Fig 1.
Example mid-sagittal images acquired with bSSFP Spiral and FLASH Spiral to demonstrate differences in image quality and velum blurring.
Table 1.
Acquisition parameters at 1.5T according to sequence and acquisition sampling scheme.
Fig 2.
Example mid-sagittal images to demonstrate the upper vocal tract configuration at the relaxed and elevated velar positions.
Image data acquired in the same subject using Cartesian sequence 1 acquisition protocol. Reference line was selected along the primary direction of motion of the velum to indicate the selected profile when generating the intensity-time plots.
Fig 3.
Five-point scoring scale from non-diagnostic (a) to excellent (e) image used to visually score image quality.
Fig 4.
Example mid-sagittal images at elevated and relaxed velum positions acquired with sequence 1 and 3 Cartesian sampling and sequence 5 with radial and spiral acquisitions.
Table 2.
Mean velum thickness and standard deviation in millimeters (mm) of all subjects measured in the relaxed (nasal breathing) and elevated (sustained phonation of /a/) velar positions.
Table 3.
Mean and standard deviation velum signal homogeneity measured from selected frames of the dynamic data at both the relaxed (nasal breathing) and elevated (sustained phonation of /a/) velar positions for all sequences.
Fig 5.
Intensity-time plots for spiral (a,c,e,g) and radial (b,d,f,h) acquisitions at different spatial-temporal resolution sets.
Selected ROIs in the velum (blue) and in the neighboring oral cavity (red) were used to perform CNR measurements. At the highest frame rate of 25 fps (sequence 5), spiral acquisition shows adequate temporal fidelity (g) while radial acquisition shows temporal blurring and averaging of consecutive closure events (h).
Table 4.
Mean and standard deviation CNR measured in a short section of the intensity-time plots.
Fig 6.
Histogram representation of the image quality cumulative visual scoring performed by 2 independent observers.
Cumulative scoring represented by the sum of each observer independently (maximum scoring of 10) for all sequences and sampling schemes. Mean and standard deviation of visual scoring of both observers is presented numerically on top of each bar plot.