Improving the detectability of highly coherent targets in short-lag spatial coherence images with multi-line transmission

We hypothesize that the combination of ultrasound Short-Lag Spatial Coherence (SLSC) imaging and Multi-Line Transmission (MLT) can provide enhanced visibility of highly-coherent targets within soft tissues, improving the frame-rate at the same time. Images of a biopsy needle inserted within a lab-made agar/gelatin phantom and an ex vivo bovine meat sample were acquired after implementing single-line transmission (SLT) and MLT with an increasing number of simultaneously transmitted beams. The received signals were then beamformed with standard Delay and Sum (DAS) and SLSC algorithms. Results show that MLT SLSC images have darker background than SLT SLSC and DAS B-mode images, which is due to the rapid signal decorrelation at short lags caused by inter-beam interferences. This effect in turn provides increased needle contrast with MLT SLSC imaging, particularly as the number of multiple beams increase, which is promising for a more accurate biopsy needle detection.