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Medical AI Inquiry: You was designed to assist in medical decision-making based on the provided user questions. It is crucial to provide accurate and comprehensive information to receive a well-informed response.  Labels: OBJECTIVE, METHODS, RESULTS. Meshes: Adult, Aged, Aged, 80 and over, Cardiac-Gated Imaging Techniques, Echo-Planar Imaging, Electrocardiography, Female, Humans, Image Enhancement, Leg, Magnetic Resonance Angiography, Male, Middle Aged, Peripheral Arterial Disease, Reproducibility of Results, Sensitivity and Specificity, Spin Labels, Young Adult.
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Do unenhanced calf MR angiography at 3.0 T using electrocardiography-gated partial-fourier fast spin echo imaging with variable flip angle? Context: This study was to evaluate diagnostic performance of unenhanced electrocardiography-gated fast spin echo based MRA with variable flip angle on 3.0 T for assessment of calf arteries in patients with peripheral arterial occlusive disease (PAOD). 64 patients underwent unenhanced MRA (UE), time-resolved contrast-enhanced MRA of the calf and bolus-chase contrast-enhanced lower peripheral MRA (BCE). Diagnostic performance of UE was evaluated and compared with contrast-enhanced MRA in 61 patients and x-ray angiography in 10 patients. With UE, 852 of 960 segments (88.75%) were diagnostic even in patients with arrhythmia, demonstrating similar image quality with those on BCE (P > 0.05). For those diagnostic segments, statistics revealed good agreement between unenhanced and contrast-enhanced techniques with a Kappa value of 0.77 and 0.75 for stenosis detection and visualized vessel length, respectively. When using X-ray angiography as reference standard, no significant difference was found between UE and contrast-enhanced MRA concerning sensitivity and specificity in depiction of severe stenosis and occlusion (P > 0.05).
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Although further technical refinements are required, this optimized UE technique may be used as a supplement to contrast-enhanced MRA particularly in patients with PAOD in whom venous contamination occurs frequently. Final Decision: yes