The Need for Oblique or Lateral Ventilation Images in the Diagnosis of Pulmonary Embolism

Abstract

Numerous recent textbooks in nuclear medicine suggest that, for the evaluation of pulmonary embolism, a single posterior initial-breath xenon-133 view followed by equilibrium and washout images is sufficient to evaluate ventilation. One recent text suggests that lateral initial breath views should be included. Two cases in which the additional views were essential for correct interpretation are presented in support of this latter position. Because anterior abnormalities are not well represented on low photon-energy xenon-133 posterior images, it is recommended that, in all ventilation-perfusion studies for pulmonary embolism, at least both oblique or both lateral initial breath views must be obtained. Other views, such as anterior or anterior oblique views, may be needed and can be obtained before or following perfusion imaging.