کد مقاله کد نشریه سال انتشار مقاله انگلیسی نسخه تمام متن
6039760 1188825 2008 9 صفحه PDF دانلود رایگان
عنوان انگلیسی مقاله ISI
The post-stimulation undershoot in BOLD fMRI of human brain is not caused by elevated cerebral blood volume
موضوعات مرتبط
علوم زیستی و بیوفناوری علم عصب شناسی علوم اعصاب شناختی
پیش نمایش صفحه اول مقاله
The post-stimulation undershoot in BOLD fMRI of human brain is not caused by elevated cerebral blood volume
چکیده انگلیسی
Functional magnetic resonance imaging (fMRI) based on blood oxygenation level dependent (BOLD) contrast is the most widely used technique for imaging human brain function. However, the dynamic interplay of altered cerebral blood flow (CBF), cerebral blood volume (CBV), and oxidative metabolism (CMRO2) is not yet fully understood. One of the characteristics of the BOLD response is the post-stimulation undershoot, that is increased deoxyhemoglobin, which has been suggested to originate from a delayed recovery of elevated CBV or CMRO2 to baseline. To investigate the CBV contribution to the post-stimulation BOLD undershoot, we performed bolus-tracking experiments using a paramagnetic contrast agent in eight healthy subjects at 3 T. In an initial BOLD experiment without contrast agent, we determined the individual hemodynamic responsiveness. In two separate experiments, we then evaluated the relative CBV (rCBV) during visual stimulation and the post-stimulation undershoot, respectively. The results confirm a pronounced rCBV increase during stimulation (31.4 ± 8.6%), but reveal no change in rCBV relative to baseline in the post-stimulation phase (0.7 ± 7.2%). This finding renders a CBV contribution to the BOLD MRI undershoot unlikely and - in conjunction with a rapid post-stimulation return of CBF to baseline - supports the idea of a prolonged elevation of oxidative metabolism.
ناشر
Database: Elsevier - ScienceDirect (ساینس دایرکت)
Journal: NeuroImage - Volume 40, Issue 2, 1 April 2008, Pages 473-481
نویسندگان
, , , , , ,