Hyperacute Seizure: MR Susceptibility SWI

Exam

MR Susceptibility (SWI) or GRE Sequences

Purpose

1. Need to identify sites of cortical vein thrombosis based on SWI blooming artifact.

2. Need to identify venous pial collateral found adjacent to the actual venous occlusion based on the presence of serpiginous dilated cortical veins which flow in opposite direction than normal and in doing so reverse their size from increasing in size as they approach and dural sinus to a reduction in expected size.

3. Need to assess for status of the deep central venous system. If there is venous congestion (CVT in the the vein of Galen, ICV(s), or straight sinus) assess the severity grade, which reflects the extent of available central veneous collateralization.

4. Need to assess the patency of the dural sinuses. This is often less obvious, because of bone artifact, since most dural sinus are adjacent to the skull.

5. Need to detect hemorrhagic conversion.

6. Need to assess for arterial blooming artifact, since some cases have concurrent arterial and venous thrombosis problems.

Prior Study

CT Head
MR T1-W Sequences
MR T2 or FLAIR
MR Diffusion

Findings

MR Susceptibility SWI

There is venous prominence (hyperemia) of the deep medullary veins without blooming artifact, which can reflect physiologically increased venous flow rate, or can be the result of congestion associated with a downstream venous outlet obstruction. [Yes/No]

There is SWI venous prominence within the deep medullary veins with blooming artifact, which implies significant venous stasis rather than physiologic hyperemia. [Yes/No]

There is reduction in size of the ipsilateral major deep central veins indicating significant reduction in transcapillary blood flow. [Yes/No]

There is SWI blooming artifact in proximal arteries indicating recent thrombosis. [Yes/No]

There is SWI blooming along major cortical veins indicating recent thrombosis. [Yes/No]

There is SWI susceptibility artifact in the parenchyma included within the stroke-zone indicating sequestered infarction. [Yes/No]

There is SWI susceptibility artifact within the stroke-zone to indicate hemorrhagic conversion. [Yes/No]

There is SWI signal consistent with abnormal or physiologic brain calcification (focal absent nodular signal loss). It should be noted that chronic brain nodular calcification (as in sequelae of neonatal infections) are often not evident as a signal loss on SWI. [Yes/No]