TABLE 1.

Sequence Parameters of 1.5 T and 0.55 T Magnetic Resonance Imaging

Parameter	1.5 T			0.55 T
Sequence	PDwcoronal	PDwsagittal	T2axial	PDwcoronal	PDwsagittal	T2axial
Fat suppression	No	No	No	No	No	No
Repetition time, ms	2000	2170	4000	1800	1800	4080
Echo time, ms	11	11	67	18	18	100
Voxel size reconstruction, mm3	0.3 × 0.3 × 2.0	0.2 × 0.2 × 2.0	0.3 × 0.3 × 3.0	0.3 × 0.3 × 2.0	0.3 × 0.3 × 2.0	0.4 × 0.4 × 4.0
Voxel size acquisition, mm3	0.62 × 0.59 × 2.0	0.49 × 0.42.2.0	0.76 × 0.55 × 3.0	0.86 × 0.69 × 2.0	0.85 × 0.67 × 2.0	0.9 × 0.7 × 4.0
Interpolation	Yes	Yes	Yes	Yes	Yes	Yes
Field of view, mm	150 × 150	120 × 120	132 × 170	185 × 220	128 × 149	185 × 220
Acquisition time, min:s	3:04	3:49	1:02	4:03	4:39	5.03
Standard no. slices	13	16	19	13	16	19
Averages	3	2	2	2	2	2
Concatenations	1	1	1	2	2	2
Flip angle, degrees	150	150	150	130	130	130
Receiver bandwidth, Hz/pixel	160	160	191	80	80	80
Acceleration technique	GRAPPA	GRAPPA	GRAPPA	No	No	No
Acceleration factor	2	2	2	NA	NA	NA
Acceleration software	NA	NA	NA	DRS	DRS	DRS

On both scanners, we applied PDw sequences in coronal and sagittal sequences and T2-weighted sequences in axial orientation. The differences between acquired and reconstructed voxel are depending on the zero-filling interpolation technique used on both scanners. All 0.55 T examinations were performed using a software acceleration technique based on artificial intelligence, which improves the image sharpness and reduces the image noise (Deep Resolve Sharp, Siemens Healthineers, Erlangen, Germany).

PDw, proton density-weighted; NA, not available; DRS, Deep Resolve Sharp.