***TASK*** the task is to summarize an input biomedical literature in six sentences 
    ***INPUT*** the input is a biomedical literature 
    ***OUTPUT*** the output is the summary of an input biomedical literature in six sentences 
    ***DOCUMENTATION*** 
    ***EXAMPLES*** 
    Input: BACKGROUND AND PURPOSE : Endovascular therapy is an alternative for the treatment of AIS result ing from large intracranial arterial occlusions that depends on the use of iodinated RCM . The risk of RCM-mediated AKI following endovascular therapy for AIS may be different from that following coronary interventions because patients may not have identical risk factors . MATERIAL S AND METHODS : All consecutive patients with large-vessel AIS undergoing endovascular therapy were prospect ively recorded . We recorded the baseline kidney function , and RCM-AKI was assessed according to the AKIN criteria at 48 hours after RCM administration . We compared the rate of RCM-AKI 48 hours after the procedure and sought to determine whether any preexisting factors increased the risk of RCM-AKI . RESULTS : We identified 99 patients meeting inclusion criteria . The average volume of contrast was 189 ± 71 mL , and the average creatinine change was −4.6 % at 48 hours postangiography . There were 3 patients with RCM-AKI . Although all 3 patients died as a result of their strokes , return to baseline creatinine levels occurred before death . There was a trend toward higher rates of premorbid diabetes mellitus , chronic renal insufficiency , preadmission statin and NSAID use , and a higher serum creatinine level on admission for the RCM-AKI group . The volume of procedural contrast was similar between groups ( those with and those without RCM-AKI ) ( P = .5 ) . CONCLUSIONS : In this small study , the rate of RCM-AKI  following endovascular intervention for AIS was very low . A much larger study is required to determine its true incidence Purpose — The aim of this guideline is to provide a focused up date of the current recommendations for the  endovascular  treatment of  acute ischemic stroke . When there is overlap , the recommendations made here supersede those of previous guidelines . Methods — This focused up date analyzes results from 8 r and omized , clinical trials of endovascular treatment and other relevant data published since 2013 . It is not intended to be a complete literature review from the date of the previous guideline publication but rather to include pivotal new evidence that justifies changes in current recommendations . Members of the writing committee were appointed by the American Heart Association/American Stroke Association Stroke Council ’s Scientific Statement Oversight Committee and the American Heart Association/American Stroke Association Manuscript Oversight Committee . Strict adherence to the American Heart Association conflict of interest policy was maintained throughout the consensus process . Recommendations follow the American Heart Association/American Stroke Association methods of classifying the level of certainty of the treatment effect and the class of evidence . Prerelease review of the draft guideline was performed by 6 expert peer review ers and by the members of the Stroke Council Scientific Statement Oversight Committee and Stroke Council Leadership Committee . Results — Evidence -based guidelines are presented for the selection of patients with acute ischemic stroke for endovascular treatment , for the endovascular procedure , and for systems of care to facilitate endovascular treatment . Conclusions — Certain endovascular procedures have been demonstrated to provide clinical benefit in selected patients with acute ischemic stroke . Systems of care should be organized to facilitate the delivery of this care OBJECTIVE We sought to determine the percentage of patients presenting with code stroke who would be excluded from computed tomography angiography , computed tomography perfusion , or both based on their emergency department laboratory results ( creatinine and glomerular filtration rate ) and the incidence of contrast-induced nephropathy in patients with code stroke who receive contrast . DESIGN We conducted a retrospective analysis of our prospect i ve code stroke data base . SETTING The study took place in an emergency department at a university medical center . RESULTS A total of 131 consecutive patients with code stroke were identified . Of these , 11 ( 8.4 % ) would not have received contrast based on a creatinine level greater than 1.5 mg/dL on initial evaluation . However , 10 of these 11 patients ( 91 % ) had a history of renal disease . A total of 3 % of patients who received contrast developed contrast-induced nephropathy . CONCLUSIONS Our findings suggest that the use of contrast agents in patients with code stroke before availability of renal function tests appears safe in patients who do not have a known history of renal disease BACKGROUND AND PURPOSE : Contrast-induced nephropathy ( CIN ) is one of the most common causes of in-hospital acute renal failure . The aim of this study was to assess the risk for CIN after repeated administration of the nonionic , dimeric , iso-osmolal contrast agent iodixanol regardless of pre-existing renal function . Changes in serum creatinine ( SCr ) levels were compared with those of control subjects who did not receive iodinated contrast media ( CM ) . MATERIAL S AND METHODS : Between January 2005 and March 2007 , a total of 100 consecutive patients were prospect ively included . Patients underwent a CT perfusion ( CTP ) study of the brain from clinical signs of acute cerebral infa rct ion . CTP was performed with an intravenous bolus of 60 mL of iodixanol-270 . Precontrast and postcontrast SCr levels were obtained , and the CTP study was repeated within 32 hours and postcontrast SCR was assessed . The control group consisted of 100 patients scheduled for plain cranial CT examination , who were not exposed to iodinated CM .  RESULTS : Mean baseline SCr level was 0.96 ± 0.35 mg/dL in the contrast group and 1.14 ± 0.74 mg/dL in the control group . After repeated administration of CM , a total of 7 patients had a relative increase of greater than or equal to 25 % compared with baseline . In the control group , a relative increase of 25 % or more was seen in 12 patients . The difference in the incidence of the rise in SCr of > 25 % was not significantly different ( P = .094 ) . CONCLUSION : Multiple contrast-enhanced studies with intravenously administered iodixanol are not associated with a higher risk for CIN compared with a control group receiving no CM BACKGROUND AND PURPOSE : Concerns have recently grown regarding the safety of iodinated contrast agents used for CTA and CTP imaging . We tested whether the incidence of AN , defined by a ≥25 % increase in the post−contrast scan creatinine level , was higher among patients with ischemic stroke who underwent a functional contrast-enhanced CT protocol compared with those who had no iodinated contrast administration . MATERIAL S AND METHODS : The contrast-exposed group consisted of 575 patients with acute ischemic stroke who underwent CTA ( n = 313 ) , CTA/CTP ( n = 224 ) , or CTA/CTP followed by conventional angiography ( n = 38 ) within 24 hours of stroke onset and were consecutively enrolled in a prospect i ve cohort study . The nonexposed group consisted of 343 patients with ischemic stroke , consecutively admitted to the same institution , who did not receive iodinated contrast material .  Patients were stratified by baseline eGFR . In the primary analysis , the Fisher exact test was used to compare the incidence of AN between the contrast-exposed and the nonexposed patients at 24 , 48 , and 72 hours and on a cumulative basis . A secondary analysis compared the incidence of AN in patients who underwent conventional angiography following CTA/CTP versus patients who underwent CTA/CTP only . RESULTS : The incidence of AN was 5 % in the exposed and 10 % in the nonexposed group ( P = .003 ) . Patients who underwent conventional angiography after contrast CT were at no greater risk of AN than patients who underwent CTA/CTP alone ( 26 patients , 5 % ; and 2 patients , 5 % , respectively ; P = .7 ) . CONCLUSIONS : Administration of a contrast-enhanced CT protocol involving CTA/CTP and conventional angiography in selected patients does not appear to increase the incidence of CIN BACKGROUND AND PURPOSE : 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 . MATERIAL S AND 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 abstract ion , 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 . CONCLUSION : 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 
    Output:
    
Conclusions — Nonr and omized evidence suggests that CTA/CTP are not associated with statistically significant increase in risk of AKI in patients with stroke , even those with known chronic kidney disease