 Diagnostic accuracy of dual energy CT in the assessment of traumatic bone marrow edema of lower limb and its correlation with MRI. Bone marrow edema is assumed to be caused as a result of rivicular microfraction. It is responsible for pain even in the absence of substantial soft tissue injuries. Bone marrow edema remains undetected in radiographs. On MRI, marrow edema is seen as an area of signal loss on T1 weighted image in a walling bone with increased signal intensity on T2 weighted and short to inversion recovery images. Despite MRI being the most widely known technique for assessment of bone marrow edema, in conditions where MRI is contraindicated are inaccessible, bone marrow edema remains undetected and diagnosed for ear interfering with overall healing and rehabilitation of patient. Fortunately, dual energy CT has a much as a viable alternative in such situation as DECT make attenuation measurements at tube voltage 80 and 140 kV that can be subjected to three material decomposition allowing for mathematical substructure of substances with relevant photograph electric effects such as iodine or calcium. The same technique is used to calculate a virtual non-calcium image from an unenhanced image which make bone marrow accessible for CT diagnosis. Despite the promising role of DECT in the assessment of bone marrow edema in general and traumatic bone marrow edema in particular, there have been limited clinical studies evaluating its usefulness. Considering this gap, our study was planned to assess the diagnostic accuracy of DECT in detecting bone marrow edema in patient of trauma of lower limb and correlation with MRI. Aim to assess the diagnostic accuracy of dual energy CT in detecting bone marrow edema in patient of trauma of lower limb and correlated with MRI. Objective to assess bone marrow edema on DECT and MRI to compare their diagnostic accuracy in assessing bone marrow edema. Cross-section study was conducted on 40 patients over a period of 18 months. Patient irrespective of sex aged 18 to 17 years with lower extremity trauma and suspected fracture were included in the study. Pregnant females patient with metallic implant were excluded from the study. For all patients with lower extremity trauma, CT examination was conducted using a dual energy CT system equipped with two X-ray tubes. Acquisition of the injured knee, ankle joint images were performed with dual energy protocol. Dual energy CT examination parameters vary as follows. Tube A, tube voltages of 80 kV, difference current time product of 20 to 50 mA Tube B is like 140 kV where SN indicates the use of integrated TIN filter. Reference current time product of 150 mA, 1 to 80.6 mm collimation, 0.5 second rotation time. IV contrast material were not used in each patient. All the images were processed on a workstation using single wire software that allow analysis of images using clear material decomposition. It acquires the attenuation measurement from two different kV settings and calculate a virtual non-calcium image using a three material decomposition method. To further improve the assessment of the marrow spacer special filter technique the select two potracellis also applied. VNC image were presented in the form of color-coded image. Axial, sag and coronal multi-tunnel color-coded reformation were all created for further assessment and analysis. The information was color-coded with color lookup table which code bone marrow edema in shades of grey allowed to orange and red parallel to the progressive increase of the density. 3D volume rending map coding bone marrow edema in shades of green normal bone in blue were used. After initial CT MRI of the affected part was performed. The examination were performed with MRI system using Hitachi using the dedicated cord for knee and ankle. It was evaluated with T1 weighted images and star images or images were analyzed on a workstation using software that allow for three-dimensional reconstruction and measurement. Bone marrow edema was identified as per protocol described by using upon DECP image analysis dual energy color-coded regions were evaluated whether edema existed in the bone marrow edema or not. Edema existed in the bone marrow. It displayed in the green or yellow on the dual energy color-coded images. Then the circular region of interest over each region on the dual energy color-coded image and in the adjacent region. The ROI were placed at the location of highest edema intensity which was green or yellow on the color-coded images to obtain attenuation value. MRI finding were considered as final on analysis of the MRI images. The diagnosis of bone marrow edema was based on the signal intensity increase in the star and T2 images with the signal decay on T1 weighted images. All the observations were made by three observers. Funnel observation was made when there was an agreement of two or more observers. Result in hours 30, 40 patients with low-aluminum trombine suspected fracture were analyzed. In majority of the cases we encountered trombine fracture on a knee joint at the time gap between injury and DECP T range from 16 to 24 days. In the present, 33 patients, 7.5% had ankle injury while remaining 37, like around 92.5% patient has had knee injury. Incidentally, knee injuries were predominant. In this study, mean attenuation at fracture site was observed as 170.75 plus minus 33.99 while the same at the adjacent side was observed at 19.73 plus minus 22.50 H1. The difference in the attenuation at fracture site and adjacent site among the patient enrolled in the study was found to be 151.03 plus minus 35.03 which was considered statistically significant. Subject to interpretation by DECP based on attenuation found bone marrow edema in 45% cases while the rest of the cases no edema was found. On MRI evaluation, bone marrow edema was found to be present in 42.5% cases only while the rest of the cases edema was not found. Both DECP and MRI indicate presence of edema in 16 out of 17 cases whereas the CECP indicate edema in two cases that were not indicated by MRI. Sensitivity, Pacificity, PPV and non-PV on DECP against MRI for detection of bone marrow edema was found to be 94.1%, 91.3%, 88.9% and 95.5% respectively. Diagnostic accuracy of DECP against MRI was found to be 92.5%. Among the 17 cases in which MRI indicate the presence of edema, the attenuation of DECP was higher as compared to 23 cases where MRI indicate no edema. Difference in attenuation among cases where MRI indicated edema or no edema was found to be statistically significant. This is the area of bone marrow edema. Here you can see in the CT, a plain CT in such image, there is like a little hyperdensity can be seen. In the area of bone marrow edema, the screen signal can be seen. On MRI, the low intensity signal can be seen. Here same in the coronal section. Discussion, traumatic bone injuries are not just limited to bone fractures or soft tissue injuries but they are impacted on bone marrow too. The bone marrow edema pattern represents a footprint of injury mechanism improved diagnostic confidence in the detection of concomitant injuries. In recent year, dual energies, computer tomography has emerged as a promising alternative for assessment of post-traumatic bone marrow edema with encouraging accuracy. In this study, we used the dual energy CT virtual non-calcium technique to assess bone marrow with MRI imaging serving as a standard of reference. Because of the ability of the ECT to subtract calcium from cancerless bone, it was able to depict bone marrow edema. In present study, a significant difference of 15.8 in, I mean, H2 unit was between fractures at an adjacent cell, thus reflecting a possibility of bone marrow edema. In the present study, out of 14 patients were found to have bone marrow edema whereas bone marrow edema was detected in 17 cases by MRI. The findings suggest that DECT has higher positive T rate as compared to MRI. As far diagnostic efficacy of DECT against MRI was concerned, DECT found DECT to be 94.1% sensitive to 91.3% specific and reported a positive predictor and negative predictor value of DECT as 88.9 and 95.5 respectively. There was substantial agreement between DECT and MRI. In this present study, we concluded the observatory and took the observation made by two or more observer as the final observation. We achieved a more objective assessment which proved out to be more sensitive and specific. Conclusion, the present study showed that DECT is useful method for evaluation of chromatic lower extremity fracture for presence of bone marrow edema. The finding of the present study endorsed the findings of previous study that have also showed that DECT can use an alternative to MRI for evaluation of chromatic injury suspected for bone marrow edema. Addition of DECT as alternative will help in providing additional tool where MRI facilities contraindicated and could reduce the long term burden of bone marrow edema. Further studies to validate the finding of the present study are recommended. Thank you.