E04: Principles of Diagnostic Investigations in the Diabetic Foot

Ordering a test is easy; reading it correctly in a person with diabetes is not. Neuropathy hides the pain of infection, ischaemia blunts the signals tests are built to detect, and renal impairment, hyperglycaemia and malnutrition shift the baseline. Reference ranges built for healthy adults can mislead here, so a result that is reassuring on paper can be dangerous in the foot in front of you.

The module teaches each result as a lever on probability. It covers why the white cell count is a poor rule-out, the neutrophil-to-lymphocyte ratio, red cell indices, albumin as a negative acute-phase reactant, CRP for detection and monitoring, ESR as the bone marker, procalcitonin, toe pressures when the ankle index is unreliable, the probe-to-bone test with a plain X-ray, MRI and nuclear imaging, and what a culture can and cannot tell you. C11 teaches imaging selection and acquisition; E04 teaches the reasoning that connects any result to a decision.

Content is tiered at Foundation, Core and Advanced level, with two algorithms and three case vignettes. You receive the Teaching Document, the Evidence Base, the slide deck and a narrated video.