Figure 4: The relationship between white zone visibility, the length of intervening parts and crypt depth. In (A) the intervening part is long and the crypt is deep. In (B) the intervening part is short. In (C) the crypt is shallow with a long intervening part. In (D) no crypts are evident. Magnifying endoscopy with NBI would show a clear mucosal pattern with a distinct white zone in (A) and neither a mucosal pattern nor a white zone in (D) It is necessary to clarify how long the intervening part needs to be (B) and how deep the crypt needs to be (C) in order for the white zone to be distinct.