Huan Tan PhD, Presenter: Nothing to Disclose

Ioannis Koktzoglou PhD, Abstract Co-Author: Nothing to Disclose

Christopher Glielmi PhD, Abstract Co-Author: Employee, Siemens AG

Robert R. Edelman MD, Abstract Co-Author: Research support, Siemens AG Royalties, Siemens AG

Nonenhanced, navigator-gated, multi-shot inversion-prepared MR angiography techniques such as NATIVE TrueFISP have proven accurate for evaluating the patency of the renal arteries. However, the scan time for NATIVE TrueFISP is variable, and sometimes lasts 10 minutes or longer depending on breathing patterns. A highly efficient 3D extension of the recently described QISS (quiescent-interval single shot) technique has been implemented which allows the entire extent of the renal arteries to be depicted within a single breath-hold. The purpose of this study was to optimize imaging parameters for breath-hold 3D QISS and compare image quality with navigator-gated NATIVE TrueFISP.

The study was approved by our IRB. Six healthy volunteers (5 male and 1 female, age 25–55) were imaged on a 1.5T scanner (Siemens MAGNETOM Avanto, Erlangen, Germany). The following parameters were evaluated for 3D QISS: quiescent inflow period (QI), magnetization preparation (saturation vs. inversion, axial vs. oblique), excitation flip angle, and cardiac synchronization (ECG gated vs. ungated). NATIVE TrueFISP images were acquired for comparison with standard parameters. Quantitative evaluation was performed by calculating renal artery SNR and CNR.

The mean scan was 20 seconds for 3D QISS and 215 seconds for NATIVE TrueFISP. Image quality for 3D QISS was comparable to NATIVE TrueFISP despite a near 10-fold reduction in scan time, with slightly better depiction of intra-renal arterial branches. For extra-renal and intra-renal arterial segments, 3D QISS showed SNR of 43 ± 11 and 29 ± 6 with CNR of 37 ± 11 and 23 ± 9, respectively. For NATIVE TrueFISP, the comparable values were SNR of 43 ± 9 and 28 ± 7 with CNR of 33 ± 10 and 17 ± 6, respectively (p > 0.05 for SNR and CNR, Friedman’s Test). The optimized protocol for 3D QISS included: 90° flip angle, oblique inversion preparation, max allowable QI, ECG gating.

In this initial feasibility study, breath-hold 3D QISS provided comparable image quality, SNR, and CNR to navigator-gated NATIVE TrueFISP despite a ten-fold reduction in scan time.

Single breath-hold 3D QISS offers an alternative to navigator-gated methods for nonenhanced renal MRA, providing an order-of-magnitude decrease in scan time with no significant loss of image quality.

Tan, H, Koktzoglou, I, Glielmi, C, Edelman, R, Order-of-Magnitude Scan Time Reduction for Nonenhanced Renal MR Angiography Using a Breath-hold 3D Quiescent-interval Single Shot (QISS) Acquisition.  Radiological Society of North America 2011 Scientific Assembly and Annual Meeting, November 26 - December 2, 2011 ,Chicago IL. http://archive.rsna.org/2011/11009901.html