Non-Contrast Enhanced Magnetic Resonance Angiography Using Delta-Flow Technique In Lower Extremity Arteries With 3.0T MR: Comparison With Contrast Enhanced Magnetic Resonance Angiography

Peripheral arterial occlusive disease is a common vascular disorder in the aging populations. Knowledge of the location, severity, and extent of this disease is imperative for accurate diagnosis and treatment planning. Contrast enhanced magnetic resonance angiography (CE-MRA) has been widely used for lower extremity arterial stenosis, but with the recognition of the possible link between gadolinium-based contrast agents and nephrogenic systemic fibrosis, especially in patients with renal insufficiency, the interest in non-contrast enhanced magnetic resonance angiography (NCE-MRA) technique has strongly emerged. Delta-Flow NCE-MRA is based on ECG-gated 3D partial-fourier FSE sequence. The purpose of this study is to evaluate the diagnostic value of Delta-Flow NCE-MRA for lower extremity arterial stenosis with 3.0T MR, in order to provide a reliable checking method for clinic.Thirty patients included 24 men and 6 women with arterial disease in lower extremity underwent NCE-MRA before clinical routine contrast enhanced magnetic resonance angiography (CE-MRA). All the source images were subtraction from mask images followed by maximum intensity projection (MIP) reconstruction. The arteries were divided into nine groups:common iliac artery, internal iliac artery, external iliac artery, femoral artery, deep femoral artery, popliteal artery, anterior tibial artery, posterior tibial artery and peroneal artery. Image quality of the two methods were analyzed. Cohen’s kappa was used to assess agreement between the two methods in the diagnosis of normal and significant stenosis (≥50%).All patients successfully underwent both NCE-MRA and CE-MRA studies, a total of 540 arterial segments were obtained in the 30 patients. 532 diagnostic valuable arterial segments were obtained in NCE-MRA. In calf region, vein artifacts presented more frequently on CE-MRA (Z=4.92, P< 0.01), in abdomen and thigh regions, vein artifacts presented more frequently on NCE-MRA (Z=4.58, P<0.01; Z=3.56, P<0.01). Significant stenosis was found in 142 of the 532 arterial segments on CE-MRA,10 high-grade stenoses at CE-MRA were upgraded to occlusion. There was content agreement (Kappa=0.95、0.94, P< 0.05) between the two methods for the diagnosis of normal and significant stenosis (≥50%).For the imaging of lower extremity arterial stenosis, Delta-Flow NCE-MRA shows similar image quality and diagnostic agreement with CE-MRA, thus can be used as an alternative method for lower extremity CE-MRA in patients who have renal insufficiency or who cannot use contrast media.