Fig. 1
Arterial and portal venous phases from the T1-VIBE sequence for one subject before co-registration. The arterial phase is shown in the (left) images, and the portal venous phase in the (right). The (top row) displays the sagittal view. The (bottom row) shows the axial orientation of the same MRI. Images in the same row depict the exact same section. Due to variations in the breathing cycle, the abdominal organs do not remain in a fixed position. Brown reference lines aid visualization. Vertical lines in the top images indicate the moving abdominal border: the right line marks the border in the arterial phase, while the left line marks the border in the portal venous phase, where less air was exhaled. Horizontal lines in these images illustrate the movement of the heart (top line) and vessels (bottom lines) between phases due to breathing. Yellow arrows in the axial images point to identical spatial positions where the hepatic veins are visible in the portal venous phase. The horizontal lines indicate the borders of the liver and spleen during the arterial phase and demonstrate how they shift due to breathing.
