106 Active Sarcoidosis

CASE 106

Clinical Presentation

A 48-year-old man with uveitis is referred by ophthalmology for suspected sarcoidosis.

Fig. 106.1 Whole-body planar image, anterior and posterior projections, ⁶⁷Ga.

Fig. 106.2 Selected “whole-body” SPECT image, coronal projection, ⁶⁷Ga.

Technique

• A 7.5 mCi dose of ⁶⁷Ga-citrate is injected intravenously 3 days before scan.

• Whole-body imaging in anterior and posterior projections

Dual-detector gamma camera

Medium-energy collimators

Energy peak at 93-, 185-, and 300-keV photopeaks

Image Interpretation

Whole-body planar images (Fig. 106.1) and “whole-body” SPECT images (Fig. 106.2) demonstrate intense right paratracheal and symmetric bilateral hilar uptake; this pattern has been termed the lambda sign because it resembles the Greek letter. Coupled with intense, symmetric uptake in the parotid glands and lacrimal glands, this is a characteristic pattern of sarcoidosis. The colon activity is physiologic.