3D radial acquisition methods are capable of acquiring images in which artifacts from undersampling and data inconsistencies manifest as relatively benign, incoherent streaking artifacts in high contrast imaging scenes¹. However, in cases in which quantification is desired or when the tissue of interest has naturally low signal, such as the lungs, streaking artifacts can lead to decreased apparent SNR and errors in derived parametric maps. As Figure 1 shows, a source of streaking artifacts can be anatomy outside of the imaging volume of interest, in this case the subject's arms. Artifacts are accentuated when this anatomy undergoes motion. The purpose of this pilot study is to investigate the potential for outer volume suppression to improve image quality for body imaging with 3D radial sampling.Four healthy volunteers were imaged on a 3.0T scanner (Discovery MR750, GE Healthcare, Waukesha, WI) with a 3D ultrashort echo time (UTE) sequence² (TR/TE=2.9/0.1ms, FA=4^o, res=1.25mm isotropic, #projections=40,000, axial slab excitation). For out-of-volume saturation, two successive quadratic phase 90^o saturation pulses (TR=12.6ms; BW=12.5kHz; PW=10ms) were played to the right and left of the field of view of interest (the lungs). The pulses were played every 80 TRs (257 ms), the minimum time allowable while observing SAR limits. A 32-channel, full torso coil was used for the free-breathing acquisition with respiratory gating using respiratory bellows and a gating efficiency of 50%. Each subject was scanned with and without out-of-volume saturation bands. Scan times were 3:54 (min:sec) without saturation and 4:07 with saturation. These two scans were repeated with the volunteer instructed to move their upper arms throughout the duration of the scan to simulate motion common with alert pediatric subjects. This resulted in 4 scans for each volunteer. An experienced cardiothoracic radiologist ranked the images by overall image quality for each subject from best to worst (1=best, 4=worst).Figure 2 shows the effect of out-of-volume suppression on the visibility of streaking artifacts. Figure 3 shows a table of the rankings assigned to the images for each subject by the radiologist. Figure 4 highlights a region in the lung where the effect of motion and the spatial saturation pulses was most apparent. In the coronal views of another subject (Figure 5), use of out-of-volume saturation resulted in more feature detail for the cases with movement. These cases corroborated the results of the image rankings.Saturation pulses were effective at reducing streaking artifacts, especially near the anterior surface of the arm. Radiologist scoring suggested that saturation did not have a substantial effect in the images without arm motion, but produced better images when motion was present. The scan time penalty of implementing these pulses was minimal, as they only increased scan time by 13 seconds (5%) in this case. While saturation proved effective at nulling the tissue and muscle, the short T1 of fat allowed for regrowth between successive saturation pulses and had considerable signal (Figure 2). This suggests either the need for fat saturation or more frequent saturation, both of which are limited by the increase in SAR. The design of SAR minimized suppression could substantially increase the efficacy of saturation, which is roughly ~60% for the 257ms spacing between pulses.We have demonstrated the feasibility of using out-of-volume saturation pulses with a 3D radial UTE acquisition to reduce streaking artifacts and improve image detail in low contrast and low SNR areas, particularly when patient motion is present. These saturation pulses are worth implementing in 3D radial acquisitions if the extra SAR can be tolerated, given that they only increased scan time by 13 seconds (5%) in this case and appeared to improve image quality and detail.