Multiorgan dysfunctions in diabetic patients: the role of functional imaging

Functional imaging plays a central role in the evaluation of some of the clinical problems faced by diabetic patients. In cardiovascular disease, myocardial perfusion imaging, particularly when complemented by gated SPECT, is a powerful tool not only for establishing the diagnosis of coronary artery disease, but also for providing prognostic information in both the general and diabetic populations. Although promising, its role in screening of asymptomatic diabetic patients is yet to be established, and its role as a potential 'one-stop shop' also needs further study. PET is currently the gold standard for viability assessment, and also provides prognostic data, but its widespread use is limited by cost and availability. Hybrid imaging with PET/CT is promising, and could revolutionise cardiac imaging by combining functional and anatomic information. In the investigation of the diabetic foot, labelled leukocyte imaging is the nuclear medicine test of choice to diagnose osteomyelitis. It is likely that SPECT/CT will further improve diagnostic accuracy, but more studies are needed. Combined leukocyte and bone marrow imaging is of value in distinguishing osteomyelitis from neuropathic osteoarthropathy in the diabetic foot; PET and PET/CT may also be of value in these cases, but their wider role is currently inconclusive. The value of bone scintigraphy in the diabetic foot, even as a screening test, is questionable. Functional imaging methods can also be employed in the evaluation of other diabetic complications, including the assessment of left ventricular function, renal scarring and gastric emptying, but these methods are not widely used in current clinical practice.