title: Renal safety of CT angiography and perfusion imaging in the emergency evaluation of acute stroke.
abstract: OBJECTIVE
  Multimodal CT imaging with contrast-enhanced CT angiography (CTA) and CT perfusion (CTP) is increasingly being used to guide emergency management of acute stroke. However, little has been reported about the safety of intravenous contrast administration associated with these studies in the acute stroke population, including cases in which baseline creatinine values are unknown. We investigated the incidence of contrast-induced nephropathy (CIN), defined as a 25% or more increase in baseline creatinine levels within 72 hours of contrast administration and chronic kidney disease in patients receiving CTA+/-CTP at our regional stroke center.
  
  
  METHODS
  We analyzed 198 patients who underwent contrast CT studies for evaluation of acute ischemic or hemorrhagic stroke at our center (2003-2007). Through retrospective chart abstraction, we analyzed serial creatinine levels (baseline to day 3) and later values (>/=day 4) where available. The incidences of CIN and/or chronic kidney disease were documented. After power analysis, CIN and non-CIN groups were compared by using the unpaired t test, Wilcoxon rank sum test, or Fisher exact test.
  
  
  RESULTS
  None of the 198 patients developed chronic kidney disease or required dialysis. Of 175 patients with serial creatinine measurements between baseline and day 3, 5 (2.9%) developed CIN. The incidence of CIN was 2% in patients who were scanned before a baseline creatinine level was available.
  
  
  CONCLUSIONS
  The incidence of renal sequelae is relatively low in acute stroke patients undergoing emergent multimodal CT scanning. Prompt CTA/CTP imaging of acute stroke, if indicated, need not be delayed in those with no history of renal impairment.
authors: Division of Neurology, Department of Medicine, North & East Greater Toronto Area Ontario Regional Stroke Centre, and Sunnybrook Health Sciences Centre, Toronto, Ontario, Canada. julia.hopyan@sunnybrook.ca
authors: J J
authors: JJ
authors: Hopyan
authors: D J
authors: DJ
authors: Gladstone
authors: G
authors: G
authors: Mallia
authors: J
authors: J
authors: Schiff
authors: A J
authors: AJ
authors: Fox
authors: S P
authors: SP
authors: Symons
authors: B H
authors: BH
authors: Buck
authors: S E
authors: SE
authors: Black
authors: R I
authors: RI
authors: Aviv
mesh_terms: D000208:Acute Disease; D000368:Aged; D002533:Cerebral Angiography / Q000009:adverse effects*; D003287:Contrast Media / Q000009:adverse effects*; D003404:Creatinine / Q000097:blood*; D004632:Emergency Medical Services / Q000379:methods; D005260:Female; D006801:Humans; D007674:Kidney Diseases / Q000139:chemically induced* / Q000000981:diagnostic imaging*; D008297:Male; D012189:Retrospective Studies; D020521:Stroke / Q000097:blood* / Q000000981:diagnostic imaging*
chemical_list: D003287:Contrast Media; D003404:Creatinine