## 5 Conclusions  
We demonstrated here that a clinical ultrasound linear array designed for 2-D imaging can be used to obtain high-resolution and -contrast volumetric US images with a 3-D synthetic aperture scanning method. We developed and experimentally implemented an advanced scanning scheme combining rotation and translation motions of the array. The angular sampling period was adjusted and tapered to optimize the scan duration without compromising the image quality. An acquisition duration of 10s was achieved for a volume of 9 cm\({}^{3}\). The image contrast was further enhanced by the addition of electronically steered exciting beams. The method is expected to benefit applications that require high image quality but a relatively low volumetric scanning rate such as longitudinal monitoring of pathological tissues. **Supplementary Materials:** The following are available online at [[https://www.mdpi.com/2076-3417/11/2/493/s1](https://www.mdpi.com/2076-3417/11/2/493/s1)]([https://www.mdpi.com/2076-3417/11/2/493/s1](https://www.mdpi.com/2076-3417/11/2/493/s1)). Video S1: Video of the experimental setup showing the motion of the stages for an acquisition performed at \(\Delta\alpha_{2}\approx 4^{\circ}\) with L = 30 mm. Video S2: The 3-D volume images of the net presented in Figure 10 compared for the scan performed using the rotate-translate geometry (left) and the scan performed with translation only (right). Rotating maximum amplitude projection images around an arbitrarily selected z-axis are displayed with a 10\({}^{\circ}\) angle between the projections. The gray scale display is between \(-\)30 and 0 dB for both images. The image display was obtained with the 3-D project option of the software ImageJ [46]. Figure S1: US images of Ph1 performed with different translation ranges L. (a) Optical picture showing the spatial distribution of microspheres. (b-d) Maximum amplitude projection (MAP) images along the y-axis for L = 30, 20, and 10 mm, respectively. This figure displays the full-size MAP images of Figure 4c,d. **Author Contributions:** Conceptualization, J.G. ; methodology and investigation, T.L., I.Q., and J.G. ; software, T.L., I.Q., and J.G. ; validation, T.L., I.Q., S.L.B., and J.G. ; formal analysis, I.Q. and J.G. ; writing--original draft preparation, T.L., I.Q., and J.G. ; writing--review and editing, S.L.B. ; supervision, S.L.B. ; project administration, J.G. ; funding acquisition, J.G. All authors have read and agreed to the published version of the manuscript. **Funding:** This research was funded by the Mission for Transversal and Interdisciplinary Initiatives of the Centre National de la Recherche Scientifique (MITI CNRS, Defi Imag'IN 2017-2018), Groupement des Entreprises Francaises dans la L'Utte contre le Cancer (Gefluc) Paris- Ile de France (2017), and Sorbonne Universite (Emergence 2019-2020). This work was performed by a laboratory member of France Life Imaging network (grant ANR-11-INBS-0006). **Institutional Review Board Statement:** Not applicable. **Informed Consent Statement:** Not applicable. **Data Availability Statement:** The data presented in this study are available on request from the corresponding author. **Acknowledgments:** [PERSON] thanks the Universite de Bretagne Occidentale for their support to the 12-month visiting stay (Conges pour Recherches ou Conversions Thematiques) at the Laboratoire d'Imagerie Biomedicale from September 2019. The authors thank the Life Imaging Facility of Paris Descartes University (Platerforme Imageries du Vivant--PIV) and the platform PLEMO 3D of Sorbonne Universite for their technical support and fruitful discussions. The authors thank [PERSON] (Laboratoire d'Imagerie Biomedicale, LIB) for the mechanical design of some scanner elements, and [PERSON] (Institut des Systemes Intelligents et de Robotique, ISIR) for machining the elements. The authors thank [PERSON] for her work at the early stage of the system development. **Conflicts of Interest:** The authors declare no conflict of interest.