A spectacular lecture by Samantha Minc, MD, of Duke University at DFCon2026 brought an important distinction into sharp focus: intimal and medial arterial calcification are not the same thing. Her talk, “Between a Rock and a Hard Place: Conquering the Calcified Vessel,” deserves a hearty thank-you for making this clinically consequential subject so accessible. Special thanks as well to Katharine “Kate” McGinigle, MD, MPH, of UNC, whose contributions to our USC–UNC research on medial arterial calcification and amputation risk help connect this distinction to limb-preservation practice.
It is easy to see calcium on a foot radiograph and mentally file it under “atherosclerosis.” But where that calcium lives matters. So does the biology behind it. These processes can point to different clinical phenotypes, even when they occur in the very same patient.
The comparison in Dr. Minc’s slide cites Kim and Guzman’s review of medial artery calcification in peripheral artery disease. The original graphic below builds on that framework, with additional clinical context from contemporary reviews and PAD guidelines. It is an educational synthesis, not a reproduction of her slide or a transcript of her lecture.
Same mineral, different address
Intimal calcification occurs within atherosclerotic plaque in the inner layer of the artery. The surrounding plaque process may narrow or occlude the lumen. The calcium is part of that plaque biology, but a calcium deposit is not itself a measurement of how severe the stenosis is.
Medial arterial calcification (MAC) involves the muscular wall, often near its elastic structures. It is particularly associated with diabetes, chronic kidney disease and aging. Rather than simply growing an atherosclerotic plaque into the lumen, it makes the arterial wall stiff and less compliant.
This is active biology, not merely passive mineral settling into an old pipe. Smooth-muscle cell changes and disrupted regulation of mineralization contribute to MAC. Lanzer and colleagues’ state-of-the-art review makes the case that medial calcification deserves to be understood as a disease process in its own right.
Different phenotypes, not two separate waiting rooms
The patient with prominent smoking and lipid-related atherosclerotic disease and the patient with diabetes, neuropathy and kidney disease may have different dominant vascular problems. But these are not exclusive categories. Diabetes also accelerates atherosclerosis, and a peripheral artery can contain both intimal and medial calcium.
“Not the same disease” does not mean “never the same patient.” Nor does “not simply an intraluminal plaque” mean “benign.” In a prospective observational cohort of 979 patients with diabetic foot ulcers, pedal MAC was associated with higher amputation risk, including greater risk when it accompanied PAD. That is an association, not proof that calcium alone caused an individual patient’s outcome. Read the study.
The foot film is a clue, not a flow study
Patchy, irregular calcification may suggest intimal plaque. Linear, parallel “rail-track” calcification may suggest medial disease. These patterns help us ask better questions; they do not answer every question.
A study comparing radiographs and CT with histology showed that imaging classification is imperfect. A plain film cannot reliably assign every deposit to one arterial layer, quantify a stenosis, or establish whether tissue has enough perfusion to heal. We need to resist both shortcuts: “calcium means blockage” and “medial calcium means no ischemia.”
When the pressure number looks better than the foot
Stiff, noncompressible arteries can produce a falsely reassuring or elevated ankle-brachial index (ABI). The 2024 multisociety PAD guideline classifies ABI above 1.40 as noncompressible and recommends toe-brachial index testing with waveforms in that setting. A normal-range ABI can also coexist with clinically important disease.
For a person with diabetes and a foot ulcer or gangrene, the IWGDF/ESVS/SVS guideline recommends combining pedal Doppler waveforms with ABI and toe-brachial index. No single test result reliably excludes PAD. Toe pressures are generally less affected by calcification than ankle pressures, but they are not immune. When toe pressure cannot be measured, transcutaneous oxygen pressure or skin-perfusion pressure can help.
The practical point is straightforward: a reassuring number does not close the vascular assessment when the wound, examination or waveform remains concerning. Read the patient, the film and the physiology together.
Connecting the dots across DF Blog
We have been circling this distinction for years. Here is a reading path through the most directly related posts:
- Mönckeberg: from a 1903 autopsy to today’s foot film connects the history of medial calcification with neuropathy, pedal disease and limb-risk assessment.
- Our USC–UNC work on MAC score and major amputation examines how a plain-film score can complement WIfI staging in patients with chronic limb-threatening ischemia.
- Pedal calcification, hemodynamic response and amputation after revascularization asks why technical success does not always translate into adequate distal perfusion.
- Toe pressures in diabetic foot ulcers with MAC explores the limits of a single pressure measurement for predicting healing.
- We moved to the toe to escape calcification, and it followed us there takes the digital-artery problem further. The proposed numerical correction discussed there should not be treated as a universally validated substitute for multimodal vascular assessment.
- The “Iron Curtain” of the foot explores the pathology beneath distal arterial obstruction.
- Are We Flying Blind? looks at the limitations of bedside PAD testing in diabetes.
- Pedal acceleration time considers another approach to characterizing distal arterial flow.
- Calcium makes everything harder connects calcification with the challenges of microsurgical limb preservation.
- Influence of calcification on peripheral vascular assessment is an earlier reminder that this diagnostic blind spot is not new.
The take-home
Intimal calcium tells us about plaque. Medial calcium tells us about the arterial wall. Neither tells the whole story of the foot.
Thank you, Dr. Minc, for a spectacular DFCon lecture and for prompting this conversation. Better distinctions should lead to better questions, better assessment and, ultimately, more opportunities to preserve a functional limb.
#DiabeticFoot #PAD #CLTI #MedialArterialCalcification #LimbPreservation #DFCon #ActAgainstAmputation
Selected sources
- Kim TI, Guzman RJ. Medial artery calcification in peripheral artery disease. Front Cardiovasc Med. 2023;10:1093355.
- Lanzer et al. Medial Arterial Calcification: JACC State-of-the-Art Review. 2021.
- Vos et al. Radiography and Computed Tomography Detection of Intimal and Medial Calcifications in Leg Arteries in Comparison to Histology. 2022.
- IWGDF/ESVS/SVS Intersocietal PAD Guideline. 2023.
- 2024 ACC/AHA multisociety guideline for lower-extremity peripheral artery disease.
- Chen et al. Pedal medial arterial calcification in diabetic foot ulcers: A significant risk factor of amputation and mortality. 2024.
Educational discussion, not an individual diagnostic or treatment recommendation. Credit to Dr. Minc recognizes the lecture that inspired this post; the synthesis and original graphic are not represented as her reviewed or endorsed materials.
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