This is a real-world medical entrance exam question, please give the true answer based on the question and selection. Topic name: CT SCAN, Subject name: Radiology
[{'content': 'Viual non-contrast CT is obtained in \nSelect and explain. \nA. Spiral CT, B. Multidetector CT, C. Dual source CT, D. HRCT', 'role': 'user'}, {'content': "Answer: C \nExplanation: Dual-energy (DE) CT implies acquiring of data sets simultaneously at two different photon spectra in a single CT acquisition. Using the DE data sets obtained with Iodinated contrast material, an un-enhanced CT image, or 'Viual non-contrast' (VNC)-CT image of the abdomen can be generated using DE post-processing algorithms.", 'role': 'assistant'}]