This is a real-world medical entrance exam question, please give the true answer based on the question and selection. Topic name: Urogenital System, Subject name: Radiology
[{'content': 'The investigation of choice to evaluate IVC & Renal Vein thrombosis in Renal Cell Ca is : \nSelect and explain. \nA. IVP, B. Color Doppler, C. CT Scan, D. Ultra sound', 'role': 'user'}, {'content': 'Answer: C \nExplanation: Ans. is \'c\' i.e. CT scan Diagnosis of Renal Vein & IVC thrombosisVenography (Inferior vena cavogram & selective renal venography) is the most reliable and definitive diagnostic investigation for establishing the presence of thrombus. However its invasive and rarely used now a days.MRI - is the best non-invasive imaging modality for IVC and renal vein thrombosis.CT - is next best to MRI, with sensitivity and specificity as high as 92% and 100% (Ref: Grainger, 7/e, p 1523) Sutton writes - "MR and CT are both highly accurate in the demonstration of venous invasion."Doppler - is able to detect the venous thrombosis as echogenic material in the venous lumen and absence of flow. But it has got its limitations and is thus inferior to CT & MR.Also rememberCT is the imaging modality of choice for diagnosing and staging renal cells ca.', 'role': 'assistant'}]