Changes

NCCT is performed as a first line in neuroimaging as it is usually considered gold standard inruling out hemorrhage despite MRI being equivalent to Non-contrast CT in this regard due to theease of availability, rapid results, and safety in both stable and unstable patients .Advancements in technology enabling thinner slices (sub millimeter) and enhanced tissuedifferentiation allows for a role of NCCT in arterial occlusion and early infarction with has avariable detection rate of about 65% in cases imaged within 6 hours. A description of thesesigns is below.<ref name=Mirza2016/>

scan score developed in 2001 offering a reproducible grading system to score early ischemia inanterior circulation strokes to better direct treatment and reduce the variability of observations. Using two standard axial CT slices; one at the level of the thalamus and basal ganglia, andone just rostral to the basal ganglia, the MCA territory is divided into 10 regions,each accounting

treatment . The ASPECTS method is not without its limitations; such as difficulty in scoring

or tilt and motion artifacts. (ASPECTS diagram).<ref name=Mirza2016/> {|class="wikitable"|+ CT findings that generally contraindicate thrombolysis<ref name="FrankGrotta2013">{{cite journal|last1=Frank|first1=Benedikt|last2=Grotta|first2=James C.|last3=Alexandrov|first3=Andrei V.|last4=Bluhmki|first4=Erich|last5=Lyden|first5=Patrick|last6=Meretoja|first6=Atte|last7=Mishra|first7=Nishant K.|last8=Shuaib|first8=Ashfaq|last9=Wahlgren|first9=Nils G.|last10=Weimar|first10=Christian|last11=Lees|first11=Kennedy R.|title=Thrombolysis in Stroke Despite Contraindications or Warnings?|journal=Stroke|volume=44|issue=3|year=2013|pages=727–733|issn=0039-2499|doi=10.1161/STROKEAHA.112.674622}}</ref>|-| Edema, dense middle cerebral artery sign, loss of insular ribbon, lenticular hypodensity, acute infarction, sulcal effacement, or ASPECT-score of 8 or 9|-| Mass effect, infarction of >1/3 of the middle cerebral artery territory, midline shift, or ASPECT-score of ≤7|-| ASPECT-score of ≤7|}

==Subsequent MRI==MRI is more sensitive than seldom performed after CT of stroke in detecting ischemic changesSwedish practice, similar to CT with respect to<ref>{{NU Hospital Group}}</ref> but can offer additional diagnostics:[[File:Stroke imaging algorithm.png|thumb|350px|center|Algorithm.]] diagnosing hemorrhage, and it remains {{Main|MRI of the gold standard for imaging head in acute focal neurologicalstroke}} deficits . Multimodal MRI (different imaging sequences) provides detailed visualization ==Reporting==Report even the absence of:*Intracranial hemorrhagebrain and vessel anatomy, including perfusion data with a higher sensitivity and specificity than*Delineable infarctionCT to detect stroke mimics . The complete MR imaging protocol requires approximately 15to 20 minutes to performIn case of angiography, and an additional 10 minutes for patient positioning and transfer, asreport:well as calculation *Normal/Unremarkable contrast filling of larger vessels of the apparent diffusion coefficient cerebrum and mean transit time maps cerebellum (or pathology thereof). MRIcomes with an advantage of decreased exposure to radiation with higher costs, lesser availability,claustrophobia experienced by patients as a drawback, along with absolute contraindicationssuch as metallic implants or pacemakers.<ref name=Mirza2016/>{{Reporting}}