[[File:Contrast CT.jpg|thumb|170px|[[CT with IV contrast]]]]
====In low renal function====[[File:On the origin and progress of renal surgery, with special reference to stone in the kidney and ureter and to the surgical treatment of calculous anuria. Together with a critical examination of (14783803013).jpg|link=CT with IV contrast in low renal function|thumb|180px|right|[[CT with IV contrast in low renal function]]]]{{Main|CT with IV contrast in low renal function}}Decreased renal function and several other conditions increase the risk of '''contrast-induced nephropathy''', which is a potentially lethal renal injury to the kidney following intravenous radiocontrast.<ref name="RudnickFeldman2008">{{cite journal|last1=Rudnick|first1=M.|last2=Feldman|first2=H.|title=Contrast-Induced Nephropathy: What Are the True Clinical Consequences?|journal=Clinical Journal of the American Society of Nephrology|volume=3|issue=1|year=2008|pages=263–272|issn=1555-9041|doi=10.2215/CJN.03690907}}</ref> ===Contrast medium reaction====
{{Main|Contrast medium reaction}}
In a more severe reaction:<ref name=SURF>Unless otherwise specified in lists and table: {{cite web|url=http://www.mastcellssjukdom.se/wp-content/uploads/2015/12/Nationella_rekommendationer_%C3%B6verk%C3%A4nslighetsreaktioner_kontrastmedel__PDF_2014-10-17.pdf|title=Hypersensitivity reactions against contrast media - Swedish Society of Uroradiology [Swedish: Överkänslighetsreaktioner mot kontrastmedel – SURFs kontrastmedelsgrupp] ], 2014-10-17}}</ref>
Before a contrast CT of a patient with known allergic-like or unknown-type of contrast reaction to the same class of contrast medium (such as iodinated), the American College of of Radiology recommends premedication with a glucocorticoid, preferably starting 12 or 13 hours before contrast administration.<ref>{{cite web|url=https://www.acr.org/-/media/ACR/Files/Clinical-Resources/Contrast_Media.pdf#page=11|Page 9 in: Manual on Contrast Media|website=American College of Radiology, Committee on Drugs and Contrast Media|accessdate=2018-08-25}} Version 10.3. 2018. ACR </ref>
===Hyperthyroidism=In low renal function====[[File:On the origin and progress of renal surgery, with special reference to stone in the kidney and ureter and to the surgical treatment of calculous anuria. Together with a critical examination of (14783803013).jpg|link=CT with IV contrast in low renal function|thumb|180px|right|[[CT with IV contrast in low renal function]]]]{{Main|CT with IV Iodinated contrast in low renal functionand hyperthyroidism}}Decreased renal function and several other conditions increase the risk of '''Iodinated contrast-induced nephropathy'''can cause thyrotoxicosis in people with hyperthyroid diseases, mainly toxic multinodular goiter, Graves’ disease, which is a potentially lethal renal injury to the kidney following intravenous radiocontrastor Hashimoto’s thyroiditis.<ref name="RudnickFeldman2008YıldızKuşkonmaz2016">{{cite journal|last1=RudnickYıldız|first1=M.Sema|last2=FeldmanKuşkonmaz|first2=H.Şerife Mehlika|title=Contrast-Induced NephropathyEffect of iodinated contrast media on thyroid: What Are the True Clinical Consequences?a brief review|journal=Clinical Journal of the American Society of NephrologyHealth Sciences|volume=36|issue=1|year=20082016|pages=263–27212|issn=15551986-90418049|doi=10.221517532/CJNjhsci.2016.03690907278}}</ref>
==Peroral==