Egolf David, Barber Quinn, Zemp Roger
Department of Electrical and Computer Engineering, University of Alberta, Edmonton, Alberta, Canada.
Photoacoustics. 2021 Mar 11;22:100258. doi: 10.1016/j.pacs.2021.100258. eCollection 2021 Jun.
Recently, -norm based reconstruction approaches have been used with linear array systems to improve photoacoustic resolution and demonstrate undersampled imaging when there is sufficient sparsity in some domain. However, such approaches have yet to beat the half-wavelength resolution limit. In this paper, the ability to beat the half-wavelength diffraction limit is demonstrated using a 5 MHz ring array photoacoustic tomography system and -norm based reconstruction approaches. We used the array system to image wire targets at depth in both intralipid scattering solution and water. The minimum observable separation was estimated as , improving on the half-wavelength resolution limit of . This improvement was demonstrated even when using a random projection transform to reduce data by , enabling substantially faster reconstruction times. This is the first photoacoustic tomography approach capable of beating the half-wavelength resolution limit with a single laser shot.
最近，基于 -范数的重建方法已与线性阵列系统一起使用，以提高光声分辨率，并在某些域中存在足够稀疏性时展示欠采样成像。然而，此类方法尚未突破半波长分辨率极限。在本文中，使用5兆赫环形阵列光声断层扫描系统和基于 -范数的重建方法展示了突破半波长衍射极限的能力。我们使用该阵列系统对脂质内散射溶液和水中深度处的金属丝目标进行成像。估计最小可观测间距为 ，优于 的半波长分辨率极限。即使使用随机投影变换将数据减少 ，也证明了这种改进，从而实现了显著更快的重建时间。这是第一种能够通过单次激光照射突破半波长分辨率极限的光声断层扫描方法。
