• 제목/요약/키워드: Quantitative CT

검색결과 339건 처리시간 0.023초

Selection and evaluation of reference genes for gene expression using quantitative real-time PCR in Mythimna separata walker (Lepidoptera: Noctuidae)

  • ZHANG, Bai-Zhong;LIU, Jun-Jie;CHEN, Xi-Ling;YUAN, Guo-Hui
    • Entomological Research
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    • 제48권5호
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    • pp.390-399
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    • 2018
  • In order to precisely assess gene expression levels, the suitable internal reference genes must be served to quantify real-time reverse transcription polymerase chain reaction (RT-qPCR) data. For armyworm, Mythimna separata, which reference genes are suitable for assessing the level of transcriptional expression of target genes have yet to be explored. In this study, eight common reference genes, including ${\beta}$-actin (${\beta}$-ACT), 18 s ribosomal (18S), 28S ribosomal (28S), glyceraldehyde-3-phosphate (GAPDH), elongation fator-alpha ($EF1{\alpha}$), TATA box binding protein (TBP), ribosomal protein L7 (RPL7), and alpha-tubulin (${\alpha}$-TUB) that in different developmental stages, tissues and insecticide treatments of M. separata were evaluated. To further explore whether these genes were suitable to serve as endogenous controls, three software-based approaches (geNorm, BestKeeper, and NormFinder), the delta Ct method, and one web-based comprehensive tool (RefFinder) were employed to analyze and rank the tested genes. The optimal number of reference genes was determined using the geNorm program, and the suitability of particular reference genes was empirically validated according to normalized HSP70, and MsepCYP321A10 gene expression data. We found that the most suitable reference genes for the different experimental conditions. For developmental stages, 28S/RPL7 were the optimal reference genes, both $RPL7/EF1{\alpha}$ were suitable for experiments of different tissues, whereas for insecticide treatments, $28S/{\alpha}-TUB$ were suitable for normalizations of expression data. In addition, $28S/{\alpha}-TUB$ were the suitable reference genes because they have the most stable expression among different developmental stages, tissues and insecticide treatments. Our work is the first report on reference gene selection in M. separata, and might serve as a precedent for future gene expression studies.

Bone Regenerative Effects of Biphasic Calcium Phosphate Collagen, Bone Morphogenetic Protein 2, Mesenchymal Stem Cells, and Platelet-Rich Plasma in an Equine Bone Defect Model

  • Eun-bee Lee;Hyunjung Park;Jong-pil Seo
    • 한국임상수의학회지
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    • 제40권2호
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    • pp.85-92
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    • 2023
  • Fractures in the horse industry are challenging and a common cause of death in racehorses. To accelerate fracture healing, tissue engineering (TE) provides promising ways to regenerate bone tissues. This study aimed to evaluate the osteogenic effects of biphasic calcium phosphate collagen (BCPC) graft, bone morphogenetic protein 2 (BMP2), mesenchymal stem cell (MSC), and platelet-rich plasma (PRP) treatments in horses. Four thoroughbred horses were included in the study, and, in each horse, three cortical defects with a diameter of 5 mm and depth of 10 mm were formed in the third metacarpal bones (MC) and metatarsal bones (MT). The defects were randomly assigned to one of six treatment groups (saline, BCPC, BMP2, MSC, PRP, and control). Injections of saline, BMP2, PRP, or MSCs were made at 1, 3, and 5 weeks after defect surgery. Bone regeneration effects were assessed by radiography, quantitative computed tomography (QCT), micro-computed tomography (μCT), histopathological, and histomorphometric evaluation. The new bone ratio (%) in the histomorphometric evaluation was higher in the BMP2 group than in the control and saline groups. Radiographic and QCT values were significantly higher in the BCPC groups than in the other groups. QCT values of the BMP2 group were significantly higher than in the control and saline groups. The present study demonstrated that BCPC grafts were biologically safe and showed osteoconductivity in horses and the repeated injections of BMP2 without a carrier can be simple and promising TE factors for treating horses with bone fractures.

DECT의 VNC 적용으로 조영제와 석회화의 식별 에너지 영역 분석 (Discrimination Energy Range Analysis of Contrast Agents and Calcification using by VNC Application of DECT)

  • 김현주
    • 한국방사선학회논문지
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    • 제18권2호
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    • pp.179-185
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    • 2024
  • DECT의 다양한 에너지 스펙트럼 영상 구현기능을 적용하여 조영제와 석회화의 정량적 구분 가능성을 알아보기 위해 CNR과 SNR을 비교하여 화질의 변화를 분석하고, 기존 방법인 2회 스캔 적용 시와 실험에서 적용한 VNC 영상 구현 1회 스캔 시 선량 감소수준을 알아보았다. 그 결과 70 keV 영역에서 조영제와 석회화가 가장 잘 구분되었고, CNR, SNR도 우수하였으며 스캔 선량은 약 26.5% 감소효과가 있었다. 따라서 DECT 적용은 에너지별 가상 분광 영상 구현으로 석회화의 명암을 형성하여 시각적 그리고 정량적 구분에 매우 유의미한 결과를 도출할 수 있었다. 향후 환자의 나이, 성별 및 체형 등을 고려한 임상 연구를 시행하여 결과를 도출한다면 혈관 내 조영제가 유입된 상태에서도 석회화 정량 분석이 가능하여 환자의 검사 선량과 다 회 검사에 대한 부담감 감소에 큰 효과가 있을 것으로 사료된다.

Automated Segmentation of Left Ventricular Myocardium on Cardiac Computed Tomography Using Deep Learning

  • Hyun Jung Koo;June-Goo Lee;Ji Yeon Ko;Gaeun Lee;Joon-Won Kang;Young-Hak Kim;Dong Hyun Yang
    • Korean Journal of Radiology
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    • 제21권6호
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    • pp.660-669
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    • 2020
  • Objective: To evaluate the accuracy of a deep learning-based automated segmentation of the left ventricle (LV) myocardium using cardiac CT. Materials and Methods: To develop a fully automated algorithm, 100 subjects with coronary artery disease were randomly selected as a development set (50 training / 20 validation / 30 internal test). An experienced cardiac radiologist generated the manual segmentation of the development set. The trained model was evaluated using 1000 validation set generated by an experienced technician. Visual assessment was performed to compare the manual and automatic segmentations. In a quantitative analysis, sensitivity and specificity were calculated according to the number of pixels where two three-dimensional masks of the manual and deep learning segmentations overlapped. Similarity indices, such as the Dice similarity coefficient (DSC), were used to evaluate the margin of each segmented masks. Results: The sensitivity and specificity of automated segmentation for each segment (1-16 segments) were high (85.5-100.0%). The DSC was 88.3 ± 6.2%. Among randomly selected 100 cases, all manual segmentation and deep learning masks for visual analysis were classified as very accurate to mostly accurate and there were no inaccurate cases (manual vs. deep learning: very accurate, 31 vs. 53; accurate, 64 vs. 39; mostly accurate, 15 vs. 8). The number of very accurate cases for deep learning masks was greater than that for manually segmented masks. Conclusion: We present deep learning-based automatic segmentation of the LV myocardium and the results are comparable to manual segmentation data with high sensitivity, specificity, and high similarity scores.

IL-34 Aggravates Steroid-Induced Osteonecrosis of the Femoral Head via Promoting Osteoclast Differentiation

  • Feng Wang;Hong Sung Min;Haojie Shan;Fuli Yin;Chaolai Jiang;Yang Zong;Xin Ma;Yiwei Lin;Zubin Zhou;Xiaowei Yu
    • IMMUNE NETWORK
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    • 제22권3호
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    • pp.25.1-25.11
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    • 2022
  • IL-34 can promote osteoclast differentiation and activation, which may contribute to steroid-induced osteonecrosis of the femoral head (ONFH). Animal model was constructed in both BALB/c and IL-34 deficient mice to detect the relative expression of inflammation cytokines. Micro-CT was utilized to reveal the internal structure. In vitro differentiated osteoclast was induced by culturing bone marrow-derived macrophages with IL-34 conditioned medium or M-CSF. The relative expression of pro-inflammation cytokines, osteoclast marker genes, and relevant pathways molecules was detected with quantitative real-time RT-PCR, ELISA, and Western blot. Up-regulated IL-34 expression could be detected in the serum of ONFH patients and femoral heads of ONFH mice. IL-34 deficient mice showed the resistance to ONFH induction with the up-regulated trabecular number, trabecular thickness, bone value fraction, and down-regulated trabecular separation. On the other hand, inflammatory cytokines, such as TNF-α, IFN-γ, IL-6, IL-12, IL-2, and IL-17A, showed diminished expression in IL-34 deficient ONFH induced mice. IL-34 alone or works in coordination with M-CSF to promote osteoclastogenesis and activate ERK, STAT3, and non-canonical NF-κB pathways. These data demonstrate that IL-34 can promote the differentiation of osteoclast through ERK, STAT3, and non-canonical NF-κB pathways to aggravate steroid-induced ONFH, and IL-34 can be considered as a treatment target.

Segmental Liver Stiffness Evaluated with Magnetic Resonance Elastography Is Responsive to Endovascular Intervention in Patients with Budd-Chiari Syndrome

  • Peng Xu;Lulu Lyu;HaitaoGe;Muhammad Umair Sami;Panpan Liu;Chunfeng Hu;Kai Xu
    • Korean Journal of Radiology
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    • 제20권5호
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    • pp.773-780
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    • 2019
  • Objective: To assess segmental liver stiffness (LS) with MRI before and after endovascular intervention in patients with Budd-Chiari syndrome (BCS). Materials and Methods: Twenty-three patients (13 males and 10 females; mean age, 42.6 ± 12.6 years; age range, 31-56 years) with BCS as a primary liver disease were recruited for this study. Two consecutive magnetic resonance elastography (MRE) examinations were performed before the endovascular treatment. Fifteen patients who underwent endovascular intervention treatment also had follow-up MRE scans within three days after the procedure. LS was measured in three liver segments: the right posterior, right anterior, and left medial segments. Inter-reader and inter-exam repeatability were analyzed with intraclass correlation coefficients (ICCs) and Bland-Altman analysis. Segmental LS and clinical characteristics before and after the intervention were also compared. Results: Within three days of the endovascular intervention, all three segmental LS values decreased: LS of the right posterior segment = 7.23 ± 0.88 kPa (before) vs. 4.94 ± 0.84 kPa (after), LS of the right anterior segment = 7.30 ± 1.06 kPa (before) vs. 4.77 ± 0.85 kPa (after), and LS of the left medial segment = 7.22 ± 0.87 kPa (before) vs. 4.87 ± 0.72 kPa (after) (all p = 0.001). There was a significant correlation between LS changes and venous pressure gradient changes before and after treatments (r = 0.651, p = 0.009). The clinical manifestations of all 15 patients significantly improved after therapy. The MRE repeatability was excellent, with insignificant variations (inter-reader, ICC = 0.839-0.943: inter-examination, ICC = 0.765-0.869). Bland-Altman analysis confirmed excellent agreement (limits of agreement, 13.4-19.4%). Conclusion: Segmental LS measured by MRE is a promising repeatable quantitative biomarker for monitoring the treatment response to minimally invasive endovascular intervention in patients with BCS.

자궁경부암의 방사선치료성적 (Results of Radiotherapy for the Uterine Cervical Cancer)

  • 김철용;최명선;서원혁
    • Radiation Oncology Journal
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    • 제6권1호
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    • pp.63-73
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    • 1988
  • One hundred fifty-four patients with the carcinoma of the uterine cervix were studied retrospectively to assess the result and impact of treatment at Department of Radiation Oncology, Korea University, Hae-Wha Hospital from Feb 1981 through Dec. 1986. Prior to radiotherapy, the patients were evaluated and staged by recommendation of FIGO including physical examination, pelvic examination, cystoscopy, rectosigmoidoscopy, chest X-ray, IVP. Ba enema. Also, an additional pelvic CT scan was obtained for some of the patients. The patients were treated by radiotherapy alone or adjuvant postoperative irradiation; in case of radiation therapy only, whole pelvic irradiation was given with Co-60 teletherapy unit via AP and PA parallel opposing fields or 4-oblique fields, 180 cGy per day, 5 days per week and intracavitary insertion was performed. In satges Ia, Ib, and IIa with small primary lesion, external irradiation was initially given to pelvis up to $2,000\~3,000\;cGy/2frac{1}{2}\;-3frac{1}{2}$ weeks and then intracavitary insertion was performed using Fletcher-Mini-Declos Applicator with cesium-137 cources and followed by external irradiation of $1,000\~2,000\;cGy/1frac{1}{2}\;-2frac{1}{2}$weeks via AP and PA parallel opposing fields with midline shield to spare of bladder and rectum. However, if the primary lesion is large, external irradiation was given without midline shield. More than stages IIb, the patients were treated by external beam irradiation up to 5,400cGy/30f for 6 weeks via 4-oblique portals and at the dose of 5,040cGy/28f the field was cut 5cm from the top margin for spare of small bowel, and followed by intracavitary irradiation, If there was residual tumor an additional dose of $900\~l,200cGy/5\~7f$ was given to parametrium and/or residual tumor area. Total dose of radiation to A and B-point were as follows; A-point; In early stages, Ia, Ib, IIa; $8,000\~9,000$ B-point $5,000\~6,000 cGy$ A-point; In advanced stages IIb, IIIa, IIIb; $9,000\~10,000$ B-point $60,000\~7,000cGy$ The results were obtained and as fellows; 1 The patients distribution according to FIGO staging system were stage Ia 6, Ib 27, IIa 28, IIb 54, IIIa 12, IIIb 18, and stage IVa 9. 2. Value of CT scan were demonstration of cervix tumor mass, parametrial and pelvic side wall tumor spread, pelvic and inguinal lymph nodes metastases, and hydronephrosis. Three dimensional quantitative demonstration of tumor volume is also important in planning radiation therapy. Another advantage of CT scan was detection of recurrent tumor after radiation or surgery. 3. Local control rate of tumor according to the size was $91.3\%$ for less than 5cm in size and $44.6\%$ in tumor over 5cm (p<0.0068). 4. Thirty out of 50 recurrent sites has locoregional failures and 17 cases has distant metastases. And the para-aortic lymph nodes were the most common site for distant metastases. 5. The most common complication was temporal rectal bleeding which was controlled most by conservative management. However, 4 patients required for endoscopic cauterization. 6. The 5-year survival rates showed; stage la and Ib $95\%,\;stage\;IIa\;81\%\;stage\;lIb\;67\%,\;stage\;IIIa\;37.7\%,\;stage\;IIIb\;23\%$ and 3-year survival rate of stage IVa showed $11.6%$, retrospectively.

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PET 검사 시 Reconstructed data와 Re-sliced data의 표준섭취계수와 Metabolic Tumor Volume의 비교 평가 (Evaluation of Standardized Uptake Value and Metabolic Tumor Volume between Reconstructed data and Re-sliced data in PET Study)

  • 도용호;이홍재;김진의
    • 핵의학기술
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    • 제20권2호
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    • pp.3-8
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    • 2016
  • PET 검사에서 SUV는 암의 원발 부위, 전이여부 파악 및 병기결정, 재발여부 판단에 도움을 주는 지표이다. 특히 항암, 방사선치료 후 효과 판정을 위한 검사 시 이전 검사와의 SUV 비교 평가가 중요시 된다. 그러나 핵의학과 에서 자체적으로 데이터를 저장하는 외장하드, mini PACS 등의 저장 장치는 데이터 손실의 가능성을 가지고 있다. 이에 본 연구에서는 workstation의 reconstructed data (R-D)와 병원 PACS로 전송한 R-D, re-sliced data (S-D) 사이의 SUV를 비교 평가하여 자체 저장장치의 데이터 손실 시 PACS로 전송한 데이터의 사용가능 여부를 확인 하고자 한다. Biograph Truepoint 40, mCT 40, mCT 64, mMR (Siemens, Germany)장비에서 2015년 1월부터 2월까지 $^{18}F-FDG$ PET 검사를 시행한 20명($60.5{\pm}8.3$세)의 데이터를 분석하였다. Workstation의 R-D와 PACS의 R-D, S-D 데이터를 Syngo.via 프로그램으로 전송하여 liver, aorta, tumor 부위의 max SUV($SUV_{max}$), peak SUV ($SUV_{peak}$)와 tumor의 metabolic tumor volume (MTV)를 측정하였다. Workstation과 PACS의 R-D에서 liver, aorta, tumor의 평균 $SUV_{max}$$2.95{\pm}0.59$, $2.35{\pm}0.61$, $10.36{\pm}6.15$ 이었고 $SUV_{peak}$$2.70{\pm}0.51$, $2.07{\pm}0.43$, $7.67{\pm}3.73$으로 동일하였으며 통계적으로 유의한 차이가 없었다(p>0.05). PACS의 S-D는 R-D대비 평균 $SUV_{max}$는 5.18%, 7.22%, 12.11%, $SUV_{peak}$는 2.61%, 3.63%, 10.07% 감소하였으며 통계적으로 유의한 차이가 있었다(p<0.05). R-D와 S-D에서 결과 값의 상관계수는 $SUV_{max}$에서 0.99, 0.96, 0.99이었고 $SUV_{peak}$에서 0.99, 0.99, 0.99로 모두 양의 상관관계가 있었다. Bland-Altman 분석에서 2표준편차는 $SUV_{max}$에서 0.125, 0.290, 1.864이었고 $SUV_{peak}$에서 0.053, 0.103, 0.826이었다. Tumor의 MTV는 workstation과 PACS의 R-D에서 모두 $14.21{\pm}12.72cm^3$로 동일하였다(p>0.05). PACS의 S-D에서는 R-D 대비 0.12% 감소하였으며 통계적으로 유의한 차이가 없었다(p>0.05). R-D와 S-D에서 상관계수는 0.99이었고 Bland-Altman 분석에서 2표준편차는 2.243이였다. 본 논문에서 PACS에 저장된 R-D의 경우 workstation의 R-D와 비교하여 $SUV_{max}$, $SUV_{peak}$, MTV 모두에서 동일한 값을 보였으나 S-D의 경우 상관관계는 높지만 MTV를 제외한 $SUV_{max}$, $SUV_{peak}$는 통계적으로 유의한 차이가 있었다. R-D를 안정성 있는 병원 PACS에 저장한다면 자체 저장장치의 데이터 손실 시 이전 PET 데이터와의 비교에서 신뢰성 있는 SUV 분석이 가능할 것이라 생각된다.

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PET/CT 검사에서 매개변수 입력오류에 따른 표준섭취계수 평가 (The Evaluation of SUV Variations According to the Errors of Entering Parameters in the PET-CT Examinations)

  • 김지아;홍건철;이혁;최성욱
    • 핵의학기술
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    • 제18권1호
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    • pp.43-48
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    • 2014
  • PET/CT검사에서 표준섭취계수(standardized uptake value, SUV)는 병소의 악성 여부를 판별하는 지표로서 인체내 각 장기의 생리적인 변화에 대한 정량분석을 가능하게 한다. 따라서 그 결과에 영향을 줄 수 있는 매개변수를 올바르게 입력하는 것이 매우 중요하다. 본 연구에서는 그 매개변수 중 방사능량, 체중, 방사성 동위원소 섭취시간의 입력오류에 따른 결과의 차이를 측정하여 수용 가능한 결과의 오차범위를 평가하고자 한다. 1994 NEMA 모형 내부에 열소, 테프론, 그리고 공기 3개의 삽입물을 위치시켰다. 총 27.3 MBq의 $^{18}F$를 열소와 배후 방사능 비율이 4:1로 되도록 채우고 GE Discovery STE 16(GE Healthcare, Milwaukee, USA)로 촬영하였다. 촬영 후 입력된 방사능량, 체중, 섭취 시간의 값을 기준 값에서 ${\pm}5%$, 10%, 15%, 30%, 50% 만큼 오차를 발생시킨 후 영상을 다시 재구성하였다. 재구성된 영상에서 각 삽입물 부위에 한 개, 배후방사능 부위에 총 네 개의 관심영역을 그린 후 $SUV_{mean}$과 백분율오차를 측정하여 비교 평가하였다. 기준 영상의 열소, 테프론 그리고 공기와 배후방사능에서의 $SUV_{mean}$은 각각 4.5, 0.02, 0.1 그리고 1.0이였다. 방사능량 오차 변화에 따른 $SUV_{mean}$의 최대값과 최소값은 열소에서 9.0, 3.0, 테프론에서 0.04, 0.01, 공기에서 0.3, 0.1, 배후 방사능에서 2.0, 0.6로 변화된 값을 보였다. 이 때 백분율오차는 모두 동일하게 최대 100%에서 최소 -33%로 나타났다. 체중 오차 변화의 경우 열소에서 2.2, 6.7, 테프론에서 0.01, 0.03, 공기에서 0.09. 0.28, 배후방사능에서 0.5, 1.5로 변화된 값을 보였다. 이 때 백분율오차는 테프론의 최소 -50%, 최대 52%를 제외하고 모두 최소 -50%에서 최대 50% 로 동일하게 나타났다. 섭취시간 오차의 경우 열소에서 3.8, 5.3, 테프론에서 0.01, 0.02, 공기에서 0.1, 0.2, 배후방사능에서 0.8에서 1.2로 변화된 값을 보였다. 백분율오차는 열소와 배후방사능은 최소 -14%에서 최대 17%로 동일하게 나타났으며 테프론의 경우 최소 -11%에서 최대 21%, 공기의 경우 최소 -12%에서 최대 20%로 나타났다. 일반적으로 수용 가능한 오차의 범위를 5%로 설정할 경우, 본 실험 결과에서 방사능량과 체중의 오차가 ${\pm}5%$ 이내 일 때 $SUV_{mean}$의 오차가 5% 범위에 포함되었다. 이러한 결과들을 고려해 볼 때 검사장비에 입력되는 방사능량과 체중에 직접적인 영향을 줄 수 있는 선량검량계와 체중계의 검교정은 오차범위 5% 이내로 이루어져야 한다. 섭취 시간의 경우 삽입물의 종류에 따라 서로 다른 오차 범위를 보였으며 열소와 배후방사능에서 오차가 ${\pm}15%$ 이내일 때 $SUV_{mean}$에 5% 내의 오차가 발생하였다. 따라서 검사 시 촬영용 스캐너를 포함하여 두 개 이상의 시계를 사용할 경우 각각의 시간 오차들도 함께 고려되어야 할 것이다.

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소아 심장 전산화단층촬영 검사에서 4 chamber의 동시 조영증강 영상에 대한 최적화 방안 (Optimization of the Empirical Method to the Enhancement Image of the Four Chambers at the Same Time in the Pediatric Cardiac Computed Tomography)

  • 박찬혁;이재승;임인철
    • 한국방사선학회논문지
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    • 제8권6호
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    • pp.279-285
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    • 2014
  • 본 연구는 소아 심장 전산화단층촬영 검사에서 조영제의 과다 사용을 최소화하며 피폭 선량 저감화를 목적으로 조영제의 주입속도 및 심장 도달 시간 등의 변수를 고려한 스캔 지연 시간을 경험론적 방법으로 수식화함으로써 4개의 심방과 심실이 동시 조영증강 영상을 획득할 수 있는 최적화 방안을 제시하고자 하였다. 소아 심장전산화단층 검사를 시행한 소아 환자 30명을 대상으로 정성적 평가, 정량적 평가, 선량평가를 실시하였다. 결론적으로 본 연구에서 개발한 체중에 따른 조영제 양과 주입속도에 따른 스캔 지연 시간을 계산하는 경험론적 방법을 적용함으로써 왼 오른 심방과 심실의 동시 조영증강에서 소아 심장 판독에 적합한 300 HU 값 이상으로 나타났고 명확성, 선예도, 노이즈에 대한 정성적 영상 평가에서 질적 우수성을 보였으며 선량평가에서도 소아가 받는 피폭선량도 명확하게 감소되었다. 따라서 본 연구는 임상에서 조영제 과다 사용으로 인한 부작용 감소 효과를 기대 할 수 있었으며 방사선 피폭 저감화를 기대 할 수 있는 이점을 가지고 최적의 영상을 만드는데 중요한 역할을 할 것으로 판단되었다.