PMC9610681_01
(a-c) Preoperative magnetic resonance (MR) imaging. (a): An MR constructive interference in steady state image showed no arterial compression on the right trigeminal nerve. (b) A time-of-flight MR angiography demonstrated a slightly abnormal high-intensity signal from a vein adjacent to the right trigeminal nerve (red circle). (c) A maximum-intensity projection MR angiography revealed a retrograde venous flow in the left transverse and sigmoid sinus (red arrowhead).
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F1
Although the characteristics of her facial pain were consistent with typical Type 1 TN, magnetic resonance imaging (MRI) indicated no apparent arterial abnormalities near the right trigeminal nerve [Figure 1a]. However, time-of-flight (TOF) magnetic resonance angiography (MRA) showed an abnormal high-intensity signal in the vein adjacent to the right trigeminal nerve [Figure 1b] and the cortical veins and transverse sigmoid sinus on the left side were dilated [Figure 1c].
(a) A preoperative angiography from the left brachial artery revealed an occlusion of the brachiocephalic vein and retrograde flow to the cranial venous system through the left jugular vein and lateral sinus (blue arrows), causing dilated cortical and diplopic veins. (b) The late phase of the angiography showed that the flow ultimately drained through the right jugular vein (blue arrows). (c) A postoperative maximumintensity projection magnetic resonance (MR) angiography demonstrated the disappearance of the retrograde venous flow in the left transverse-sigmoid sinus. (d) The abnormal high-intensity signal adjacent to the right trigeminal nerve on the time-of-flight MR angiography was reduced.
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F2
AVF in the left forearm. Angiography from the left brachial artery revealed occlusion of the brachiocephalic vein and retrograde flow to the cranial venous system through the left jugular vein and lateral sinus, presenting with dilated cortical and diploic veins [Figure 2a]. The flow ultimately drained through the right jugular vein [Figure 2b]. Postoperative MRI showed the resolution of both the IVR [Figure 2c] and the abnormal signal adjacent to the right trigeminal nerve [Figure 2d].