Update on functional imaging in the evaluation of diabetic foot infection

Abstract

Diabetic foot infection is a preventable complication of diabetes mellitus. It is an essential component of diabetic foot disease, which is characterised by a triad of neuropathy, ischaemia and infection. These factors may lead to foot ulceration, sepsis and amputation resulting in increased morbidity and poor quality of life. Confirming or excluding infection can be difficult especially when routine laboratory tests and plain radiographs are inconclusive. Early diagnosis and localization of diabetic foot infection is extremely important to institute timely, appropriate therapy. Structural imaging using computed tomography and magnetic resonance imaging all have individual applications towards the diagnostic workup of this condition but have their own limitations. Scintigraphic detection is based on physiochemical changes and hence provides a functional evaluation of bone pathology.We describe the evolution of functional nuclear medicine imaging including immunoscintigraphy in diabetic foot infection and highlight current applications of physiological 18-Fluoro-deoxyglucose positron emission tomography (18-FDG-PET) and computed tomography (18-FDG-PET/CT) in such patients.18-FDG-PET/CT is a promising modality for imaging diabetic foot infection. Future studies will allow standardisation of technological details and options of 18-FDG-PET/CT interpretation in diabetic foot infection.

Magnetic Resonance Imaging Data Features to Evaluate the Efficacy of Compound Skin Graft for Diabetic Foot

“…It was found that MRI could be used to monitor and evaluate the curative effect of treating DF. As a noninvasive monitoring method, it is simple to operate and very sensitive and accurate to the pathological changes of DF patients, which is consistent with the results of this study [27]. In short, MRI image data features based on the deep learning algorithm can provide auxiliary information for the efficacy evaluation of compound skin transplantation for DF, which has a great application value.…”

Imaging of the Diabetic Foot

“…32,33 Hybrid imaging modalities, such as technetium 99m hexamethylpropyleneamine oxime-labeled WBC ( 99m Tc-HMPAO-WBC) with SPECT/CT, usually combined with bone marrow scintigraphy, are highly effective and improve the accuracy of radiolabeled leukocyte scintigraphy in diagnosing DFO and defining when an infection has resolved with treatment. 34 However, WBC diagnostic performance can be hampered by the subacute or chronic nature of DFIs because WBC uptake consists mostly of labeled neutrophils that are usually involved in acute infections. 22 Also, the sensitivity of this test can be reduced in patients with vascular insufficiency due to a reduction in WBC migration.…”

What does the orthopaedic surgeon want in the radiology report?

“…19e21 In cases with diagnostic uncertainty on morphological imaging, providing guidance on the use of most relevant functional imaging, such as 18-Fluoro-deoxyglucose positron emission tomography (18-FDG-PET) and SPECT-CT would provide clarification. 22…”