Sei Nishida1,2, Toshihiko Aso2,3, Shigetoshi Takaya2,4,5, Yuki Takahashi1,2, Takayuki Kikuchi1, Takeshi Funaki1, Kazumichi Yoshida1, Tomohisa Okada2,6, Takeharu Kunieda1,7, Kaori Togashi6, Hidenao Fukuyama2, Susumu Miyamoto1. 1. Department of Neurosurgery, Kyoto University Graduate School of Medicine, Kyoto City, Kyoto Prefecture, Japan. 2. Human Brain Research Center, Kyoto University Graduate School of Medicine, Kyoto City, Kyoto Prefecture, Japan. 3. Department of Psychiatry, Kyoto University Graduate School of Medicine, Kyoto City, Kyoto Prefecture, Japan. 4. Department of Neurology, Kyoto University Graduate School of Medicine, Kyoto City, Kyoto Prefecture, Japan. 5. Senri Rehabilitation Hospital, Mino City, Osaka Prefecture, Japan. 6. Department of Radiology, Kyoto University Graduate School of Medicine, Kyoto City, Kyoto Prefecture, Japan. 7. Department of Neurosurgery, Ehime University Graduate School of Medicine, Toon City, Ehime Prefecture, Japan.
Abstract
BACKGROUND: The development of noninvasive approaches for identifying hypoperfused brain tissue at risk is of major interest. Recently, the temporal-shift (TS) maps estimated from resting-state blood oxygenation level-dependent (BOLD) signals have been proposed for determining hemodynamic state. OBJECTIVE: To examine the equivalency of the TS map and the cerebrovascular reactivity (CVR) map derived from acetazolamide-challenged single-photon emission computed tomography (SPECT) in identifying hemodynamic impairment in patients with arterial occlusive diseases. METHODS: Twenty-three patients with arterial occlusive diseases who underwent SPECT were studied. With a recursive TS analysis of low-frequency fluctuation of the BOLD signal, a TS map relative to the global signal was created for each patient. The voxel-by-voxel correlation coefficient was calculated to examine the image similarity between TS and SPECT-based cerebral blood flow (CBF) or CVR maps in each patient. Furthermore, simple linear regression analyses were performed to examine the quantitative relationship between the TS of BOLD signals and CVR in each cerebrovascular territory. RESULTS: The within-patient, voxel-by-voxel comparison revealed that the TS map was more closely correlated with SPECT-CVR map ([Z(r)] = 0.42 ± 0.18) than SPECT-CBF map ([Z(r)] = 0.058 ± 0.11; P < .001, paired t-test). The regression analysis showed a significant linear association between the TS of BOLD signals and CVR in the anterior circulation where the reduction of CVR was evident in the patient group. CONCLUSION: BOLD TS analysis has potential as a noninvasive alternative to current methods based on CVR for identification of tissue at risk of ischemic stroke.
BACKGROUND: The development of noninvasive approaches for identifying hypoperfused brain tissue at risk is of major interest. Recently, the temporal-shift (TS) maps estimated from resting-state blood oxygenation level-dependent (BOLD) signals have been proposed for determining hemodynamic state. OBJECTIVE: To examine the equivalency of the TS map and the cerebrovascular reactivity (CVR) map derived from acetazolamide-challenged single-photon emission computed tomography (SPECT) in identifying hemodynamic impairment in patients with arterial occlusive diseases. METHODS: Twenty-three patients with arterial occlusive diseases who underwent SPECT were studied. With a recursive TS analysis of low-frequency fluctuation of the BOLD signal, a TS map relative to the global signal was created for each patient. The voxel-by-voxel correlation coefficient was calculated to examine the image similarity between TS and SPECT-based cerebral blood flow (CBF) or CVR maps in each patient. Furthermore, simple linear regression analyses were performed to examine the quantitative relationship between the TS of BOLD signals and CVR in each cerebrovascular territory. RESULTS: The within-patient, voxel-by-voxel comparison revealed that the TS map was more closely correlated with SPECT-CVR map ([Z(r)] = 0.42 ± 0.18) than SPECT-CBF map ([Z(r)] = 0.058 ± 0.11; P < .001, paired t-test). The regression analysis showed a significant linear association between the TS of BOLD signals and CVR in the anterior circulation where the reduction of CVR was evident in the patient group. CONCLUSION: BOLD TS analysis has potential as a noninvasive alternative to current methods based on CVR for identification of tissue at risk of ischemic stroke.
Authors: Ayse Ceren Tanrıtanır; Kersten Villringer; Ivana Galinovic; Ulrike Grittner; Evgeniya Kirilina; Jochen B Fiebach; Arno Villringer; Ahmed A Khalil Journal: Front Neurol Date: 2020-05-05 Impact factor: 4.003