Improving diagnostic accuracy in aortic prosthetic graft infection
Aortic graft infection (AGI) occurs infrequently and its clinical appearance may vary extensively. The natural course of AGI may be devastating and potentially life-threatening. Despite prevention matters, prosthetic grafts remain sensitive to infection, and the clinical dilemma in suspected graft infection is how to obtain a reliable, non-invasive proof of infection. If infection is suspected, CT angiography (CTA) is usually performed. However, CTA alone appeared not always sufficient to identify the exact localization of the source of infection and its’ extension. In the search for more reliable and accurate diagnostic tools, 18F-Fluorodeoxyglucose Positron Emission Tomography (18F-FDG PET) had already proven to be of additional value in the detection of infectious foci, not related to vascular surgery. 18F-FDG PET can either be evaluated semi-quantitatively using the maximal standardized uptake value, the tissue-to-background ratio, and visually using the Visual Grading Scale. The results of interpretation of 18F-FDG PET scan images may vary between nuclear medicine physicians. Moreover, there are no strict guidelines or recommendations available for the interpretation of these PET images in suspected AGI.
Texture analysis, a relatively new quantitative measure, could be helpful in decreasing inter- and intra-observer variability and possibly improve the diagnostic accuracy in AGI. In conclusion, AGI remains a challenging complication for the vascular surgeon. There is still no consensus on diagnostic work up and therapeutic strategy. The role of 18F-FDG PET scan is becoming increasingly important in the detection of AGI; however, an accurate assessment of the uptake and pattern, including a cut-off value is warranted.
Texture analysis, a relatively new quantitative measure, could be helpful in decreasing inter- and intra-observer variability and possibly improve the diagnostic accuracy in AGI. In conclusion, AGI remains a challenging complication for the vascular surgeon. There is still no consensus on diagnostic work up and therapeutic strategy. The role of 18F-FDG PET scan is becoming increasingly important in the detection of AGI; however, an accurate assessment of the uptake and pattern, including a cut-off value is warranted.