“…Baran et al [9] described a case of circle of Willis DE where the internal carotid artery (ICA) diameter was 11mm and the middle cerebral artery (MCA) 7mm, but used no criteria as guidelines. Fielies et al [13] described a case of MCA DE that measured 12.5mm but also did not refer to any criteria. In these cases, the vessels were grossly dilated making visual assessment easier and more accurate.…”