Neuroradiology: What is the hyperintensity of the upper MRA venous sinus?

3D TOF MRA is a noninvasive imaging technique that is widely used in a variety of cerebral vascular diseases MRI examination

High signals of reverse blood flow can often be seen on 3T MRA

Figure 1: Pterygoid plexus (PP)/Emissary vein (EV) 5-point classification: Grade I = Part of the blood flow signal (arrow) of PP/EV is higher than the background signal and lower than the arterial signal; Level II = Part of the blood flow signal (arrow) of PP/EV is equal to the arterial signal; Level III = High signal (arrow) area <= 1/3 cavernous sinus area; Level IV = High signal (arrow) area> 1/3 sponge Sinus area:

Figure 2: Five-point classification of the inferior petrosal sinus (IPS) and cavernous sinuses (CS): Grade I = the blood flow signal (arrow) of some IPS is higher than the background signal and lower than the arterial signal; Ⅱ Grade=Partial IPS blood flow signal (arrow) is equal to arterial signal; Grade III=high signal (arrow) area<=1/3 cavernous sinus area; IV=high signal (arrow) area>1/3 cavernous sinus area:

Example 1: 72 years old, male, grade IV for PP/EV

Example 2: 72 years old, male, without DAVF

Example 3: 67 years old, male, right cavernous sinus DAVF (Cognard I)

In June 2021, Shingo Kakeda and others from Japan reported on Neuroradiology 364 cases (728 sides) of patients without arteriovenous shunt.

In the end, the author believes that ASL is a simple and useful MRI sequence for the identification of reverse venous blood flow and cavernous sinus DAVF

Translator's Note: This article means that the cavernous sinus high signal on MRA is not uncommon, most of which are caused by reverse venous blood flow

Literature source: Neuroradiology.

Source of pictures and texts | Introduction to cerebrovascular diseases and critical illness literature

3D TOF MRA is a noninvasive imaging technique that is widely used in a variety of cerebral vascular diseases MRI examination

High signals of reverse blood flow can often be seen on 3T MRA

Figure 2: Five-point classification of the inferior petrosal sinus (IPS) and cavernous sinuses (CS): Grade I = the blood flow signal (arrow) of some IPS is higher than the background signal and lower than the arterial signal; Ⅱ Grade=Partial IPS blood flow signal (arrow) is equal to arterial signal; Grade III=high signal (arrow) area<=1/3 cavernous sinus area; IV=high signal (arrow) area>1/3 cavernous sinus area:

Example 1: 72 years old, male, grade IV for PP/EV

Example 2: 72 years old, male, without DAVF

Example 3: 67 years old, male, right cavernous sinus DAVF (Cognard I)

In June 2021, Shingo Kakeda and others from Japan reported on Neuroradiology 364 cases (728 sides) of patients without arteriovenous shunt.

In the end, the author believes that ASL is a simple and useful MRI sequence for the identification of reverse venous blood flow and cavernous sinus DAVF
.
For the sigmoid and transverse sinuses, ASL will produce false positive results due to the reverse blood flow from the jugular vein.
This is the limitation of ASL.
Imaging experts should be wary of this limitation of ASL
.

Translator's Note: This article means that the cavernous sinus high signal on MRA is not uncommon, most of which are caused by reverse venous blood flow
.
If ASL is negative (mostly ASL negative), it indicates reverse blood flow; if ASL is positive, it may be caused by reverse blood flow, or it may be DAVF
.

Literature source: Neuroradiology.
2021 Jun;63(6):889-896.
doi: 10.
1007/s00234-020-02588-5.
Epub 2020 Oct 21.
High-signal venous sinuses on MR angiography: discrimination between reversal of venous flow and arteriovenous shunting using arterial spin labeling

Source of pictures and texts | Introduction to cerebrovascular diseases and critical illness literature