The hypertransradiant hemithorax: the importance of lateral decentring, and the explanation for its appearance due to rotation.
Experimental evidence is presented indicating that 80% of the increase in unilateral film blackening on the chest radiograph resulting from rotation of the patient is due to asymmetrical absorption of the X-ray beam. Scatter contributes 20% to this increase in blackening. The effect on the radiograph of lateral decentring is also described. In the rotated patient, the hypertransradiant hemithorax always occurs on the side to which the patient is rotated, and is independent of the projection. If this rule is broken, then decentring or a thoracic abnormality is present.
D000042:Absorption; D006801:Humans; D008961:Models, Structural; D013902:Radiography, Thoracic / Q000379:methods*; D012399:Rotation; D012542:Scattering, Radiation; D013679:Technology, Radiologic