Evaluation of the orbit using contrast-enhanced radial 3D fat-suppressedT₁weighted gradient echo (Radial-VIBE) sequence

Abstract

Objective: Contrast-enhanced fat-suppressed T 1 weighted (T1W) two-dimensional (2D) turbo spin echo (TSE) and magnetization-prepared gradient echo (MPRAGE) sequences with water excitation are routinely obtained to evaluate orbit pathology. However, these sequences can be marred by artefacts. The radial-volume-interpolated breath-hold examination (VIBE) sequence is a motion-robust fatsuppressed T1W sequence which has demonstrated value in paediatric and body imaging. The purpose of our study was to evaluate its role in assessing the orbit and to compare it with routinely acquired sequences. Methods: A Health Insurance Portability and Accountability Act-compliant and institutional review board-approved retrospective study was performed in 46 patients (age range: 1-81 years) who underwent orbit studies on a 1.5-T MRI system using contrast-enhanced Radial-VIBE, MPRAGE and 2D TSE sequences. Two radiologists blinded to the sequence analysed evaluated multiple parameters of image quality including motion artefact, degree of fat suppression, clarity of choroidal enhancement, intraorbital vessels, extraocular muscles, optic nerves, brain parenchyma and evaluation of pathology. Each parameter was assessed on a 5-point scale, with a higher score indicating the more optimal examination. Mix model analysis of variance and interobserver variability were assessed.Results: Radial-VIBE demonstrated superior quality (p , 0.001) for all orbit parameters when compared with MPRAGE and 2D TSE. Interobserver agreement demonstrated average fair-to-good agreement for degree of motion artefact (0.745), fat suppression (0.678), clarity of choroidal enhancement (0.688), vessels (0.655), extraocular muscles (0.675), optic nerves (0.518), brain parenchyma (0.710) and evaluation of pathology (0.590). Conclusion: Radial-VIBE sequence demonstrates superior image quality when evaluating the orbits as compared with conventional MPRAGE and 2D TSE sequences. Advances in knowledge: Radial-VIBE employs unique non-Cartesian k-space sampling in a radial or spokewheel fashion which provides superior image quality improving diagnostic capability in the evaluation of the orbits. INTRODUCTIONTraditionally, contrast-enhanced T 1 weighted (T1W) fatsuppressed two-dimensional (2D) turbo spin echo (TSE) sequence and three-dimensional (3D) magnetizationprepared gradient echo (MPRAGE) sequence with water excitation (WE) are used to evaluate the orbits. However, they are susceptible to eyelid or globe motion-related artefacts and inhomogeneous fat saturation.

Speed in Clinical Magnetic Resonance

“…Superior image quality has been demonstrated, regardless of parameter used for assessment, including overall motion artifact, depiction of intraorbital vessels, extraocular muscles, and optic nerves, and evaluation of pathology. 24 Imaging of the soft tissues of the neck is commonly degraded due to swallowing, breathing, and inadvertent patient motion, with contrast-enhanced radial VIBE scoring significantly better than conventional VIBE in all evaluated image quality measures in this application as well. 25 For the head and neck, radial VIBE represents a motion-robust improvement over a conventional VIBE acquisition.…”

High Acceleration Three-Dimensional T1-Weighted Dual Echo Dixon Hepatobiliary Phase Imaging Using Compressed Sensing-Sensitivity Encoding: Comparison of Image Quality and Solid Lesion Detectability with the Standard T1-Weighted Sequence

“…With recent technological developments in MRI including faster scanning acquisitions and new MRI contrast agents (1234), liver MRI is now widely utilized as a primary diagnostic test for the evaluation of malignant liver tumors (5678). However, liver MRI has its inherent problems of low speed, when compared to multidetector CT, resulting in image blurring with decreased spatiotemporal resolution and motion-related artifacts (91011).…”

An accurate interactive segmentation and volume calculation of orbital soft tissue for orbital reconstruction after enucleation

“…However, it is labor-intensive and time-consuming. Several studies have focused on segmenting the interested tissues of orbit using semiautomatic or even automatic approaches based on computer image processing techniques [14][15][16][17]. However, due to the complicated structure and the small volume of orbit, as well as the unclear boundary of soft tissues in CT images, effective and precise segmentation of intraorbital fat and extraocular muscles remains a tough task [14,18].…”