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Background And Purpose: The oxygen extraction fraction (OEF) is an effective metric to evaluate metabolic reserve in chronic ischemia. However, OEF is considered to be accurately measured only when using positron emission tomography (PET). Thus, we investigated whether OEF maps generated by magnetic resonance quantitative susceptibility mapping (QSM) at 7 Tesla enabled detection of OEF changes when compared with those obtained with PET.
Methods: Forty-one patients with chronic stenosis/occlusion of the unilateral internal carotid artery or middle cerebral artery were examined using 7 Tesla-MRI and PET scanners. QSM images were obtained from 3-dimensional T2*-weighted images, using a multiple dipole-inversion algorithm. OEF maps were generated based on susceptibility differences between venous structures and brain tissues on QSM images. OEF ratios of the ipsilateral middle cerebral artery territory against the contralateral side were calculated on the QSM-OEF and PET-OEF images, using an anatomic template.
Results: The OEF ratio in the middle cerebral artery territory showed significant correlations between QSM-OEF and PET-OEF maps (=0.69; <0.001), especially in patients with a substantial increase in the PET-OEF ratio of 1.09 (=0.79; =0.004), although showing significant systematic biases for the agreements. An increased QSM-OEF ratio of >1.09, as determined by receiver operating characteristic analysis, showed a sensitivity and specificity of 0.82 and 0.86, respectively, for the substantial increase in the PET-OEF ratio. Absolute QSM-OEF values were significantly correlated with PET-OEF values in the patients with increased PET-OEF.
Conclusions: OEF ratios on QSM-OEF images at 7 Tesla showed a good correlation with those on PET-OEF images in patients with unilateral steno-occlusive internal carotid artery/middle cerebral artery lesions, suggesting that noninvasive OEF measurement by MRI can be a substitute for PET.
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http://dx.doi.org/10.1161/STROKEAHA.117.017166 | DOI Listing |
Stroke
September 2025
Division of Neonatology, Department of Pediatrics, Willem-Alexander Children's Hospital, Leiden University Medical Center, the Netherlands. (B.O.v.O., M.R., M.S.S., E.L., L.S.d.V., S.J.S.).
Background: Monochorionic twins, characterized by placental sharing and vascular anastomoses, carry a high risk of brain injury, including perinatal arterial ischemic stroke (PAIS). However, the pathophysiology and timing-related risk factors of PAIS remain unclear.
Methods: Retrospective cohort of all monochorionic twins with neuroimaging-confirmed PAIS born from 2005 to 2024 and evaluated at a Dutch national referral center.
Biochem Biophys Rep
December 2025
Henan University of Chinese Medicine, Zhengzhou, 450046, China.
Introduction: 5-Hydroxymethyl furfural (5-HMF) is a furan compound with a molecular formula of CHO. Studies have found that 5-HMF has many pharmacological effects, such as improving hemorheology, anti-inflammatory, antioxidant activity and anti-myocardial ischemia. Identifying the preventive effect of 5-HMF against ischemic stroke and its possible mechanism was the aim of this investigation.
View Article and Find Full Text PDFExp Ther Med
November 2025
Department of Neurosurgery, Nanchong Shenxin Hospital, Nanchong, Sichuan 637003, P.R. China.
Wide-necked anterior communicating artery (ACoA) aneurysms pose challenges for endovascular coiling due to the risk of coil protrusion. This case report describes a new endovascular technique for managing ruptured wide-necked ACoA aneurysms, addressing the risk of coil protrusion during embolization. This method employs a combined microcatheter and guidewire-assisted embolization method, enabling coil deployment without needing adjunctive devices such as stents or balloons.
View Article and Find Full Text PDFDrug Des Devel Ther
September 2025
Department of Anesthesiology, Women's Hospital, School of Medicine, Zhejiang University, Hangzhou, Zhejiang Province, People's Republic of China.
Purpose: Spinal anesthesia-induced hypotension can cause detrimental effects on both the mother and the fetus, and it remains a significant concern in obstetric anesthesia. The use of vasopressors is considered the most reliable and effective approach. Previous studies have shown that norepinephrine appears to be superior to phenylephrine in maintaining maternal heart rate and cardiac output.
View Article and Find Full Text PDFCureus
August 2025
Department of Neurosurgery, The University of Osaka Graduate School of Medicine, Suita, JPN.
Fungal cerebral aneurysms, particularly those resulting from direct invasion by fungal sinusitis, are rare and often fatal when involving the cavernous segment of the internal carotid artery (ICA). We present a case of a ruptured fungal ICA aneurysm caused by sinusitis, successfully treated with parent artery occlusion (PAO). In this case, an 80-year-old woman presented with right ptosis, facial pain, and cranial nerve III, IV, and VI palsies.
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