Usefulness of emission CT in 67Ga tumor and inflammation scintigraphy

67Ga-citrate widely used for tumor imaging has some drawbacks. Poor blood elearance of 67Ga is sometimes a cause of poor visualization of the abnormal uptake in lesions. Physiological accumulations of 67Ga (e. g. liver, colon, pulmonary hilus, etc.) also conceal the abnormal 67Ga uptake in lesions. We have evaluated the usefulness of 67Ga SPECT (single photon emission CT) to overcome these drawbacks inherent in conventional gamma-camera images. 67Ga SPECT was more useful to recognize the location and the extension of lesions in transaxial planes, therefore, comparison of the lesions with transmission CT was easily made. Abnormal accumulation in or near the liver was easily discriminated from the physiological accumulation of 67Ga in the liver. Further evaluation of the lesions which had been detected by other imaging methods (e. g. transmission CT, ultrasonography, etc.), 67Ga SPECT was more useful than conventional gamma-camera imaging. In conclusion, 67Ga SPECT was useful in selected cases when performed after conventiond 67Ga imaging. (author)