ISNVD Abstract Book

can be accomplished using T2*, phase or susceptibility mapping from the phase images. SWI is also
useful in assessing blood products such as microbleeds and hemorrhages -possibly due to traumatic
brain injury, vascular dementia, or MS. SWI-MRA can reveal arteries and veins on the order of a few
hundred microns by means of a dual-echo sequence. MRA and MRV data can be obtained at the same
time.
For more conventional imaging, T2WI is used to show tissue with long T2 components such as edema,
CSF, tumors, and MS lesions. 3D T2 FLAIR is used because the images have suppressed CSF signal. FLAIR
shows periventricular lesions well without the interference from CSF. Lesion quantity and volume can
lso be assessed with FLAIR. Eventually it may be possible to compare lesion volume with blood flow or
patient’s physiological changes over time. T1WI is used at two parts of the scanning protocol to image
the head: initially before contrast agent injection, and after contrast agent injection. Lesions that
enhance post-contrast are considered as acute.
PWI is used to evaluate the hemodynamics of the brain. From this data it is possible to assess mean
transit time (MTT) which is the time it takes for contrast agent to pass through the microvasculature; the
cerebral blood volume (CBV) and the cerebral blood flow (CBF).
Not all these scans need to be run on every patient. The full protocol below is used in a research mode.
While the full protocol scan takes roughly 1 hour, 22 minutes to run, there are shorter protocols with
and without contrast that can reduce the scan time. Removing the contrast-dependent sequences can
reduce the total scan time to approximately 52 minutes. For a post-treatment scan without contrast and
azygous data, the scan time would be reduced to approximately 34 minutes: lesions, iron content,
anatomy from 2D TOF MRV, and blood flow would still be able to be assessed.
Scanning Procedure
Initially, register the patient along with his/her height and weight. This plays an important role in
flow quantification (FQ).
Activate appropriate (head, neck and spine) coils for imaging the region of interest.
Make sure to put the pulse trigger on the subject's (left/right) index finger or for a better flow
quantification cardiac gating can be used.
Initially, we start imaging the head using SWI, T2, MPRAGE, FLAIR, VIBE, and PWI sequences.
Make sure to use the head and neck coils. Inject 5cc of contrast agent on the 10 th
measurement of PWI sequence.
Later, move the table to center at the neck and acquire T2, 3D CE MRAV, and flow
quantification (FQ) sequences. Make sure to use the head neck coils. Inject the remaining
contrast agent on the 3 rd measurement of 3D CE MRAV.
The FQ plane will be set perpendicular to the CSF flow at C2/C3 neck level with a VENC of
10cm/sec, and set perpendicular to the internal jugular veins (IJV’s) at the C2/C3, C5/C6 and
C7/T1 neck levels with a venc of 50cm/sec.
Next, move the table center back to the head and acquire the data using the post gadolinium
sequences - VIBE, and MPRAGE.
To image the azygous, move the table to center at the mid sternum. Use the neck and spine
coils. Acquire 2D TOF MRV and FQ sequences. Use a VENC of 50 cm/sec for the FQ sequence.