Article Figures & Data
Figures
- Figure 1.
Regions of interest in the CSF ventricular system. Sagittal (A) and coronal (B) T1-weighted images with boxes indicating respective (C, D) magnified representations are shown. Selected regions of interest for the analysis of CSF flow comprise the lateral ventricle (a), third ventricle (b), aqueduct (c), and fourth ventricle (d).
- Figure 2.
CSF flow in the aqueduct during normal breathing. The traces represent real-time MRI signal intensity time courses at 50 ms temporal resolution, where relative signal strength (arbitrary units) is proportional to through-plane flow velocity. Although subject 6 (#6, male, 26 years) presents with pronounced cardiac-related pulsations, subjects 7 (#7, male, 43 years) and 8 (#8, male, 25 years) reveal a stronger, though variable, component that reflects a respiratory modulation of CSF flow.
- Figure 3.
CSF flow in the third ventricle during forced inspiration. The series of images (magnified views) from top left to bottom right was selected from a real-time MRI movie at 50 ms temporal resolution (every seventh frame, subject 5). The corresponding period of 4.2 s covers one inspiration (2.5 s) in a coronal view through the third ventricle (compare Fig. 1D). Considerable through-plane flow is demonstrated by the marked MRI signal increase in the third ventricle during inspiration (arrow).
- Figure 4.
Inspiration drives CSF flow in the third ventricle. MRI signal intensity time courses for subjects 1 (#1, female, 43 years), 5 (#5, male, 19 years), and 6 (#6, male, 26 years) for a protocol comprising normal breathing (10 s) followed by eight periods of forced inspiration (black boxes = 2.5 s) and expiration (2.5 s) are shown. The two columns represent repeated measurements for each subject.
- Figure 5.
Inspiration drives CSF flow along the entire ventricular system. MRI signal intensity time courses for subject 7 (male, 43 years) for a protocol comprising normal breathing (10 s) followed by forced inspiration (black boxes = 2.5 s) and expiration (2.5 s) are shown. a, lateral ventricle; b, third ventricle; c, aqueduct; d, fourth ventricle (compare Fig. 1).
- Figure 6.
Breath holding abolishes CSF flow in the third ventricle. MRI signal intensity time courses for subjects 1 (#1, female, 43 years), 5 (#5, male, 19 years), and 9 (#9, male, 22 years) for a protocol comprising normal breathing and intermediate breath holding after inspiration (black bar = 12 s) are shown.
