 Good morning, Dr. Vishwas Kumar, postgraduate resident department of radio diagnosis from Atal Bihari Vajpayee Institute of Medical Sciences and Dr. Harpal Hospital, New Delhi. My title of paper presentation is MDCT perfusion imaging evaluation of focal elevations. Aim and objective of this study is to evaluate the role of MDCT perfusion imaging in focal elevations and to differentiate benign and malignant focal elevations on the basis of MDCT perfusion imaging. Introduction, focal elevations is a discreet abnormality of the liver parankaima. In the early stage of liver lesion, there are usually no typical clinical manifestations that can be detected by conventional imaging methods. Its incidence of detection is increasing due to advancement in imaging. Focal liver lesion can either be benign or malignant. Early detection and differentiation of benign from malignant liver lesion is extremely important for planning treatment, monitoring of disease evolution and prognosis. Multi-detective computer tomography has emerged as the modality that is frequently employed in the preoperative diagnosis, staging of disease, treatment planning and follow-up of patients with known or suspected liver lesions. It is the preferred imaging technique for the routine liver. Volume perfusion using a series of dynamically captured CT images of the volume being started. Computer tomography perfusion evaluated the temporal changes in the tissue density following intravenous administration of iodinated contrast material. Qualitative as well as quantitative evaluation of hepatic perfusion is feasible with CT perfusion. CT perfusion efficiently locates abnormal tissue perfusion which is difficult to detect accurately with conventional CT. CT perfusion parameters such as blood flow, blood volume, mean transit time, portal liver perfusion, arterial liver perfusion and hepatic perfusion index. I used to functionally assess the perfusion of pathological tissue in comparison to normal tissue. This study is an effort to assess the role of MD-CT perfusion imaging in the characterization of focal liver lesions and differentiate them into benign and malignant liver lesions and help in deciding for the course of management. Materials and methods. The study was conducted in the Department of Radio Diagnosis at Tuttleby-Harivach Institute of Medical Sciences and Dr. R. M. Hospital New Delhi. The patient effort for the CT perfusion scan after signing a written consent were included. The study included a dull patient with at least one focal liver lesion detected on ultrasound or MRI and effort for CT scan or patients with incidentally detected focal liver lesion or CT abdomen done for any other indication. The study was performed on 128 slides CT scanner system. The study was a cross-section observational study. The duration of study is 1.5 years and the total number of 34 cases were included in the study. Inclusion criteria are dull patient with focal liver lesion referred for CT scan. Exclusion criteria, pediatric age group. Patients who have already undergone surgical dissection or palliative treatment, patient with impaired renal function, patient with history of contrast allergy, lactating and pregnant females. Methodology, non-contrast CT scan of the liver extending from diaphragm to iliac rest in cranial cordial direction was obtained during breath hold at the end of expiration. Perfusion CT of the liver was done in quiet breathing. After intravenous injection of non-ionic iodinated contrast medium with a flow rate of four to five ml per second followed by 20 ml of normal saline at the rate of four to five ml per second using a power injector. Scanning was initiated after a delay of four seconds from the start of contrast injection and images were acquired for a duration of 49.9 seconds with total coverage of 15 centimeter of the liver. Reconstruction and post-processing was done to generate CT perfusion maps using inbuilt single volume perfusion CT body software. Region of interest was drawn at center as well as at the edge of the lesion and also drawn in the background liver paracoma which acted as a control. CT perfusion values for the lesion and background liver paracoma including blood flow, blood volume, arterial liver perfusion, venous perfusion, hepatic perfusion index and mean transit time were calculated. Results, the maximum number of patient lying in the age group of 41 to 60 years in the study and there is a male preponderance of 55.9% in comparison to females in the study. A total of 14 patients were diagnosed with benign focal levelation whereas a total of 20 patients were diagnosed with malignant focal levelation in this study. This is a table showing comparison of CT perfusion parameters between benign and malignant focal levelations out of which blood volume, arterial liver perfusion and hepatic perfusion index shows a statistically significant difference with the p-value of less than 0.05. This is a table showing different types of focal levelation which were diagnosed in the study. Among benign focal levelation, hemangioma was found to be the most common whereas metastasis and cholangiocarsinoma were found to be most common among malignant focal levelation. Final diagnosis was based on clinical findings, lab investigations, serology, classical imaging findings, CT perfusion parameters and histological analysis. ROC curve analysis to differentiate malignant from benign focal levelations. The CT perfusion parameters, blood volume and arterial liver perfusion shows a sensitivity of 100% whereas hepatic perfusion index shows a maximum specificity of 85.71% in the study. This is a table showing mean values of CT perfusion parameters in hemangioma, hepatocellular carcinoma, metastasis and cholangiocarsinoma. Case one is of hydrated cyst. Post-contrast CT shows daughter cyst within the lesion and perfusion map shows lower values of blood flow and blood volume in the lesion as compared to the normal liver. Case two is of pyogenic abscess. Post-contrast CT shows classic cluster sign of pyogenic liver abscess. Perfusion map shows hyperfused rims surrounding the abscess with raised blood flow when compared to the non-involved hepatic palchima. Case three is of biopsy-proved hepatic tuberculosis. Post-contrast CT shows no enhancement of the lesion. Perfusion map showed decreased blood flow and blood volume in the lesion. Case four is of hemangioma in the right lobe of liver. Post-contrast CT shows intense peripheral nodular and centripetal enhancement of the lesion. Perfusion map at the periphery of the lesion shows increased blood flow and blood volume parameters. Case five is of biopsy-proven hepatocellular carcinoma. Post-contrast CT shows heterogeneous enhancement of the lesion. Perfusion map show increased blood flow and blood volume and arterial liver perfusion parameter at the periphery of the lesion. Case six is of biopsy-proven liver metastasis. From primary GB melignancy, post-contrast CT shows heterogeneous enhancement of the lesion with central area of necrosis. Perfusion map shows increased blood flow, blood volume and hepatic perfusion index at the periphery of the lesion. Case seven is of hypervascular mats from unknown primary in the colon. Post-contrast CT shows heterogeneously enhancing lesion and perfusion map shows increased blood flow and blood volume at the periphery of the lesion. Case eight is of cholendic carcinoma. Post-contrast CT shows biolobaric central and peripheral dilated biliary radicals and perfusion map shows increased arterial liver perfusion, hepatic perfusion index at the periphery of the lesion. Coming on to the discussion, CT perfusion is a non-invasive imaging modality which permits the qualitative as well as quantitative assessment of liver perfusion. Majority of the patients with focal liver lesion were in the age group of 41 to 60 years in the study. There is a male pre-ponderance of 55.9% when compared to females. The most common benign focal liver lesion was found to be hemangioma. Whereas the most common malignant focal liver lesions were metastasis and cholendic carcinoma in the study. CT perfusion parameters including blood volume, arterial liver perfusion, hepatic perfusion index values in differentiating malignant from benign focal liver lesions showed a statistically significant difference. Other CT perfusion parameters like blood flow, portal venous perfusion and mean transit time demonstrates no statistically significant difference. Conclusion, CT perfusion is an important quantifiable functional imaging technique which is helpful in differentiating malignant from benign focal liver lesions by determining alteration in perfusion parameters of the lesion. Hence the single CT can provide valuable information regarding morphology as well as functional images. CT perfusion can be included as a part of standard CT protocol in order to provide functional information of focal liver lesion. CT perfusion parameters including blood volume, arterial liver perfusion and hepatic perfusion index showed significant difference in differentiating malignant from benign focal liver lesion. However, there is increased radiation exposure compared to conventional CT scan which research on low dose radiation imaging techniques will advance the knowledge and understanding of tumor physiology. These are the list of references. Thank you.