Symbia T6: Accessory Spleen Demonstrated by SPECT•CT
Symbia T6 SPECT•CT delineates the extent of ectopic splenic tissue
William Pavlosky, MD
Case study data provided by Timmins and District Hospital, Timmins, Ontario, Canada
A 9-year-old boy presented with occasional abdominal pain. Ultrasonography showed a large cyst in the upper pole of left kidney along with absence of spleen. A 99mTc sulfur colloid SPECT•CT study with integrated diagnostic non-contrast CT was performed to detect rudimentary or accessory splenic tissue as well as abdominal morphological detail with thin-slice CT.
Fig. 1: Initial planar images show normal-sized liver with uniform tracer uptake with non-visualization of normal-sized spleen in the right flank. A small foci of uptake in the left flank in the posterior view suggests possibility of presence of rudimentary hypoplastic splenic tissue.
Fig. 2: Non-contrast diagnostic CT images acquired with 1.5 mm slice thickness show large renal cyst in the up-per pole of left kidney. No evidence of hemorrhage within the cyst was seen on CT, which would correlate with the symptoms of abdominal pain.
Fig. 3: Fused SPECT•CT images show uptake of 99mTc sulfur colloid in soft-tissue mass in the splenic fossa, which is suggestive of hypoplastic spleen.
Fig. 4: CT images show small specs of calcification within the hypoplastic spleen which may reflect small infarcts.
Fig. 5: Fused images also demonstrated a small soft-tissue mass in the left flank at the level of upper pole of left kidney adjacent to the lateral abdominal wall, which also showed 99mTc sulfur colloid uptake, confirming that this mass was an accessory spleen.
The renal cyst was drained percutaneously, while the hypoplastic spleen and accessory spleen were left alone based on the SPECT•CT findings, which helped localize these splenic tissue remnants and determined that these were not compressing adjacent vascular or bowel structures. Diagnostic CT performed on the Symbia™ T6 as an integrated SPECT•CT procedure was instrumental in obtaining clear delin-eation of the accessory and hypoplastic splenic tissue due to high resolution and lack of motion artifacts obtained due to fast CT with breath-hold.
In a 9-year-old boy, the use of multislice CT enabled fast scanning for breath-hold abdominal CT acquisition, which clearly defined abdominal structures thereby enabling accurate fusion of SPECT and CT to delineate the extent of ectopic splenic tissue and its relationship with surrounding structures especially bowel loops, peritoneum and abdominal wall.