Rapid Responses to:

EDITORIALS: J M Wardlaw and A J Farrall Diagnosis of stroke on neuroimaging BMJ 2004; 328: 655-656 [Full text]

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Rapid Responses published:

Project now published as an HTA monograph

Phillip P Simons   (19 March 2004)

Important Reminder

Alan S Meltzer   (22 March 2004)

"Scan all immeadiately "or "scan whatever the cost"

Robert J Sellar   (22 March 2004)

Economics of CT Scanning

timothy g morley   (23 March 2004)

Scan with MRI where possible

Dennis P Briley, Tom Meagher   (29 March 2004)

The value of acute stroke imaging. Better the devil you know!

Mark W Parsons, Romesh Markus, Richard Lindley, Christopher Levi   (31 March 2004)

Project now published as an HTA monograph 19 March 2004
Phillip P Simons, Communications Manager National Coordinating Centre for HTA, University of Southampton SO16 7PX Send response to journal: Re: Project now published as an HTA monograph	The project (reference 12 in the article) has now been published in the HTA monograph series (volume 8, number 1). Further details are at this URL: http://www.ncchta.org/project.asp?PjtId=1073 Competing interests: None declared
Important Reminder 22 March 2004
Alan S Meltzer, Retired (previously a senior medical advisor, Laboratory Centre for Disease Control, Health Canada) 350 Wellington St (#402) Kingston Ontario K7K 7J7 Send response to journal: Re: Important Reminder	Editor - Wardlaw and Farrall are to be congratulated on their important reminder that appropriate and timely neuroimaging can save lives and improve outcomes in patients with strokes. Undoubtedly earlier diagnosis is essential if the full benefits of early intervention are to be realized. For those of us who remember the dark days when patients with strokes were "written off" the new diagnostic technology and the current innovative therapies herald an exciting era in the management of stroke patients. Of course the other side of the coin is that physicians and the general public need to be aware of the early signs and symptoms of stroke. This is particularly important in the case of previously healthy young women who are on oral contraceptives. Some of these preparations have been associated with arterial thromboembolism, cerebral thrombosis and cerebral hemorrhage. Early diagnosis and appropriate treatment will certainly help to minimize the impact of such life-threatening complications, particularly when relatively young individuals are involved. Competing interests: None declared
"Scan all immeadiately "or "scan whatever the cost" 22 March 2004
Robert J Sellar, consultant neuroradiologist Western General Edinburgh EH3 5PA Send response to journal: Re: "Scan all immeadiately "or "scan whatever the cost"	The editorial "Diagnosis of stroke on nueroimaging" with its subtitle "scan all immeadiately" strategy improves outcomes and reduces cost is not born out by the evidence base. By far the largest randomised controlled studies on the use of aspirin in acute stroke were IST and CAST which published side by side. The latter study states that "for about 800 of the 40,000 patients in CAST and IST; the initial diagnosis was wrong, and the patient had had a haemorrhage before randomisation. There was no indication in either trial, however, that these misdiagnosed patients were damaged by aspirin so any hazard cannot be large"(1).So how does the proposed emergency scan improve outcomes? The policy of "scan all immeadiately" also has cost implications not considered by the authors. They calculate that scanning costs will be £44- 103. This is derived at by taking the running costs of a CT scanner and dividing this by the number of scans performed. This will not now work. The authors state that the average District General Hospital will have to do 3 extra scans a day. If one of these is done out of hours the new European working time directive will require all of those involved, typically a consultant radiologist, a radiographer and a nurse to take most of the following day off. These professionals will require replacing at a cost of about £ 140,000 year on top of that £44 costing of the scan. In summary the policy "scan all immeadiately", although a good slogan, fails to do what it says on the tin; it doesnt improve outcomes and could seriously damage the health of radiology departments. Finally should the academics who wrote the editorial have declared as one of their interests that they don't do on call? 1 CAST: a randomised placebo-controlled trial of early aspirin use in 20 000 patients with acute ischaemic stroke The Lancet 1997; 349: 1641-1649 Competing interests: None declared
Economics of CT Scanning 23 March 2004
timothy g morley, radiologist Radiological practice, Sixtus Hospital , Haltern, Germany (Zip 45721) Send response to journal: Re: Economics of CT Scanning	Colleague Sellar suggests that CT scans are far too costly, (especially due to new European laws) and coming as he does from Scotland his credibility on economic matters might be all too uncritically accepted. Here in Germany, my remuneration is about €100 (state regulated, "GOÄ"). This dramatically reduces my need for ancillary staff, I have never used a radiographer (the age of mouseclicks is upon us) for an out-of-working hours exam. and since this service is offered on a private/commercial basis, I have to drag myself out of bed,punctually (?) as usual, the next morning. Yours Faithfully, Tim Morley Competing interests: None declared
Scan with MRI where possible 29 March 2004
Dennis P Briley, Consultant Neurologist Stoke Mandeville Hospital HP21 8AL, Tom Meagher Send response to journal: Re: Scan with MRI where possible	We agree with Wardlaw and Farrall (1) that a “scan all immediately” strategy for stroke is optimal. The editorialists indicate that while MRI has advantages in imaging acute stroke, there are some perceived disadvantages. It has been our experience that the advantages of an early imaging strategy with MRI outweighs disadvantages. By combining diffusion weighted imaging with a T2 weighted gradient sequence there is a high sensitivity to both infarction and haemorrhage. The room times for this technique are similar to CT and most patients can be scanned by MRI (2) . The interpretation of the scans are more straightforward and have high reproducibility (3). In a British DGH where there may not be ready access to a specialist neuroradiologist or stroke specialist, we feel MRI with diffusion-weighted imaging carries significant advantages in ease of interpretation with a higher sensitivity and specificity compared to CT scanning, particularly in patients in whom the diagnosis is less obvious. 1. Wardlaw JM, Farrall AJ. Diagnosis of stroke on neuroimaging. BMJ 2004;328:655-6. 2. Buckley BT, Wainwright A, Meagher T, Briley D. Audit of a policy of magnetic resonance imaging with diffusion-weighted imaging as first-line neuroimaging for in-patients with clinically suspected acute stroke. Clinical Radiology 2003;58:234-237. 3. Schulz UGR, Briley D, Meagher T, Molyneux A, Rothwell PM. Sensitivity of diffusion weighted MR-Imaging performed several weeks after a minor stroke or TIA. JNNP 2003;74:734-8 Competing interests: None declared
The value of acute stroke imaging. Better the devil you know! 31 March 2004
Mark W Parsons, Director of Stroke Unit Mater Hospital, Newcastle, Australia,2300, Romesh Markus, Richard Lindley, Christopher Levi Send response to journal: Re: The value of acute stroke imaging. Better the devil you know!	For the vast majority of stroke physicians, the conclusions reached by Professor Wardlaw and colleagues in their recent NHS health technology assessment study1 would not be regarded as being in any way controversial. The authors should be congratulated on providing this data however, as the potential value of obtaining a rapid clinico-radiological stroke diagnosis is still questioned in some circles. It is interesting to compare the approach of health systems to management of the most common and potentially serious acute vascular syndromes. In suspected acute coronary syndromes, many organizations set a benchmark of 10 minutes between hospital arrival time, completion of an initial clinical assessment and an electrocardiograph2. This information plus, later return of biomarker levels, enable risk stratification and facilitate appropriate acute and preventive therapies. A similar philosophy of urgency in stroke management has traditionally been lacking. This is despite evidence that in ischaemic stroke, improved outcomes are seen when reperfusion is initiated early3. The evidence provided by Wardlaw and Farrell may assist in changing attitudes towards urgency in stroke imaging, however, challenges will remain in translation and implementation at the local level. A hyperacute stroke assessment and management algorithm using a risk stratification approach has recently been introduced across 29 Emergency Departments in NSW Australia4. The package is currently under evaluation, however, the key assessment components are a standardized stroke severity scale and guidelines for immediate, urgent or less urgent non-contrast head CT scanning. As Wardlaw and Farrell indicate, CT scanning can be combined with angiographic and perfusion imaging, adding 10-15 minutes to scanning time, but providing information on large artery patency and cerebral perfusion. CT perfusion (CTP) and CT angiography (CTA) images from one of our patients are below. The CTP colour maps have been converted to black and white. The patient was imaged at 4 hours after stroke onset with a large area of left middle cerebral artery (MCA) ischaemia. Non-contrast CT (not shown) was normal. CTP maps (top row) show large areas of reduced cerebral blood flow (CBF) and delayed mean contrast transit time (MTT), with a smaller region of reduced cerebral blood volume (CBV). Preliminary evidence suggests that tissue with reduced CBF and normal CBV is at risk of infarction but still potentially salvageable, whereas tissue with reduced CBV is likely to be destined for infarction.5 CTA shows distal M1 MCA occlusion (arrow). The patient was given tPA, and transcranial ultrasound demonstrated recanalisation of the MCA during tPA infusion, with improvement in the National Institutes of Health Stroke Scale from a score of 21 at baseline to 13 immediately post tPA. Follow-up CT shows that the final infarct is very similar in size to the acute CBV lesion (arrows) and that much of the tissue that had decreased CBF but normal CBV acutely was salvaged from infarction. These newer CT techniques provide additional diagnostic detail and sophistication and, if further validated may be useful in the identification of critically hypoperfused but potentially salvageable tissue, the “ischaemic penumbra”. We completely agree with the "scan all immediately" recommendation. Patients with stroke should not be denied the newly proven benefits of rapid radiological diagnosis of their "brain attack". Furthermore, improvements in stroke assessment will be vital to promote new research in acute interventions. This should be a public health priority. 1. Wardlaw JM, Seymour J, Cairns J, Sandercock PAG, Keir S, Lewis SC, et al. What is the best imaging strategy for acute stroke? NHS Health Technology Assessment Project No 96/08/01. Southampton: HTA Monographs, 2003 (in press). www.ncchta,org (accessed 30 Dec 2003). 2. Aroney CN, Boyden AN, Jelinek MV, Thompson P, Tonkin AM, White H. Management of unstable angina. Guidelines 2000. Med J Aust 2000; 173 Suppl: S65-88. 3. The ATLANTIS ECASS and NINDS rt-PA Study Group Investigators. Association of outcome with early stroke treatment: pooled analysis of ATLANTIS, ECASS, and NINDS rt-PA stroke trials. The Lancet. 2004;363:768-774 4. Towards A Safer Culture (TASC) Program. http://www.racp.edu.au/hpu/cssp/cands3.htm 5. Wintermark M, Reichhart M, Thiran J-P, et al. Prognostic accuracy of cerebral blood flow measurement by perfusion computed tomography in acute stroke patients. Ann Neurol. 2002;51:417-432. Competing interests: None declared Editorial note The patient whose case is described has given signed informed consent to publication.