Browsing by Author "Algin, Oktay"

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    A comparison between the CS-TOF and the CTA/DSA for WEB device management
    (Sage Publications, 2021-05-06) Algin, Oktay; Yuce, G.; Koc, U.; Ayberk, G.
    Purpose There is no study on the role of three-dimensional compressed sensing time of flight MR angiography (3D-CS-TOF) in the management of the WEB device. We evaluated the efficacy of 3-tesla 3D-CS-TOF for the management and follow-up of the WEB device implantations. Materials and methods Seventy-three aneurysms of 69 patients treated with the WEB device were retrospectively examined. Morphological parameters and embolization results of the aneurysms were assessed and compared on 3D-CS-TOF, CTA, and DSA images. Results Occluded, neck remnant, and recurrent aneurysms were observed in 61 (83.6%), 7 (9.6%), and 5 (6.8%) aneurysms, respectively. Inter- and intra-reader agreement values related to aneurysm size measurements were perfect. Aneurysms size, age, and proximal vessel tortuosity were negatively correlated with the visibility of the aneurysms and parent vessels on 3D-CS-TOF images (p = 0.043; p = 0.032; p < 0.001, respectively). Subarachnoid hemorrhage and age are associated with 3D-CS-TOF artifacts (p = 0.031; p = 0.005, respectively). 3D-CS-TOF findings are in perfect agreement with DSA or CT angiography (CTA) results (p < 0.001). Conclusion According to our results, 3D-CS-TOF can be an easy, fast, and reliable alternative for the management or follow-up of WEB assisted embolization.
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    Joint partial fourier and compressed sensing reconstruction for accelerated time-of-flight MR angiography
    (IEEE, 2018) Kılıç, Toygan; Çukur, Tolga; Algin, Oktay; Sarıtaş, Emine Ülkü
    Time-of-flight (TOF) magnetic resonance (MR) angiography is a popular tool for non-contrast-enhanced angiographic imaging of intracranial vasculature. However, strategies that lead to enhancement of inflow effects come at the expense of prolonged scan times. This study proposes a combination of two dimensional (2D) acceleration in the phase-encode dimensions via compressed sensing (CS) and one dimensional (1D) partial Fourier (PF) data acquisition in the readout dimension to reduce echo time. An improved projections-onto-convex-sets (POCS) reconstruction framework is utilized, which decomposes the problem into 1D PF projections along the readout dimension, and 2D CS projections along the phase-encode dimensions. This framework enables scan-efficient TOF MR angiography imaging to help maintain high vessel-background contrast.
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    Long-term efficacy and safety of wovenendobridge (web)-assisted cerebral aneurysm embolization
    (SAGE, 2022) Algin, Oktay; Corabay, Seniha; Ayberk, Gıyas
    Purpose: Long-term compaction, compression, migration, and recurrence rates of the WovenEndoBridge devices remain unknown. The purpose of this study was to detect these rates and safety profiles of the WovenEndoBridge within 7 years period. Materials and methods: Eighty-three aneurysms of 79 patients treated with the WovenEndoBridge device were retrospectively evaluated using an occlusion scale (e.g. complete occlusion, neck remnant, and aneurysm remnant) on angiography images. Results: The residual aneurysm was observed in 11 (13%) aneurysms. The mean and median diameters of the recurrent aneurysms were 6 and 7 mm. Most of the recurrent aneurysms were complex type and/or ruptured. Mean diameters and the neck-tobody ratios of all residual aneurysms in the preoperative imaging exams were above 4 mm and 0.6, respectively. The median values of preoperative height and neck measurements were higher in the recurrent aneurysms than in the adequate occlusion group (p=0.006, p=0.019, respectively). There was a statistically significant positive relationship between preoperative height/ neck measurements and the mean diameters of residual aneurysms (rs =0.32 and p=0.003; rs=0.28 and p=0.011, respectively). The WovenEndoBridge compaction/compression and migration were observed in 5 (45%) and 2 (18%) of the recurrent aneurysms. In 7 (64%) of the residual aneurysms, thrombosed areas were found within the aneurysm. In the follow-up period, four aneurysms (4.8%) were retreated due to widened residual aneurysm. Other aneurysms were improved or stable within 7 years. Discussion: Our adequate occlusion rate was 87%. Occlusion rates are less favorable than aneurysms with a long height, wide neck, or high neck-to-body ratio. Our study confirms the high safety and efficiency of the WovenEndoBridge. Compaction, compression, and/or migration of the WovenEndoBridge and the presence of intra-aneurysmal thrombosis are the main reasons for the recurrences.