 Hello. Hello everyone. I'm going to present a paper on the evaluation of retoperectomal tumor using CT. It was a cross-sectional study. Before starting, I would like to thank my professor, Dr. Nandiraj sir, Dr. Achan Pradip sir, Dr. Manupratap sir, Dr. Prathibamnam. Let's start with brief introduction. Retoperectomalium is a complex anatomical space in the body where tumor grows often silently to larger extent before even clinical presentation. Among the various imaging modalities, CT plays a vital role in the evolution of retoperectomal tumors. It determines the epicenter of the tumor's size. Tumor composition, extent, vascularity, and effects on adjacent structure helps in treatment planning and therefore early and accurate diagnosis is crucial. The aim of my study is to evaluate various CT imaging findings of retoperectomal tumor and to associate it with histological findings, materials, and methods. A cross-sectional study was done at the Department of Radio Diagnosis, Mysore Medical College, for a duration of 12 months. The study includes 30 patients. Each patient was subjected to plane and contrast enhancements to characterize retoperectomal tumors. The results were evaluated and evaluated descriptively by Microsoft Excel 2016. Let's briefly talk about few of the imaging features of retoperectomal tumor. Here, the first case showed large heterogeneous lesion with non-enhancing area noted in retoperectomal with negative bixen with renal kidney. Suggestive of it's not of renal argin. Next, large heterogeneous lesion noted arising from the left kidney with positive bixen. Suggestive of it's of renal argin. Step methodologically proven that it's a case of renal cell carcinoma. Another case showed very different large solid lesion with predominant fat component noted displacing the liver enter immediately and right kidney inferiorly. Tissue diagnosis proved that it's a case of retoperectomal liposarcoma. Another case showed multiple homogenously enhancing lesions of varying sizes, not in pre-parivatic region, encasing the AVC and IOT, giving an appearance of sandwich sign. It's a case, a classical case of retoperectomal lymphoma. Next, another case, multiloculated thin-walled cystic lesion, non-enhancing cystic lesion noted in retoperectomal, possibly abutting right kidney and displacing the adjacent structure. Tissue diagnosis came as retoperectomal lymphoma. Another case showed large heterogeneous lesion displacing the vascular structures and there was evidence of enterothoracic extension, displacing the right kidney inferiorly and there was no non-visualization of super inner gland, giving an appearance of phantom organs in case of neuromplastoma. Let's come to results part. Here, barograph representing age distribution of the patient. In my study, there was peak incidence in 6th and 7th decade age groups. On the right hand side showed tumor distribution, whether it's of renal origin, adrenal origin, preampillary origin or primary retoperectomal tumor. In my study, it includes 36.6% of cases were primary retoperectomal tumors. Next, come to characteristics of the tumor. One is tumor composition, whether the lesion or solid or cystic, is there presence of fat or is there presence or absence of fat, calcification necrosis in solid tumors, enhancement pattern, effect on adjacent structure in the form of displacement, infiltration, vascular encasement, distant metastasis, benign versus malignant. In my study, 24 cases were malignant. My study was compared with the previous studies conducted by Choudhary et al. and Stephen D.H. et al. These studies showed similar imaging features and concluded that CET plays an important role. I am interpreting my study. My study includes 30 patients out of which 17 were males, 13 were females, most common age groups, seen in 6th and 7th decade people. It's a pathological confirmed radiological diagnosis in 26 cases out of which 80 cases were malignant, 20 cases were benign. Among these, primary retoperectomal tumor or the most common tumor accounting for 36.6%, among these, lymphoma was the most common tumor followed by lymph nodal metastasis. Four other tumors were liposarcoma, extraditional neuroblastoma, paragangrioma and lymphangeoma. Majority of the tumor were solid. One exceptional case was cystic, it was lymphangeoma. Most common enhancement pattern in my study is heterogeneous enhancement. Inflation of adjacent organ was seen in 5 cases, vascular encasement in 7 cases and distant metastasis in 6 cases. Let's come to discussion part. CET plays an important role in characterizing the tumor. This helps in narrowing down the differential diagnosis, therefore helping in treatment planning. Malignant lesions were more common than benign lesions. Similar findings were also seen in the studies conducted by Choudhary et al and Stephen DH et al. But the number of benign cases in Stephen DH et al was less compared to my study. Both above studies concluded that CET plays an important role in diagnosing the retoperectomal tumors. Primary retoperectomal tumor constitutes maximum cases in my study, accounting for 36.6% of cases with lymph nodal mass being the maximum, accounting for 63.63%. Similar finding was noted in study conducted by Chinvan DH et al. The identification of fat and calcification in the retoperectomal tumor significantly shortened the list of differential diagnosis. In the study, 4 cases showed fat attenuation within the lesion. 3 were benign, 1 was malignant, signifying that the fat was more commonly found in benign lesions. The presence of necrosis most commonly found in malignant tumors. My study includes 18 cases showed necrosis out of which 16 cases were malignant, 2 cases were benign, which includes pheochromocytoma and parachroma. Vascular encasement is also a feature of malignant tumor. In my study, all 7 cases showed vascular encasement which were malignant, which include lymphoma, neuroblastoma, periamplaric carcinoma. Among the cases with periamplaric carcinoma, 3 out of 5 cases had vascular involvement. Similar findings were seen in the study conducted by Lee E. Es et al. In my study, there were 3 cases of neuroblastoma, median age group of 1 and a half years, in which 1 case showed intratheurastic extension. I am concluding my study. The basic purpose of my study was to use CTO as an imaging tool to help arriving the accurate radiological diagnosis of retroperitonal tumor based on various imaging characteristics thus guiding in treatment planning. These are my references. Thank you.