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
Viual non-contrast CT is obtained in 
Select and explain. 
A. Spiral CT, B. Multidetector CT, C. Dual source CT, D. HRCT
C: Dual source CT
Answer: C: Dual source CT 
Explanation: 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.