Dual Images Research Articles

An efficient reversible data hiding algorithm using two steganographic images

Reversible data hiding (RDH) algorithms are concerned with concealing data within images such that the original image can be fully recovered upon the extraction of hidden data. A substantial interest has grown recently in RDH algorithms that are based on using dual images in order to increase the embedding capacity. In this paper, we propose a RDH algorithm that is based on this concept. Effectively, embedding and extraction of data in the proposed algorithm is performed in three successive phases. In the first phase, four simple rules are used to embed about one bit in each pixel in the two images. On the other hand, the other two phases employ the concept of prediction for embedding secret data bits but without using any complex predictors. Specifically, these phases use one image as the prediction of the other image. Performance evaluation of the proposed algorithm showed its ability to embed around 1.23 bits per pixel with stego image quality above 48dB. Moreover, the proposed algorithm is of low computational complexity and requires no communication of overhead information.

Real-time two-color interferometric technique for simultaneous measurements of temperature and solutal fields

Development of a real-time Mach–Zehnder based dual wavelength interferometry technique for studying the double-diffusive convection phenomena is presented. The interferometer employs two different monochromatic light sources with wavelengths of λ1=632.8nm and λ2=457.9nm. A high resolution color CCD sensor has been employed to record the interferograms that carry phase information pertaining to the coupled effects of the two wavelengths used. Phenomenon of double-diffusive convection has been set up in a two-layered salt-stratified solution that is destabilized by isothermal heating at the bottom wall of the test cell. The resultant changes in the thermal and solutal fields have been simultaneously captured using the developed interferometric technique. Experiments have been performed at a stability ratio of Rρ=1.02 and thermal Rayleigh number of RaT=6.0×105. The work presents a detailed methodology for quantitative determination of temperature and/or concentration fields from a single dual wavelength interferogram. Results have been presented in the form of dual color interferometric images and contours of whole-field temperature distribution as a function of experimental run time. The two-dimensional contours of concentration field at time instant t=0min have been presented. The observed variations in the fringe patterns are primarily due to thermal gradients prevailing in the fluid layer. In addition to the quantitative studies, interferometer also acts as a flow visualization tool and fringe patterns give qualitative insights into the flow field. The fringe patterns indicate towards the possibility of the existence of mechanical coupling between the two fluid layers wherein the direction of circulatory movement of fluids in each layer is oppositely oriented.

Integrated ultrasound and gamma imaging probe for medical diagnosis

In the last few years, integrated multi-modality systems have been developed, aimed at improving the accuracy of medical diagnosis correlating information from different imaging techniques. In this contest, a novel dual modality probe is proposed, based on an ultrasound detector integrated with a small field of view single photon emission gamma camera. The probe, dedicated to visualize small organs or tissues located at short depths, performs dual modality images and permits to correlate morphological and functional information. The small field of view gamma camera consists of a continuous NaI:Tl scintillation crystal coupled with two multi-anode photomultiplier tubes. Both detectors were characterized in terms of position linearity and spatial resolution performances in order to guarantee the spatial correspondence between the ultrasound and the gamma images. Finally, dual-modality images of custom phantoms are obtained highlighting the good co-registration between ultrasound and gamma images, in terms of geometry and image processing, as a consequence of calibration procedures.

Method for Filling and Sharpening False Colour Layers of Dual Energy X-ray Images

Abstract An X-ray scanning and image processing have a vast range of applications in the security. An image of a content of some package being passed for example to an airplane or to the court house may help to figure out if there are any dangerous objects inside that package and to avoid possible threatening situation. As the raw X-ray images are not always easy to analyze and interpret, some image processing methods like an object detection, a frequency resolution increase or a pseudocolouring are being used. In this paper, we propose a pseudocoloring improvement over material based approach. By addition of the edge detection methods we fill and sharpen colour layers over the image, making it easier to interpret. We demonstrate the effectiveness of the methods using real data, acquired from a professional dual energy X-ray scanner.

3D multimodal spatial fuzzy segmentation of intramuscular connective and adipose tissue from ultrashort TE MR images of calf muscle

To develop and evaluate an automated algorithm to segment intramuscular adipose (IMAT) and connective (IMCT) tissue from musculoskeletal MRI images acquired with a dual echo Ultrashort TE (UTE) sequence. The dual echo images and calculated structure tensor images are the inputs to the multichannel fuzzy cluster mean (MCFCM) algorithm. Modifications to the basic multichannel fuzzy cluster mean include an adaptive spatial term and bias shading correction. The algorithm was tested on digital phantoms simulating IMAT/IMCT tissue under varying conditions of image noise and bias and on ten subjects with varying amounts of IMAT/IMCT. The MCFCM including the adaptive spatial term and bias shading correction performed better than the original MCFCM and adaptive spatial MCFCM algorithms. IMAT/IMCT was segmented from the unsmoothed simulated phantom data with a mean Dice coefficient of 0.933 ±0.001 when contrast-to-noise (CNR) was 140 and bias was varied between 30% and 65%. The algorithm yielded accurate in vivo segmentations of IMAT/IMCT with a mean Dice coefficient of 0.977 ±0.066. The proposed algorithm is completely automated and yielded accurate segmentation of intramuscular adipose and connective tissue in the digital phantom and in human calf data. Magn Reson Med 77:870-883, 2017. © 2016 International Society for Magnetic Resonance in Medicine.

Dual time-point (18)F-FDG PET/CT to assess response to radiofrequency ablation of lung metastases.

To establish the usefulness of dual time-point PET/CT imaging in determining the response to radiofrequency ablation (RFA) of solitary lung metastases from gastrointestinal cancer. This prospective study included 18 cases (3 female, 15 male, mean age 71±15 yrs) with solitary lung metastases from malignant digestive tract tumors candidates for RFA. PET/CT images 1h after injection of 4.07MBq/kg of (18)F-FDG (standard images) were performed at baseline, 1 month, and 3 months after RFA. PET/CT images 2h after injection centered in the thorax at 1 month after RFA were also performed (delayed images). A retention index (RI) of dual time-point images was calculated as follows: RI=(SUVmax delayed image-SUVmax standard image/SUVmax standard image)*100. Pathological confirmation of residual tumor by histology of the treated lesion was considered as local recurrence. A negative imaging follow-up was considered as complete response. Local recurrence was found in 6/18 lesions, and complete response in the remaining 12. The mean percentage change in SUVmax at 1 month and at 3 months showed a sensitivity and specificity for PET/CT of 50% and 33%, and 67% and 92%, respectively. The RI at 1 month after RFA showed a sensitivity and specificity of 83% and 92%, respectively. Dual time point PET/CT can predict the outcome at one month after RFA in lung metastases from digestive tract cancers. The RI can be used to indicate the need for further procedures to rule out persistent tumor due to incomplete RFA.

Multi-Channel Tirf Imaging of Cardiac Calcium Signals

Total internal reflectance fluorescence imaging uses an evanescent wave to focus on structures and events in a thin layer within ∼100 nm of the plasmalemma of cells that adhere tightly to an underlying glass surface. To resolve Ca2+ signals that are exchanged between Ca2+ transporters in the sarcolemma, sarcoplasmic reticulum, and mitochondria of cardiac cells we use a Leica DMI 6000 B to record rapidly interlaced fluorescence images with 3 wave length of laser excitation (405, 488 and 561 nm) and two 2 emission bands (Photometrics DV2) to produce as many as 6 channels of nearly simultaneous fluorescence images originating from both genetically targeted Ca2+ sensors, and conventional dissolved synthetic probes. To extract biological information from the collected stream of data we designed a flexible computer program (Con2k) that operates with stored recipes to separate intended and artifactual fluorescence signals and follow their time course. Sequential application of spatial and spectral correction matrices serve to: a) fine tune the match of dual emission images, b) identify and compensate for motion (contraction, swelling, puff-induced), and c) automatically eliminate cross talk between fluorescence signals (targeted and untargeted probes and auto fluorescence). Thereafter the corrected image sequence are analyzed with existing routines to track and follow Ca2+ sparks and other events in μ-domains ryanodine receptors and mitochondria. The developed program serves to guard against multiple artifacts, take full advantage of the superior z-resolution of the TIRF microscope, focus on new fluorescent peptide probes that are genetically engineered to measure Ca2+, pH, and ROS, at specific locations with improved speed, and streamline multi-parameter analysis of extensive data streams. NIH HL 19152.

Trabecular bone score in patients with liver transplants after 1 year of risedronate treatment.

The aim of this study was to analyse the effect of risedronate on Trabecular Bone Score in liver transplant patients with low bone mass, during 1-year follow-up. In this retrospective cohort study, trabecular bone score (TBS) was calculated from dual X-ray absorptiometry images of the lumbar spine (LS), collected from a prospective randomized open-label 1-year trial performed in liver recipient patients. A total of 89 patients with osteopenia or osteoporosis were randomized to receive RIS plus calcium and vitamin D3 or calcium and vitamin D3. TBS was low in both groups at baseline, 6 and 12 months. Baseline TBS at the LS showed degraded microarchitecture in 22.8% of patients, partially degraded in 40.3%, and normal values in 36.8% of the patients. After 1 year of treatment, no difference in TBS was observed between both groups. No correlations were found between bone mineral density (BMD) and TBS values at any follow-up time point. No relationship was found between BMD, TBS or immunosuppressive drugs with incidental fracture. No significant effect in TBS was observed in liver transplant patients treated with RIS or calcium and vitamin D3 after 1 year of follow-up. In these patients, the clinical usefulness of this new tool should be established.

The Value of Tc-99m Mibi for Differential Diagnosis of Biliary Atresia and Hepatitis in Rats

Cholestatic diseases in neonates which characterized by deterioration of bile passage to intestine. We investigated the usability of Tc-99m MIBI as a hepatobiliary scintigraphy radiopharmaceutical for diferential diagnosis of biliary atresia and hepatitis in experimental model. A total of 20 males Wistar albino rats who had weights ranging from 200-350 g were included in this study. Rats were randomly divided into 4 groups. Control group, sham operated group, biliary atresia group and chemical hepatitis group (with carbon tetrachloride) were created, respectively. Blood flow phases, consantration and early excreation phases was performed after an intravenous injection through the internal jugular vein of 37 MBq Tc-99m MIBI using a gamma camera. Dual late static images were obtained at the same position at 15, 30, 60, 90 and 120 min after injection. In control group, radiopharmaceutical passage into the small intestine was seen between 45 and 60 min and evidently seen between 120 and 150 min as large hyperactive focus on midline or non-linear (snaky) radiopharmaceutical accumulation at the level of kidney. In biliary atresia group, radiopharmaceutical concentration was seen normal in liver but passage into the small intestine was not seen all rats. In carbon tetrachloride group, blood flow, concentration and early excretion scintigraphic images did not differ from control group and radiopharmaceutical passage into the small intestine was seen between 45 and 60 min. Although radiopharmaceuticals passage into the intestine was not shown in all rats of biliary atresia group. We suggest that Tc-99m MIBI as a radiopharmaceutical of hepatobiliary scintigraphy would be the contribution of the differential diagnosis of biliary atresia and hepatitis in humans.

NIMG-43DUAL VOLUME VISUALIZATION (3D-DSA AND CROSS-SECTIONAL IMAGING) FOR SURGICAL PLANNING OF INTRACRANIAL MENINGIOMAS

INTRODUCTION: Many techniques about planning for the surgery of intracranial brain tumors have been considered for getting more information about the relationship between tumors and adjacent vasculatures. Especially for the surgery of meningiomas, it is essential to distinguish passing arteries from feeders. It is also very important to preserve venous structures. Dual volume visualization is apt and powerful method to know about these vascular structures. METHODS: Between Feb. 2012 and Dec. 2014, a total of 20 patients underwent brain tumor surgery after undergoing dual volume visualization. The tumors comprised of 1 glioblastoma, 1 medulloblastoma, and 18 meningiomas. The locations of meningiomas were as follows : 6 parasagittal; 4 falx; 2 convexity; 1 tentorial; 1 foramen magnum; 2 sphenoid wing; 1 petroclival; and 1 olfactory groove. RESULTS: In cases involving glioblastoma and medulloblastoma, the boundary between the distinctive tumor mass of the intrinsic tumor and the normal brain is unclear, resulting in post-operative assessments showing greater direct damage done to the normal brain than that caused by vessel injury. Vascular supply and disfiguring observed in preoperative dual volume visualization images closely resembled the actual observations made during the surgery of meningiomas. Three out of eighteen meningioma cases demonstrated new deficits. One case exhibited tumor bed bleeding and perilesional edema leading to aggravation of motor weakness and deterioration. One exhibited venous infarction and a separate delayed hemorrhage leading to motor weakness and deterioration. One developed facial palsy. CONCLUSIONS: The advantages of this technique are as follows: 1. It enables the visualization of arteries and veins, individually; 2. the 3D rotation allows for convenient presurgical orientation; 3. it permits simulating craniotomies. This technique could reduce the incidence of newly developed neurological deficits as a result of identifying which veins to preserve during surgery and predicting the arteries that may shift.

Multifunctional theranostic contrast agent for photoacoustics- and ultrasound-based tumor diagnosis and ultrasound-stimulated local tumor therapy

Biomedical imaging-guided cancer therapy should have capabilities of both accurate tumor diagnosis and high therapeutic efficacy for the personalized treatment. Various biomedical imaging-guided cancer therapies are currently being investigated to overcome current limitations that include low sensitivity of diagnosis and poor drug delivery to the tumor site. Here, we report the development of a multifunctional theranostic contrast agent demonstrating high sensitive photoacoustic and ultrasound imaging and effective local delivery of anticancer drug to a tumor site. A microbubble (porphyrin-MB) was developed using phospholipid–porphyrin conjugates to enhance ultrasound and photoacoustic signal intensities simultaneously. Paclitaxel-loaded human serum albumin nanoparticles (PTX-HSA-NPs) were then conjugated onto the surface of the microbubble. The developed PTX-HSA-NPs conjugated porphyrin-MB (porphyrin-MB-NPs) provided sensitive, dual modal images of a tumor at 700nm optimal laser wavelength for photoacoustic imaging and 5–14MHz operating frequency for the ultrasound imaging. In addition, porphyrin-MB-NPs efficiently suppressed tumor growth by ultrasound exposure. Exposure to the focused ultrasound triggered the collapse of porphyrin-MB-NPs, resulting in the local release of PTX-HSA-NPs and enhanced penetration into the tumor site. The increased preferential accumulation and penetration of PTX-HSA-NPs suppressed tumor growth 10-fold more than without exposure to ultrasound. In conclusion, the developed porphyrin-MB-NPs establish a new paradigm in simultaneous bi-functional ultrasound/photoacoustic imaging diagnosis and locally triggered release of nanomedicine and enhanced chemotherapy efficiency.

Dual adrenal venous phase contrast-enhanced MDCT for visualization of right adrenal veins in patients with primary aldosteronism.

To evaluate the frequency of visualization of the right adrenal vein (RAV) on dual adrenal venous phase multi-detector computed tomography (MDCT) in patients with primary aldosteronism. Images of contrast-enhanced dual adrenal venous phase MDCT (45- and 55-second delays) in 90 patients with primary aldosteronism who underwent adrenal venous sampling were retrospectively evaluated. The degree of RAV visualization on each phase image was evaluated by two radiologists using a five-point scale and RAV visualization rates were estimated. The RAV visualization rates on the first- and second-phase images were 89% and 91% by radiologist A, and 93% and 90% by radiologist B, respectively. No significant differences in the score of RAV visualization were observed between the first- and second-phase images by the two readers (P = 0.164 and P = 0.06). The kappa values for inter-observer agreement of RAV visualization on the first- and second-phase images were 0.57 and 0.46, respectively. The consensual RAV visualization rates on the first- and second-phase images were 91% and 92%, respectively. The overall RAV visualization rate by using both phase images was 98%. Dual adrenal venous phase MDCT can visualize the RAV in almost all patients with primary aldosteronism. • Dual adrenal venous phase MDCT images can visualize the right adrenal veins. • The adrenal venous phase lies between the arterial and portal phases. • Anatomical information will contribute to the technical success of adrenal venous sampling.

A FPGA Implementation of Dual Images based Reversible Data Hiding Technique using LSB Matching with Pipelining

Background: In this digital era, the authentication and proof of ownership has become a vital part in all the multimedia data content like audio, image and video. Data Hiding is one of the familiar methodologies used to authenticate and resolve the issues of copyrights of the digital data. Methods: In this paper the FPGA (Field Programmable Gate Array) implementation of Data Hiding using reversible Dual Image concept is carried out on a gray scale image. Here the FPGA implementation is carried out with and without the concept of pipelining. Findings: In the data hiding process the secret key is embedded in the host image content and analyzed with the values of PSNR (Peak Signal to Noise Ratio) and Embedding capacity. In the last, a comparison for the pipelined and non pipelined mode of data hiding process has been done for the values of area, power and timing. From the results it is noted that the pipelined mode of data hiding gives better result in terms of very less embedding time compared to non pipelined mode with a lesser power consumption. As this data hiding methodology involves only simple operation it is easy to implement as FPGA chip using Verilog HDL Modelling language. Here the entire data hiding operation is carried out by the hardware chip, not by software running on hardware, hence the process of data hiding is fast when compared with all other software implementations. As the whole process of embedding is taking place in real time, we can embed this FPGA data hiding chip as a separate co-processor the data hiding operation with any multimedia device.

P06.02: Is there a difference in the fetal right myocardial performance index (RMPI) measured from single and dual Doppler images?

P06.02: Is there a difference in the fetal right myocardial performance index (<scp>RMPI</scp>) measured from single and dual Doppler images?

Dual image based reversible data hiding method using neighbouring pixel value differencing

Dual image based reversible data hidings are recently proposed where dual copies of a cover image are used to embed the secret data. In this paper, a novel reversible data hiding method based on neighbouring pixel value differencing is proposed to increase embedding capacity with a good image quality. The mean value of neighbouring pixels and the difference values are used to decide the size of embedding bits per the sub-block. The receiver can extract the secret data and recover the cover image from dual stegoimages. The experimental results show that the proposed method has a higher capacity and still a good image quality where it could embed 767,922 bits and maintain 45.58 and 45.33 dB for dual images.

SU-E-I-41: Dictionary Learning Based Quantitative Reconstruction for Low-Dose Dual-Energy CT (DECT)

Purpose: DECT collects two sets of projection data under higher and lower energies. With appropriates composition methods on linear attenuation coefficients, quantitative information about the object, such as density, can be obtained. In reality, one of the important problems in DECT is the radiation dose due to doubled scans. This work is aimed at establishing a dictionary learning based reconstruction framework for DECT for improved image quality while reducing the imaging dose. Methods: In our method, two dictionaries were learned respectively from the high-energy and lowenergy image datasets of similar objects under normal dose in advance. The linear attenuation coefficient was decomposed into two basis components with material based composition method. An iterative reconstruction framework was employed. Two basis components were alternately updated with DECT datasets and dictionary learning based sparse constraints. After one updating step under the dataset fidelity constraints, both high-energy and low-energy images can be obtained from the two basis components. Sparse constraints based on the learned dictionaries were applied to the high- and low-energy images to update the two basis components. The iterative calculation continues until a pre-set number of iteration was reached. Results: We evaluated the proposed dictionary learning method with dual energy images collectedmore » using a DECT scanner. We re-projected the projection data with added Poisson noise to reflect the low-dose situation. The results obtained by the proposed method were compared with that obtained using FBP based method and TV based method. It was found that the proposed approach yield better results than other methods with higher resolution and less noise. Conclusion: The use of dictionary learned from DECT images under normal dose is valuable and leads to improved results with much lower imaging dose.« less

Good interrater reliability of a new grading system in detecting traumatic bone marrow lesions in the knee by dual energy CT virtual non-calcium images

ObjectiveTo evaluate the capacity of dual-energy computed tomography (DECT) virtual non-calcium (VNCa) images in detecting post-traumatic bone marrow lesions (BMLs) in the knee with a new grading system. MethodsDECT and magnetic resonance (MR) imaging were used to examine acute trauma of the knee in 32 patients. VNCa images were generated by dual-energy subtraction of calcium, and the lower end of the femur and upper end of the tibia each were divided into six regions for grading of bone marrow by two musculoskeletal radiologists using a four-grading system (Grade 4, very obvious lesions; Grade 3, relatively obvious lesions; Grade 2, slight or suspicious lesion on VNCa image and mild lesion on MR image; Grade 1, normal bone marrow). CT values were obtained in the BMLs. MR images were used as the reference standard. Grade 3–4 bone marrow was regarded as a positive result to evaluate the performance of VNCa images in detecting traumatic BMLs in the knee, and receiver operating characteristic (ROC) curve analysis of VNCa images for detection of knee BMLs was performed based on CT value of the bone marrow. ResultsBone marrow rating by the two radiologists showed very good consistency (κ=0.850 and 0.869 for VNCa and MR images, respectively). VNCa and MR images had good consistency (κ=0.799 for lower end of the femur; κ=0.659 for upper end of the tibia). When Grade 3–4 bone marrow was regarded as a positive result, the sensitivity, specificity, positive predictive value, and negative predictive value of VNCa images for detection of BMLs in the lower end of the femur were 73.5%, 98.6%, 94.7%, and 91.6%, respectively, and the values in the upper end of the tibia were 91.0%, 100.0%, 100.0%, and 95.4%, respectively. The CT values of bone marrow were (−52.5±31.3) HU in positive area and (−91.2±16.9) HU in negative area for the lower end of the femur, and those were (−51.3±30.2) HU in positive area and (−104.7±17.5) HU in negative area for the upper end of the tibia (all p values<0.0001). The areas under the ROC curve of VNCa images for detection of BMLs were 0.875 for the lower end of the femur and 0.939 for the upper end of the tibia. ConclusionGood interrater reliability of this new grading system in detecting traumatic BMLs in the knee by VNCa images of DECT can be obtained with good diagnostic predictive values.

Change detection matrix for multitemporal filtering and change analysis of SAR and PolSAR image time series

This paper presents a method for analyzing Synthetic Aperture Radar (SAR) and polarimetric SAR (PolSAR) image time series based on change detection matrices (CDM) containing information on changed and unchanged pixels. These matrices are constructed for each spatial position over the time series by implementing similarity cross tests. The proposed matrix is then exploited for adaptive temporal filtering, analysis of change dynamics and multitemporal change detection. The proposed approach is illustrated on the three following data sets: 25 ascending TerraSAR-X images and 7 descending RADARSAT 2 full polarization images over Chamonix-MontBlanc, France, where the seasonal evolution of glaciers and mountains can be observed, and a time series of 11 ascending ALOS-PALSAR dual polarization images over Merapi volcano, Indonesia during a period including the 2010 eruption.

Automatic scar segmentation in dual inversion recovery images is more consistent with manual outlining than in conventional inversion recovery images

Background The dual inversion recovery (dual IR) pulse sequence has recently been shown to improve blood suppression and infarct delineation in late gadolinium enhancement (LGE) images of myocardial infarction. This resulted in significantly lower inter-observer variability in manual outlining of scar and higher expert confidence in scar detection and transmurality when compared with conventional inversion recovery (IR) images. Computer algorithms have been shown to improve the accuracy of scar segmentation within IR images. We sought to develop and optimise a set of computer algorithms to quantify scar in both IR and dual IR images. Methods

복부 CT 검사 시 이중에너지 기법을 통한 적정한 조영제 양에 관한 연구

이중에너지 기법을 이용한 복부 CT 검사에서 적정한 조영제 양에 대하여 알아보고자 하였다. 일반적인 단일에너지 복부 CT 검사를 시행했던 환자들 중 이중에너지 기법을 이용하여 추적검사를 시행한 30명을 대상으로 하였다. 단일에너지 복부 검사에서 사용했던 조영제 양 대비 30%, 40%, 50%, 60%, 70%로 각각 설정하여 영상을 획득한 후 대동맥, 하대정맥, 간문맥, 간실질에 관심영역을 설정하여 조영증강정도(hounsfield unit; HU)를 구하여 단일에너지에서 측정된 부위와의 값을 비교 분석하였다. 그 결과 기존대비 60%로 조영제를 설정한 군에서는 대동맥 HU : <TEX>$210.80{\pm}13.609$</TEX>, 하대정맥 HU : <TEX>$190.40{\pm}25.215$</TEX>, 간문맥 <TEX>$198.40{\pm}21.232$</TEX>, 간실질 HU : <TEX>$119.20{\pm}7.98$</TEX>로 각각 측정되었으며. 단일에너지 복부 CT 검사는 대동맥 HU : <TEX>$205.40{\pm}16.426$</TEX>, 하대정맥 HU : <TEX>$188.20{\pm}21.476$</TEX>, 간문맥 HU : <TEX>$195.40{\pm}22.744$</TEX>, 간실질 HU : <TEX>$121.00{\pm}6.595$</TEX> 이었다. 따라서 이중에너지를 이용하여 복부 조영 CT검사를 시행할 때 조영제의 양을 60%로 설정한 후 검사하는 것이 각 장기에서의 단일에너지 조영검사시와 비슷한 조영증강정도를 획득할 수 있어 기존 조영제 양의 감소와 동시에 조영제를 낮은 속도로 주입할 수 있어 신장기능 저하환자, 정맥혈관이 약한 환자, 과거 조영제 부작용이 있었던 환자에게 유용한 검사라 사료된다. The purpose of this study is finding optimum contrast medium quantity during abdominal CT using dual energy technique. The study subjects are 30 patients who had received general single energy abdominal CT and received double energy technique follow-up abdominal CT. dual energy technique abdominal CT images were obtained after setting contrast medium quantities at 30%, 40%, 50%, 60% and 70% of contrast medium quantity at the time of single energy technique. Then the contrast enhancement (Hounsfield Unit; HU) was estimated by setting-up the regions of interest at aorta, inferior vena cava, hepatic portal vein and hepatic parenchymal. The obtained values were compared to the values of the same parts measured during single energy technique abdominal CT. The results of the study were as following. The 60% set up group had HU in aorta : <TEX>$210.80{\pm}13.609$</TEX>, IVC : <TEX>$190.40{\pm}25.215$</TEX>, hepatic portal vein : <TEX>$198.40{\pm}21.232$</TEX> and hepatic parenchymal : <TEX>$119.20{\pm}7.98$</TEX>, The single energy abdomianl CT images had HU in aorta : <TEX>$205.40{\pm}16.426$</TEX>, IVC : <TEX>$188.20{\pm}21.476$</TEX>, hepatic portal vein : <TEX>$195.40{\pm}22.744$</TEX> and hepatic parenchymal : <TEX>$121.00{\pm}6.595$</TEX>. Therefore, it is possible to obtain contrast enhancement by dual energy technique abdominal CT similar to the same by single energy technique abdominal CT by setting-up the quantity of contrast medium at 60% of contrast medium at the time of single energy technique abdominal CT. Based on the result of this study, it is possible to decrease existing quantity of contrast medium by _% and the injection velocity can be also decreased. Accordingly, it is believed that the result of study would be quite useful for patients who have renal function disorder, weak vein or side effect of contrast medium in the past.