Obliquity refers to the effect of the angle of view on the appearance of a structure in an image. An oblique image of a circular structure may resemble an ellipse.
Selection: image of a circular structure
Parameters:
(1) maximum diameter of the structure in mm
(2) minimum diameter of the structure in mm
Data check: maximum diameter >= minimum diameter
obliquity ratio =
= (maximum diameter) / (minimum diameter)
Interpretation:
• minimum value: 1
• A value of 1 is seen with an observatoin perpendicular to the imaging plane.
• A ratio > 1.5 is considered evidence of an oblique view. A bronchus with a ratio > 1.5 is excluded from analysis of bronchial wall dimensions.
To read more or access our algorithms and calculators, please log in or register.
