The estimated values from two proposed models.

<p>Perfusion parameters. ATT: traveling time from a labeling plane to an imaging slice, F: arterial flow parameter, δ: transit time from the arterial compartment to the capillary/tissue compartment in imaging slice. All values represented in the form of Mean ± SD^{<a href="http://www.plosone.org/article/info:doi/10.1371/journal.pone.0156687#t001fn001" target="_blank">*</a>} were measured in gray matter from ALADDIN with multiphase bSSFP readout fitted to bSSFP model and T₁ model.</p

Monte Carlo simulation results for the bSSFP model.

<p>The error percentage of the mean (indicating the accuracy) (<b>a</b>) and the coefficient of variation (indicating the precision) (<b>b</b>) are shown as a function of the signal-to-noise ratio (SNR) that ranged from 5 to 20 with a step size of 5.</p

Feasibility of quantifying arterial cerebral blood volume using multiphase alternate ascending/descending directional navigation (ALADDIN)

In this study, we evaluated the feasibility of a new 2D inter-slice bSSFP-based arterial spin labeling (ASL) technique termed, alternate ascending/descending directional navigation (ALADDIN), to quantify aCBV using multiphase acquisition in six healthy subjects. As a result of fitting to the proposed model, aCBV values in gray matter  were in good agreement with those from literature

Diagram for segmented multiphase bSSFP sequence.

<p>(a) Initial 10 phase encoding scans with linearly increasing flip angles were discarded as dummy scans. Each measurement consisted of 288 phase encoding steps, which were subdivided into nine K-space datasets with 32 phase encoding lines per dataset. Since each K-space reflected different stage of flow dynamics, nine dynamic phases could be obtained. In order to fill 96 phase encoding lines per K-space, three measurements were performed. (b) ALADDIN acquisition scheme was composed of sequential ascending and descending orders, which were alternated in every measurement. Therefore, six measurements were needed to complete nine K-space datasets in both ascending and descending orders.</p

Schematic diagram for ALADDIN with multiphase bSSFP readout.

<p>Diagram demonstrates magnetization changes in the labeling and imaging slices and also in the arterial and capillary/tissue compartments. δ represents the transit time from the arterial compartment to the capillary/tissue compartment in the imaging slice. See the main text for detailed information.</p

Comparison of estimated arterial cerebral blood volumes (aCBVs) (Mean ± SD^*) between multiphase bSSFP and AVAST (N = 5).

<p>Comparison of estimated arterial cerebral blood volumes (aCBVs) (Mean ± SD^{<a href="http://www.plosone.org/article/info:doi/10.1371/journal.pone.0156687#t003fn002" target="_blank">*</a>}) between multiphase bSSFP and AVAST (N = 5).</p

Representative results of fitting to the proposed models.

<p>(a) Location of region of interest (ROI) which is drawn manually (red arrow). (b) Dynamic signal difference in the ROI shown in (a) and results of curve fitting with T₁ model (green line) and bSSFP model (purple line). The data was acquired with 450% gap and 0-ms inter-slice time delay. ΔS represents signal difference between control and labeling scans.</p

Comparison of estimated arterial cerebral blood volumes (aCBVs) (Mean ± SD^*) between bSSFP model and T₁ model (N = 6).

<p>Comparison of estimated arterial cerebral blood volumes (aCBVs) (Mean ± SD^{<a href="http://www.plosone.org/article/info:doi/10.1371/journal.pone.0156687#t002fn002" target="_blank">*</a>}) between bSSFP model and T₁ model (N = 6).</p

Representative arterial cerebral blood volume (aCBV) maps from the same subject as shown in Fig 6.

<p>The values in the color scale bar are displayed in the unit of mL/100 mL.</p

ROI analysis in superior sagittal sinus (SSS).

<p>(a) Images of baseline, labeling effects from feet to head (Des − Asc), and labeling effects from head to feet (Asc − Dsc) from a representative slice used for measurement of SSS perfusion signals. (b)−(e) Multiphase signal differences between labeling and control scans in SSS measured from all the 6 subjects for inter-slice gap sizes of 450% (b,c) and 300% (d,e) and inter-slice delay time (TD) of 0 ms (b,d) and 500 ms (c,e). Vertical bars represent the standard deviation across the 6 subjects.</p