Multi Detector CT 와 Dual-Layer Spectral Detector CT의 대동맥혈관 조영술에 대한 조영제 프로토콜에 관한 비교연구

정용환(Yong-Hwan Chung),이재현(Jae-Hyun Lee),이종민(Jong-Min Lee),김태은(Tae-Eun Kim),강승원(Seung-Won Kang),권순안(Soon-Ahn Kwon),민관홍(Gwan-Hong Min) 대한CT영상기술학회 2017 대한CT영상기술학회지 Vol.19 No.2

목적 : CT Angio Aorta 검사 시 조영제의 low flow-rate와 Volume을 이용하여 Dual-Layer Spectral Detector CT의 Spectral 기법의 유용성을 알아보고자 한다. 대상 및 방법 : 2016년 10월부터 12월까지 본원에 CT Angio Aorta를 시행하기 위해 내원한 환자중 64명을 대상으로 진행하였다. 사용된 장비는 Brilliance iCT, 256-Slice Multi Detector CT와 IQON, 128-Slice Dual-Layer Spectral Detector CT를 사용하였으며, 3D영상 재구성 software 와 영상 평가를 위한 분석은 Rapidia와 PACS를 이용하였으며 조영제는 Iomeron 350를 이용하였다. MDCT는 100kVp, 250mAs, pitch 0.993, Rotation time 0.75sec로 검사하였고 Carina level의 Ascending aorta 에 ROI를 설정하여 CT number값이 150HU에 도달 한 다음 15초 후에 Arterial phase를 획득하였다. 조영제의 flow rate는 3.5cc/sec로 양은 체중에 관계없이 130cc로 고정하였고 추가로 Normal Saline 30cc를 주입하였다. 영상 재구성은 Conventional 기법인 FBP를 이용하여 재구성하였다. SDCT는 120kVp, 120mAs, pitch 0.601, Rotation time 0.5sec로 검사하였고 Carina level의 Ascending aorta 에 ROI를 설정하여 CT number값이 90 HU에 도달한 다음 15초 후에 Arterial phase를 획득하였다. 조영제의 flow rate는 1.5cc/sec로 양은 체중에 관계없이 50cc로 고정하였고 추가로 Normal Saline 30cc를 주입하였다. 영상재구성은 SpDS를 이용하여 spectral기법인 MonoE 60keV로 하였다. 선량의 평가는 PACS에서 제공하는 Exam information에 표시된 DLP 값을 이용하여 비교하였다. 정량적 영상 평가는 5년 이상 경력의 방사선사 3명이 측정한 다음 평균값을 이용하여 CNR을 산출하여 비교하였으며, 측정부위는 carina level의 Descending aorta, SMA, Right Common femoral artery의 3곳이며 CT number와 Standard Deviation을 측정하였다. 정성적 이미지 평가는 영상의학과 교수 1명과 전공의 1명이 4점 척도로 대동맥 조영증강 정도를 Brachiocephalic artery, Celiac artery, SMA, Renal artery를 평가하였다. 결과 : 선량을 비교한 결과 DLP값은 MDCT에서 664 ~ 1090mGy*cm로 나타났고, SDCT에서 716 ~ 1167mGy*cm로 나타나 두 가지 방식은 통계적으로 유의한 차이가 없음을 알 수 있었다. (P = 0.2748) 정량적 평가의 결과 CT number와 Noise값은 Descending aorta에서 MDCT는 평균 450±10과 15.47±2, SDCT는 평균 281±45과 10.7±1.6이며 SMA에서 MDCT는 평균 458±7과 18.7±1.88, SDCT는 평균 280±44과 13.88±2.13이며 Right Common femoral artery에서 MDCT에서 평균 432±13과 15.49±3.87, SDCT에서 평균 253±3과 11.35±2.72로 나타났다. CNR은 Descending aorta에서 MDCT는 평균 93±11, SDCT는 평균 108±14이며 SMA에서 MDCT는 평균76±7, SDCT는 평균 86±13이며, Right Common femoral artery에서 MDCT는 평균 95±2, SDCT는 평균 103±19로 나타났다. 정성적 평가의 결과 (Brachiocephalic artery)에서 MDCT 와 SDCT가 동일하게 평균 3.7점으로 평가했고 Celiac artery에서 MDCT는 평균 3.8점, SDCT는 평균 3.5점으로 평가했다. SMA에서는 MDCT와 SDCT가 평균 3.8점으로 동일하게 평가했고 Renal artery에서 MDCT는 평균 3.6점, SDCT는 평균 3.5점으로 평가했다. 모든 영상을 3.5점 이상으로 우수하게 평가했고 두 검사방법이 통계적으로 유의한 차이가 없음을 알 수 있었다 (P > 0.05). 결론 : CT Angio Aorta 검사 시 SDCT를 이용한 Spectral 재구성법 영상은 화질의 저하 없이 조영제의 양을 62.5% 감소시키고 초당 주입속도를 1.5cc/sec Flow-rate로 낮출 수 있다. Purpose : To evaluate the usefulness of the spectral technique of Dual-Layer Spectral Detector CT using low flow-rate and volume of contrast agent for CT angio Aorta. Materials and Methods : From October to December 2016, We performed this study on 64 patients who visited CT Angio Aorta. The equipment used is Brilliance iCT, 256-Slice Multi Detector CT and IQON, 128-Slice Dual-Layer Spectral Detector CT. MDCT was tested at 100kVp, 250mAs. The arterial phase was obtained 15 seconds after the CT number reached 150 HU by setting the ROI to the ascending aorta of the carina level. The flow rate of the contrast agent was 3.5 cc/sec, and the amount was fixed at 130 cc regardless of body weight. In addition, 30 cc of normal saline was injected. Image reconstruction was reconstructed using FBP, a conventional technique. SDCT was tested at 120kVp, 120mAs. The arterial phase was obtained 15 seconds after the CT number reached 90 HU by setting the ROI to the ascending aorta of the carina level. The flow rate of the contrast agent was 1.5 cc/sec, and the amount was fixed to 50 cc regardless of body weight. Image reconstruction was performed with the spectral technique MonoE 60keV using SpDS. The radiation doses were compared using the DLP values shown in the Exam information provided by PACS. In the quantitative image evaluation, CNR was calculated and compared using the average value measured by three radiological technologist with a career of 5 years or more, The measurement sites were the carina level Descending aorta, SMA, and right common femoral artery. CT numbers and standard deviations were measured. The qualitative image evaluation was evaluated by a radiologist and a resident majoring radiology using 4 point scale method Brachiocephalic artery, Celiac artery, SMA, and renal artery were evaluated for aortic enhancement. Results : Results of radiation dose comparison, The DLP values were 664~1090mGy * cm in MDCT and 716~1167mGy * cm in SDCT. There was no statistically significant difference between the two methods.(P = 0.2748) Results of quantitative evaluation, The CT number and noise value are given in the Descending aorta The mean MDCT was 450 ± 10 and 15.47±2, the mean SDCT was 281±45 and 10.7±1.6, in SMA The mean MDCT was 458±7 and 18.7±1.88, the mean MDCT was 280±44 and 13.88±2.13, in Right Common femoral artery The mean of MDCT was 432±13 and 15.49 ± 3.87, and the mean of SDCT was 253±3 and 11.35±2.72. CNR was 93±11 for MDCT and 108±14 for SDCT in Descending aorta, In SMA, mean MDCT was 76±7, mean SDCT was 86±13, In the right common femoral artery, the mean MDCT was 95±2 and the mean SDCT was 103±19. As a result of the qualitative evaluation, there was no statistically significant difference between the two methods. (P > 0.05) Conclusion : Spectral reconstruction using SDCT for CT angio aorta can reduce the amount of contrast agent by 62.5% and decrease injection rate per second to 1.5cc / sec without degradation of image quality.

단색에너지(keV)와 조영제 희석비율 변화에 따른 HU(Hounsfield Unit)값 분석 : Spectral CT 이용

정희라(Hee-Ra Jung),강진우(Oh-Jun Kwon),권오준(Jin-woo Kang),김호진(Ho-Jin Kim),정다빈(Dabin Jung),이재현(Jae-Hyun Lee),허영철(Yeong-Cheol Heo) 한국방사선학회 2020 한국방사선학회 논문지 Vol.14 No.5

본 연구의 목적은 Spectral CT에서 단색에너지(keV)와 조영제 희석비율의 변화에 따른 HU 값의 변화를 분석하고자 하였다. 검사장비로는 Spectral CT를 사용하였고, 20 cc syringe의 팬텀을 이용하여 조영제의 희석비율을 8:2, 7:3, 6:4, 5:5, 4:6, 3:7 총 6단계로 설정하였다. 이때 조영제는 비이온성 요오드 조영제(350 mg/ml)를 이용하였다. 획득한 데이터를 IQon-Spectral CT V4.7.5 프로그램을 사용하여 Monoenergy(MonoE) 40 keV, 45 keV, 50 keV, 55 keV, 60 keV, 65 keV, 70 keV, 75 keV, 80 keV 총 9단계로 변화시켜 syringe axial 영상을 재구성하였다. 재구성한 syringe axial 단면 영상의 세 위치에서 HU 값을 측정하였으며, 총 1,620회 측정하였다. keV와 조영제 희석비율의 변화에 따른 HU 값을 분석한 결과, MonoE별 희석비율에 따른 HU 비교에서 모든 MonoE에서의 HU 값이 희석비율 8:2에서 가장 높았으며 3:7에서 가장 낮았다(p<0.05). 희석비율별 MonoE에 따른 HU 비교에서 모든 희석비율에서의 HU 값이 40 keV에서 가장 높았으며 80 keV에서 가장 낮았다(p<0.05). 인자별 상관성은 keV에 따른 HU 값은 -15.014 ± 0.298의 음의 상관성(R2=0.519)이 있었고 희석비율에 따른 HU값 은 -61.372 ± 3.608의 음의 상관성(R2=0.152)이 있었다(p<0.05). 결론적으로 keV 값과 조영제 희석비율이 증가할수록 HU 값은 감소하는 것을 확인하였으며 본 연구가 Spectral CT의 HU 값 관련 인자 연구에 있어 기초자료를 제공할 수 있을 것이라 사료된다. The purpose of this study was to analyze the changes in the values of Hounsfield Unit (HU) according to the changes in monoenergy (keV) and dilution ratio of the contrast agent, using the spectral CT. Spectral CT was used as the testing device, while 20 cc syringe phantom was used to set a total of six dilution ratios of the contrast agent: 8:2, 7:3, 6:4, 5:5, 4:6, and 3:7. Here, the non-ionic iodine solution (350 mg/ml) was used as a contrast agent. The syringe axial image was reconstructed by adjusting the obtained data on nine MonoE levels; 40 keV, 45 keV, 50 keV, 55 keV, 60 keV, 65 keV, 70 keV, 75 keV, and 80 keV. The HU values were measured at the three points of the reconstructed syringe axial image. The measurements were taken 1,620 times in total. In the analysis of the HU values according to the changes in keV and dilution ratio of the contrast agent, the highest and lowest HU values were obtained from dilution ratio 8:2 and dilution ratio 3:7, respectively, across every MonoE in the comparison of HU according to dilution ratio per MonoE (p<0.05), while the highest and lowest HU values were obtained from 40 keV and 80 keV, respectively, across all dilution ratios in the comparison of HU according to MonoE per dilution ratio (p<0.05). For the correlation per each parameter, a negative correlation of -15.014 ± 0.298 was found for HU per keV (R2=0.519) and a negative correlation of -61.372 ± 3.608 was found for HU per dilution ratio (R2=0.152) (p<0.05). To conclude, an increase in keV or dilution ratio of the contrast agent was shown to decrease the HU, and the findings in this study are anticipated to serve as the basic data in the research of HU-related parameters in Spectral CT.

Quantification of Fat Concentration and Vascular Response in Brown and White Adipose Tissue of Rats by Spectral CT Imaging

Xin-Gui Peng,Zhen Zhao,Di Chang,Yingying Bai,Qiuzhen Xu,Shenghong Ju 대한영상의학회 2020 Korean Journal of Radiology Vol.21 No.2

Objective: The purpose of the study was to non-invasively characterize and discriminate brown adipose tissue (BAT) from white adipose tissue (WAT) in rats using spectral computed tomography (CT) with histological validation. Materials and Methods: A lipid-containing phantom (lipid fractions from 0% to 100%) was imaged with spectral CT. An in vivo, non-enhanced spectral CT scan was performed on 24 rats, and fat concentrations of BAT and WAT were measured. The rats were randomized to receive intraperitoneal treatment with norepinephrine (NE) (n = 12) or saline (n = 12). Non-enhanced and enhanced spectral CT scans were performed after treatment to measure the elevation of iodine in BAT and WAT. The BAT/ aorta and WAT/aorta ratios were calculated and compared, after which isolated BAT and WAT samples were subjected to histological and uncoupling protein 1 (UCP1) analyses. Results: The ex-vivo phantom study showed excellent linear fit between measured fat concentration and the known gravimetric reference standard (r2 = 0.996). In vivo, BAT had significantly lower fat concentration than WAT (p < 0.001). Compared to the saline group, the iodine concentration of BAT increased significantly (p < 0.001) after injection of NE, while the iodine concentration of WAT only changed slightly. The BAT/aorta ratio also increased significantly after exposure to NE compared to the saline group (p < 0.001). Histological and UCP1 expression analyses supported the spectral CT imaging results. Conclusion: The study consolidates spectral CT as a new approach for non-invasive imaging of BAT and WAT. Quantitative analyses of BAT and WAT by spectral CT revealed different characteristics and pharmacologic activations in the two types of adipose tissue.

A Phantom Study of 100 kVp Spectral Data Accuracy Using Iodine Density in Dual-Layer Detector CT

김효정(Hyo-Jung Kim),노시온(Si-On Noh),김윤호(Yun-Ho Kim),방예빈(Ye-Bin Bang),장범석(Beom-Seok Jang),조남용(Nam-Yong Cho),서준현(Jun-Hyun Seo) 대한CT영상기술학회 2023 대한CT영상기술학회지 Vol.25 No.2

특정 질병에서는 HU 값만으로는 조직을 구별하기 어렵고, 환자의 체형과 CT 장비, 검사 조건에 따라서 HU 값이 상이하다. 그에 따라 CT 영상의 새로운 진단평가 기준으로 Iodine Density(IoD) 평가가 사용되고 있다. 기존에 120 kVp 이상에서만 획득할 수 있었던 IQon CT 스펙트럼 데이터 중 IoD를 인용하여 100 kVp에서도 획득할 수 있는 7500 CT의 스펙트럼 데이터의 정확성을 평가하고자 연구를 진행하였다. 7500 CT와 IQon CT의 IoD 비교 값은 오차 범위 내에서 측정되었으며, 100 kVp와 비교 실험 및 콜리메이터 변화 실험에서도 오차범위 내에서 측정되었다. 연구 결과 100 kVp의 정확성은 확인되었고, CTDI를 10%씩 감소시키며 IoD를 측정하였을 때 40% 감소한 선량에서 유의미한 값이 나오는 최소 선량임을 확인하였다. 100 kVp에서 CTDIvol을 약 40% 감소시킨 프로토콜을 만들어 임상에서도 소아, 체질량지수가 낮은 환자에게 유용하게 적용할 수 있을 것이라 생각한다. In certain diseases, it can be challenging to differentiate tissues based solely on the HU value. The HU value differs depending on factors such as the patient's body type, CT equipment, and testing conditions. Accordingly, iodine density evaluation is being used as a new diagnostic criterion for CT images. The study was conducted to evaluate the accuracy of the 7500 spectral data that can be obtained even at 100 kVp. It cited iodine density as one of the IQon CT spectral data that could only be obtained at 120 kVp or higher. The iodine density comparison between the 7500 CT and IQon CT was measured within the error range. This was also observed in comparison experiments and collimator change experiments with 100 kVp. As a result of the study, the accuracy of 100 kVp was confirmed, and the CTDI was reduced by 10%. Additionally, when measuring iodine density, it was found that the minimum dose had a significant value, with a reduction of 40%. It is believed that a protocol that reduces CTDIvol by approximately 40% at 100 kVp can be utilized in clinical trials for children and patients with a low body mass index.

Spectral CT: Preliminary Studies in the Liver Cirrhosis

Peijie Lv,XiaoZhu Lin,Jianbo Gao,Kemin Chen 대한영상의학회 2012 Korean Journal of Radiology Vol.13 No.4

Objective: To investigate the value of spectral CT imaging in the diagnosis and classification of liver cirrhosis during the arterial phase (AP) and portal venous phase (PVP). Materials and Methods: Thirty-eight patients with liver cirrhosis (Child-Pugh class A/B/C: n = 10/14/14), and 43 patients with healthy livers, participated in this study. The researchers used abdominal spectral CT imaging during AP and PVP. Iodine concentration, derived from the iodine-based material-decomposition image and the iodine concentration ratio (ICratio) between AP and PVP, were obtained. Statistical analyses {two-sample t test, One-factor analysis of variance, and area under the receiver operating characteristic curve (A [z])} were performed. Results: The mean normalized iodine concentration (NIC) (0.5 ± 0.12) during PVP in the control group was significantly higher than that in the study group (0.4 ± 0.10 on average, 0.4 ± 0.08 for Class A, 0.4 ± 0.15 for Class B, and 0.4 ± 0.06 for Class C) (All p < 0.05). Within the cirrhotic liver group, the mean NIC for Class C during the AP (0.1 ± 0.05) was significantly higher than NICs for Classes A (0.1 ± 0.06) and B (0.1 ± 0.03) (Both p < 0.05). The ICratio in the study group (0.4 ± 0.15), especially for Class C (0.5 ± 0.14), was higher than that in the control group (0.3 ± 0.15) (p < 0.05).The combination of NIC and ICratio showed high sensitivity and specificity for differentiating healthy liver from cirrhotic liver, especially in Class C cirrhotic liver. Conclusion: Spectral CT Provides a quantitative method with which to analyze the cirrhotic liver, and shows the potential value in the classification of liver cirrhosis. Objective: To investigate the value of spectral CT imaging in the diagnosis and classification of liver cirrhosis during the arterial phase (AP) and portal venous phase (PVP). Materials and Methods: Thirty-eight patients with liver cirrhosis (Child-Pugh class A/B/C: n = 10/14/14), and 43 patients with healthy livers, participated in this study. The researchers used abdominal spectral CT imaging during AP and PVP. Iodine concentration, derived from the iodine-based material-decomposition image and the iodine concentration ratio (ICratio) between AP and PVP, were obtained. Statistical analyses {two-sample t test, One-factor analysis of variance, and area under the receiver operating characteristic curve (A [z])} were performed. Results: The mean normalized iodine concentration (NIC) (0.5 ± 0.12) during PVP in the control group was significantly higher than that in the study group (0.4 ± 0.10 on average, 0.4 ± 0.08 for Class A, 0.4 ± 0.15 for Class B, and 0.4 ± 0.06 for Class C) (All p < 0.05). Within the cirrhotic liver group, the mean NIC for Class C during the AP (0.1 ± 0.05) was significantly higher than NICs for Classes A (0.1 ± 0.06) and B (0.1 ± 0.03) (Both p < 0.05). The ICratio in the study group (0.4 ± 0.15), especially for Class C (0.5 ± 0.14), was higher than that in the control group (0.3 ± 0.15) (p < 0.05).The combination of NIC and ICratio showed high sensitivity and specificity for differentiating healthy liver from cirrhotic liver, especially in Class C cirrhotic liver. Conclusion: Spectral CT Provides a quantitative method with which to analyze the cirrhotic liver, and shows the potential value in the classification of liver cirrhosis.

Dual-Energy CT: New Horizon in Medical Imaging

구현우,구진모 대한영상의학회 2017 Korean Journal of Radiology Vol.18 No.4

Dual-energy CT has remained underutilized over the past decade probably due to a cumbersome workflow issue and current technical limitations. Clinical radiologists should be made aware of the potential clinical benefits of dual-energy CT over single-energy CT. To accomplish this aim, the basic principle, current acquisition methods with advantages and disadvantages, and various material-specific imaging methods as clinical applications of dual-energy CT should be addressed in detail. Current dual-energy CT acquisition methods include dual tubes with or without beam filtration, rapid voltage switching, dual-layer detector, split filter technique, and sequential scanning. Dual-energy material-specific imaging methods include virtual monoenergetic or monochromatic imaging, effective atomic number map, virtual non-contrast or unenhanced imaging, virtual non-calcium imaging, iodine map, inhaled xenon map, uric acid imaging, automatic bone removal, and lung vessels analysis. In this review, we focus on dual-energy CT imaging including related issues of radiation exposure to patients, scanning and post-processing options, and potential clinical benefits mainly to improve the understanding of clinical radiologists and thus, expand the clinical use of dual-energy CT; in addition, we briefly describe the current technical limitations of dual-energy CT and the current developments of photon-counting detector.

K-각 영상을 이용한 스펙트럼 전산화단층촬영 기반 3차원 융합진단영상화에 관한 연구

김번영,이승완,임도빈 한국방사선학회 2019 한국방사선학회 논문지 Vol.13 No.4

The purpose of this study was to obtain the K-edge images using a spectral CT system based on a photon-counting detector and implement the 3D fusion imaging using the conventional and spectral CT images. Also, we evaluated the clinical feasibility of the 3D fusion images though the quantitative analysis of image quality. A spectral CT system based on a CdTe photon-counting detector was used to obtain K-edge images. A pork phantom was manufactured with the six tubes including diluted iodine and gadolinium solutions. The K-edge images were obtained by the low-energy thresholds of 35 and 52 keV for iodine and gadolinium imaging with the X-ray spectrum, which was generated at a tube voltage of 100 kVp with a tube current of 500 μA. We implemented 3D fusion imaging by combining the iodine and gadolinium K-edge images with the conventional CT images. The results showed that the CNRs of the 3D fusion images were 6.76-14.9 times higher than those of the conventional CT images. Also, the 3D fusion images was able to provide the maps of target materials. Therefore, the technique proposed in this study can improve the quality of CT images and the diagnostic efficiency through the additional information of target materials. 본 연구의 목적은 광자계수검출기 기반 스펙트럼 전산화단층촬영을 이용하여 K-각 영상을 획득하고, 이를 통해 3차원 융합진단영상을 구현하여 임상적 이용 가능성을 평가하고자 하였다. 실험을 통한 K-각 영상 획득을 위해 스펙트럼 전산화단층촬영 시스템을 이용하였다. 희석된 iodine과 gadolinium 조영제가 주입된 6개의 튜브를 돼지고기에 삽입하여 팬텀을 제작하였다. 100 kVp 관전압과 500 μA 관전류 조건에서 발생된 X-선을 이용하였으며, iodine과 gadolinium의 K-각 흡수에너지를 고려한 35 및 52 keV에 저 에너지 문턱값을 설정하여 K-각 영상을 획득하였다. 융합진단영상은 일반적인 전산화단층촬영 영상과 스펙트럼 전산화단층촬영을 통해 획득한 iodine 및 gadolinium 영상을 정합하여 획득하였다. 두 가지 조영제 기반 융합진단영상의 CNR은 일반적인 CT보다 평균적으로 6.76-14.9배 높았으며, 3차원 융합진단영상은 각 조영제의 물질 지도 정보를 제공할 수 있었다. 따라서 본 연구에서 제안하는 방법을 통해 전산화단층영상의 화질을 향상시킬 수 있으며 특정 물질의 추가적인 정보를 제공을 통해 진단의 효율성을 증가시킬 수 있다.

Achieving safe and high-performance gastrointestinal tract spectral CT imaging with small-molecule lanthanide complex

Xiaoling Che,Chunmei Yang,Liping Pan,Didi Gu,Guidong Dai,Jian Shu,Lu Yang 한국생체재료학회 2023 생체재료학회지 Vol.27 No.00

Background Non-intrusive imaging of gastrointestinal (GI) tract using computed tomography (CT) contrast agents is of the most significant issues in the diagnosis and treatment of GI diseases. Moreover, spectral CT, which can generate monochromatic images to display the X-ray attenuation characteristics of contrast agents, provides a better imaging sensitivity for diagnose inflammatory bowel disease (IBD) than convention CT imaging. Methods Herein, a convenient and one-pot synthesis method is provided for the fabrication of small-molecule lanthanide complex Holmium-tetraazacyclododecane-1, 4, 7, 10-tetraacetic acid (Ho-DOTA) as a biosafe and high-performance spectral CT contrast agent for GI imaging with IBD. In vivo CT imaging was administered with both healthy mice and colitis mice induced by dextran sodium sulfate. Results We found that Ho-DOTA accumulated in inflammation sites of large intestines and produced high CT contrast compared with healthy mice. Both in vitro and in vivo experimental results also showed that Ho-DOTA provided much more diagnostic sensitivity and accuracy due to the excellent X-ray attenuation characteristics of Ho- DOTA compared with clinical iodinate agent. Furthermore, the proposed contrast media could be timely excreted from the body via the urinary and digestive system, keeping away from the potential side effects due to long-term retention in vivo. Conclusion Accordingly, Ho-DOTA with excellent biocompatibility can be useful as a potential high-performance spectral CT contrast agent for further clinical imaging of gastrointestinal tract and diagnosis of intestinal system diseases.

Optimal Monochromatic Imaging of Spectral Computed Tomography Potentially Improves the Quality of Hepatic Vascular Imaging

Xiao-Ping Yin,Bu-Lang Gao,Cai-Ying Li,Huan Zhou,Liang Zhao,Ya-Ting Zheng,Yong-Xia Zhao 대한영상의학회 2018 Korean Journal of Radiology Vol.19 No.4

Objective: To investigate the efficiency of spectral computed tomography (CT) optimal monochromatic images in improving imaging quality of liver vessels. Materials and Methods: The imaging data of 35 patients with abdominal CT angiography were retrospectively analyzed. Hepatic arteries, portal veins, and hepatic veins were reconstructed with mixed energy (quality check, QC), 70 keV and optimal monochromatic mode. Comparative parameters were analyzed including CT value, image noise (IN), contrast-to-noise ratio (CNR), signal-to-noise ratio (SNR), and subjective qualitative analysis. Results: The optimal monochromatic value for assessment of the common hepatic artery, portal vein, and hepatic vein ranged between 49 keV and 53 keV, with a mean of 51 keV. There were statistically significant differences (p < 0.001) among the optimal monochromatic, 70 keV and QC images with regards to the hepatic vascular CT value, IN, CNR, SNR, and subjective qualitative score. CNR of the common hepatic artery in the optimal monochromatic, 70 keV and QC groups was 24.6 ± 10.9, 18.1 ± 8.3, and 11.6 ± 4.6, respectively (p < 0.001) with subjective scores of 4.7 ± 0.2, 4.0 ± 0.3, and 3.6 ± 0.4, respectively (p < 0.001). CNR of the hepatic portal vein was 6.9 ± 2.7, 4.3 ± 1.9, and 3.0 ± 2.1, respectively (p < 0.001) with subjective scores of 4.5 ± 0.3, 3.9 ± 0.4, and 3.3 ± 0.3, respectively (p < 0.001). CNR of the hepatic vein was 5.7 ± 2.3, 4.2 ± 1.9, and 2.7 ± 1.4, respectively with subjective scores of 4.3 ± 0.3, 3.8 ± 0.4, and 3.2 ± 0.3, respectively (p < 0.001). Conclusion: Optimal monochromatic images can lead to improvement in the imaging parameters and optimization of the image quality of the common hepatic artery, hepatic portal vein and hepatic vein compared with conventional mixed kV and with 70 keV datasets.

Preliminary Application of High-Definition CT Gemstone Spectral Imaging in Hand and Foot Tendons

Kai Deng,Cheng-Qi Zhang,Wei Li,Jun-Jun Wang,Xin-Yi Wang,Tao Pang,Guang-Li Wang,Cheng Liu 대한영상의학회 2012 Korean Journal of Radiology Vol.13 No.6

Objective: To assess the feasibility of visualizing hand and foot tendon anatomy and disorders by Gemstone Spectral Imaging (GSI) high-definition CT (HDCT). Materials and Methods: Thirty-five patients who suffered from hand or foot pain were scanned with GSI mode HDCT and MRI. Spectrum analysis was used to select the monochromatic images that provide the optimal contrast-to-noise ratio (CNR) for tendons. The image quality at the best selected monochromatic level and the conventional polychromatic images were compared. Tendon anatomy and disease were also analyzed at GSI and MRI. Results: The monochromatic images at about 65 keV (mean 65.09 ± 2.98) provided the optimal CNR for hand and foot tendons. The image quality at the optimal selected monochromatic level was superior to conventional polychromatic images (p = 0.005, p < 0.05). GSI was useful in visualizing hand and foot tendon anatomy and disorders. There were no statistical differences between GSI and MRI with regard to tendon thickening (χ2 = 0, p > 0.05), compression (χ2 = 0.5, p > 0.05), absence (χ2 = 0, p > 0.05) and rupture (χ2 = 0, p > 0.05). GSI was significantly less sensitive than MRI in displaying tendon adhesion (χ2 = 4.17, p < 0.05), degeneration (χ2 = 4.17, p < 0.05), and tendinous sheath disease (χ2 = 10.08, p < 0.05). Conclusion: GSI with monochromatic images at 65 keV displays clearly the most hand and foot tendon anatomy and disorders with image quality improved, as compared with conventional polychromatic images. It may be used solely or combined with MRI in clinical work, depending on individual patient disease condition. Objective: To assess the feasibility of visualizing hand and foot tendon anatomy and disorders by Gemstone Spectral Imaging (GSI) high-definition CT (HDCT). Materials and Methods: Thirty-five patients who suffered from hand or foot pain were scanned with GSI mode HDCT and MRI. Spectrum analysis was used to select the monochromatic images that provide the optimal contrast-to-noise ratio (CNR) for tendons. The image quality at the best selected monochromatic level and the conventional polychromatic images were compared. Tendon anatomy and disease were also analyzed at GSI and MRI. Results: The monochromatic images at about 65 keV (mean 65.09 ± 2.98) provided the optimal CNR for hand and foot tendons. The image quality at the optimal selected monochromatic level was superior to conventional polychromatic images (p = 0.005, p < 0.05). GSI was useful in visualizing hand and foot tendon anatomy and disorders. There were no statistical differences between GSI and MRI with regard to tendon thickening (χ2 = 0, p > 0.05), compression (χ2 = 0.5, p > 0.05), absence (χ2 = 0, p > 0.05) and rupture (χ2 = 0, p > 0.05). GSI was significantly less sensitive than MRI in displaying tendon adhesion (χ2 = 4.17, p < 0.05), degeneration (χ2 = 4.17, p < 0.05), and tendinous sheath disease (χ2 = 10.08, p < 0.05). Conclusion: GSI with monochromatic images at 65 keV displays clearly the most hand and foot tendon anatomy and disorders with image quality improved, as compared with conventional polychromatic images. It may be used solely or combined with MRI in clinical work, depending on individual patient disease condition.