Sometimes a chemical contrast medium is injected into the body to enhance and improve the quality of the image. Gadolinium contrast media is used as a dye or contrast agents. The main difference between MRI with contrast and MRI without contrast is that, when a contrast is injected it is done with the intention of highlighting certain parts of soft tissue. Whereas an MRI without Contrast is cleaner than the other. Most MRI Scans are done without the contrast medium. Contrast material, Gadolinium is generally very safe. Patients with normal kidney function can pass out most of the contrast material in urine form, within 24 hours. Contrast materials usually do not produce any kind of allergic reaction.