Young Cheol Yoon MD, Abstract Co-Author: Nothing to Disclose

Yousun Chong MD, Presenter: Nothing to Disclose

Ji Hyun Koo MD, Abstract Co-Author: Nothing to Disclose

Ki Jeong Park MD, Abstract Co-Author: Nothing to Disclose

Yu Jin Oh MD, Abstract Co-Author: Nothing to Disclose

Ah Yeong Kim MD, Abstract Co-Author: Nothing to Disclose

To compare the metal artifacts and acquisition time among the slice encoding for metal artifact correction (SEMAC) images, SEMAC with dual-source parallel radiofrequency transmission images, and fast spin echo (FSE) images in 3.0T MR imaging.

Our institutional review board approved this retrospective study and informed consent was waived. A phantom study was performed by using a titanium alloy pedicle screw. Total of 16 patients (3 men and 13 women) who underwent spine surgery, using pedicle screws, were included for this clinical study. The T1-weighted FSE images, the SEMAC images, and the SEMAC with dual-source parallel RF transmission images were obtained. The SNR was calculated in the phantom study. As a qualitative study, four imaging findings (visibility of the dural sac, visibility of neural foramens, visibility of bone-implant interface, overall artifacts) were evaluated by using five-point scales, independently by two observers.

In the phantom study, the mean SNR was 71.2, 25.7, and 28.4, and the scan time was 2 minutes 24 seconds, 12 minutes 53 seconds, and 8 minutes 36 seconds for the FSE images, the SEMAC images, and the SEMAC with dual-source parallel RF transmission images, respectively. In the clinical study, FSE images were ranked lower than that of the SEMAC images and the SEMAC with dual-source parallel RF transmission images. Further, the ranking of the SEMAC images and the images of the SEMAC with dual-source parallel RF transmission were not statistically different for all four imaging findings. The mean scan time was 9 minutes 51 seconds and 6 minutes 31 seconds for the SEMAC images and the SEMAC with dual-source parallel RF transmission images, respectively.

SEMAC can reduce metallic artifacts and improve the visualization of anatomical structures around the metal implants. With additional dual source parallel RF transmission technique can reduce the acquisition time of SEMAC images without a loss of SNR and image quality.

Reduction of acquisition time of SEMAC with additional use of dual source parallel RF transmission technique can help to reduce the possibility of motion artifact and patient’s discomfort.

Yoon, Y, Chong, Y, Koo, J, Park, K, Oh, Y, Kim, A, Reducing Metallic Artifacts in Postoperative Spinal Imaging: Slice Encoding for Metal Artifact Correction with Dual-Source Parallel Radiofrequency Excitation MR Imaging at 3.0T.  Radiological Society of North America 2012 Scientific Assembly and Annual Meeting, November 25 - November 30, 2012 ,Chicago IL. http://archive.rsna.org/2012/12031795.html