Adenosine Stress Dual Energy Cardiac Perfusion CT에서 심근관류 결손부위와 주변 정상심근의 조영증강 정도에 따른 Dual Energy Image의 유용성에 관한 연구

부재철(Jae Cheol Boo),한영길(Young Gil Han),이현진(Hyun Jin Lee),임근교(Geun Gyo Im),김순배(Soon Bae Kim) 대한CT영상기술학회 2011 대한CT영상기술학회지 Vol.13 No.2

I. Purpose This study aimed to determine the clinical effectiveness of dual energy imaging by comparative analysis with reference to the HU values measured from 140 kVp, 80 kVp, and mixing images with a ratio of 7 : 3 between them in normal myocardium and myocardial perfusion defect regions. This idea of comparative evaluation is based on the characteristics of dual energy that the HU values from the images from SP-DECT (adenosine stress cardiac perfusion CT using dual energy) vary with energy changes in X-ray caused by the increase or decrease of contrast agents. II. Meterial and Methods Subjects were patients who underwent dual source cardiac CT from September 14, 2009 to August 20, 2010 and were found to be with coronary artery disease. Each of them completed SP-DECT. Out of the images acquired, we used the images that were suspected to be with perfusion defect (PD) as a result of comparison With cardiac MRI and coronary angiography. They were sorted into stress-induced PD (SPD, N: 32) and myocardial infarction (MI, N: 31) by using our judgment. Next, measurement of HU values was made using ROIs in the PD site and normal myocardium adjacent to it. The size of each ROI was chosen as large as possible within the measurement areas and the number of ROIs was determined to be more than 2 to be averaged. For comparative evaluation, standard deviations of the means were calculated. III. Result The group means of standard deviations were 9.35 for MI and 27.53 for the SPD group, and in relation to the MI group, the mean of standard deviations of normal myocardium was 47.17, while in relation to the SPD that was 50.38. Our one way ANOVA analysis with SPSS (version 12.0, SPSS Inc, Chicago, IL, USA) of the data classified into three groups: SPD, MI, and normal myocardium (normal as against each of the SPD and MI groups) found that there were significant differences among the three groups, with p-value being .000(p<0.05). The Scheffe post hoc test also showed significant differences among the three groups, with p-value being .000(p<0.05). IV. Conclusions The results of this study of patients who underwent SP-DECT and were suspected to be with PD showed that, in terms of the mean of standard deviations of the HU values acquired, there were significant differences among the groups of adenosine stress induced PD, MI, normal myocardium. This suggests that at the time of the perfusion examination, contrast agents increase in the ascending order of normal myocardium, SPD, and MI. Differently phrased, given that contrast agents travel through blood vessels and blood flow in normal myocardium is considered to be normal, it can be interpreted that blood flow in the SPD group is worse than normal, but better than in the MI group. Another implication is that with these values a quantification analysis is feasible. In short, SP-DECT will be useful in increasing the accuracy of perfusion evaluation of ischemic heart disease in that it allows for more diverse imaging presentations by using characteristics of dual energy in relation to contrast agents, thereby making available comparative evaluation of images and facilitating quantitative analysis. 목적 Dual energy를 이용한 adenosine stress cardiac peifusion CT(SP-DECT) 검사에서 조영제의 증강정도에 따라 X-ray의 에너지 변화에 의한 영상의 HU값이 변화되는 특성을 이용하여 140 kVp, 80 kVp와 두영상을 혼합(7:3)한 mixing image의 정상심근과 myocardial perfusion defect부위의 HU값을 비교 측정하여 진단적 유용성을 알아보고자 한다. 대상 및 방법 연구대상은 2009년 09월 14일부터 2010년 8월 20일까지 dual source cardiac CT검사를 받은 환자 중 coronary artery disease가 있는 환자를 SP-DECT검사를 시행하였고 cardiac MRI와 coronary angiography와 비교해 perfusion defect(PD)가 있다고 판명된 영상을 사용하였다. 그 중 판독상에 stress에 기인한 PD(SPD, N:32)와 myocardial infarction(MI, N:31)로 분류하여 PD가 있는 부위와 인접한 정상심근에 ROI를 이용해서 각각의 HU수치를 측정하였다. ROI크기는 측정부위가 벗어나지 않는 정도에서 최대한 크게 하였고 최소 2부위 이상 측정하여 평균을 구하였다. 그리고 평균의 표준편차를 계산하여 비교 평가하였다. 결과 MI의 표준편차의 평균은 9.35이고 MI에 대한 normal myocardium의 표준편차의 평균은 47.17이였다. 그리고 SPD는 27.53이고 SPD의 normal myocardium은 50.38이였다. 그리고 두 집단의 전체 normal myocardium과 SPD, MI로 분류하여 SPSS(version 12.0, SPSS Inc, Chicago, IL, USA)를 이용하여 One way ANOVA로 분석한 결과 p value값이 .000(p<0.05)으로 나와 유의한 차이가 있는 것으로 나타났다. 그리고 Scheffe 사후검증결과 normal myocardium, SPD, MI 모두 p value값이 .000(p<0.05)으로 세 집단간 모두 유의한 차이가 나타났다. 결론 본 연구 결과 SP-DECT를 시행하고 PD가 있는 환자 중 adenosine stress에 기인한 PD와 MI, 그리고 normal myocardium간에는 HU수치의 표준편차 값이 유의한 차이를 보였으며 이것은 perfusion검사 당시 normal myocardium, SPD, MI 순서로 조영제가 증강이 되는 것을 의미한다. 즉 조영제는 혈류를 따라 가기 때문에normal myocardium의 혈류가 정상이라고 했을 때 SPD는 정상심근 보다는 혈액의 흐름이 잘 안 된다고 볼 수 있고 MI 보다는 혈액의 흐름이 잘된다고 할 수 있을 것이다. 그리고 이러한 값들을 가지고 정량적인 수치화도 기능할 것이다. 결론적으로 SP-DECT는 조영제에 대한 dual energy의 특성을 이용하여 여러 영상을 제공해 줌으로써 그 영상들을 서로 비교 평가 할 수 있고 보다 객관적인 정량화가 가능하다는 점에서 ischemic heart disease의 관류평가에 유용한 도움을 줄 수 있을 것이라 사료된다.

Adenosine Stress Cardiac Perfusion CT에서 심근관류 평가에 대한 Dual Energy Scan의 유용성

부재철(Jae Cheol Boo),최문화(Moon Hwa Choi),원성화(Seong Hwa Won),임우택(Woo Taek Lim),김도윤(Do Yun Kim),김순배(Soon Bae Kim) 대한전산화단층기술학회 2013 대한CT영상기술학회지 Vol.15 No.1

목적 : Ischemia와 myocardial infarction(MI)의 구분을 위해 rest와 delay scan이 추가적으로 필요한 adenosine stress single energy(SE) cardiac perfusion CT에 비해 energy에 따라 여러 영상이 재구성되는 adenosine stress dual energy(DE) cardiac perfusion CT(SP-DECT)의 유용성과 그에 따른 방사선량 감소 효과를 알아 보고자 한다. 대상 및 방법 : 심근관류 평가 기준범위(평가범위)를 알기 위해 2009년 1월 16일부터 2010년 5월 27일까지 SP-DECT를 시행한 45명의 stress 영상으로 판독결과에 의존한 후향적 분석이 이루어졌다. 방법으로 DE(140, mix, 80kVp) 영상의 해부학적으로 같은 정상심근과 PD부위의 CT number(HU)와 표준편차(SD)를 구하였다. 통계적 분석은 SPSS 17.0 독립 K표본(Kruskal-Wallis ANOVA)으로 허용 유의수준은 α=.05로 하였다. 평가범위를 적용하기 위해 2012년 5월 3일부터 2012년 9월 17일까지 시행된 관상동맥과 심근의 상태를 모르는 19명을 대상으로 SE 영상인 mix 영상 test와 DE 영상 test를 시행하여 판독결과와 비교 평가하였다. 결과 : 통계적 분석 결과 정상심근, ischemia, MI의 SD에 대하여 χ2은 134.218이고 p-value .000으로 유의한 차이가 있는 것으로 나타났다. 후향적 분석결과를 토대로 평가범위는 mix test는 HU 85.0이하-MI, 85.1~128.1-ischemia, 128.2이상-정상심근, DE test에서는 SD 13.3이하-MI, 13.4~38.2-ischemia, 38.3이상-정상심근으로 정하였다. Blind test결과 mix test에서 총 20/31부위(64.5%), 정상심근 11/18부위(61.1%), ischemia 7/8부위(87.5%), MI 2/5부위(40%)가 일치하였고 DE test는 총 29/31부위(93.5%), 정상심근 17/18부위(94.4%), ischemia 7/8부위(87.5%), MI 5/5부위(100%)가 일치하였다. 선량 분석결과 DLP와 유효선량의 평균은 stress scan에서 340.06 mGy, 2.85 mSv, rest scan 372.3 mGy, 2.92mSv, delay scan 138.5 mGy, 0.69 mSv이었다. 결론 : SP-DECT는 SE의 단일영상에 비해 rest와 delay 영상을 배제한 stress 영상으로 정상심근 및 ischemia, MI의 정량적 구분이 가능하였다. 결론적으로 SP-DECT에서 multi-image HU·SD측정 방법은 기존의 심근관류 protocol에 비해 방사선량과 조영제의 감소 및 검사시간의 단축 효과를 기대할 수 있을 것이라 사료된다. Purpose : It aims to examine the efficacy of adenosine stress dual energy(DE) cardiac perfusion CT(SP-DECT) - which reconstitutes several images or scans depending on energy rather than the adenosine stress single energy(SE) cardiac perfusion CT that additionally needs rest and delay scan for distinguishing ischemia with myocardial infarction(MI) - and its consequent effect of decreasing radiation dose. Materials and Methods : In order to understand the standard range(evaluation range) of evaluating myocardium, from January 16, 2009 to May 27, 2010, a retrospective study has been conducted as relying on the result of reading the stress scans of 45 people who had carried out SP-DECT. As a method, the standard deviation(SD) of the following two - the anatomically same normal myocardium of DE scan(140, mix, 80 kVp) and the CT number(HU) of PD part - was calculated. For the statistical analysis, the acceptable significance level was determined as α=.05 with use of SPSS 17.0 Independent K Standard(Kruskal-Wallis ANOVA). To apply the evaluation range, from May 3 to September 17, 2012, both mix scan test of SE scan and DE scan test have been conducted with target of 19 people who did not recognize the states of the coronary arteries and myocardia, and its result was compared to the reading result and it was also evaluated. Results : As the result of the statistical analysis, it appeared that there was a significant difference between χ2 of 134.218 and p-value .000 in the matter of SD of normal myocardium, ischemia and MI. Based on the result of the retrospective study, the evaluation range was determined as the following: in mix test, HU 85.0 or less - MI, 85.1~128.1 - ischemia, and 128.2 or more - normal myocardium, and in DE test, SD 13.3 or less - MI, 13.4~38.2 - ischemia, and 38.3 or more - normal myocardium. As the result of blind test, in mix test, total 20/31 parts (64.5%), normal myocardium 11/18 parts (61.1%), ischemia 7/8 parts (87.5%), and MI 2/5 parts (40%) were coincided. In DE test, total 29/31 parts (93.5%), normal myocardium 17/18 parts (94.4%), ischemia 7/8 parts (87.5%), and MI 5/5 parts (100%) were coincided. As the result of dose analysis, in the case of stress scan, DLP and the averages of effective dose were 340.06mGy, 2.85mSv, rest scan 372.3mGy, 2.92mSv, delay scan 138.5mGy, and 0.69mSv. Conclusions : Compared to single scan of SE, SP-DECT as the stress scan excluding rest and delay scan was possible to carry out the quantitative distinction of normal myocardium, ischemia, and MI. Consequently, it is regarded that at SP-DECT, if the multi-image HU-SD calculating method, rather than the existing myocardial protocol, is used, the deduction of both radiation dose and contrast media, as well as the effect of shortening test duration can be expected.

Liver Volumetry에 있어 Graphic Tablet System과 Mouse System의 유용성 비교에 관한 연구

박성모(Sung Mo Park),부재철(Jae Cheol Boo),이현진(Hyun Jin Lee),김순배(Soon Bae Kim),김경수(Kyung Soo Kim) 대한CT영상기술학회 2007 대한CT영상기술학회지 Vol.9 No.1

Purpose Survival capacity of donor and recipient in liver transplantation is important item after the prognosis after operation. Wished to ready Graphic Tablet’s Usefulness and liver volume log standardization guide through correct liver volume relationship sounding. Materials and Methods From August, 2005 to February, 2007, did to 38 donor and recipients that conduct liver Transplantation Dynamic CT examination for living donor liver transplantation and man 23 woman 15 people age is 18 - 55 and was average age 35 years old. Measured reconstruction image using Graphic Tablet and Mouse in Rapidia 3.0 that is 3D Workstation by each 1.25mm, 2.5mm, 5mm, 10m mm Thickness from liver upper lobe to lower lobe. Capacity measurement method that go portal vein bifurcation discernment that increase in liver volume as possible except and divided liver left and right lobe via middle hepatic vein coming hepatic vein bifurcation. A Group measured 1.25mm, 2.5mm, 5mm, 10m mm relationship liver right lobe by Mouse. B Group measured 1.25mm, 2.5mm, 5mm, 10m mm relationship liver right lobe by Tablet. C Group analyzed A Group and B Group’s liver volume measured value and actuality liver volume course comparison. D Group analyzed efficiency about liver volume measurement time required and party different nature in user side. Found the most suiTable liver volume measurement Parameter analyzing error of actuality liver volume course after value and living donor liver transplantation as result that is measured by Mouse and Graphic Tablet before operation. Results Accuracy of Graphic Tablet appeared than Mouse high as result that use each Thickness different Mouse and Graphic Tablet and compare with actuality liver right lobe’s volume as result that measure liver right lobe. Accuracy of Thickness appeared in the widest 10mm low and Thickness decreases, accuracy was expose that rise. Accuracy roses but increased capital of reflex as Thickness that decrease decreased Thickness A and liver volume log time increased. Graphic Tablet appeared high than Mouse time required and accuracy side as result that analyze liver volume log efficiency. Conclusion Capacity measurement that go that use Graphic Tablet conclusively could heighten step that do believability about examination result and could shorten capacity measurement time required that go.

Dual Energy CT를 이용한 통풍 검사의 유용성과 요산결절로 오인될 수 있는 artifact에 대한 고찰

한영길(Young Gil Han),부재철(Jae Cheol Boo),김도윤(Do Yun Kim),임근교(Geun Gyo Im),김순배(Soon Bae Kim) 대한CT영상기술학회 2012 대한CT영상기술학회지 Vol.14 No.1

I. Objective The objective of the study is to examine the usefulness of a dual energy CT which uses two different types of energy to differentiate the soft tissue and bones on the urate crystal of the goat in diagnosing gouts. II. Subjects and Method From April 13th, 2011 to August 16th, 2011, a dual energy foot CT was conducted on 44 of the in-patients who were diagnosed or suspected of the gout. Scan data were reconstructed using 3D-workstation (LEONARDO)’ s gout software and then, two specialists from the diagnostic imaging department assessed whether the artifacts are either the urate crystal or those that may be mistaken for one. The patients included 30 patients whose gout diagnosis were confirmed by other medical opinions her than CT test (male: 27, female 3, average age: 53.3, range: 19~76) and 14 patients who were confirmed negative for gout (male: 11, female: 3, average age: 50.7, range: 28~68) and the diagnostic result on the gout and the presence of urate crystal by a dual energy CT were compared for analysis. III. Results Urate cystal was observed in 27 patients out of 30 whose gout diagnosis were confirmed and it was not observed in three patients. 14 out of 14 patients, who did not have gout, did now show urate crystal in all cases. Based on the confirmed diagnosis, 30 gout patients showed 90% sensitivity to the dual energy CT test and 14 patients who were confirmed negative for gout showed 100% specificity. Furthermore, the false positive rate was found to be 0%, the false negative rate, 10% and the accuracy rate 93%. The evaluation results on the artifact that could be mistaken for urate crystal indicated that the artifacts were observed in the thick skin of 19 patients and toe nail parts of 15 patients among 30 patients with confirmed gout. Among 14 patients who did not have gout, artifacts were observed in the thick skin of seven patients and the toe nail part of four patients. IV. Conclusion The findings from the study indicated that the dual energy CT showed a high accuracy in assessing the urate crystal of the gout. However, because the artifacts which could be mistaken for urate crystal in the thick skin and toil nail area in some patients were found, more thorough observation and consideration on diagnosing the urate cystal would be required. Despite this, a dual energy gout CT has high sensitivity and accuracy and it can even determine the location and the volume of urate crystal which were not accurately determined. Thus, a dual energy gout CT will be helpful in assessing the degree of calcification, location and the progress in the treatment of urate crystal for the gout patients who requires the continuous treatment and follow-ups. 목적 서로 다른 두 게의 에너지를 사용하여 통풍에 대한 요산결절을 연부조직 및 뼈와 구분하여 나타내는 특성을 이용한 dual energy CT의 통풍 검사에 대한 유용성과 진단에 있어서 통풍 결절로 오인될 수 있는 artifact에 대해서 알아보고자 한다. 대상 및 방법 2011년 4월 13일부터 2011년 8월 16일까지 내원 환자 중 통풍을 진단받았거나 통풍이 의심되는 환자 44명을 대상으로 dual energy foot CT검사를 시행하였다. Scan data는 3D-workstation(LEONARDO)의 gout software를 이용하여 재구성한 후 영상의학과 전문의 2명이 요산결절 및 요산결절로 오인될 수 있는 artifact의 여부를 평가하였다. 대상 환자들은 CT검사를 제외한 다른 임상 소견들을 통해 통풍으로 확진된 환자 30명(남자: 27명, 여자 3명, 평균연령: 53.3세, 범위: 19~76세)과 통풍이 아니라고 확진된 환자 14명(남자: 11명, 여자: 3명, 평균연령: 50.7세, 범위: 28~68세)으로 구분하여 통풍에 대한 진단결과와 dual energy CT의 요산결절 여부를 비교 평가하였다. 결과 통풍으로 확진을 받은 환자 30명 중 27명에서 요산결절이 발견되었으며 3명에서는 발견되지 않았고 통풍이 아닌 환자 14명 중 14명 모두에게서 요산결절이 발견되지 않았다. 확진을 근거로 통풍환자 30명에 대한 dual energy CT검사의 민감도는 90%, 통풍이 아닌 환자 14명에 대한 특이도는 100%였다. 그리고 위양성발생률은 0%, 위음성발생률은 10%였고 정확도는 93%로 나타났다. 요산결절로 오인될 수 있는 artifact의 평가 결과는 통풍환자 30명 중 19명 환자의 thick skin과 15명의 toe nail부분에서 artifact가 보였고 통풍이 아닌 환자에서도 14명 중 7명의 thick skin과 4명의 toe nail 부분에서 artifact가 관찰되었다. 결론 본 연구결과 dual energy CT는 통풍에 대한 요산결절의 침착 여부를 평가하는데 높은 정확성을 보였다. 그러나 일부의 환자에게서 발바닥의 굳은살과 발톱부위에 요산결절로 오인될 수 있는 artifact가 발생됨에 따라 요산결절을 진단함에 있어 보다 세심한 관찰과 판단이 요구된다. 그럼에도 불구하고 dual energy gout CT는 높은 민감도와 정확도를 가지며 기존에는 정확하게 알 수 없었던 요산결절의 위치와 부피까지도 파악할 수 있었다. 따라서 지속적인 치료와 follow-up이 요구되는 통풍 환자에게 dual energy gout CT는 요산결절의 침착 정도와 위치, 치료의 경과를 평가하는데 있어서 유용한 도움을 줄 수 있을 것이라 사료된다.

Adenosine Stress Cardiac Perfusion CT에서 Vitrea Software를 적용한 심근 관류 색지도의 유용성에 관한 연구

최문화(Moon Hwa Choi),설형기(Hyung Gi Seol),이현진(Hyun Jin Lee),부재철(Jae Cheol Boo),임근교(Geun Gyo Im),김순배(Soon Bae Kim) 대한CT영상기술학회 2012 대한CT영상기술학회지 Vol.14 No.1

목적 Dual energy를 이용한 adenosine stress perfusion CT(SP-DECT) 검사에서 얻어진 심근관류 영상은 Vitrea advanced ver. 6.0 software(Vitrea)를 이용하여 American heart association(AHA) 16분절로 나누어진다. 분절별 결손 부위를 색상으로 구분할 수 있는 색지도 영상으로 나타내어 adenosine stress perfusion MRI(SP-MRI) 영상과 Vitrea의 색지도 영상에 해당하는 결손 부위를 비교 평가하여 임상적 유용성에 대해 알아보고자 하였다. 대상 및 방법 연구대상은 2011년 1월부터 7월까지 관상동맥질환(coronary artery disease)이 있는 환자 중 perfusion defect(PD)가 있다고 판명된 환자를 대상으로 SP-MRI와 SP-DECT 검사를 시행하였다. 먼저 SP-MRI 검사로 얻은 Short Axis 영상과 SP-DECT 검사를 통해서 얻어진 data를 기본으로 Vitrea에서 AHA 16분절의 색지도 영상을 분절별로 관류 감소 정도를 비교 측정하여 sensitivity, specificity, positive predictive value, negative predictive value, accuracy 등을 평가하였다. 결과 Vitrea를 이용한 SP-DECT의 색지도 영상을 관류 결손 분절 별로 SP-MRI와 비교하였다. 모두 30명의 환자에서 총 40개의 심근분절을 측정하였고 SP-MRI와 SP-DECT에서 일치된 관류 결손 분절은 187개, SP-MRI는 관류 결손 분절이면서 SP-DECT에서는 정상으로 측정된 분절은 31개, SP-MRI에서 정상 분절이면서 SP-DECT에서는 관류 결손으로 측정된 분절은 35개로 측정되었으며 SP-MRI와 SP-DECT에서 일치된 정상 분절은 227개로 측정되었다. 결론 본 연구는 Vitrea를 이용하여 나타낸 SP-DECT의 AHA 16분절의 색지도 영상과 SP-MRI의 Short Axis 영상을 비교 분석하였다. 총 480개의 분절이 비교되었으며 sensitivity 85.7%, specificity 86.6%, positive predictive value 84.2%, negative predictive balue 87.9%, accuracy 86.2%로 평가되어 Vitrea의 색지도 영상은 SP-MRI와 비교하였을 때 높은 진단 유용성을 증명하였다. SP-DECT는 짧은 검사시간, 높은 공간 해상도, 그리고 MRI의 금기사항을 지난 환자들에 대한 적용이 가능하므로 SP-DECT를 이용한 Vitrea의 심근관류 평가에서 진단의 정확성을 높이는데 유용한 도움을 줄 수 있을 것이라 사료된다. I. Purpose Myocardial perfusion imaging obtained from an adenosine stress cardiac perfusion CT(SP-DECT) test using dual energy can be represented in color-mapped images which are divided into American heart association(AHA) 16 segments by use of Vitrea advanced ver. 6.0 software. This study intended for an insight into a clinical usefulness of Vitrea advanced ver. 6.0 software by comparing and measuring the lost part for the color-mapped image of adenosine stress perfusion MRI(SP-MRI) image with a clinical significance, through the use of characteristics with which lost part of each segment can be distinguished by color. II. Materials and Methods For the study conducted from January to July, 2011, the images of the patients diagnosed to have had perfusion defect, among the coronary artery disease patients who went through all SP-DECT tests using SP-MRI and dual energy, were compared with each other. To begin with, based on the Short Axis image taken through the SP-MRI test and the data through the SP-DECT test, comparison and measurement were conducted as to the degree of perfusion reduction, by segment, in color-mapped images of AHA 16 segment in order to represent Sensitivity, Specificity, Positive predictive value, Negative predictive value, and Accuracy. III. Results A comparison was made between the color-mapped image of SP-DECT using the Vitrea advanced ver. 6.0 software and SP-MRI per perfusion defect segment. A total of 30 patients showed a measure of 480 myocardial segments in total, perfusion defect segments consistent in SP-MRI and SP-DECT had a measure of 187, whereas 31 segments were measured to be a normal segment in SP-DECT and a perfusion defect segment in SP-MRI. 35 segments were measured to be normal in SP-MRI and a perfusion defect segment in SP-DECT, whereas the number of normal segments showing consistency in SP-MRI and SP-DECT reached 227 according to the measure. IV. conclusion This study conducted a comparative analysis of the color-mapped image in 16 segments of SP-DECT represented by U5e of Vitrea advanced ver. 6.0 software and the Short Axis image of SP-MRI. A total of 480 segments were used for a comparison with the following according to a measure : sensitivity 85.7%, specificity 86.6%, positive predictive value 84.2%, negative predictive value 87.9%, and accuracy 86.2%. The color-mapped image of Vitrea advanced ver. 6.0 software verified its high diagnostic usefulness as compared to the SP-MRI. SP-DECT enables simple study process and short inspection time, high space resolution, and applications to patients with MRI contradictions, it is considered that useful assistance will be possibly provided for raising diagnostic accuracy in myocardial perfusion assessment of Vitrea advanced ver. 6.0 software using SP-DECT.

DSCT에서 ECG Pulsing Manual Mode를 이용한 심장판막질환의 선량감소 방안과 기능평가의 유용성

이현진(Hyun Jin Lee),권순용(Soon Yong kwon),부재철(Jae Cheol Boo),강충환(Chung Hwan Kang),임근교(Geun Gyo Im),김순배(Soon Bae Kim) 대한전산화단층기술학회 2011 대한CT영상기술학회지 Vol.13 No.1

목 적: 기존의 심장 판막 질환 검사를 위해 사용되었던 pulsing off mode를 대체하여 pulsing manual mode를 사용할 경우 심장 CT검사의 단점으로 존재하였던 피폭선량은 줄이면서 같은 진단 효과를 나타낼 수 있는 pulsing manual mode의 유용성에 대해서 알아보고자 한다. 대상 및 방법: 연구대상은 2010년 1월부터 6월까지 심장 판막 질환(AS, AR, MS, MR) 중 하나 이상을 지니고 있는 환자 80명(남자 38명, 여자 42명)을 대상으로 하였다. 사용 장비는 DSCT(SOMATOM Definition, Siemens)를 사용하였고 retrospectⅣe ECG gating technique을 사용하였다. 검사방법은 pulsing off mode로 검사한 환자 40명, pulsing manual mode로 검사한 환자 40명을 대상으로 하였고 두 그룹 모두 R-R interval 0~90%를 10% 간격으로 multi-recon.하고 BestDiast phase로 recon.하였다. 평가방법은 전문의 1명, 전공의 1명이 재구성된 영상을 관상동맥의 motion artifact 없이 깨끗한 묘사, ascending aorta와 left ventricle의 확장 평가, AV와 MV의 형태와 artifact 유무 간별의 항목을 기준으로 하여 exceⅡent(3), good(2), fair(1), poor(0)의 4단계로 평가하였다. 더불어 AV와 MV의 개구면적을 측정하는 phase를 조사하여 R-R interval 20~70% 사이에 위치하고 있는지 알아보았다. Phantom 연구는 ECG patient monitor simulator를 사용하여 heart rate 60 bpm과 80 bpm의 pulsing off mode와 pulsing manual mode의 CTDⅣol 값을 비교해 보았다. 결 과: SPSS(Version 12.0, SPSS Inc., Chicago, IL, USA)를 이용하여 평가 분석한 결과 모든 항목에서 p value 값이 0.05 이상으로 나와 두 그룹 사이에 유의한 차이가 없었다. Valve의 개구면적 측정을 위한 phase 위치 분석에서는 AR과 MS 평가를 위한 diastole phase는 약 98%가 20~70%의 pulsing 구간 내에 포함되었지만 AS와 MR 평가를 위한 systole phase는 pulsing 구간 외인 10% phase에 위치한 경우가 전체에 약 40%를 차지하였다. Phantom scan을 통해 pulsing off mode와 pulsing manual mode의 HR 60, 80 bpm에서 선량 평가에서는 pulsing manual mode에서 pulsing off mode보다 HR 60 bpm에서 25%, 80 bpm에서 27% CTDⅣol 값이 적게 나타났다. 결 론: 본 연구 결과 pulsing off mode와 pulsing manual mode를 사용하여 개구면적을 평가하였을 때 pulsing 범위를 벗어난 phase에서도 모두 평가가 가능하였고 판독을 위한 평가항목에서도 두 그룹간 차이를 구별할 수 없는 결과가 도출되었다. 반면 pulsing manual mode가 pulsing off mode에 비해 평균 26% 적은 CTDⅣol 값이 나타나 환자의 피폭을 줄일 수 있었다. 결론적으로 pulsing off mode 대신 pulsing manual mode를 사용함으로써 영상의 질은 적절히 유지하면서 환자의 피폭을 줄일 수 있어 심장 판막 질환 환자에게 유용하게 사용될 수 있을 것이라고 사료된다. Ⅰ. Purpose This study aimed to examine the effectⅣeness of the use of pulsing manual mode in examination of valvular heart disease based on the idea that replacing the pulsing off mode, which has been conventionaⅡy used for examining valvular heart disease with the pulsing manual mode wiⅡ help to reduce the radiation dose during cardiac CT examinations without compromising the image quality. Ⅱ. Materials and methods Subjects were a total of 80 patients, 38 males and 42 females, who had been treated with more than one of valvular heart disease including AS, AR, MS, and MR from January to June 2010. The equipment used was DSCT (SOMATOM Definition, Siemens) and the retrospectⅣe ECG gating technique was employed in this study. The whole subjects were dⅣided into two groups, with one group of 40 patients subjected to the pulsing off mode and the other group to the pulsing manual mode. For both groups, the R-R interval with 10% interval in the range of 0% to 90% was multiple-reconstructed in combination with BestDiast phase. For qualitatⅣe analysis, one radiologist and one orthopaedic surgeon evaluated based on the items consisting of clear delineation without motion artifact in coronary artery, extension of ascending aorta and left ventricle, morphology of AV and MV, and the presence or absence of artifacts, using a four-point scale: exceⅡent (3), good (2), fair (1), and poor (0). Along with this, based on the measurement of aperture areas of AV and MV, examination of whether they were located between 20% and 70% of the R-R interval was carried out. With respect to Phantom study, using the ECG patient monitor simulator, the values of CTDⅣol were compared between the pulsing off mode and pulsing manual mode at the heart rates of 60 bpm and 80 bpm. Ⅲ. Results The results from the evaluation of image qualities using SPSS (Version 12.0, SPSS Inc., Chicago IL, USA) found that in aⅡ the evaluation items, there was no significant difference between the two groups with p-value being more than 0.05. When it comes to the analysis of phase locations for measuring aperture areas, when using the pulsing off mode, for the diastole phase for evaluating AR and MS, in about 98% of cases, the end of diastole was found to be located in the pulsing intervals between 20% and 70%, while for the systole phase for evaluating AS and MR, in about 40% of cases, the end of systole was within the 10% phase, which is outside of the pulsing interval. The evaluation of radiation dose at the HRs of 60 and 80 bpm by using Phantom scan revealed that the values of CTDⅣol were found to be lower in the pulsing manual mode than in the pulsing off mode, with 25% lower at 60 bpm and 27% lower at 80 bpm, respectⅣely. Ⅳ. Conclusion This study results demonstrated that evaluation of aperture areas is possible even in the phases exceeding the pulsing intervals, regardless of which mode is adopted, either the pulsing off mode or the pulsing manual mode. On the other hand, the results showed that the pulsing manual mode produced lower CTDⅣol values compared to the pulsing off mode, thus reducing patients’ exposures to radiation dose. In conclusion, it is likely that using the pulsing manual mode rather than the pulsing off mode wiⅡ aⅡow the reduction of valvular heart disease patients’ exposure to radiation dose, while maintaining good image quality.