Clinical Presentation

A 50-year-old man with a productive cough presents with atypical chest pain. Cardiac catheterization is negative, and a chest radiograph shows bilateral patchy opacities in both lungs.

Fig. 47.1

Fig. 47.2

Technique

Lung Ventilation Scan

• A 40.0 mCi dose of ^99mTc-DTPA is placed in the aerosolizer (delivers < 1 mCi to the lungs).

• Use a low-energy, all-purpose collimator.

• Energy window 20% centered at 80 keV.

• Views are anterior, right anterior oblique, left anterior oblique, posterior, right posterior oblique, left posterior oblique, right lateral view, and left lateral.

Lung Perfusion Scan

• A 3.0 mCi dose of ^99mTc-MAA is administered intravenously with the patient supine.

• The patient should cough and take several deep breaths before administration of the MAA to clear any areas of resting atelectasis.

• The patient should breathe normally during tracer injection.

• Use a low-energy, all-purpose collimator.

• Energy window 20% centered at 140 keV.

• Imaging time is 500,000 counts per view.

• Matrix size is 128 × 128.

• Views are anterior, right anterior oblique, left anterior oblique, posterior, right posterior oblique, left posterior oblique, right lateral view, and left lateral.

Image Interpretation