A Study on Cerebral Hemodynamic Analysis of Moyamoya Disease by Using Perfusion MRI

동경래,구은회,이재승,정운관 한국물리학회 2013 THE JOURNAL OF THE KOREAN PHYSICAL SOCIETY Vol.63 No.8

This study examined the clinical applications of perfusion magnetic resonance imaging (MRI) inpatients with moyamoya disease (MMD). Twenty-two patients with moyamoya disease (9 men and13 women) with a mean age of 9.3 years (range: 4 - 22 years) were enrolled in this study. PerfusionMRI was performed by scanning the patients7.5 cm upward from the base of the cerebellum beforetheir being process for post-treatment. The scan led to the acquisition of the following four mapimages: the cerebral blood volume (CBV), the cerebral blood flow (CBF), the mean transit time(MTT) for the contrast medium, and the time to peak (TTP) for the contrast medium. The lesionswere assessed using the CBV, the CBF, the MTT and the TTP maps of perfusion MRI; the MTTand the TTP were measured in the lesion areas, as well as in the normal and the symmetric areas. Perfusion defects were recognizable in all four perfusion MRI maps, and the MTT and the TTPshowed a conspicuous delay in the parts where perfusion defects were recognized. The MTT and theTTP images of perfusion MRI reflected a significant correlation between the degrees of stenosis andocclusion in the posterior cerebral artery (PCA), as well as the development of collateral vessels. The four perfusion MRI maps could be used to predict the degrees of stenosis and occlusion inthe posterior circulation, as well as the development of the collateral vessels, which enabled ahemodynamic evaluation of the parts with perfusion defects. Overall, perfusion MRI is useful forthe diagnosis and the treatment of moyamoya disease and can be applied to clinical practice.

1차 의료기관의 엑스선 발생장치 정도관리에 관한 현황조사: 광주광역시 지역을 중심으로

동경래,이선주,권대철,구은회,정재은,이규수 대한방사선방어학회 2010 방사선방어학회지 Vol.35 No.1

A Study on Evaluation of the Dependences of the Function and the Shape in a ^99mTc-DMSA Renal Scan on the Difference in Acquisition Count

동경래,심동오,김호성,박용순,정운관,조재환 한국물리학회 2013 THE JOURNAL OF THE KOREAN PHYSICAL SOCIETY Vol.62 No.4

In a nuclear medicine examination, methods to acquire a static image includes the preset count method and preset time method. The preset count method is used mainly in a static renal scan that utilizes ^99mTc-DMSA (dimoercaptosuccinic acid), whereas the preset time method is used occasionally. When the preset count method is used, the same number of acquisition counts is acquired for each time but there is a difference in the scan time. When the preset time method is used, the scan time is constant, but the number of counts acquired is not the same. Therefore, this study examined the difference in information on the function and shape of both sides of the kidneys depending on the count acquired in a renal scan that utilizes ^99mTc-DMSA. The study involved patients who had 40 - 60% of the relative function of one kidney among patients who underwent a ^99mTc-DMSA renal scan in the nuclear medicine department in the period from January 11 to March 31, 2012. A gamma camera was used to obtain a acquisition count continuously using 100,000 counts and 300,000 counts, and an acquisition time of 7 minutes (exceeding 300,000 counts). The function and shape of the kidney were evaluated by measuring the relative function of both sides of the kidneys, geometric mean, and size of kidney before comparative analysis. According to the study results, there was no significant difference in the relative function and geometric mean of both sides of the kidneys depending on the acquisition count. On the other hand, the size of the kidney tended to be larger with increasing acquisition count.

The Study on the Attenuation of X-ray and Imaging Quality by Contents in Stomach

동경래,지연상,김창복,최성관,문상인,디터 케빈 대한방사선과학회 2009 방사선기술과학 Vol.32 No.1

This study examined the change in the attenuation of X-rays with the ROI (Region of Interest) in DR (Digital Radiography) according to the stomach contents by manufacturing a tissue equivalent material phantom to simulate real stomach tissue based on the assumption that there is some attenuation of X-rays and a difference in imaging quality according to the stomach contents. The transit dosage by the attenuation of X-rays decreased with increasing protein thickness, which altered the average ROI values in the film and DR images. A comparison of the change in average ROI values of the film and DR image showed that the image in film caused larger density changes with varying thickness of protein than the image by DR. The results indicate that NPO (nothing by mouth) is more important in film system than in DR system.

A Study on the Flip Angle for an Optimal T1-weighted Image based on the 3D-THRIVE MRI Technique: Focusing on the Detection of a Hepatocellular Carcinoma (HCC)

동경래,구은회,이재승,정운관,김영재 한국물리학회 2014 THE JOURNAL OF THE KOREAN PHYSICAL SOCIETY Vol.64 No.8

This study examined the optimal flip angle (FA) for a T1-weighted image in the detection of ahepatocellular carcinoma (HCC). A 3D-T1-weighted high-resolution isotropic volume examination(THRIVE) technique was used to determine the dependence of the signal to noise ratio (SNR) andthe contrast-to-noise ratio (CNR) on the change in FA. This study targeted 40 liver cancer patients(25 men and 15 women aged 50 to 70 years with a mean age of 60.32 ± 6.2 years) who visitedthis hospital to undergo an abdominal MRI examination from January to June 2013. A 3.0 TeslaMRI machine (Philips, Medical System, Achieva) and a MRI receiver coil for data reception witha 16-channel multicoil were used in this study. The THRIVE (repetition time (TR): 8.1 ms, echotime (TE): 3.7 ms, matrix: 172 × 172, slice thickness: 4 mm, gap: 2 mm, field of view (FOV):350 mm, and band width (BW): 380.1 Hz) technique was applied as a pulse sequence. The timerequired for the examination was 19 seconds, and the breath-hold technique was used. Axial imageswere obtained at five FAs : 5, 10, 15, 20 and 25 . The signal intensities of the liver, the lesion andthe background noise were measured based on the acquired images before the SNR and the CNRwere calculated. To evaluate the image at the FA, we used SPSS for Windows ver. 17.0 to conducta one-way ANOVA test. A Bonferroni test was conducted as a post-hoc test. The SNRs of thehemorrhagic HCC in the 3D-THRIVE technique were 35.50 ± 4.12, 97.00 ± 10.24, 66.09 ± 7.29,53.84 ± 5.43, and 42.92 ± 5.11 for FAs of 5, 10, 15, 20, and 25 , respectively (p = 0.0430), whereasthe corresponding CNRs were 30.50 ± 3.84, 43.00 ± 5.42, 36.54 ± 4.09, 32.30 ± 2.79, and 31.69± 3.21 (p = 0.0003). At a small FA of 10, the SNR and the CNR showed the highest values. Asthe FA was increased, the SNR and the CNR values showed a decreasing tendency. In conclusion,the optimal T1-weighted image FA should be set to 10 to detect a HCC by using the 3D-THRIVEabdominal MRI technique. PACS numbers: 87.61.-c, 87.61.

표지시간 변화에 의한 99mTc과 적혈구 표지효율

동경래,김호성,최성관 대한방사선과학회 2007 방사선기술과학 Vol.30 No.3

For the preparation of 99mTc-labeled RBC, 10~20㎍/kg of Stannous(Ⅱ) chloride and 10~40min of preparation was used. For finding out the effect of contrast agent, the blood samples were collected in three days, seven days, and 1 months after the diagnostic procedure. In the normal volunteer, the concentration of reducing agent and preparation time did not effect on the radiochemical yield. But in the patients, 10mg of Stannous(Ⅱ) chloride and 60min incubation times was shown high radiochemical yield. Contrast agent has a significant effect on the radiochemical yield. Although the blood samples which were collected after seven days of diagnostic procedure did not effect on the radiochemical yield of 99mTc- labeled RBC, but the radiochemical yield of 99mTc-labeled RBC which was prepared with a sample of high concentration of contrast agent in blood led to low radiochemical yield. For these samples, the modified method showed high radiochemical yield than previous in vivo preparation method. The recommended method is followed. Blood collecting was performed at 30 minutes after injection of reducing agent, and it is centrifuged for removal of plasma. After addition of 99mTcO-4, sample reservoir was rotated. After addition of normal saline, and it is centrifuged for separation of saline. Then 99mTc-labeled RBC was obtained after removal of saline.

^(99m)Tc, ^(123)I, ^(131)I을 이용한 갑상선섭취 계수율에 따른 불능시간과 보정방법에 관한 연구

동경래,정운관 조선대학교 에너지.자원신기술연구소 2004 에너지·자원신기술연구소 논문지 Vol.26 No.1

Coefficient incapability time of thyroid gland intake that use ^(99m)Tc, ^(123)I, ^(131)I research about under the influence of property and the revision method. Work that measure the thyroid gland intake rate and examine thyroid gland function using number of flash meter of radionuclide and Nal(TI) crystallization is the most fundamental and important test in nuclear medicine. Iodin freight of these thyroid gland function test is captured and bases to concept that is stored by thyroid gland. Thyroid gland intake rate of radionuclide in thyroid gland function test is influenced greatly depending on coefficient incapability time of thyroid gland intake. It by effect of coefficient incapability time non-linear by it because can give difficulty to drop correct diagnosis because take count longevity to be less actuality Counts more be Radioactivity iodin intake rate of thyroid gland (secession coefficient of neck - secession coefficient of femoral region) / by (standard time fare secession coefficient - back radioactivity) ×lOO define earched his revision methods after use ^(99m)Tc, ^(123)I, ^(131)I and Lucite cylindrical phantom(human body and neck form of resentment style Phantom that consist to almost resemblant component parts) in this experiment and study special qualitys of coefficient incapability time of thyroid gland intake.

Study on the Health Recovery Effects of Injection Omega-3 Fatty Acid to Mouse by Exposing Radiation

동경래,곽종길,공창기 (사)한국방사선산업학회 2021 방사선산업학회지 Vol.15 No.2

This study is to determine the radioprotective effects of Squalene (SQ) extracted fromnatural products, a large amount of which is contained in the liver of centrophorusatromarginatus. For this purpose, SQ was administered to mice exposed to a session of 3 Gy whole-body irradiation;then, first, Caspase-3 and Caspase-9 in the cell signaling pathways, which led to apoptosis, weremeasured to examine cell activity; second, nitric oxide (NO) was measured to observe inflammatoryresponses in cells. There were a total of seven experimental groups; considering the fact that it mighttake the specimens long to be absorbed into living tissues, seven- and three-day factors were appliedto the pretreatment groups and three- and seven-day factors. To determine the radioprotectiveeffects of SQ, a 10 MeV LINAC radiation therapy system was used to expose mice to a session ofwhole-body irradiation in a dose of 3 Gy, which induces the greatest biochemical changes in livingtissues, at the dose rate of 300 cGy·min-1. It has been confirmed that squalene with good antioxidanteffects gives radioprotection by promoting NO generation and by inhibiting Caspase that a naturalproduct with a lower level of chemical toxicity can be used as a radioprotector.

비조영증강 MDCT에서 관전압과 절편 두께에 따른 요로결석의 HU 측정

동경래,정명진,전재두,김미현,권대철,정운관 (사)한국방사선산업학회 2018 방사선산업학회지 Vol.12 No.2

To distinguish urinary stones, we tried to identify the components of urinary stone using HU of nonenhancement MDCT. HU was measured according to the tube voltage and the slice thickness of the section of urinary stone. After injecting urinary stone into a small plastic bottle, experimental phantom was prepared using pork similar to human body. 640 slice MDCT. HU of urinary stone was measured according to each tube voltage and slice thickness in the obtained images. HU of urinary stones according to tube voltage were 135 kVp (373.68±30.20 HU), 100 kVp (525.94±44.93 HU) and 80 kVp (691±80.80 HU), and the slice thickness was 0.5 mm (752±25.71 HU) minimum (545.96±29.89 HU), 1.5 mm (462.68±46.35 HU), 2 mm (360.43±66.19 HU). It was found that the HU of urinary stone was increased with decreasing tube voltage, and the HU of urinary stone was decreased with increasing thickness of the section. Non-enhancement MDCT for urinary stone is thought to be useful for the diagnosis of urinary stone using thin slice thickness using low tube voltage.

Quantitative Analysis of the Breath-holding Half-Fourier Acquisition Single-shot Turbo Spin-echo Technique in Abdominal MRI

동경래,구은회,이재승,정운관 한국물리학회 2013 THE JOURNAL OF THE KOREAN PHYSICAL SOCIETY Vol.62 No.2

A consecutive series of 50 patients (28 males and 22 females) who underwent hepatic magnetic resonance imaging (MRI) from August to December 2011 were enrolled in this study. The appropriate parameters for abdominal MRI scans were determined by comparing the images (TE = 90 and 128 msec) produced using the half-Fourier acquisition single-shot turbo spin-echo (HASTE) technique at different signal acquisition times. The patients consisted of 15 normal patients, 25 patients with a hepatoma and 10 patients with a hemangioma. The TE in a single patient was set to either 90 msec or 128 msec. This was followed by measurements using the four normal rendering methods of the biliary tract system and the background signal intensity using the maximal signal intensity techniques in the liver, spleen, pancreas, gallbladder, fat, muscles and hemangioma. The signal-to-noise and the contrast-to-noise ratios were obtained. The image quality was assessed subjectively, and the results were compared. The signal-to-noise and the contrast-to-noise ratios were significantly higher at TE = 128 msec than at TE = 90 when diseases of the liver, spleen, pancreas, gallbladder, and fat and muscles, hepatocellular carcinomas and hemangiomas, and rendering the hepatobiliary tract system based on the maximum signal intensity technique were involved (p < 0.05). In addition, the presence of artifacts, the image clarity and the overall image quality were excellent at TE = 128 msec (p < 0.05). In abdominal MRI, the breath-hold half-Fourier acquisition single-shot turbo spin-echo (HASTE) was found to be effective in illustrating the abdominal organs for TE = 128 msec. Overall, the image quality at TE = 128 msec was better than that at TE = 90 msec due to the improved signal-to-noise (SNR) and contrast-to-noise (CNR) ratios. Overall, the HASTE technique for abdominal MRI based on a high-magnetic field (3.0 T) at a TE of 128 msec can provide useful data.