Objective: To evaluate the feasibility of nonenhanced renal artery MR angiography (MRA) with respiratory-gated time spatial labeling inversion pulse (time-slip) and its clinical application.
Methods: Thirty-two consecutive patients underwent the 1.5 T MRI (TOSHIBA EXCELART Vantage) examination to visualize renal artery with contrast-enhanced MRA (CEMRA) and the examination with time-slip technology. Signal to noise ratio (SNR) and contrast to noise ratio (CNR) were measured on CEMRA and Time-slip images, respectively. Two experienced radiologists assessed the imaging quality of renal artery MRA on 3D-MIPs reconstructed images.
Results: Sixty-four renal arteries and 3 accessory renal arteries in 32 patients were visualized on both time-slip and CEMRA. SNR values on Time-slip and CEMRA were 102.7 +/- 16.2 and 83.9 +/- 17.7 (t = -4.625, P < 0.001); CNR were 97.8 +/- 16.1 and 78.8 +/- 18.3 (t = -4.554, P < 0.001), respectively. Time-slip MIP images obtained higher quality than CEMRA did (Z = -2.318, P = 0.02), and venous contamination was sharply reduced on Time-slip technology when compared with CEMRA (Z = -4.895, P = 0.001).
Conclusion: Non-enhanced renal artery MRA with respiratory-gated time-slip technology can provide higher SNR images of renal artery than conventional CEMRA, which can provide more information for clinical decision-making.