Figure 3

Basal Slice Analysis. In the normal right ventricle (A) the angle between the left ventricular long axis (black dashed line) and basal slice (dashed white box) is approximately 90°. In PH patients (B), assuming the basal slice is prescribed as per recommendations [16] the angle becomes more obtuse as the right ventricle dilates. The basal slice will now include right atrium (seen centrally) with a shoulder of right ventricle seen laterally (C, arrow heads). The impact this interpretation has on delineation is shown in D. Also in B note how the most basal part of the right ventricle 'hoods' beyond the TV plane (arrows) and is effectively ignored by the acquisition.