A 48-year-old man experienced recurrent vertigo refractory to antiplatelet medications. Cerebral angiography showed occlusion of bilateral vertebral arteries with poor collateral circulation. PET using 15O2 gas showed reduced blood flow and metabolic rate of oxygen and elevated oxygen extraction fraction in bilateral cerebellar hemispheres. Subsequent 18F-FRP170 (1-(2-18F-fluoro-1-[hydroxymethyl]ethoxy)methyl-2-nitroimidazole) PET, which depicts hypoxic but viable tissue, revealed elevated tracer uptake in the same regions. After superficial temporal artery-posterior cerebral artery anastomosis, 15O-gas PET showed normalization of blood flow, metabolic rate of oxygen, and oxygen extraction fraction in bilateral cerebellar hemispheres. Abnormally elevated 18F-FRP-170 uptake was also resolved in those regions.
From the Department of Neurosurgery and Cyclotron Research Center, Iwate Medical University, Morioka, Japan.
Received for publication April 7, 2018; revision accepted December 11, 2018.
Conflicts of interest and sources of funding: This work was partly supported by Grants-in-Aid for Strategic Medical Science Research from the Ministry of Education, Culture, Sports, Science and Technology of Japan (S1491001); and Scientific Research from Japan Society for the Promotion of Science (JP15K10313 and JP18K09002). None declared to all authors.
Correspondence to: Kuniaki Ogasawara, MD, Department of Neurosurgery, Iwate Medical University, 19-1 Uchimaru, Morioka, 020-8505 Japan. E-mail: firstname.lastname@example.org.