This is a real-world medical entrance exam question, please give the true answer based on the question and selection. Topic name: Pancreas, Subject name: Surgery
Which of the following is/ are the imaging criteria for unresectable carcinoma of pancreas? 
Select and explain. 
A. Metastatic spread to vertebrae, B. Invasion in duodenal wall, C. Irregular increase in density of omental fat, D. All the above
D: All the above
Answer: D: All the above 
Explanation: Ans. is 'd' i.e., All the above Imaging criteria of unresectable pancreatic carcinoma* Vascular invasion is a relative criterion for the lack of resectability, depending on the extent of vascular involvement. A circumferential vessel involvement over 50% makes tumor unresectable, However, in between 25% of vascular invasion makes its resectability questionable.* Metastatic spred outside the pancreas makes tumor irresectable.* Tumor invasion into adjacent organs signifies unresectability.* Ascites is seen in advanced stages and implies peritoneal carcinomatosis or invasion of the lesser sac. Irregular increase in density of the omental fat is highly suggestive of peritoneal carcinomatosis.