Advantages of a T1-Weighted Gradient-Recalled Echo (GRE) Sequence With a Radial 3D Sampling Approach Versus 2D Turbo Spin-Echo and Cartesian 3D GRE Sequences in Head and Neck MRI

Contrast-Enhanced T1-Weighted Head and Neck MRI: Prospective Intraindividual Image Quality Comparison of Spiral GRE, Cartesian GRE, and Cartesian TSE Sequences

“…The parameters for the Cartesian GRE and TSE sequences were selected based on longstanding institutional clinical protocols. The parameters for the spiral GRE sequence were selected based on the vendor's recommendation after in-house and external optimization [1,13].…”

“…The readers subjectively assessed image quality using 5-point Likert scales, based on earlier studies [1,3,13]. The following qualitative measures were recorded: overall image quality (scores provided for the whole head and neck; only the neck, from clavicle to mandible; and only head, from mandible to orbits; 1, nondiagnostic; 2, severely limited; 3, moderately limited; 4, minimally limited; 5: excellent image quality); conspicuity of the a priori specified lesion (scores provided for the whole head and neck, only the neck, and only the head; 1: virtually unable to visualize; 2: blurry but visualized; 3: acceptable visualization; 4: good visualization; 5: excellent visualization); quality of fat suppression (1: inhomogeneous with definite diagnostic interference; 2: inhomogeneous with probable diagnostic interference; 3: inhomogeneous but probably no diagnostic interference; 4: incomplete but without diagnostic interference; 5: complete and homogeneous); artifacts, including from motion, pulsation, dental material (e.g., filling or implant; not evaluated in patients without dental material), flow, and signal foldover (1: markedly prominent artifact with definite diagnostic interference; 2: prominent artifact with probable diagnostic interference; 3: prominent artifact but probably no diagnostic interference; 4: minimal artifact without diagnostic interference; 5: no artifact); delineation of muscular contours (1: insufficient delineation to evaluate; 2: prominently reduced discrimination; 3: moderately reduced discrimination; 4: minimally and only focally reduced discrimination; 5: ubiquitous excellent discrimination); delineation of vessel contours, based on large vessels such as the internal carotid arteries and jugular veins (1: insufficient delineation to evaluate; 2: prominently reduced discrimination; 3: moderately reduced discrimination; 4: minimally and only focally reduced discrimination; 5: ubiquitous excellent discrimination); and differentiation between mucosa and pharyngeal muscles at the level of the oropharynx (1: insufficient to evaluate; 2: prominently…”

“…2). In addition, consistent with the approach in an earlier study [1], a freehand ROI was placed on the dorsal neck muscles and the nuchal subcutaneous fat on an image slice in which the quality of fat suppression was subjectively deemed optimal for each sequence; for each of these two structures, the ROI was placed bilaterally. An image at the same slice position was selected for all three sequences, and the ROI copy-and-paste function was used to transfer the ROI across the images.…”

“…The head and neck contains a variety of interfaces between air and anatomic structures such as vessels, muscles, fat and bone. Also, artifacts may arise from physiologic processes such as fluid pulsation, respiration, or swallowing, or from foreign material and implants in the oral cavity [1,2]. T1-weighted (T1W) MRI sequences are essential components of head and neck MRI protocols.…”

“…These sequences offer high signal-to-noise ratio (SNR) at a short acquisition time but are susceptible to image distortion and artifacts that result from their Cartesian readout schemes [1,[3][4][5].…”