Assessment of Internal Jugular Vein Size in Healthy Subjects with Magnetic Resonance and Semiautomatic Processing

Figure 1

(a) shows the segmentation IJVl on a TOF MR image by two different operators (operator 1, yellow line; operator 2, blue line). (b) shows a graphical representation of Dice similarity coefficient (DSC): how it is computed and how it can be interpreted. Yellow area corresponds to the ROI identified by operator 1 (ROI1), blue area corresponds to the ROI identified by the operator 2 (ROI2), and green area is the overlapping region of the yellow and blue ROIs (). The DSC is computed as ). A schematic representation of different DSC values is reported on the right side of panel (b): from 0 (no overlap of the two areas) to 1 (perfect overlap of the two areas). Note that for equal cross-sectional areas, the other reliability indexes ( and ICC) are perfect (equal to 1); instead, DSC can change, depending on the overlap of the two ROIs.

(a)

(b)