High resolution MR eye protocol optimization: Comparison between 3D-CISS, 3D-PSIF and 3D-VIBE sequences

Purpose: The purpose of this study was to compare selected MRI pulse sequences and to evaluate their utility for depicting specific anatomic regions in the eye. Methods: A High-Resolution (HR) 0.08 x 0.08 x 0.60 mm(3) MRI protocol was developed on a 1.5-T clinical system and applied in the left eye of an albino rabbit, utilizing a small field of view surface coil. The comprehensive MRI protocol consisted of two 3D (T2/T1) w sequences (3D-PSIF and 3D-CISS), and one 3D T1w sequence (3D-VIBE). The T1w 3D-VIBE sequence was acquired, before and after intravenous injection of 0.2 mmol/kgr gadolinium-DTPA. Signal-to-Noise Ratios (SNR) and Contrast-to-Noise Ratios (CNR) amongst specific eye anatomical areas were calculated for each sequence. The presence of artifacts was rated subjectively utilizing a 5 point scale. Results: 3D-PSIF and 3D-CISS provide better delineation and visualization of the eye as compared with 3D-VIBE sequences. 3D-CISS images present the highest SNR and revealed better discrimination of the ocular surrounding tissues; its basic drawback though is related to ghost artifacts appearing in the anterior chamber and resulting in the lowest image quality. In post-contrast imaging, the T1w 3D-VIBE sequence provided the best overall image quality. Moreover, 3D (T2/T1) w sequences can provide good anatomic depiction of the eye segments. Agreement between the two independent readers was good. Conclusions: Optimization of a comprehensive MR eye imaging protocol is achieved. A higher SNR, a better spatial resolution and a reduction of the total scan time were obtained, thus making clinical MRI systems more reliable in eye imaging. (C) 2015 Associazione Italiana di Fisica Medica. Published by Elsevier Ltd. All rights reserved.