Transition into driven equilibrium of the balanced steady-state free precession as an ultrafast multisection T2-weighted imaging of the brain

Abstract

Background and purpose: Current T2-weighted imaging takes >3 minutes to perform, for which the ultrafast transition into driven equilibrium (TIDE) technique may be potentially helpful. This study qualitatively and quantitatively evaluates the imaging of transition into driven equilibrium of the balanced steady-state free precession (TIDE) compared with TSE and turbo gradient spin-echo on T2-weighted MR images.

Materials and methods: Thirty healthy volunteers were examined with T2-weighted images by using TIDE, TSE, and turbo gradient spin-echo sequences. Imaging was evaluated qualitatively by 2 independent observers on the basis of a 4-point rating scale regarding contrast characteristics and artifacts behavior. Image SNR and contrast-to-noise ratio were quantitatively assessed.

Results: TIDE provided T2-weighted contrast similar to that in TSE and turbo gradient spin-echo with only one-eighth of the scan time. TIDE showed gray-white matter differentiation and iron-load sensitivity inferior that of TSE and turbo gradient spin-echo, but with improved motion artifacts reduction on qualitative scores. Nonmotion ghosting artifacts were uniquely found in TIDE images. The overall SNRs of TSE were 1.9-2.0 times those of turbo gradient spin-echo and 1.7-2.2 times of those of TIDE for brain tissue (P < .0001). TIDE had a higher contrast-to-noise ratio than TSE (P = .169) and turbo gradient spin-echo (P < .0001) regarding non-iron-containing gray matter versus white matter. TIDE had a lower contrast-to-noise ratio than turbo gradient spin-echo and TSE (P < .0001) between iron-containing gray matter and white matter.

Conclusions: TIDE provides T2-weighted images with reduced scan times and reduced motion artifacts compared with TSE and turbo gradient spin-echo with the trade-off of reduced SNR and poorer gray-white matter differentiation.

Fig 1.

TSE (A, D), TGSE (B, E), and TIDE (C, F) images of a 38-year-old healthy man. The results show similar T2 contrast of the neocortex (A–C). At the basal ganglia, iron-containing gray matter (eg, globus pallidus) has a much higher intensity in the TIDE image compared with the other 2 results (D–F). Ghosting artifacts appear in the TIDE image (arrow in C).

Fig 2.

TSE (A, D), TGSE (B, E), and TIDE (C, F) images of a 25-year-old healthy man. Motion artifacts can be found in the TSE and TGSE images, due to eyeball movement (open arrows in A and B) and CSF flow (open arrows in D and E). Magnetic susceptibility artifacts appear in the TIDE image (solid arrows in C). Occasional basilar artery flow artifacts are seen in the TIDE image (thin arrow in C).

Fig 3.

TSE (A, D), TGSE (B, E), and TIDE (C, F) images of a 57-year-old woman with stroke history. A hyperintense lesion appears near the left lateral ventricle (white arrows in A–C). The degrees of hyperintensity are different in these images. Similar contrast of a late subacute hematoma involving the right corpus striatum is found in all sequences (black arrows in D–F).

Fig 4.

A 9-day-old neonate with seizures, presenting with involuntary movements, was imagined with TSE (A) and TIDE (B) sequences. A motion artifacts-free T2-weighted image can be acquired with TIDE, depicting a clear brain anatomy.

Fig 5.

TSE (A), TGSE (B), and TIDE (C) images of a 26-year-old female volunteer. CSF motion artifacts (double arrows) are seen on TSE and TGSE images, while eyeball motion artifacts (open arrows) are seen on the TGSE image. The trigeminal nerves (arrows) are clearly demonstrated on TIDE, which is free of the aforementioned motion artifacts but are somewhat blurred on TSE and TGSE.

Fig 6.

TSE (A, D), TGSE (B, E), and TIDE (C, F) images of a 40-year-old male volunteer at the levels of the centrum semiovale (star, A–C) and thalamus (triangle, D–F). The gray-white matter junctions (double arrows) are clearly demonstrated on TSE but are blurred on TGSE and TIDE.