**2.4 Gallium-67: Hybrid SPECT/CT imaging**

Ga-67 scintigraphy is primarily characterized by poor spatial resolution and low specificity due to paucity of anatomical and morphological information. (Bar-Shalom et al., 2006) studied patients with multiple infectious conditions including FUO and concluded that SPECT/CT was found to be beneficial in determining the precise anatomical sites of infection in 85% of discordant studies. In particular, substantial benefits were observed in scans of the chest and abdomen. In our own experience the addition of SPECT/CT to Ga-67 scintigraphy has a definite incremental value that helps resolve many difficult clinical scenarios (Figure 4).

Fig. 4. A 21-year-old female with history of polycystic kidney disease referred for Ga-67 scintigraphy to evaluate suspected infected right renal cyst. Ga-67 scintigraphy shows linear intense tracer accumulation in the infra-hepatic region. SPECT/CT images localize the abnormal uptake to an area in the upper pole of right kidney just above a hypodensity (renal cyst) that shows photopenia on SPECT images. Subsequent guided biopsy drained abscess just beneath the renal capsule.
