Miriam Reichert BDS, Presenter: Nothing to Disclose

John Nicholas Morelli MD, Abstract Co-Author: Nothing to Disclose

Val Murray Runge MD, Abstract Co-Author: Research Grant, Bayer AG Research Grant, Bracco Group

James Earl Dix MD, Abstract Co-Author: Nothing to Disclose

Stefan Oswald Schoenberg MD, PhD, Abstract Co-Author: Nothing to Disclose

Ulrike I. Attenberger MD, Abstract Co-Author: Research Consultant, Bayer AG

The aim of this study is to compare the detectability of brain metastases at 3T utilizing a 32-channel head coil with two different 3D contrast-enhanced sequences, a T1-weighted fast spin echo based (SPACE) and a conventional magnetization prepared rapid gradient echo (MP-RAGE) sequence.

17 patients with 161 brain metastases were evaluated prospectively using both SPACE (TR/TE 700/10 ms) and MPRAGE (TR/TE 1800/2.18 ms) sequences on a 3T MR system utilizing a 32-channel head coil. 5 healthy volunteers were similarly evaluated for determination of signal-to-noise (SNR) and contrast-to-noise (CNR) values. Parameters were adjusted to equalize acquisition times between the sequences (3:30 min:s). The order in which sequences were performed was randomized. Two blinded neuroradiologists evaluated the number of detectable metastatic lesions with each sequence. Gold standard was the evaluation by an experienced neuroradiologist with access to all clinical information and all scans (pre- and post-contrast) including sagittal and coronal thin section reformats.

In the volunteer assessment, gray matter SNR was statistically significantly greater with the SPACE sequence (7.0±1.0) relative to the MPRAGE (5.2±1.0; p<0.02) sequence. White matter SNR was not statistically significantly different (SPACE: 9.7±2.6, MPRAGE: 8.9±1.4, p=0.58), and CNR was greater with the MPRAGE sequence (MPRAGE: 5.4±2.2, SPACE: 2.8±1.7, p<0.04). Overall, lesion detectability was markedly improved with the SPACE sequence (99.1% reader 1, 96.3% reader 2) compared to the MP-RAGE sequence (73.6% reader 1, 68.5% reader 2; p<0.01).

A 3D T1 fast spin echo sequence (SPACE) sequence improves detection of metastatic lesions relative to 3D T1 gradient echo based scan (MPRAGE) imaging when implemented with a 32-channel head coil at identical scan acquisition times.

3D T1-weighted SPACE is recommended for post-contrast evaluation of brain metastases at 3 T.

Reichert, M, Morelli, J, Runge, V, Dix, J, Schoenberg, S, Attenberger, U, Contrast-enhanced 3D SPACE vs MP-RAGE for the Detection of Brain Metastases: Considerations with a 32-Channel Head Coil.  Radiological Society of North America 2012 Scientific Assembly and Annual Meeting, November 25 - November 30, 2012 ,Chicago IL. http://archive.rsna.org/2012/12030005.html