Figure 1
From: Validation of bidimensional measurement in nasopharyngeal carcinoma
T2-weighted postcontrast MR image in the axial plane. The bidimensional measurement of primary tumor and retropharyngeal nodes (BDMprn) was obtained by summation of multiplying the maximum diameter by the greatest measurement perpendicular to it in nasopharyngeal tumor (A) and retropharyngeal nodes (B). BDMprn (cm2) = A1 × B1 + A2 × B2 + A3 × B3.