Detection of Splenic Tissue Using 99mTc-Labelled Denatured Red Blood Cells Scintigraphy—A Quantitative Single Center Analysis

Abstract

Background: Red blood cells (RBC) scintigraphy can be used not only for detection of bleeding sites, but also of spleen tissue. However, there is no established quantitative readout. Therefore, we investigated uptake in suspected splenic lesions in direct quantitative correlation to sites of physiologic uptake in order to objectify the readout. Methods: 20 patients with Tc-99m-labelled RBC scintigraphy and SPECT/low-dose CT for assessment of suspected splenic tissue were included. Lesions were rated as vital splenic or non-splenic tissue, and uptake and physiologic uptake of bone marrow, pancreas, and spleen were then quantified using a volume-of-interest based approach. Hepatic uptake served as a reference. Results: The median uptake ratio was significantly higher in splenic (2.82 (range, 0.58–24.10), n = 47) compared to other lesions (0.49 (0.01–0.83), n = 7), p < 0.001, and 5 lesions were newly discovered. The median pancreatic uptake was 0.09 (range 0.03–0.67), bone marrow 0.17 (0.03–0.45), and orthotopic spleen 14.45 (3.04–29.82). Compared to orthotopic spleens, the pancreas showed lowest uptake (0.09 vs. 14.45, p = 0.004). Based on pancreatic uptake we defined a cutoff (0.75) to distinguish splenic from other tissues. Conclusion: As the uptake in extra-splenic regions is invariably low compared to splenules, it can be used as comparator for evaluating suspected splenic tissues.

Accessory spleens recapitulate the immune microenvironment of the main spleen in immune thrombocytopenia

“…This is in keeping with literature data, indicating effective anti‐pneumococcal vaccination and red pulp functions in splenectomized patients with residual AcS 16,17 . These observations are also supported by the significant uptake of 99m Tc‐labelled RBCs in AcS, despite at lower levels than matched MS controls 18 . Finally, our observations reinforce prior evidence on the immunologic effects of splenectomy in ITP.…”

“…16,17 These observations are also supported by the significant uptake of 99m Tc-labelled RBCs in AcS, despite at lower levels than matched MS controls. 18 Finally, our observations reinforce prior evidence on the immunologic effects of splenectomy in ITP. These include a dampening of circulating GPIIb/IIIa-reactive T and B cells 19 and a reduction of memory B cells.…”

Case report: Misdiagnosis of accessory spleen in the left adrenal region as an adrenal tumour after splenectomy

“…At present, it is generally recognised that Tc-99m-labelled heat-denatured red-blood-cells scintigraphy is a reliable, sensitive and non invasive imaging method for confirm the qualitative clinical diagnosis of accessory spleen ( 16 , 17 ). The diagnostic principle is that the reticuloendothelial cells of the spleen can selectively absorb and destroy the function of damaged and denatured red blood cells (RBC).…”