS: Mean values of right to left ratios range from 1.004 to 1.018. rCBF was highest in cerebellum and lowest in basal ganglia and thalami. Frontal and temporal rCBF decreased while occipital and thalamic rCBF increased according to age. No sexual difference of rCBF was noted. Mean CVR was 29.9+/-12.9%. Mean CVR significantly increased to late teens, and declined thereafter. After 6th decade, CVR in both frontal lobes, left parietal lobe and right basal ganglia decreased significantly with advancing age. There was no sexual difference of CVR. CONCLUSION:: Quantitative assessment of CVR was possible by ACZ Tc-99m HMPAO brain SPECT. It revealed that rCBF and CVR changed according to age in normal Korean volunteers. There was no sexual difference.

Studies on the Radiation Induced Apoptosis by Morphological and Biochemical Analysis in A431 Cells / 대한핵의학회잡지

PURPOSE: We performed this study to evaluate the process of radiation induced apoptosis in A431 skin epithelial cancer cell line. MATERIALS AND METHODS: Low to high dose radiation (0, 2, 5, 10, 25 Gy) was given to A431 cells by Cs-137 cell irradiator. Apoptosis was evaluated by cell morphology, dye exclusion test, and DNA laddering. RESULTS: Cell viability decreased as the radiation dose increased. Number of apoptotic bodies increased as radiation dose increased. It increased most significantly at 12 hours after irradiation. Lactate dehydrogenase activity in culture medium increased according to radiation dose and time after irradiation. CONCLUSION:: Radiation-induced apoptosis which was the main course of cell death in A431 cells could be analyzed quantitatively by counting apoptotic bodies under microscope. Apoptosis increased as radiation dose increased.

Cytogenetic Radiation Adaptive Response Assessed by Metaphase Analysis and Micronuclei Test in Human Lymphocytes and Mouse Bone Marrow Cells / 대한핵의학회잡지

PURPOSE: Radiation adaptive response in human peripheral lymphocytes and mouse bone marrow cells was investigated using both metaphase analysis and micronucleus assay. We assessed the correlation between both tests. MATERIALS AND METHODS: Two groups of the human peripheral lymphocytes and mouse bone marrow cells were exposed to low dose (conditioning dose, 0.18 Gy) or high dose (challenging dose, 2 Gy) gamma-rays. The other 4 groups were exposed to low dose followed by high dose after several time intervals (4, 7, 12, and 24 hours, respectively). The frequencies of chromosomal aberrations in metphase analysis and micronuclei in micronucleus assay were counted. RESULTS: Chromosomal aberrations and micronuclei of preexposed group were lower than those of the group only exposed to high dose radiation. Maximal reduction in frequencies of chromosomal aberrations were observed in the group to which challenging dose was given at 7 hour after a conditioning dose (p<0.001). Metaphase analysis and micronucleus assay revealed very good correlation in both human lymphocytes and mouse bone marrow cells (r=0.98, p<0.001; r=0.99, p=0.001, respectively). CONCLUSION: Radiation adaptive response could be induced by low dose irradiation in both human lymphocytes and mouse bone marrow cells. There was a significant correlation between metaphase analysis and micronucleus assay

A Comparison Study of Radiostrontium Chelation with Chitin, Chitosan, EDTA and DTPA / 대한핵의학회잡지

PURPOSE: Chitin and chitosan are nontoxic natural chelators that chelate radiostrontium effectively. The purpose of this study was to compare radiostrontium chelation of chitin and chitosan with that of well known chemical chelators, namely EDTA and DTPA. MATERIALS AND METHODS: The chelaton rates of chitin, chitosan, EDTA and DTPA were compared using a column chromatography method (Sephadex G-25M, Sweden). Three kinds of chitins and four kinds of chitosans were used. All of them were water soloble. RESULTS: Phosphated chitosan showed the highest chelation yield of more than 97% at pH 7. All of chitins, chitosans, EDTA and DTPA showed chelation yield of more than 90% independent of varing pH level. CONCLUSION: Chitin and chitosan have similar chelation rate as compared with EDTA and DTPA.

Tc-99m Myocardial Perfusion SPECT Findings of Angina Patients Showing Normal Coronary Angiography

BACKGROUND: Tc-99m myocardial perfusion imaging agents have recently found wide spread use as detecting agents of coronary diseases. Unfortunately, false positive results are not infrequent. METHODS: We analyzed Tc-99m myocardial perfusion SPECT (Tc-SPECT) findings in angina patients showing normal coronary angiography. Seventy patients who underwent myocardial SPECT wihin one month of coronary angiography which revealed no significant stenosis were studied. RESULTS: Forty six (65.7%) patients showed perfusion defects on Tc-SPECT. Eighteen were due to soft tissue attenuation, thirteen were due to technical problems such as low count rate, six were associated with intraventricular conduction abnormalities, four with coronary spasms, three with old infarctions, and one with slow coronary flow. CONCLUSION: Photon attenuation and inadequate count rates were the main causes of false positive results on myocardial SPECT imaging with Tc-99m agents. However, pathological conditions such as conduction disturbance, coronary spasm or slow coronary flow were also associated with positive SPECT findings in patients with normal coronary angiograms.

Gender Difference of Accuracy in Detecting Coronary Artery Disease by Myocardial Perfusion SPECT / 대한핵의학회잡지

PURPOSE: Myocardial SPECT is an effective test for detecting coronary artery disease in the general population. But the diagnostic accuracy between sexes is not defined. The purpose of this study is to compare the diagnostic accuracy between males and females. MATERIALS AND METHODS: One hundred and seventy seven male and 98 female patients who underwent myocardial SPECT within 1 month of coronary angiography were studied. Myocardial SPECTs were considered abnormal if fixed or reversible perfusion defects were detected. Stenosis severity of > or = 50% luminal diameter reduction of any artery defined coronary artery disease (CAD). RESULTS: Overall sensitivity for detection of CAD was 98% in men and 97% in women (p=not significant). However, specificities, accuracies, and positive predictive values (PPV) in men and women were 49% vs 31% (p<0.05), 81% vs 57% (p<0.01), 78% vs 48% (P<0.01), respectively Diagnostic accuracies for detection of right coronary artery disease were not different in both sexes, however, accuracies for detection of left anterior descending artery disease and left circumflex artery disease were significantly lower in female (p<0.05). CONCLUSION: A significant difference of diagnostic accuracy between sexes, especially in LAD and LCx disease, was noted. Artifacts from breast attenuation might be a cause for the lower diagnostic accuracy in female.

Comparison of 99mTc-tetrofosmin and 99mTc-sestamibi Myocardial Perfusion SPECT in Detecting Coronary Artery Fisease / 대한핵의학회잡지

PURPOSE: Tc-99m-tetrofosmin(TF) is a recently proposed myocardial imaging agent which has similar biokinetic characteristics to Tc-99m-sestamibi(MIBI). The aim of this study was to compare TF and MIBI myocardial perfusion SPECTs in detecting coronary artery disease. MATERIALS AND METHODS: One hundred and sixty patients(l0l males, 59 females, mean age 57+/-9 yr) who had undergone both myocardial perfusion SPECT (M- SPECT) and coronary angiography within 1 month were studied. M-SPECT was performed using TF in 115 patients and MIBI in 45 patients. Stress-rest one day protocol was used in all patients A coronary stenosis was considered significant when the luminal diameter > or =50% was compromised. The chi square test was used to compare, differences in sensitivity and specificity between the two groups. RESULTS: There was no difference in age and diseased coronary artery branches between the two groups. There were more male patients in TF group: Male-to-female ratios of TF and MIBI groups were 78:37 and 23:22, respectively (p<0.05). The overall sensitivity of TF study was 92% and specificity 36%. The overall, sensitivity and specificity of MIBI study were 93% and 30% respectively. There was no difference between TF and MIBI groups in identifying individual diseased coronary artery branches. CONCLUSION: One day stress-rest myocardial SPECT using either TF or MIBI was comparable and was a very sensitive test in detecting coronary artery disease.

Comparison of Stress-rest and Rest-stress One Day Myocardial Perfusion Scintigraphies in Detecting Coronary Artery Diseases / 대한핵의학회잡지

It has been shown that both rest and stress myocardial perfusion imagings with technetium agents can be performed on the same day using two different doses injected within few hours. The purpose of this study was to compare the two protocols (stress-rest and rest-stress) in detecting coronary artery diseases. One hundred and sixty patients (101 males, 59 females, mean age 57+/-9 years) and 120 patients (79 males, 41 females, mean age 59+/-10 years) underwent stress-rest myocardial perfusion SPECT and rest-stress myocardial perfusion SPECT, respectively All of them underwent both myocardial perfusion SPECT and coronary angiography within 1 month. A coronary stenosis was considered significant when it compromised the luminal diameter by> or =50%. The chi square test was used to compare differences in sensitivity, specificity and accuracy between the two groups. The overall sensitivity, specificity and accuracy of stress-rest protocol were 99%, 35%and 68%, respectively. Those of rest-stress protocol were 96%, 47%, and 78%, respectively. There was no difference between the two protocols in identifying individual diseased coronary artery branches. Therefore, one day stress-rest and rest-stress myocardial SPECT using Tc-99m agents were comparable and were very sensitive tests in detecting coronary artery diseases.

Prognostic Implication of Normal Myocardial Perfusion Scintigraphy in Patients with Chest Pain / 대한핵의학회잡지

Myocardial scintigraphy is a widely used noninvasive procedure with high sensitivity for the detection of patients with suspected coronary artery disease. The purpose of this study was to determine the prognostic value of a normal myocardial scintigraphy in 292 patients (150 males, 142 females, mean age 53+/-12 years) with chest pain who were followed from 7 to 58 (mean 25) months. Myocardial SPECT was performed with Tc-99m MIBI in 173 patients, with Tc-99m tetrofosmin in 74 patients and with T1-201 in 45 patients. During the follow-up period, there were 2 cardiac deaths and 2 nonfatal myocardial infarctions resulting in cardiac event rate of 1.37% (0.66% per year). The cardiac event rate was not different in patients with angiographically normal coronary arteries (1/30, 3.3%) and in those who had significant coronary a disease (2/27, 7.4%) (p=0.60). In conclusion, patients with chest pain and normal myocardial scintigraphy have a low cardiac event rate, and there was no significant difference of cardiac event rates between patients with normal and abnormal coronary angiograms.

Differentiation of malignant from benign pancreatic mass by Tl-201 abdominal SPECT

The aim of the present study was to evaluate the ability of Tl-201 abdominal SPECT to differentiate between chronic focal pancreatitis and pancreatic malignancy. Seventeen patients (12 men, 5 women; mean age, 56 years; 9 pancreatic cancer, 8 chronic pancreatitis) with pancreatic mass were prospectively investigated with Tl-201 abdominal SPECT. In all patients, CT and/or US could not clarify the nature of the pancreatic mass. Focal hot uptake was present in 8 of 9 patients with pancreatic cancer, while it was present in 2 of 8 patients with chronic pancreatitis. Therefore, the sensitivity and specificity of the present study were 89% and 75%, respectively. A significant difference of Tl-201 uptakes was noted between benign and malignant masses (p& 0.05). Therefore, we concluded that Tl-201 abdominal SPECT was a useful test in differentiation of malignant from benign pancreatic mass, especially when the differentiation could not be made by other imaging modalities

Genotoxicity of therapeutic dose of I analyzed by micronuclei test in the mouse bone marrow / 대한핵의학회잡지

No abstract available.