Project Title: Improved Multi-Echo Time Arterial Spin Labeling (Multi-TE ASL) MRI with Correction for Transverse Relaxation Time (T2) in Meningiomas

Funded by Bogazici BAP Grant 19994 (2025-2027)

Principal Investigators: Prof. Dr. Esin Öztürk Işık

Researchers: Ayşe İrem Çetin, Gülce Turhan, Arda Canbaş

Project Summary: Meningiomas are the most common primary intracranial brain tumors, accounting for 36% of all cases. Although they are mostly benign tumors, they present high recurrence rates, brain invasion in higher grades, and hypervascularization. Because of the high vascular involvement, meningiomas often have increased blood perfusion (cerebral blood flow, CBF) and blood volume (cerebral blood volume, CBV) in the tumor region. Typically, CBF or CBV is assessed by measuring the leakage of a contrast agent from the intravascular to the extravascular space via dynamic susceptibility contrast (DSC) or dynamic contrast-enhanced (DCE) magnetic resonance imaging (MRI). These methods may provide relative measurements due to the absence of the expected blood-brain barrier (BBB) structure in meningiomas and the nature of the contrast agent, leading to the potential oversight of slow and subtle changes. Alternatively, arterial spin labeling (ASL) MRI does not need intravenous contrast agent administration to image CBF. Multi-echo time Multi-TE ASL is an ASL technique sensitive to subtle changes in blood flow and exchange dynamics. This method has been employed to measure CBF, water exchange time (Tex), and intra-voxel transit time (ITT) in healthy volunteers and in an aging study. The multi-TE ASL model showed robust performance, assuming a constant tissue transverse relaxation time (T2) for the whole brain. However, T2 values differ in brain tumors due to hypervascularity and heterogeneous tissue composition, so this assumption might lead to errors in measuring blood flow and exchange dynamics to evaluate vascularity and vascular-tumor permeability. Therefore, our goal in this study is to apply the T2-corrected Multi-TE ASL for the first time to assess vascularity and vascular-tumor permeability in meningiomas.

Keywords: Brain imaging, Meningiomas, Arterial Spin Labelling, Transverse Relaxation (T2) Time

Objectives:

To apply the BBB-ASL to the meningiomas and update the BBB-ASL model with the T2 correction for the first time

To identify differences in BBB-ASL maps before and after T2 correction

To characterize the differences in T2 and BBB-ASL maps between different grades of meningiomas

Initial Results:

Publications:

Conference Proceedings:

1. Cetin AI, Ozakcakaya M, Turhan G, Mahroo A, Padrela BE, Konstandin S, Hoinkiss DC, Breutigam NJ, Keil VC, Danyeli AE, Ozduman K, Eickel K, Mutsaerts HJMM, Günther M, Pamir MN, Dincer A, Petr J, Ozturk-Isik E. Comparison of T2 values estimated from Multi-TE M0 and Arterial Spin Labeling MRI. European Society for Magnetic Resonance in Medicine and Biology. Girona, Spain. September 30-October 3, 2026 (Lightning Talk, #54680).

2. Cetin AI, Turhan G, Emekli AS, Kaya D, Van Nederpelt DR, Padrela BE, Mahroo A, Konstandin S, Hoinkiss DC, Breutigam NJ, Keil VC, Barkhof F, Eickel K, Vrenken H, Mutsaerts HJMM, Günther M, Dincer A, Petr J, Ozturk-Isik E. Regional Perfusion and Permeability Assessment in MS Using BBB-ASL MRI. European Society for Magnetic Resonance in Medicine and Biology. Girona, Spain. September 30-October 3, 2026 (Lightning Talk, #54654).

3. Canbas A, Cengiz S, Hatay GH, Isak B, Kaya D, Ozcan A, Dincer A, Ozturk-Isik E. ¹H-MRSI Detection of Metabolite Changes in Amyotrophic Lateral Sclerosis Within Intrinsic Connectivity Networks and Deep Gray Matter Nuclei. European Society for Magnetic Resonance in Medicine and Biology. Girona, Spain. September 30-October 3, 2026 (Lightning Talk, #54548).

4. Canbaş A, Baş A, Danyeli AE, Yakıcıer CM, Pamir NM, Özduman K, Dinçer A, Öztürk-Işık E. Gliomlarda IDH Mutasyonunun MEGA-PRESS ve Dikkat Tabanlı Derin-Sığ Ağ (ADSN) ile Non-invaziv Öngörüsü. Ulusal Sinirbilim Kongresi 2026. İstanbul, Türkiye. 10-13 Eylül 2026 (Sözlü Sunum).

5. Cetin AI, Turhan G, Padrela BE, Mahroo A, Canbas A, Konstandin S, Hoinkiss DC, Breutigam NJ, Keil V, Danyeli AE, Ozduman K, Eickel K, Mutsaerts H, Günther M, Petr J, Dincer A, Ozturk-Isik E. Beyin tümörlerinde Enine Relaksasyon Süresi (T2) Düzeltmesi ile İyileştirilmiş Kan-Beyin Bariyeri Arteriyel Fırıl Etiketleme (BBB-ASL) Manyetik Rezonans Görüntüleme. Ulusal Sinirbilim Kongresi. İstanbul, Türkiye. 10-13 Eylül 2026 (Sözlü Sunum).

6. Cetin AI, Turhan G, Padrela BE, Mahroo A, Canbas A, Konstandin S, Hoinkiss DC, Breutigam NJ, Keil V, Danyeli AE, Ozduman K, Eickel K, Mutsaerts H, Günther M, Petr J, Dincer A, Ozturk-Isik E. Voxelwise T2-Corrected Multi-TE ASL for Perfusion and Permeability Difference in Gliomas and Meningiomas. International Society for Magnetic Resonance in Medicine. International Society for Magnetic Resonance in Medicine. Cape Town, South Africa. May 09-14, 2026 (Digital Poster #06296)

7. Canbas A, Bas A, Danyeli AE, Yakicier CM, Pamir NM, Ozduman K, Dincer A, Ozturk-Isik E. Non-Invasive Prediction of IDH Mutation in Gliomas Using MEGA-PRESS and an Attention Deep Shallow Network (ADSN). International Society for Magnetic Resonance in Medicine. Cape Town, South Africa. May 09-14, 2026 (Traditional Poster #06048)