Table 1:

Degree of pseudostenosis artifacts

Contrast Material Concentration & SystemGrade for Pseudostenosis Artifact
Right M1Left M1
300 mg I/mL
150 mg I/mL
  • Note:—FPD indicates flat panel detector; I.I., image intensifier; M1, sphenoidal segment of middle cerebral artery. Grades: 0, no stenosis; 1, mild stenosis less than 30%; 2, moderate stenosis of 30%–69%; 3, severe stenosis more than 70%.