Efficacy and safety of 128 slice CT low-dose scanning technique combined with low-density contrast agent in computed tomography angiography of diabetic foot and lower limb.

Objective: To evaluate the efficacy and safety of 128 slice CT low-dose scanning technology combined with low-density contrast agent in lower extremity computed tomography angiography (CTA) for patients with diabetic foot.

Methods: A retrospective study was conducted on 342 patients with diabetic foot admitted to Shaanxi Kangfu Hospital from March 2021 to May 2023. Of these, 181 received 128 slice CT low-dose scanning technology combined with low-density contrast medium for lower extremity CTA examination (research group), and 161 patients underwent conventional dose contrast medium for CTA examination (control group). Diagnostic outcomes of the two groups were compared, along with image quality, contrast agent dosage, patient tolerance to contrast agents, and incidence of adverse reactions.

Results: No significant difference was observed in diabetic foot detection rate between the two groups (90.06% in research group vs. 86.96% in control group, P > 0.05). No significant difference in image quality or vascular CT values was found between the two groups (P > 0.05). Although the research group exhibited slightly higher image noise and lower signal-to-noise ratio (SNR) and contrast-to-noise ratio (CNR), these differences were not significant (all P > 0.05). The volume computed tomography dose index (CTDIvol), effective dose (ED), and iodine uptake in the research group were significantly lower than those of the control group (all P < 0.05). In terms of the incidence of adverse reactions, patients in the research group had a good tolerance to contrast agents, with an 8.29% incidence of mild discomfort (such as nausea and mild rash) and no reports of severe allergic reactions. In contrast, the incidence of mild discomfort reactions in the control group was 14.91% (P < 0.05). Among the diabetic foot patients, 46.20% had mild stenosis, while 53.80% had moderate-to-severe stenosis. The detection rate of moderate-to-severe stenosis was 84.67% (138/163) in the research group and 82.86% (116/140) in the control group (P > 0.05). The ROC curve results indicated good diagnostic accuracy in both groups (AUC of 0.690 in research group and 0.783 in control), with significant difference between the two groups (P > 0.05).

Conclusion: 128 slice CT low-dose scanning technology combined with low concentration contrast medium shows good effectiveness and safety for CTA of lower limbs in patients with diabetic foot. It provides an optimized scheme for vascular assessment of diabetic foot patients, reducing contrast agent exposure, lowering the risk of complications, and maintaining diagnostic accuracy.