Scintigraphic Detection of Splenosis and Accessory Spleen by Using Tc-99m Labelled Denatured Red Blood Cells

Abstract

Objective: To evaluate the usefulness of Tc-99m labeled denatured red blood cell scintigraphy (DRBCS) in the detection of splenosis and accessory spleen. Methods: The retrospective study reviewed 7 patients who were suspected of splenosis and accessory spleen in 2007-2014. Six patients had undergone total splenectomy before the DRBCS study. Multi-planar, SPECT and SPECT/CT images of DRBCS were reviewed by visual analysis. Image findings were correlated with other imaging modalities and clinical follow-up. Results: DRBCSs were positive in 6 patients; 5 splenosis and 1 accessory spleen. A single lesion was detected in each patient. Locations were in splenic bed (5 patients) and in pelvic cavity (1 patient). Mean lesion size was 3.7 + 2.4 cm. SPECT or SPECT/CT imaging could eliminate false-negative results in 2 patients. Lesion uptake intensity in 4 patients was higher than in the liver. Two patients had subsequently undergone resection of the lesions and were pathological confirmed splenosis and accessory spleen. The sensitivity of DRBCS was comparable with other imaging modalities. However, DRBCS was more specific for the splenic tissue. Conclusion: DRBCS is useful for the detection of splenosis and the accessory spleen. The detection sensitivity of DRBCS is better than US. DRBCS is more specific to spleen tissue, compared with US and CT. Furthermore, SPECT/CT imaging increases sensitivity, localization and lesion characterization. Clinical impact of DRBCS is apparent including pre-surgical localization, elimination of additional follow-up imaging and invasive procedure.

Keywords

• Accessory spleen
• denatured red blood cell
• immune thrombocytopenia
• splenosis
• spleen scintigraphy
• Siriraj Med J 2019;71: 143-149