Department of Biomedical Engineering, Duke University, Durham, NC, USA.
Department of Mechanical Engineering, University of Colorado Boulder, Boulder, CO, USA.
Methods Mol Biol. 2022;2393:683-699. doi: 10.1007/978-1-0716-1803-5_37.
Ultrasound image quality is intrinsically linked to the hardware used to collect image data. For deep abdominal imaging, diffraction-limited resolution prevents the detection of small targets such as cancerous lesions. Larger ultrasound arrays produce finer lateral image resolution and improved image quality. We introduced a method called "swept synthetic aperture" (SSA) imaging to synthetically create large effective arrays with reduced complexity of both transducer and scanner hardware. A commercial 2-D transducer array and ultrasound scanner were used to form a large effective aperture. Array position and orientation were carefully prescribed throughout a sweep of the transducer using mechanical fixtures to rigidly control the motion. Calibration of the mechanical fixture was measured using a point target phantom and applied in post-processing. Improvements in resolution and contrast as functions of aperture size were measured from point and lesion target phantoms, respectively. SSA imaging presents a technique to both evaluate the performance of large array designs in the presence of clutter-inducing body wall targets and achieve high-quality imaging from reduced-complexity ultrasound hardware.
超声图像质量与用于采集图像数据的硬件密切相关。对于深部腹部成像，衍射极限分辨率阻止了对小目标（如癌性病变）的检测。更大的超声阵列可产生更精细的横向图像分辨率和更高的图像质量。我们引入了一种称为“扫频合成孔径”（SSA）成像的方法，该方法可通过减少换能器和扫描仪硬件的复杂性来合成具有较大有效孔径的阵列。使用商业 2-D 换能器阵列和超声扫描仪来形成大的有效孔径。在使用机械夹具进行严格控制的情况下，在换能器的扫频过程中仔细规定了阵列的位置和方向。使用点目标幻影测量了机械夹具的校准，并在后期处理中进行了应用。从点和病变目标幻影中分别测量了分辨率和对比度作为孔径尺寸的函数的改善。SSA 成像提出了一种技术，用于评估在引起杂波的体壁目标存在下的大阵列设计的性能，并从简化的超声硬件实现高质量成像。
