Issues in Imaging for Stroke Shawn Halpin MRCP

Issues in Imaging for Stroke Shawn Halpin MRCP FRCR LLM University Hospital of Wales, Cardiff

National Intercollegiate WP for Stroke 2004 Hospital care specialist teams weekly MDT SITS MOST

contd. . . “initial assessment by experienced clinician” “non specialist care costs lives, increases dependancy, less cost effective” brain imaging within 24 hours MRI if CT delayed for 10 days

Audit data: How many patients imaged within 24 hours? Wales criticised for worst UK performance But 97% patients scanned within 24 hours of request

New report Immediate imaging for certain stroke subgroups thrombolysis, unconscious, warfarin Immediate review by an expert in stroke

Immediate (1 hr) scan? Trivial to provide

Immediate clinical diagnosis Very difficult large/small vessel; TIA; migraine; SAH; dissection, watershed, global etc 3 patient with limb fractures referred as acute stroke patients

Plain scan in early stroke: Usually normal

Rush to treat: Undoubtedly some non-stroke patients will be treated with r. TPA

Early CT signs:

Add specialist neuroradiological advice Non Trivial Network? Interested DGH radiologists? Every DGH radiologist?

Alternative? Perfusion scanning CT or MR Make decisions based on physiology

Reichenbach et al AJNR 20 1999

45 yr old, large ophthalmic aneurysm

Perfusion during occlusion

Tissue Classification

Advantages of Physiology No false positives Treat only those with viable tissue Use as triage: a tool to spare the expert in stroke?

Radiology will enthusiastically support acute stroke BUT Give us the tools to do it Help us with the out of hours reporting Bear in mind we have other responsibilities too: Most radiologists cover all emergencies, not just neuro And there are not many of us!

1. Plain scan only Who reports? Fear of onerous on call duty Consultant radiologists ideal In each hospital? Network in Wales, or wider UK local/extended? Network outside Wales? Radiographer or stroke team report? ?

2. ASPECT score More radiologist experience needed Greater physician input Give drug or not? No longer a yes/no, now a maybe Further need for experienced clinician Use of the Alberta Stroke Program Early CT Score (ASPECTS) for Assessing CT Scans in Patients with Acute Stroke AJNR Am J Neuroradiol 22: 1534 ﾐ 1542, September 2001. Alternatively, what percentage of the MCA territory is low density?

2. ASPECTS score reporting Need consultant radiologist In house local network outsource

3. Assess other pathology Need consultant radiologist As before

4. Perfusion data Need Neuroradiologist or highly specialised other person this may change in the future, but not yet Similar issues with location

Suggestion: All hospitals support IST 3 Start slowly, learn where the problems are Build resources based on local experience Radiologist, radiographer, stroke team Look to develop perfusion scanning, 24/7 services over time