Investigation of a Technique for Eliminating of Chemical Shift Artifacts with T1-Weighted FLAIR Images at 3.0T, in Thoracic Spine Imaging Examination
E Lavdas1, P Mavroidis2*, K Vassiou3, V Roka4, I Fezoulidis5, M Vlychou6, (1) Techological Education Institute of Athens, Athens, Greece,(2) University of Texas Health Science Center, UTHSCSA, San Antonio, TX, USA and Karolinska Institutet and Stockholm University, Sweden (3) University of Thessaly, Larissa, Greece,(4) Health Center of Farkadona, Trikala, Greece,(5) University Hospital of Larissa, Larissa, Greece,(6) University Hospital of Larissa, Larissa, GreecePO-BPC-Exhibit Hall-8 Saturday Room: Exhibit Hall
Purpose: The goal of this study is to assess the effect of chemical shift artifacts and fat suppression between contrast-enhanced T1-weighted fast spin-echo (FSE) sequence with fat suppression and contrast-enhanced T1-weighted fluid attenuated inversion recovery (FLAIR) sequence with fat suppression in magnetic resonance imaging (MRI) of the thoracic spine at 3.0T.
Methods: Forty patients underwent thoracic spine imaging with clinical indication of suspected intraspinal metastatic disease. T1-weighted FSE (TR/TE/ETL/NSA: 680/17 ms/2/2, matrix size=384x224, scan time=2.36 min) and fast T1-weighted FLAIR (TR/TI/TE/ETL/NSA: 3200/1150/29 ms/7/2, matrix size=448x224, scan time=3.13 min) sequences were compared in the sagittal plane, during the same imaging session on 3.0T MR system using by synergy body phase-array surface coil. Qualitative analysis between T1-weighted FLAIR sequence and T1-weighted FSE for the extent of chemical shit artifact was performed using a scale of 1-5 (1=no artifacts; 2=minimal artifacts; 3=minor artifacts; 4=major artifacts; 5=image not diagnostic due to artifacts).
Results: With respect to the results of the qualitative analysis, T1-weighted FSE sequence showed image quality deterioration of 3.0-3.2 (SD:1.7) averaged over the total patient population, while in T1-weighted FLAIR sequence, image quality deterioration was 1.7 (SD:1.2). More specifically, T1-weighted FLAIR sequence is scored to be significantly better than T1-weighted FSE sequence. Due to chemical shift artifacts in the T1-weighted FSE, 14 of the patients were found to be of non-diagnostic value. On the contrary, in 11 of those 14 patients, no chemical shift artifacts were observed in the T1-weighted FLAIR sequence. Regarding the efficiency of fat suppression, both sequences achieved successful fat suppression.
Conclusions: The present study provides evidence that post contrast T1-weighted FLAIR sequence with fat suppression may be considered superior to post contrast T1-weighted FSE sequence with fat suppression in thoracic spine at 3.0T because it can resolve the problem of chemical shift artifacts that are likely to appear.