<prompt> IV contrast is not used inHRCTMRIIVPMyelography  <response>: IV contrast agent is given in :-X-ray based investigation Radiocontrast agent :- Radiography simple x-ray, CT-Scan.MRI MR contrast agents.Ultrasound USG contrast agents.IVP intravenous pyelography as the name suggests, the contrast agent is given intravenously.In myelography, the contrast agent is injected into subarachnoid space. 