• Journal of the Korean Society of Radiology
• /
• v.15 no.7
• /
• pp.943-948
• /
• 2021

The purpose of this study was to investigate changes in surface dose due to increased scattering of gamma rays from patients injected with ^99mTc and ¹⁸F, which are radioactive isotopes, in close contact with materials with high atomic number such as the walls of the stable room. Prepare ^99mTc and ¹⁸F by injecting 20 and 10 mCi respectively into the NEMA phantom, and then measuring the surface dose for 60 minutes by positioning the phantom at a height of 1 m above the surface, at a distance of 0, 5 and 10 cm from the wall, and at the same location as the phantom facing the wall. Each experiment was repeated five times for reproducibility of the experiment and one way analysis of variability (ANOVA) was performed for significance testing and Tukey was used as a post-test. The study found that surface doses of 220.268, 287.121, 243.957, and 226.272 mGy were measured at ^99mTc, respectively, in the case of empty space and in the case of 0, 5 and 10 cm, while those of ¹⁸F were measured at 637.111, 724.469, 657.107, and 640.365 mGy, respectively. In order to reduce changes in surface dose depending on the patient's location while waiting, it is necessary to keep the distance from the ground or the wall where the patient is closely adhered to, or install an air mattress, etc., to prevent the scattered lines as much as possible, considering the scattered lines due to the wall etc. in future setup of the patient waiting room and safety room, and in addition to the examination, the external skin width may be reduced.

• Bulletin of the Korean Chemical Society
• /
• v.30 no.5
• /
• pp.1107-1112
• /
• 2009

The aim of this study is to develop and synthesize $5-HT_{1A}$ receptor imaging agents with WAY-100635 moiety and $^{99m}Tc(CO)_3$ core. WAY-100635 is commonly known as $5-HT_{1A}$ antagonist and its labeled compound ([$^{11}C$] WAY-100635) has been used as effective radioligand for imaging brain $5-HT_{1A}$ receptors with PET(Positron Emission Tomography). However, there are several restrictions in using a radioisotope of C-11 and requires for more effective radioisotopes and ligands. In order to produce a structure most similar to WAY-100635, WAY-100635 derivatives containing a cysteine chelator were designed and confirmed by using in silico (Hyperchem). The novel compounds (7a, 7b, 7c) were prepared in five or 7 steps with yields of 16%, 36% and 42%, respectively and radiolabeled with $[^{99m}Tc(CO)_3(H_2O)_3]^{+}$. The labeling yield was 99% for all the newly synthesized compounds. [$^{99m}Tc(CO)_3$]- WAY-100635 derivatives show a neutral charge which were confirmed by paper electrophoresis.

• The Korean Journal of Nuclear Medicine Technology
• /
• v.24 no.1
• /
• pp.20-26
• /
• 2020

Purpose It is intended to figure out the errors derived from changes in depth and volume when measuring the Standard source and ^99mTc-pertechnetate by using a Dose calibrator. Then recommend appropriate measurement depth and volume. Materials and Methods As a Dose calibrator, CRC-15βeta and CRC-15R (Capintec, New Jersey, USA) was used, and the measurement sources were ⁵⁷Co, ¹³³Ba, ¹³⁷Cs and ^99mTc-pertechnetate was also adopted due to its high frequency of use. The Standard source was respectively measured the changes according to its depth without changing the volume, in a range of 0 cm to 15 cm from the bottom of the ion chamber. ^99mTc-pertechnetate was measured at each depth by changing the volume with 0.1 mL, 0.3 mL, 0.5 mL, 0.7 mL and 0.9 mL Respectively. And the depth range was from 0 cm to 15 cm at the bottom of the ion chamber. Results In the case of Standard source ⁵⁷Co, ¹³³Ba, ¹³⁷Cs and ^99mTc-pertechnetate, there were significant differences according to the measurement depth(p<0.05). ^99mTc-pertechnetate has a negative correlation coefficient according to the depth, and the error of the measured value was negligible at a depth from 0 cm to 7 cm at 0.3 mL and 0.5 mL, and the range of error increased as the volume increased. Conclusion In clinical practice, it is sometimes installed differently than the Standard depth recommended by the equipment company. If it's measured at the recommended depth and volume, it could be thought that unnecessary exposure of the operator and the patient will be reduced, and more accurate radiation exams will be possible in quantitative analysis.

• The Korean Journal of Nuclear Medicine Technology
• /
• v.24 no.1
• /
• pp.27-32
• /
• 2020

Purpose Glomerular Filtration Rate(GFR) is an important indicator for evaluating renal function and monitoring the progress of renal disease. Currently, the method of measuring GFR in clinical trials by using serum creatinine value and ^99mTc-DTPA(diethylenetriamine pentaacetic acid) renal dynamic scan is still useful. After the Gates method of formula was announced, when ^99mTc-DTPA Renal dynamic scan is taken, it is applied the GFR is measured using a gamma camera. The purpose of this paper is to measure the GFR by applying the Gates method of formula. It is according to effect activity and matrix size that is related in the GFR. Materials and Methods Data from 5 adult patients (patient age = 62 ± 5, 3 males, 2 females) who had been examined ^99mTc-DTPA Renal dynamic scan were analyzed. A dynamic image was obtained for 21 minutes after instantaneous injection of ^99mTc-DTPA 15 mCi into the patient's vein. To evaluate the glomerular filtration rate according to changes in activity and matrix size, total counts were measured after setting regions of interest in both kidneys and tissues in 2-3 minutes. The distance from detector to the table was maintained at 30cm, and the capacity of the pre-syringe (PR) was set to 15, 20, 25, 30 mCi, and each the capacity of post-syringe (PO) was 1, 5, 10, 15 mCi is set to evaluate the activity change. And then, each matrix size was changed to 32 × 32, 64 × 64, 128 × 128, 256 × 256, 512 × 512, and 1024 × 1024 to compare and to evaluate the values. Results As the activity increased in matrix size, the difference in GFR gradually decreased from 52.95% at the maximum to 16.67% at the minimum. The GFR value according to the change of matrix size was similar to 2.4%, 0.2%, 0.2% of difference when changing from 128 to 256, 256 to 512, and 512 to 1024, but 54.3% of difference when changing from 32 to 64 and 39.43% of difference when changing from 64 to 128. Finally, based on the presently used protocol, 256 × 256, PR 15 mCi and PO 1 mCi, the GFR value was the largest difference with 82% in PR 15 mCi and PO 1 mCi. conditions, and at the least difference is 0.2% in the conditions of PR 30 mCi and PO 15 mCi. Conclusion Through this paper, it was confirmed that when measuring the GFR using the gate method in the ^99mTc-DTPA renal dynamic scan. The GFR was affected by activity and matrix size changes. Therefore, it is considered that when taking the ^99mTc-DTPA renal dynamic scan, is should be careful by applying appropriate parameters when calculating GFR in the every hospital.

• 대한핵의학회:학술대회논문집
• /
• 2000.05a
• /
• pp.71.2-71.2
• /
• 2000

• The Korean Journal of Nuclear Medicine Technology
• /
• v.14 no.2
• /
• pp.155-158
• /
• 2010

Purpose: $^{99m}Tc$-macroaggregated albumin (MAA) hepatic arterial perfusion scintigraphy was known for useful method to evaluate patients receiving intraarterial chemotherapy for liver cancer. This study evaluate about usefulness of normal liver on hepatocellular carcinoma (HCC) from HCC patients. This study is to see the usefullness of Hepatic Arterial Perfusion Scintigraphy (HAPS) by measuring mass size, shape, lung shunting and tumor to normal ratio (T/N ratio) in relative blood stream of HCC patients compared with HCC on normal liver. Materials and Methods: From June 2009 to September 2009, HAPS studies were performed on 7 patients (men 6, women 1, mean 64) who were diagnosed HCC. HAPS was performed after proper hepatic artery $^{99m}Tc$-MAA of 5 mCi (185 MBq) injection by catheter. We performed anterior, posterior, both lateral view, SPECT of chest and abdomen. Then we set up ROI and calculated lung shunting, T/N ratio for each count, count/pixel (mean value). Results: Tumor and liver size analyzed by ROI of anterior, posterior view are 2.0-10.8 cm (mean 3.75 cm), 8.8-18.5 cm (mean 14.6 cm). T/N ratio analyzed by total tumor and total normal mean value are 2.41-5.76 (mean 3.8). lung shunting analyzed by total liver count is 3.14-13.92% (mean 6.77%). Conclusion: HAPS with $^{99m}Tc$-MAA can evaluate mass size, location, quantitative analysis through T/N ratio. also HAPS can evaluate detection of arteriovenous shunt through lung uptake before radioisotope therapy. Therefore HAPS with $^{99m}Tc$-MAA can be useful method in aspect of evaluation and treatment of HCC.

• Journal of Radiation Industry
• /
• v.4 no.1
• /
• pp.79-83
• /
• 2010

The pollutants in subsurface soil are advected by groundwater flow and transported by the hydrodynamic dispersion. In this study, laboratory-scale experiments by using a radioisotope were conducted to evaluate the characteristics of the transport and dispersion of pollutants in the soil. The hydraulic model of the laboratory-scale was manufactured based upon its geometric similarity. Tc-99m having a short half-life was used with a tracer and it was injected instantaneously into the soil. Tc-99m milked from a $^{99}Mo/^{99m}Tc$ portable generator fabricated for medical purposes had 0.141 MeV of gamma radiation. The experiments are performed by the different conditions like the variations of groundwater velocity and the results are analyzed by the measured CPS of Tc-99m.

• The Korean Journal of Nuclear Medicine
• /
• v.33 no.4
• /
• pp.368-380
• /
• 1999

Purpose: The purpose of this study was to evaluate and compare the scintigraphic findings and diagnostic accuracy of double-phase Tc-99m sestamibi scan in primary and secondary hyperparathyroidism (HPT). Materials and Methods: We retrospectively reviewed 16 cases of primary (18 lesions) and 11 cases of secondary HPT (44 lesions) who underwent Tc-99m-sestamibi scan before the surgical intervention. Scan was performed using LEM camera (Siemens, Germany) after the injection of 740MBq of Tc-99m sestamibi. Routine image consisted of baseline and 3-hour delayed images and each image was obtained using both parallel and pine hole collimator. The study population was 27 patients (male/female=5/22, age: $49.1{\pm}10.8$). Results: Eighteen lesions of primary HPT consisted of 13 adenomas and S hyperplasias, while all lesions of secondary HPT were hyperplasias. Among the case of primary HPT, we could detect all the lesions of 13 adenomas but only 2 lesions of 5 hyperplasias (40%) could be detected by double phase scintigraphy. Three cases of primary lesion showed decreased uptake in delayed images compared with baseline. The sensitivity, specificity, positive predictive value and accuracy of primary and secondary HPT were 58.8% (10/17), 83.3% (10/12), 83.3% (10/12), 75.9% (22/29), and 37.5% (15/40), 50% (2/4), 88.2% (15/17), 38.6% (17/44), respectively. Overall sensitivity, specificity, positive predictive value and accuracy were 43.9% (25/57), 75% (12/16), 86.2% (25/29), and 53.4% (39/73). There were no statistical difference between the weight of primary and secondary HPT lesion (p>0.05). Conclusion: Tc-99m sestamibi scan is fairly good modality to detect parathyroid lesion in patient with primary HPT before the surgical intervention. However, since some of cases may reveal decreased uptake in delayed image, a careful attention to the findings of baseline images may be helpful. Still the low accuracy of sestamibi scan in diagnosis of secondary HPT prohibits routine use of it for this disease.

• The Korean Journal of Nuclear Medicine
• /
• v.39 no.6
• /
• pp.489-490
• /
• 2005

Purpose: The thyroglossal duct runs from the base of the tongue to the thyroid. Rarely the thyroid completely fails to migrate and results in ectopic thyroid tissue, which can be demonstrated scintigraphically. A 31-year old female patient was referred for thyroid scintigraphy due to protruding mass at the base of the tongue. She was mildly hypothyroid. Te-99m pertechnetate thyroid scan was performed to rule out ectopic thyroid gland. There showed a focal area of intense tracer uptake in sublingual area, suggesting the sublingual thyroid. In addition there noted diffusely increased tracer uptake in both breasts. The patient delivered a baby 6 months prior to the scan and was on breast-feeding. Free Tc-99m pertechnetate physiologically secrets into the salivary glands, the stomach, the gastrointestinal tract, the genitourinary tract and the mammary glands and sodium-iodide symporter plays a role in the accumulation of free Tc-99m pertechnetate. We report simultaneous visualization of lactating breasts and ectopic thyroid gland in the base of the tongue.

• Journal of Korean Academy of Oral and Maxillofacial Radiology
• /
• v.20 no.1
• /
• pp.53-62
• /
• 1990

This experiment was performed to clarify the effects of /sup 60/Co gamma irradiation on secretory function, amylase activity and contents of nucleic acids of parotid gland in rat. Experimental animals were divided into 6th hours, 3rd, 7th, 14th and 28th days after irradiation and control. The experimental animals are singly irradiated with 20Gy (2,000rad) through protective lead block. Secretory function of parotid gland was evaluted by uptake and clearance of /sup 99m/TcO₄. /sup 99m/TcO₄. 0.2μ ci/gm, was injected into peritonium in uptake groups. Rats were sacrified with cervical dislocation after 30 minutes and gland was excised. In the clearance group. pilocarpine nitrate (8㎎/㎏) was intraperitoneally injected at 30 minutes after /sup 99m/TcO₄ injection and rats were sacrified 30 minutes after pilocarpine injection. Radioactivity of excised parotid gland was measured by using of gamma counter and stimulation-secretion coefficients, uptake radioactivity divided by clearance radioactivity, was calculated. Amylase activity and contents of DNA and RNA were determined by spectrophotometry. The results obtained were as follows: 1. In the uptake test, the radioactivity of /sup 99m/TcO₄ per unit weight increase in experimental group except 6th hours group, compared with control groups and showed a peak at 3rd days after irradiation. 2. In the clearance test, the radioactivity of /sup 99m/cO₄per unit weight rose to a peak at 3rd days after irradiation and gradually recovered thereafter. 3. Stimulation-secretion coefficient of parotid gland decreased at 6th hours, 3rd and 7th days after irradiation, and gradually increased. 4. Amylase activity of parotid gland decreased in 3rd and 7th days group, and especially lowest in 3rd days after irradiation. 5. The contents of DNA showed no definite difference in all the experimental groups, but RNA was seemed to decrease with time after irradiation.