PMC8645482_01
Patient angiography findings at initial presentation. (a) Intracranial vascular stenosis was identified on magnetic resonance angiography. (b) Digital subtraction angiography suggested bilateral stenoses from the terminal portion of the internal carotid artery to the proximal parts of the middle and anterior cerebral arteries, with extended lenticulostriate arteries.
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F1
Magnetic resonance (MR) images showed no ischaemic changes in her brain, but MR angiography showed intracranial vascular stenosis [Figure 1a]. Digital subtraction angiography showed bilateral stenoses from the terminal portion of the ICA to the proximal parts of the middle cerebral and anterior cerebral arteries [Figure 1b].
Preoperative single-photon emission computed tomography (SPECT) imaging. (a) N-isopropyl-p-[123I] iodoamphetamine SPECT showed decreased cerebral blood flow (CBF) in the right hemisphere at rest, preoperatively. (b) Paradoxical reduction of CBF after acetazolamide administration was identified in the right hemisphere before surgery.
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F2
Single-photon emission computed tomography (SPECT) imaging showed decreased cerebral blood flow (CBF) on the right side [Figure 2a], which worsened after an acetazolamide challenge [Figure 2b].
Postoperative magnetic resonance (MR) studies. (a) MR angiography on postoperative day 1 showed patency of the right superficial temporal artery to the middle cerebral artery anastomosis (arrows). (b) MR images showed no ischaemic lesions.
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F3
On the next day, MR angiography showed good patency of bypass vessels, and MR images showed neither cerebral infarction nor hemorrhage [Figure 3a and b].
Postoperative single-photon emission computed tomography (SPECT). Technetium-99m ethyl cysteinate dimer (99mTc-ECD) SPECT on postoperative day (POD) 3 did not show hyperperfusion in the right hemisphere but did show decreased cerebral blood flow (CBF) in the bilateral frontal lobe areas. Forty days after surgery, hypoperfusion of bilateral frontal lobes on SPECT was slightly improved but remained to a lesser extent. Seven days after the second revascularisation procedure, 123I-IMP SPECT showed improvement of whole-brain CBF, including in both frontal lobes.
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F4
SPECT performed on postoperative day 3 revealed decreased CBF in the bilateral frontal lobes [Figure 4]. Furthermore, blood flow in the bilateral frontal lobes was improved according to SPECT imaging performed 7 days after the second surgery [Figure 4].