Internal Haemorrhoids and Other Anorectal Lesions

Abstract

To best visualise internal haemorrhoids, the balloon must be deflated when the patient is in the prone position. The rationale being that an inflated rectal catheter balloon could compress internal haemorrhoids that might be present. Both 2D and 3D views may visualise internal haemorrhoids. On 2D they present as small protrusions, whereas on 3D they may be raised linear defects or polypoidal in shape. They lie in close proximity to the rectal catheter. Both anal papilla and rectal tumours need to also be considered when evaluating structures in the anorectal region in close proximity to the rectal catheter. If the catheter is incorrectly positioned, it may cause confusion in image interpretation. Images are presented to illustrate these points when interpreting CTC studies.