관상동맥 CT와 심근관류 CT 검사를 이용한 고농도 조영제와 저농도 조영제 간 비교 평가

차성진,고동희,전필현,고성민 대한CT영상기술학회 2024 대한CT영상기술학회지 Vol.26 No.1

최근 CT 기술의 발전으로 저관전압 사용할 수 있으면서 저농도 조영제의 임상적 유용성이 점차 입증되고 있다. 본 연구에서는환자의 혈역학적 분포와 심근의 평가를 동시에 수행할 수 있는 관상동맥 CT(Coronary Computed Tomography Angiography; CCTA) 검사와 역동적 심근관류 CT(Computed Tomography–Myocardial Perfusion Imaging; CT-MPI) 검사를 통하여 고농도와저농도 조영제 간의 차이를 비교하였다. 연구 결과 CCTA의 조직과 혈관에 대한 정량적 분석에서 고농도 조영제가 5~10% HU가 높았지만, 유의확률이 0.05 이상으로 나타났다. CCTA와 CT-MPI를 통한 심근 평가 결과 두 조영제 간 차이가 5% 이내였으며 유의확률이 0.05 이상으로 나타났다. 정성적 분석은 다섯 가지 범주로 명목적인 측정을 하였고 저농도 조영제와 고농도 조영제 간의 유의확률 0.05 이상으로 유의미한 차이점을 밝혀내지 못했다. 본 연구는 고농도와 저농도 조영제를 CCTA와 CT-MPI 검사에 적용하여 기존의 연구들과 차별성을 가졌다. CCTA와 CT-MPI를 통한 분석에서는 고농도 조영제를 사용한 영상보다저농도의 영상이 열등하지 않다는 결과를 보여준다. 연구 대상자의 표본이 더 모이고 본 연구에서 제시한 한계점을 극복한다면 CCTA와 CT-MPI에서 고농도 조영제를 사용하는 기존의 검사법에서 벗어나 저농도 조영제를 사용함으로써 환자의 조영제 부작용에 대한 부담을 크게 줄일 수 있을 것이다. With the advancement of CT technology, the use of low tube voltages, and the clinical efficacy of low-concentration contrast media are gradually being demonstrated. In this study, we compared the differences between high- and low-concentration contrast media using Coronary Computed Tomography Angiography (CCTA) and Computed Tomography–Myocardial Perfusion Imaging (CT-MPI). These imaging techniques can simultaneously evaluate the patient's hemodynamic distribution and myocardium. The study results indicated that the quantitative analysis of tissues and blood vessels in CCTA showed that high-concentration contrast media led to a 5 to 10% increase in Hounsfield Units (HU), but the probability of significance was greater than 0.05. As a result of myocardial evaluation using CCTA and CT-MPI, the difference between the two contrast agents was within 5%, and the probability of significance was greater than 0.05. Qualitative analysis utilized nominal measurements in five categories and did not reveal significant differences between low- and high-concentration contrast media with a significance probability greater than 0.05. This study differed from existing studies by utilizing high- and low-concentration contrast media for CCTA and CT-MPI examinations. Analysis using CCTA and CT-MPI shows that low-concentration images are not inferior to images obtained using high-concentration contrast media.

Comparison of 18F-Fluorodeoxyglucose Positron Emission Tomography/Computed Tomography, Hydro-Stomach Computed Tomography, and Their Combination for Detecting Primary Gastric Cancer1

장혜영,정우석,송이랑,김진숙 대한영상의학회 2015 대한영상의학회지 Vol.72 No.1

Purpose: To retrospectively compare the diagnostic accuracy for detecting primary gastric cancer on positron emission tomography/computed tomography (PET/CT) and hydro-stomach CT (S-CT) and determine whether the combination of the two techniques improves diagnostic performance. Materials and Methods: A total of 253 patients with pathologically proven primary gastric cancer underwent PET/CT and S-CT for the preoperative evaluation. Two radiologists independently reviewed the three sets (PET/CT set, S-CT set, and the combined set) of PET/CT and S-CT in a random order. They graded the likelihood for the presence of primary gastric cancer based on a 4-point scale. The diagnostic accuracy of the PET/CT set, the S-CT set, and the combined set were determined by the area under the alternative-free receiver operating characteristic curve, and sensitivity, specificity, positive predictive value (PPV), and negative predictive value (NPV) were calculated. Results: Diagnostic accuracy, sensitivity, and NPV for detecting all gastric cancers and early gastric cancers (EGCs) were significantly higher with the combined set than those with the PET/CT and S-CT sets. Specificity and PPV were significantly higher with the PET/CT set than those with the combined and S-CT set for detecting all gastric cancers and EGCs. Conclusion: The combination of PET/CT and S-CT is more accurate than S-CT alone, particularly for detecting EGCs.

측두골 질환의 진단을 위한 검사 추이분석 : 일반촬영, CT촬영과의 비교

차장원(Jang Won Cha),전진만(Jin Man Jeon),전재두(Jea doo Jeon),노지숙(Ji sook Noh) 대한전산화단층기술학회 2007 대한CT영상기술학회지 Vol.9 No.1

Purpose As there is to a disease of temporal bone, will recognize a tendency recent of an inspection for a diagnosis of a comparative analysis temporal bone disease to the patient who executed the Temporal bone CT which used CT equipment and the pati-ent who executed a general radiography inspection. Materials and methods Investigated the patient who executed a patient, general radiography inspection and the Temporal bone CT inspection that executed a Temporal bone CT inspection within a period like the patient who executed a general radiography inspection of mastoid general of mastoid at the same time by the inspection number of cases by diseases to the objects for three years until 2006 August from 2003 August. Also, general radiography inspector and CT thread inspector executed was Moniter-ing the 30 people of 155 people who inspected Temporal bone CT in the times like the general radiography 10 people who inspected of mastoid during patients until August from 2006 January. The Monitering is Investigated whether or not there was inconvenience of a inspector after inspection time an inspection, inspections whether or not there was image acquisition time, inconvenience of a patient. Results Showed the results compared with the patient 200 people who inspected general radiography of total Mastoid series to 32 people in 2005 years at 82 people in 2003 years during general radiography inspections of Mastoid series inspection case number decrease, and the annual increasing Temporal bone CT inspections of inspection case number that compared with the total 648 people who inspected Temporal bone CT to 233 people in 2005 at 96 people in 2003, and to increase. Also, Answered that were inconvenient, and general radiography than CT, patients and inspector too. and general radiography was over the 10 minutes but CT appeared to inspection time of the 10 minutes under and the time that it takes in an inspection is in an inconvenience matter in case of an inspection answered. Conclusion Inspection time is short, and there is not inconvenience and the CT inspection a patient or a inspector are increasing every year compare with general radiography inspections as accuracy of an inspection is high. Think that it must be improved in the trend that an CT inspection is enlarged to have a lot of regulation of insurance application in order to let you reduce an economic burden of a patient. As there are more advantages CT than general radiography in spite of these economic burdens recent and to diagnosis a disease of a temporal bone CT inspections than be used so as to be useful

CT Urology에서 가돌리늄 조영제 제거를 위한 이중에너지 CT의 Virtual Non-Contrast 기술의 평가

조원우,송현석,심지나,김령희,안치복,김세영 대한CT영상기술학회 2024 대한CT영상기술학회지 Vol.26 No.1

MRI 조영검사를 시행한 환자의 비뇨기계에 잔존한 가돌리늄 조영제는 CT 영상에서 높은 HU로 나타나 CT Urology를 시행하는데 제한을 주고 있다. 본 연구는 이러한 문제를 해결하기 위해 이중에너지 CT(Dual-Energy Computed Tomography; DECT)의 가상 비 조영상(Virtual Non Contrast; VNC) 기술에 주목하여 다양한 이중에너지에서 VNC를 실제 CT Urology에 적용할 수 있는지 평가하였다. MRI 조영검사를 시행하고 CT Chest 비 조영검사를 시행한 환자의 신장 측 요관에 잔존한 가돌리늄 조영제의 HU값을 측정하였다. 그 결과를 바탕으로 가돌리늄 조영제 혼합물 Max, Mean, Min Mixture를 만들어 생리식염수와 함께 팬텀에 삽입하여 에너지별로 스캔하였다. 또한, Iodine Mixture와 요로결석의 HU를 표현한 Virtual Stone을 제작하여 평가하였다. 그 결과, 70 kV와 sn150 kV를 사용한 DECT의 VNC에서 가돌리늄 조영제 혼합물의 대조도가 현저하게 감소하였으며, Min Mixture는 Normal Saline과 HU와 CNR 모두 거의 유사한 형태로 나타났으며, 요오드 조영제와 가상 요로결석과의 구별도 가능했다. 따라서 MRI 조영검사 1시간 30분의 대기시간을 가지고 CT Urology를 시행할 경우, DECT의 VNC를 활용하여 효과적인 가돌리늄 조영제를 제거한 영상을 획득할 수 있음을 확인했다. Residual gadolinium contrast agents in the urinary tract following MRI contrast-enhanced examinations often presents as elevated Hounsfield Unit (HU) values on CT scans, impeding the efficacy of CT urology procedures. This study aims to explore the feasibility of addressing this challenge through the application of the Dual-Energy Computed Tomography (DECT) Virtual Non-Contrast (VNC) technique across various energy levels. HU values of residual gadolinium contrast agent in the renal pelvis and ureter were measured in patients who underwent MRI contrast-enhanced examinations followed by non-contrast CT chest examinations. Subsequently, gadolinium contrast agent mixtures, such as Max, Mean, and Min Mixtures, were created and scanned together with normal saline using DECT at various energy levels. Additionally, an iodine mixture and a virtual stone representing urolithiasis were fabricated and evaluated. The results demonstrated a significant reduction in contrast enhancement of gadolinium contrast agent with DECT VNC at 70 kV and Sn150 kV. The Min Mixture closely resembled normal saline in both HU and Contrast-to-Noise Ratio (CNR), facilitating the differentiation between iodine contrast agent and virtual urolithiasis. Therefore, utilizing DECT VNC after a 1-hour and 30-minute interval following MRI contrast-enhanced examinations effectively eliminates gadolinium contrast agents, improving the efficacy of CT Urology imaging procedures.

컴퓨터 단층촬영을 이용한 요로결석 검사에서 저선량 CT의 적용에 대한 유용성 평가

김현진(Hyeon-Jin Kim),지태정(Tae-Jeong Ji) 한국콘텐츠학회 2017 한국콘텐츠학회논문지 Vol.17 No.6

본 연구는 컴퓨터단층촬영을 이용한 요로결석 검사에서 저선량 CT(Low dose Computed Tomography) 프로토콜의 적용에 따른 유용성을 평가하였다. 연구대상은 2016년 6월–12월까지 부산지역 일개 의료기관을 내원한 비뇨기계 환자이며 연구에 이용된 프로토콜은 통계적 반복 재구성법(Adaptive Statistical Iterative Reconstruction, ASIR)을 50% 적용한 저선량 CT 프로토콜이다. 정량적 분석 결과 횡단면상(Axial image)의 신장의 관심 영역(region of image. ROI) 내 평균 화소 값과 표준편차는 복부촬영 프로토콜 26.21±7.08, 저선량 CT 프로토콜 20.03±8.16 이며 관상면(Coronal imalge) 영상에서 신장의 관심영역 내 평균 화소 값과 표준편차는 복부촬영 프로토콜 22.07±7.35, 저선량 CT 프로토콜 21.67± 6.11 이었다. 정성적 분석결과 인공물에 대한 4명의 관찰자 평균값은 복부촬영 프로토콜 19.14±0.36, 저선량 CT 프로토콜 19.17±0.43 이며 해상도 및 대조도의 평균값은 복부촬영 프로토콜 19.35±0.70, 저선량 CT 프로토콜 19.29±0.58 이었다. 피폭선량 분석 결과 복부촬영 프로토콜의 CTDIvol 평균값은 18.02 mGy, DLP 평균값은 887.51 mGy·cm 이며 저선량 CT 프로토콜 CTDIvol 평균값은 7.412 mGy, DLP 평균값은 361.22 mGy·cm 이었다. 이로 인한 선량의 감소율은 각 58.82%, 59.29% 이었다. The aim of this study was to evaluate the usability of applied Low dose Computed Tomography(LDCT) protocol in examining urinary calculus using computed tomography. The subjects of this study were urological patients who visited a medical institution located in Busan from June to December 2016 and the protocol used in this study was Adaptive Statistical Iterative Reconstruction: low-dose CT with 50% Adaptive Statistical Iterative Reconstruction (ASIR). As results of quantitative analysis, the mean pixel value and standard deviation within kidney region of image(ROI)of the axial image were 26.21±7.08 in abdomen CT pre scan and 20.03±8.16 in low-dose CT. Also the mean pixel value and standard deviation within kidney ROI of the coronal image were 22.07±7.35 in abdomen CT pre scan and 21.67±6.11 in low dose CT. The results of qualitative analysis showed that four raters’ mean values of observed kidney artifacts were 19.14±0.36 when using abdomen CT protocol and 19.17±0.43 in low-dose CT, and the mean value of resolution and contrast was 19.35±0.70 when using abdomen CT protocol and 19.29±0.58 in low-dose CT. Also the results of a exposure dose analysis showed that the mean values of CTDIvol and DLP in abdomen CT pre scan were 18.02 mGy and 887.51 mGy·cm respectively and the mean values of CTDIvol and DLP when using low-dose CT protocol were 7.412 mGy and 361.22 mGy·cm respectively. The resulting dose reduction rate was 58.82% and 59.29%, respectively.

CT 검사에서 대동맥박리(aortic dissection)의 발생빈도에 관한 고찰

동경래(Kyung-Rae Dong),최성관(Sung-Kwan Choi),장영일(Young-Ill Jang),노상호(Sang-Ho Ro) 대한방사선과학회(구 대한방사선기술학회) 2008 방사선기술과학 Vol.31 No.2

  목 적: 혈관의 내층과 외층을 급속히 해리시키는 예후가 매우 위험한 질환으로 대동맥 박리증(aortic dissection)의 임상적 진단을 위해 CT를 시행하여 대동맥 박리 증으로 판명된 환자 수와 연령별로 발생 빈도를 조사하고자 하였다.<BR>  방법 및 대상: 2005년 1월부터 2006년 12월까지 2년간 C대학병원에 내원한 환자 중 CT를 시행한 환자 112명을 대상으로 연도별로 증감 추세를 조사해 보고, 성별, 연령별, 진료과별로 조사 해 보았으며, 정확한 관찰을 위해 CT scan 후의 재구성 영상인 MIP와 SSD 그리고 VRT영상을 획득하여 CT와 일반 Chest PA 상을 비교하여 결과를 조사 연구하였다.<BR>  결과 및 결론:<BR>  1. CT를 시행한 환자 112명을 대상으로 연도별 검사건수는 2005년도 37명으로 41.9%를 보였고, 2006년도는 65명으로 58.1%로 2005년에 비해 2006년에 1.4배 증가되었다.<BR>  2. CT를 시행한 환자의 성별분포는 남성이 45명으로 40.1%, 여성이 67명으로 59.9%를 차지하고 있고 남성 45명 중 대동맥 박리증 환자는 9명으로 20%, 여성은 67명 중 21명으로 31.3%로 대동맥 박리증 환자가 남성에 비해 여성이 1.6배 많이 발생되었다. 또한 검사자 수도 남성에 비해 여성이 1.5배 많은 것으로 나타났다.<BR>  3. CT를 시행한 환자의 연령별 분포는 30세 미만에서는 거의 볼 수 없었으며 41세에서 80세까지가 전체에 88.3%를 차지하였으며 연령이 높을수록 대동맥 박리증 질환의 발생빈도가 높게 나타났다. 연령별 발생빈도의 차이는 통계적으로 유의하였다(p<0.01).<BR>  4. CT를 의뢰한 과는 응급의학과에서 46명(41.1%), 순환기 내과에서 37명(33.0%), 흉부외과에서 13명(11.6%), 기타 과에서 16명(14.3%)으로 응급의학과와 순환기내과가 전체의 74.1%로 나타났다. 따라서 대동맥 박리증 질환의 환자는 주로 응급실로 내원하는 매우 위험한 질환이라는 것을 알 수 있다.<BR>  5. 대동맥 박리 환자 30명 중 22명(73.3%)은 일반 X-ray상 정상으로 판독되었고, 8명(26.7%)만이 일반 X-ray상 이상소견이 나왔다. 따라서 대동맥 박리 질환을 정확히 평가하기 위해서는 반듯이 CT를 시행해야 할 것으로 사료되었다.   Purpose: Aortic Dissection is very dangerous, prognostic disease, which the bloodstream flow out of the true lumen of the aorta by the bursting of aortic intima resulting in a rapid dissociation of inner and outer layer from the media. It is difficult to diagnose aortic dissection clinically by normal X-ray. This study was to investigate the occurrence frequency by age and number of patients who are identified to be aortic dissection by CT(Computed Tomography) scan.<BR>  Materials and methods: We investigated the trend of yearly fluctuation, gender, age, and department of clinical research of the 112 patients who conducted CT scan in C- University Hospital for two years from January 2005 to December 2006. The MIP and SSD which reconstructed CT image and the VRT image were obtained for the accurate observation. The result was investigated by comparing normal X-ray and CT scan.<BR>  Results and Conclusion:<BR>  1. The yearly check of 112 patients conducted CT scan showed 37 people(41.9%) in 2005, and it was increased to 65(58.1%) in 2006 by 1.4 times.<BR>  2. The gender distribution of patients given a CT scan showed 45 males(40.1%), and female 67(59.9 %). The aortic dissection patients were 9(20%) out of 45 males, 21(31.3%) out of 67 females and women were 1.6 times more than men. Women are also 1.5 times more than men in the number of examinee.<BR>  3. The age distribution of patient"s who conducted CT scan revealed that there was no patient under 30 years old while 88.3% of all patients were through 41 to 80 years old. The higher the age was, the higher the occurrence of aortic dissection was. The difference in the occurrence frequency of age was statistically significant(p<0.01).<BR>  4. The departments that requested CT scan were the emergency department 46(41.1%), circulatory internal medicine 37(33.0%), chest surgery 13(11.6%), and others 6(14.3%). The combined ratio of emergency medicine and circulatory internal medicine was 74.1% of all. The results show that the aortic dissection is a very dangerous disease whose patients visit mainly via the emergency room.<BR>  5. The aortic dissection patients had normal X-ray readings in 22(73.3%) out of 30, and only 8(26.7 percent) are abnormal in the X-ray diagnosis. Therefore, the CT scan needs to be enforced in order to assess accurately the disease of aortic dissection.

Cone-beam CT와 multi-detector CT영상에서 측정된 CT number에 대한 비교연구

김동수,한원정,김은경,Kim, Dong-Soo,Han, Won-Jeong,Kim, Eun-Kyung 대한영상치의학회 2010 Imaging Science in Dentistry Vol.40 No.2

Purpose : To compare the CT numbers on 3 cone-beam CT (CBCT) images with those on multi-detector CT (MDCT) image using CT phantom and to develop linear regressive equations using CT numbers to material density for all the CT scanner each. Materials and Methods : Mini CT phantom comprised of five 1 inch thick cylindrical models with 1.125 inches diameter of materials with different densities (polyethylene, polystyrene, plastic water, nylon and acrylic) was used. It was scanned in 3 CBCTs (i-CAT, Alphard VEGA, Implagraphy SC) and 1 MDCT (Somatom Emotion). The images were saved as DICOM format and CT numbers were measured using OnDemand 3D. CT numbers obtained from CBCTs and MDCT images were compared and linear regression analysis was performed for the density, $\rho$ ($g/cm^3$), as the dependent variable in terms of the CT numbers obtained from CBCTs and MDCT images. Results : CT numbers on i-CAT and Implagraphy CBCT images were smaller than those on Somatom Emotion MDCT image (p<0.05). Linear relationship on a range of materials used for this study were $\rho$=0.001H+1.07 with $R^2$ value of 0.999 for Somatom Emotion, $\rho$=0.002H+1.09 with $R^2$ value of 0.991 for Alphard VEGA, $\rho$=0.001H+1.43 with $R^2$ value of 0.980 for i-CAT and $\rho$=0.001H+1.30 with $R^2$ value of 0.975 for Implagraphy. Conclusion: CT numbers on i-CAT and Implagraphy CBCT images were not same as those on Somatom Emotion MDCT image. The linear regressive equations to determine the density from the CT numbers with very high correlation coefficient were obtained on three CBCT and MDCT scan.

소아 CT 방사선량에 대한 이해와 영상기법의 최적화

구현우 대한영상의학회 2005 대한영상의학회지 Vol.52 No.1

The number of CT examinations is dramatically increasing due to recent technical advances including multislice spiral CT. Although the benefits of CT outweigh the risks of radiation exposure of CT, radiologists should alert to the potential harmful effects of CT and avoid unnecessarily high CT dose, especially for pediatric CT examinations. To accomplish this, we should understand CT radiation dose and be familiar with imaging techniques of reducing CT dose without degrading diagnostic image quality. In addition, it is important to spread this balanced and useful information into CT referring clinicians, radiologists in training, and medical students.

병원규모별 소아 두부 CT 검사 선량지표 분석 평가

김현진(Hyeon jin Kim),이효영(Hyo yeong Lee),임인철(In chul Im) 한국방사선학회 2016 한국방사선학회 논문지 Vol.10 No.7

소아는 방사선 감수성이 어른에 비해 높고 몸의 크기가 작아 어른과 같은 양의 방사선에 노출 되더라도 유효선량은 어른에 비해 더 높기 때문에 불필요한 피폭 방사선량을 줄이는 것이 매우 중요하다. 따라서 본 연구에서는 소아 두부 CT 검사에 있어서 피폭 방사선량을 경감할 수 있는 방법을 모색하고자 부산지역 병원들에서 시행된 년 간소아 두부 CT 검사에 대한 CT 선량지표(CTDI)를 국내 진단참고준위와 비교하여 분석함으로써 제안점을 도출하고자 하였다. 이를 위하여 부산시내에 설치된 CT 장비 중 소아 두부 CT 검사를 시행하며, 선량보고서를 PACS로 전송하는 24개 병원 28대 CT 장비를 대상으로 하여 소아 두부 CT 검사를 의뢰받은 10세 미만의 소아 2,043명을 후향적으로 조사하였다. 결과적으로 전체병원의 소아 두부 CT의 선량지표 CTDIvol의 평균값은 31.18 mGy, DLP는 444.73 mGy·cm로 나타나 진단참고준위를 초과하는 것으로 나타났다. 연령이 낮을수록 방사선에 대한 관리가 더욱 필요하다고 할 수 있는데 연구결과 6-10세 이하의 연령에 비해 더 낮은 다른 두 연령별에서 진단참고준위를 초과하는 환자수와 초과되는 비율이 높게 나타났다. 따라서 불필요한 방사선 노출을 줄이고 선량관리를 위한 노력들이 필요하다. 이를 위해 본 연구에서는 진단참고준위를 벗어나는 선량의 정도를 파악하고 초과되는 선량지표의 원인을 분석하여 선량감소를 위한 방안을 마련하고자 한다. Even though children are exposed to the same amount of radiation, their effective dose amount is higher than those of adults. Therefore, it is very important to reduce the amount of unnecessary radiation exposure because children have a higher radiosensitivity and a smaller body size than adults. In this study, the proposal to seek ways to reduce the amount of radiation is drawn by comparing and analyzing CT Dose Index(CTDI) on the pediatric head CT which was performed at the Busan regional hospitals, to the national diagnostic reference levels. For this, the pediatric head CT scan was conducted among the CT equipments that were installed in downtown Busan. From 2,043 children 10 years old or less who were referred to the pediatric head CT scan, targeting the 28 CT equipments in the 24 hospitals that transmit dose reports to PACS, were examined retrospectively. As a result, the average value of CTDIvol, computed tomography dose index (CTDI) of infant brain, across the hospital, was 31.18 mGy, with DLP of 444.73 mGy·cm, which exceeded the diagnostic reference level. The lower the age, the more management is needed for radiation. However, the reality is that the CT examinations are being conducted with a dose that exceeds the reference level as the age of the aged is exceeded. For this purpose, the study seeks to determine the degree of doses of doses outside the diagnostic reference level and analyze the cause of the excess dose and devise measures to reduce the dose reduction.

정상 소아의 간과 비장의 CT 수치

김영통 대한영상의학회 2002 대한영상의학회지 Vol.47 No.4

Purpose: To determine the mean liver CT numbers, and differences between liver and spleen, and liver and back muscle CT numbers in normal children, and to correlate the findings with sex and age. Materials and Methods: One hundred and five normal children aged 2-14 years underwent pre-contrast CT scanning. Mean CT numbers of the liver, spleen, and back muscles were calculated, as well as the differences in CT numbers between the liver and spleen (liver-spleen CT numbers), and between the liver and back muscles (liver-back muscles CT numbers). The results were correlated with age and sex. Results: For all children, mean liver, spleen, and back muscle, and liver-spleen and liver-back muscle CT numbers were 70.22±6.51 HU, 53.28±3.0 HU, 58.31±3.57 HU, 17.13±6.57 HU, and 11.88±5.94 HU, respectively. Mean liver CT numbers and the difference between liver and spleen CT numbers were high in children aged less than seven, bet mean spleen and back CT numbers, and the difference between liver and back muscle CT numbers were not different by age. By sex, all the CT numbers did not vary according to age. The sex of a subject did not affect the CT number. Conclusion: The children’s mean liver CT number was 70.22±6.51 HU and the difference between liver and spleen CT numbers was 17.13±6.57 HU. Younger children had higher liver CT and liver-spleen CT numbers than older children. No CT numbers varied according to sex. 목적: 정상 소아에서의 평균 간 CT수치의 범위, 간과 주위 장기의 CT수치의 차이를 알아보고 나이와 성별에 따른 차이를 알아보고자 한다. 대상과 방법: 2-14세사이의 105명의 소아들은 조영전 CT를 시행하였다. 간과 비장, 등근육의 평균 CT수치를 측정하였고, 간과 비장의 CT 수치차이, 간과 등근육의 CT수치 차이를 얻었다. 그리고 나이와 성별에 의한 차이를 알아보았다. 결과: 전체 소아들의 평균 간 CT수치는 70.22±6.51 HU, 평균 비장 CT수치는 53.28±3.0 HU, 평균 등근육 CT수치는 58.31±3.57 HU, 간과 비장의 CT수치 차이는 17.13±6.57 HU, 간과 등근육의 CT수치 차이는 11.88±5.94 HU였다. 7세미만의 소아에서 평균 간 CT수치가 높았고 간과 비장의 CT수치 차이도 컸다. 비장과 등근육의 CT수치와 간과 등근육과의 CT수치의 연령에 따른 차이는 없었다. 여러 CT수치들의 성별에 의한 차이는 없었다. 결론: 소아들의 평균 간 CT수치는 70.22±6.51 HU, 간과 비장의 CT수치의 차이는 17.13±6.57 HU였으며 나이가 어릴수록 평균 간 CT수치가 높고 간과 비장의 CT수치의 차이가 컸다. 하지만 성별에 따른 차이는 없었다.