Non-contrast Magnetic Resonance Angiography Versus Contrast-enhanced Computed Tomography in Deep Inferior Epigastric Perforator (DIEP) Flap Planning: A 4-year Non-inferiority Cohort Study

Background Contrast-enhanced computed tomography angiography (CTA) is considered the “gold standard” in deep inferior epigastric perforator (DIEP) planning, despite its use of iodine-based contrast and ionizing radiation exposure. In contrast, magnetic resonance angiography (MRA) provides a radiation-free alternative, but conventional MRA requires the use of an expensive and potentially harmful gadolinium-based contrast agent. The development of contrast-free MRA protocols that preserve perforator mapping accuracy represents a promising area of investigation in DIEP flap planning. Objectives To evaluate whether an optimized non-contrast MRA protocol is non-inferior to contrast-enhanced CTA in planning for delayed DIEP flap breast reconstruction (BR). Methods This cohort study included 131 women (mean age 45.6 ± 7.1; BMI 28.5 ± 3.9 kg/m2), who underwent delayed unilateral DIEP flap BR. Group 1 (n=81) underwent a non-contrast MRA with tailored preprocedural preparation, positioning, and scanning. Group 2 (n=50) underwent standard contrast-enhanced CTA. Results MRA significantly reduced operative time (333.0 ± 30.4 vs. 348.9 ± 28.8 min; p = 0.003) and pedicle dissection time (35.7 ± 8.2 vs. 40.1 ± 5.9 min; p < 0.001). The mean fascial incision length was shorter in the MRA group (9.1±1.5 cm vs. 10.6±1.6 cm; p = 0.025). Diagnostic accuracy was 98.8% vs. 99.6% (p = 0.4145); sensitivity 98.3% vs. 100.0%, and PPV 97.5% vs. 98.7%, for MRA and CTA, respectively. The mean localization difference (ΔL) was 7.38±2.59 mm vs. 6.96±2.34 mm (p=0.238). Perfusion-related complication rates did not differ significantly between groups (p>0.05). No significant differences were observed in baseline perforator characteristics. Conclusions Optimized non-contrast MRA is a clinically reliable, non-inferior alternative to CTA in DIEP flap planning, with additional advantages of reduced operative and dissection times.