Utility of FDG-PET/CT for the Detection and Characterization of Sternal Wound Infection Following Sternotomy

Abstract

Purpose: FDG-PET/CT has the potential to play an important role in the diagnosis of sternal wound infections (SWI). The purpose of this study was to analyze the diagnostic accuracy of FDG-PET/CT for SWI in patients following sternotomy.

Methods: We performed a single-center, retrospective analysis of patients who had undergone median sternotomy and FDG-PET/CT imaging. The gold standard consisted of positive bacterial culture and/or the presence of purulent material at surgery. Qualitative patterns of sternal FDG uptake, SUV_max, and associated CT findings were determined, and an imaging scoring system was developed. The diagnostic performances were studied in both the recent (≤ 6 months between sternotomy and imaging) and remote surgery phase (> 6 months).

Results: A total of 40 subjects were identified with 11 confirmed SWI cases. Consensus interpretation was associated with a sensitivity of 91% and specificity of 97%. Combination of uptake patterns yielded an AUC of 0.96 while use of SUVmax yielded an AUC of 0.82.

Conclusions: Results suggest that FDG-PET/CT may be useful for the diagnosis of SWI with optimal diagnostic accuracy achieved by identifying specific patterns of uptake. SUV_max can be helpful in assessing subjects with remote surgery, but its use is limited in the context of recent surgery. Further studies are required to confirm these results.

Keywords: FDG-PET; Infection imaging; Sternal wound infection; Sternotomy.

Fig. 1

Flowchart for subject enrolment

Fig. 2

Anterior maximal intensity projection (MIP) images as well as sagittal PET, CT, and fused PET/CT images of the FDG sternotomy uptake patterns

Fig. 3

Relationship between sternal SUV_max in non-infected patients as a function of time since sternotomy

Fig. 4

Distribution of SUV_max in the infected and non-infected subjects, as well as in both the recent (≤ 6 months) and remote (> 6 months) surgery subgroups