Abstract
Objective
A considerable change of urinary bladder (UB) shape in PET compared with CT in integrated PET/CT system is frequently noted. This study initially evaluated this finding with and without oral contrast (OC) use. In addition, a one bed pelvic section (PLV) repeat acquisition was investigated as a solution to this problem.
Methods
18FDG PET/CTs of 88 patients were analyzed. OC was administered in 68 patients, of whom 31 had PLV images taken 5–10 min later. Three-dimensional mid-UB CT and PET matching measurements were compared. In addition, UB walls displacement between CT and PET were analyzed.
Results
The mean UB height was significantly increased (P < 0.001) in PET when compared with CT, both anteriorly and posteriorly; however, UB width and depth were not significantly different. An upward shift of superior UB wall in PET from equivalent CT images was noted, whereas there was no appreciable displacement of the other UB walls. The percent UB height increase on PET from CT was significantly greater with than without OC use. The UB height difference between PET and CT was markedly reduced on PLV when compared with the original scans.
Conclusions
Caution should be exerted during the interpretation of PET/CT scans of the pelvis as there is significant upward expansion of UB on PET compared with CT that appears to be exaggerated by OC use, likely due to additional fluid load. The PET/CT fusion errors of UB can be substantially resolved through a separate PLV acquisition presumably due to the shorter time interval of UB scan completion between CT and PET.
Similar content being viewed by others
References
Wahl RL. Why nearly all PET of abdominal and pelvic cancers will be performed as PET/CT. J Nucl Med. 2004;45:82S–95S.
Vogel WV, Oyen WJG, Barentsz JO, Kaanders JH, Corstens FHM. PET/CT: panacea, redundancy, or something in between? J Nucl Med. 2004;45:15S–24S.
Beyer T, Antoch G, Blodgett T, Freudenberg L, Akhurst T, Mueller S. Dual-modality PET/CT imaging: the effect of respiratory motion on combined image quality in clinical oncology. Eur J Nucl Med. 2003;30:588–96.
Beyer T, Antoch G, Müller S, Egelhof T, Freudenberg LS, Debatin J, et al. Acquisition protocol considerations for combined PET/CT imaging. J Nucl Med. 2004;45:25S–35S.
Gorospe L, Raman S, Echeveste J, Avril N, Herrero Y, Hernández S. Whole-body PET/CT: spectrum of physiological variants, artifacts and interpretative pitfalls in cancer patients. Nucl Med Commun. 2005;26:671–87.
Mawlawi O, Pan T, Macapinlac HA. PET/CT imaging techniques, considerations, and artifacts. J Thorac Imag. 2006;21:99–110.
Blodgett TM, McCook BM, Federle MP. Positron emission tomography/computed tomography: protocol issues and options. Semin Nucl Med. 2006;36:157–68.
Cook GJR, Wegner EA, Fogelman I. Pitfalls and artifacts in 18FDG PET and PET/CT oncologic imaging. Semin Nucl Med. 2004;34:122–33.
Purcell DD, Coakley FV, Franc BL, Hawkins RA, Boddington SE, Yeh BM. Anterior layering of excreted 18FDG in the bladder on PET/CT: frequency and cause. AJR Am J Roentgenol. 2007;189:W96–9.
Author information
Authors and Affiliations
Corresponding author
Rights and permissions
About this article
Cite this article
Heiba, S.I., Raphael, B., Castellon, I. et al. PET/CT image fusion error due to urinary bladder filling changes: consequence and correction. Ann Nucl Med 23, 739–744 (2009). https://doi.org/10.1007/s12149-009-0304-y
Received:
Accepted:
Published:
Issue Date:
DOI: https://doi.org/10.1007/s12149-009-0304-y