What scans to perform for patients entered in IST3 and how to send them to the trial office

1
What scans to perform for patients entered in
IST3 and how to send them to the trial office

• Eleni Sakka
• Joanna Wardlaw
• Peter Sandercock

2
Outline

• When to perform scans
• Before randomisation
• 24-48 hours post randomisation
• If the patient has a neurological event within
  first 7 days
• Technical details of the scans
• CT scans
• MR scans
• Sending the scan to Edinburgh
• The scan transfer form (compulsory)
• Methods of sending the scan
• Eleni the Scan technician

3
ALL IST-3 patients should have a CT or MR brain
scan

• Before randomisation to exclude
• intracranial haemorrhage
• non stroke causes of the recent stroke-like
  symptoms.
• At 24-48 hours after randomisation irrespective
  of treatment allocation (i.e. patients allocated
  control as well as those allocated rt-PA).
• At other times within 7 days of randomisation, if
  
• the patient deteriorates neurologically,
• is suspected to have had either an intracranial
  haemorrhage or a recurrent ischaemic stroke

4
Technical details of the scans initial set up
for IST-3

• Prior to starting recruitment in your centre, you
  must send a test scan to the trial office in
  Edinburgh.
• This must be the type of scan (CT, MR or both)
  that you intend to use in IST-3.
• The test scan is to
• check that the stroke imaging in your centre is
  OK for IST-3
• can be read by our software
• to chose which scan transfer mechanism suites
  you
• to iron out any unforeseen problems
• The test scan should be a typical scan as
  performed for stroke in your centre, but MUST
  meet the IST-3 scan requirements for CT or MR
  (see next slides)
• Approval to join the trial is based on the test
  scan type if CT, then you are only approved for
  CT. You cannot introduce MR without sending a
  test MR scan first.

5
Technical details of the scans CT

• Non-contrast
• Should cover the entire brain from the foramen
  magnum to the vertex, with maximum slice
  thickness
• 4 5mm through the posterior fossa
• 8 10mm for the cerebral hemispheres, with no
  slice gap
• Thinner slices from modern spiral scanners are
  OK.
• Scans should be windowed on
• a width of 80 Hounsfield Units (HU)
• A centre level of 35 40 HU
• .Correct windowing is particularly important if
  scans are to be sent as printed film
• Note we collect CT perfusion and angiography
  imaging if performed, but this is not essential
  for IST-3

6
Example of CT scan slices required
7
Technical details of the scans MR

• MR brain imaging is allowed in place of CT only
  if there is sufficient radiological support in
  the hospital to interpret the scans.
• MR sequences must include axial
• a gradient echo (T2) to exclude haemorrhage
  (haemorrhage can be overlooked on several other
  types of MR imaging sequence)
• Diffusion Weighted Imaging (DWI) to identify the
  recent infarct.
• FLAIR or T2-weighted sequences to show brain
  structure, white matter lesions, old infarcts.
• Note we collect perfusion and MR angiography
  imaging if performed, but this is not essential
  for IST-3

8
Technical details of the scans MR

• MR sequences must include axial

Gradient echo (T2)
DWI with ADC map
FLAIR or T2
Note we collect perfusion and MR angiography
imaging if performed, but this is not essential
for IST-3.
9
Sending the scans to Edinburgh please

• Send the baseline and 24-48 hour follow-up scans
  (and any extra scans performed due to further
  events within 7 days) to the Edinburgh trials
  office, either by
• electronic transfer of DICOM files (subject to
  certain conditions), or
• other methods of electronic file transfer, or
• post
• If you send hard copy film, please make a copy
  and send us the original scan we will return
  it.
• Complete and send a scan transfer form with each
  scan (compulsory), ie one form with the
  pre-randomisation and one form with the 24-48
  hour scan
• If sending MR scans, please check that you have
  sent all the sequences we require.
• Full instructions on the six different methods of
  sending scans to Edinburgh are available in the
  Scan transfer SOP1

10
Anonymising the scans

• All scans are fully anonymised before being added
  to the IST-3 database in Edinburgh
• However, if you need to anonymise the scans
  before sending them to Edinburgh, please
  substitute the patients IST-3 ID number for the
  patients name, either on the film, or if sending
  the files electronically, in the DICOM header
  name field.
• PLEASE make sure that the scan transfer form is
  correctly and completely filled in!

11
Frequently asked questions

• Q The patient also had a perfusion scan, should
  I send that as well?
• A YES. But indicate this on the scan transfer
  form PLEASE!
• Q We werent able to perform a post
  -randomisation scan within the time limit of 48
  hrs that is specified by the IST3 guidelines
• A We do accept post-randomisation scans that
  took place after the limit of 48hrs, in cases
  that it was impossible to perform a scan earlier.
  PLEASE note this on the scan transfer form,
  otherwise we will need to issue a query, which
  will delay the analysis of the scans.
• Q I am having trouble anonymising the scan
  before sending it.
• A please contact Eleni Sakka, the IST-3 imaging
  technician to advise how best to do this.
  Eleni.Sakka_at_ed.ac.uk

12
Eleni Sakka
Role IST-3 scan data manager Contact details
email eleni.sakka_at_ed.ac.uk Please contact
Eleni in the first instance with scan related
queries she will refer these to the appropriate
source where necessary.
13

• Full details of all procedures are available at
  www.ist3.com