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복부 CT검사에서 Scan Field of View 선택이 선량과 화질에 미치는 영향에 관한 연구
권용락(Yong Rak Kwon),방성호(Sung Ho Bang),남윤철(Yoon Chul Nam),김문찬(Moon Chan Kim) 대한전산화단층기술학회 2012 대한CT영상기술학회지 Vol.14 No.2
목적 현재 보편화되는 CT장치들은 다양한 bow-tie filter와 SFOV를 부가적으로 설치하고 있다. 이에 복부 CT검사에서 다양한 SFOV와 bow-tie filter를 변화시켜서 선량과 화질에 미치는 영향을 알아보고 최적의 검사방법을 권고하고자 하였다. 대상 및 방법 CT장치는 GE LightSpeed VCT XT와 Toshiba Aquillion 64MDCT을 사용하였다. 선량 측정은 Rando anthropomorphic woman phantom과 형광유리선량계를 사용하여 phantom 내ㆍ외측에서 측정을 하였으며 화질 평가는 각 장비의 자체 software을 사용하여 phantom 내측(3시, 9시, 12시, 중앙) 위치에서 noise을 측정하였다. X축의 직경 30cm인 phantom의 단면을 사용하여 GE사의 장치에서 SFOV을 small, medium, large로, Toshiba사의 장치에서는 SFOV을 medium, large로 변화시켜 평가하였다. X축의 직경 34cm인 phantom의 단면에서는 GE사의 SFOV을 medium, large로 변화시켜 평가하였다. 결과 LightSpeed VCT XT장치로 직경 30cm인 단면에서는 small SFOV 적용 시 선량 및 noise 값이 가장 낮게 측정되었고 직경 34cm인 단면에서는 선량 차이가 거의 없었으나 large SFOV 적용 시 조금 높았으며 noise 값은 medium SFOV 적용 시 낮게 측정되었다. Toshiba Aquillion 장치로 직경 30cm인 단면에서는 선량이 large SFOV 적용 시 크게 높았으나 noise 값은 12시 방향을 제외하고는 큰 차이가 없었다. 결론 환자의 크기에 따른 적절한 SFOV 선택은 환자의 피폭을 경감하고 진단에 적합한 우수한 영상을 획득하는 것이 옳은 검사방법이라고 사료된다. I. Purpose Current conventional CT equipments have various bow-tie filter and SFOV additionally, We studied the effect of a radiation dose and an image noise depending on a various SFOV and bow-tie filter and suggest the optimized method. II. Meterial and Methods The CT equipments are supplied by GE LightSpeed VCT XT and Toshiba Aquillion 64MDCT. The radiation dose has measured at the external and inner positions using the Rando anthropomorphic woman phantom and the fluorescent glass dosimeter. The image noise has evaluated at the inner positions (3, 9, 12 o’clock and middle) of a phantom’s cross section by the equipment’s software. The 30 cm diameter of X-axis has been scanned by small, medium, large SFOV of GE and medium, large SFOV of Toshiba. For the 34 cm diameter of X-axis, medium, large SFOV of GE has been. III. Result The lowest values of dose and noise have obtained by the light speed VCT XT for 30 cm of the object size at a small SFOV. The 34 cm of object size has almost none of differences dose though a higher dose at large SFOV and a lower noise at medium SFOV are shown. In Toshiba Aquillion, a dose at large SFOV is largely high for 30 cm of object size and a noise has no difference except the direction of 12 o’clock. IV. Conclusions We concluded that the optimized SFOV for the size of patients can reduce the radiation dose and help to obtain the good image for examinations.
Dong Rak Kwon,Yong Suk Moon 한국실험동물학회 2021 한국실험동물학회 학술발표대회 논문집 Vol.2021 No.7
Background: This study was conducted to investigate the synergic effects of polydeoxyribonucleotide (PDRN) combined with microcurrent therapy (MT) on an atrophied calf muscle in a cast-immobilized rabbit model. Methods: Thirty-two male New Zealand rabbits at 12 weeks of age were allocated into 4 groups. After 2 weeks cast-immobilization, 4 types of procedures [normal saline 0.2ml injection group 1 (G1-NS); 0.2ml PDRN injection group 2 (G2-PDRN); MT group 3 (G3-MT); and 0.2ml PDRN injection with MT group 4 (G4-PDRN+MT)] were performed at atrophied calf muscle. MT (alternating current, 200μA, 30 Hz, rectangular pulse) was applied 60 minutes daily for 4 weeks. Calf Circumference (CC), Compound Muscle Action Potential (CMAP) of tibial nerve, and Thickness of Gastrocnemius muscle (TGCM) using ultrasound were evaluated before and after 4 weeks of treatment. Cross Sectional Area (CSA) of GCM fibers (type I, II and total), Proliferating Cell Nuclear Antigen (PCNA), vascular endothelial growth factor, and Platelet Endothelial Cell Adhesion Molecule-1 (PECAM-1) were measured. Results: G4-PDRN+MT (18.3±1.3, 20.0±1.6, 14.3±0.5/14.1±0.6) showed significantly lower in the mean atrophic changes of right CC, CMAP, TGCM (medial/lateral) than those in the G1-NS (23.0±1.6, 23.2±1.7, 16.3±0.8/15.9±0.6), G2-PDRN (19.3±1.4, 21.9±1.7, 14.8±0.9/14.6±0.7) and G3-MT (19.9±1.5, 21.5±1.8, 15.1±0.1/14.8±0.6), respectively (P < 0.05). In addition, the mean CSAs (type I, II & total) of medial and lateral GCM muscle fibers in G4-PDRN+MT (863.73±225.0 μm2, 1,306.06±393.5 μm2, 1,192.61± 406.6 μm2/844.94±282.8 μm2, 1,210.06±305.5 μm2, 1,140.79±333.5 μm2) were the larger than those in the G1-NS (287.63±92.6 μm2, 443.09±121.25 μm2, 399.03 ± 133.7 μm2/286.20±159.7 μm2, 420.09±155.6 μm2, 400.73 ± 163.1 μm2), G2- PDRN (633.59± 123.2 μm2, 955.08±350.1 μm2, 888.29±342.4 μm2/538.71±162.5 μm2, 1,063.01±322.2 μm2, 973.86 ± 359.8 μm2), G3-MT (505.21±155.4 μm2, 817.67±231.2 μm2, 752.99± 251.8 μm2/479.24±107.8 μm2, 784.57±228.7 μm2, 744.19 ± 240.0 μm2), respectively (P < 0.05). G4-PDRN+MT (0.386±0.105, 0.489±0.105, 0.493±0.075/0.374±0.094, 0.479 ±0.113, 0.488±0.133) was significantly higher than G1-NS (0.076±0.027, 0.161±0.075, 0.059±0.032/0.063±0.016, 0.146±0.055, 0.061±0.039), G2-PDRN (0.217±0.068, 0.282± 0.106, 0.280±0.073/0.204±0.039, 0.301±0.091, 0.293±0.053) and G3-MT (0.179±0.039, 0.264±0.108, 0.265±0.089/0.181±0.046., 0.271±0.062, 0.293±0.053), respectively (P < 0.05) in terms of the PCNA, VEGF, and PECAM-1 positive cells ratio of medial and lateral GCM muscle fibers. In G3-MT and G2-PDRN, CC, TG, CMAP, and CSA (type I, II and total) and the ratios of PCNA, VEGF, and PECAM-1 positive cells were significantly greater than those in G1- NS (p<0.05). Conclusions: The PDRN injection combined with MT was more effective than PDRN injection, MT, and normal saline injection separately on atrophied calf muscle of the rabbit models.