Perioperative evaluation of blood volume flow in high-flow cerebral arteriovenous malformation using phase-contrast magnetic resonance angiography

• Multimodal treatment strategy for a non-hemorrhagic high-flow arteriovenous malformation was planned by evaluating intracranial blood flow volume using phase-contrast magnetic resonance angiography.
• Postoperative dynamic flow changes were quantitatively measured to estimate the normal perfusion pressure breakthrough.
• The systolic total blood flow volume was not sufficiently decreased at five days after the nidus resection and the difference between these systolic and diastolic total BFVs was higher at five days after the operation than before the operation.

Phase-contrast magnetic resonance angiography (PC-MRA) is useful for the quantitative measurement of blood flow volume (BFV) in the internal cerebral arteries (ICAs) and basilar artery (BA). A 45-year-old man was diagnosed with a non-hemorrhagic high-flow arteriovenous malformation (AVM) in the right temporal lobe. PC-MRA examinations of the bilateral ICAs and BA were conducted before treatment, at five days and at one and three months after the operation. The patient underwent preceding endovascular embolization of the deep part of the nidus and feeders. There were numerous feeders from the superior MCA trunk, which directly passed through the nidus to the normal brain. Therefore, the nidus was completely removed while maintaining the flow of the main superior MCA trunk in a passing artery. The BFV of the right ICA before AVM treatment was extremely high (mean: 675.7, systolic: 896.1, diastolic: 518.5 mL/min). Five days after the nidus resection, the BFV of the right ICA was decreased by almost half of that before treatment, and it was decreased even more at one month after the operation. The BFVs of the left ICA and BA were slightly increased before the operation and returned to normal values after the operation. The diastolic total BFV was immediately decreased after the operation, but the systolic total BFV was not sufficiently decreased at five days after the operation. Therefore, the difference between these systolic and diastolic total BFVs was higher at five days after the operation than before the operation. The systolic and diastolic total BFVs were decreased to normal levels one month after the operation. PC-MRA is a convenient and useful tool for quantifying BFVs in AVMs and can help plan the treatments. More research is needed to establish a definite role for PC-MRA in the quantification of flow changes in the treatment of high-flow AVMs.