Clinicians often consider alternate imaging modalities over contrast studies due to concern of acute kidney injury. In many situations, intravenous contrast can significantly improve the utility of a study. So, is contrast-induced nephropathy real? How often does acute kidney injury occur after a contrast study?
A recent study (Hinson et al. 2016) did a retrospective cohort analysis involving almost 17,934 patient charts from 2009 to 2014. Patients undergoing contrast-enhanced CT were compared to those undergoing non-contrast CT or no imaging at all. The frequency of kidney injury did not seem to be affected by whether intravenous contrast was given. A meta-analysis involving 13 studies and 25,950 patients (McDonald et al. 2013) found a similar result, as have a number of other studies. A link may exist dependent on the type of contrast (specifically iohexol and ioxaglate may have a higher risk). More studies are still necessary.
In summary, perhaps the concern of contrast-induced nephropathy is overstated. Be on the lookout for further studies on this!
Farkas, Josh. “Do CT scans cause contrast nephropathy?” PulmCrit (EMCrit). Published 29 Mar. 2015. Web. Accessed 30 Jan. 2017. <http://emcrit.org/pulmcrit/do-ct-scans-cause-contrast-nephropathy>.
Hinson, Jeremiah S., et al. “Risk of Acute Kidney Injury After Intravenous Contrast Media Administration.” Annals of Emergency Medicine (2017).
McDonald, Jennifer S., et al. “Frequency of acute kidney injury following intravenous contrast medium administration: a systematic review and meta-analysis.” Radiology 267.1 (2013): 119-128.
Image from kidney.org.au