## 3 Results
(**a**) SLT (single line transmit i.e., 1 MLT) scheme with non-coded excitation as the reference image, (**b**) 2 MLT scheme using non-coded excitation with crosstalk artifacts, (**c**) 2 MLT scheme using Golay coded excitation without crosstalk artifacts, and (**d**) 2 MLT scheme using chirp coded excitation with slight crosstalk artifacts. A dynamic range of 55 dB was used. Figure 7: Point-spread-function (PSF) of 4 MLT and 6 MLT schemes using (**a,b**) non-coded excitation; (**c,d**) Golay coded excitations; and (**e,f**) chirp coded excitations. No apodization was applied on transmit and receive. Crosstalk artifacts appeared and became more severe as increasing the MLT beams. \begin{table}
\begin{tabular}{c c c c c c c} \hline
**Imaging Schemes** & \begin{tabular}{c} **Non-** \\ **Coded** \\ **4-MLT** \\ \end{tabular} & \begin{tabular}{c} **Non-** \\ **Coded** \\ **6-MLT** \\ \end{tabular} & \begin{tabular}{c} **Golay-** \\ **Coded** \\ **4-MLT** \\ \end{tabular} & \
\begin{tabular}{c} **Golay-** \\ **Coded** \\ **4-MLT** \\ \end{tabular} &
\begin{tabular}{c} **Coded** \\ **4-MLT** \\ \end{tabular} \\ \hline CNR\({}_{\text{top}}\) & 1.28 & 1.31 & 1.18 & 1.15 & 1.24 & 1.28 \\ CNR\({}_{\text{middle}}\) & 1.53 & 1.40 & 1.49 & 1.50 & 1.56 & 1.60 \\ CNR\({}_{\text{bottom}}\) & 1.82 & 1.01 & 2.05 & 1.31 & 2.25 & 1.51 \\ CR\({}_{\text{top}}\) (dB) & 9.54 & 10.75 & 8.11 & 9.40 & 9.93 & 10.50 \\ CR\({}_{\text{middle}}\) (dB) & 17.26 & 14.49 & 20.40 & 17.76 & 19.41 & 20.01 \\ CR\({}_{\text{bottom}}\) (dB) & 11.55 & 6.50 & 14.52 & 8.12 & 16.03 & 9.99 \\ SNR (dB) & 12.71 & 10.66 & 18.15 & 16.17 & 15.94 & 13.31 \\ Frame rate (Hz) & 105.56 & 158.33 & 52.78 & 79.17 & 105.56 & 158.33 \\ \hline \end{tabular}
\end{table} 
Table 1: Quantifications of different Tukey-Tukey apodized multi-line transmit (MLT) schemes. Figure 8: Point-spread-function (PSF) of 4 MLT and 6 MLT schemes using (**a,b**) non-coded excitation; (**c,d**) Golay coded excitations; and (**e,f**) chirp coded excitations. Tukey (\(\alpha\) = 0.5)-Tukey (\(\alpha\) = 0.5) apodization scheme was applied on transmit and receive that the crosstalk artifacts were largely suppressed. Finally, in-vivo images of a healthy volunteer were acquired with the three TT-apodized 4 MLT schemes (Figure 13). From the cineloops (Supplementary Materials: Video S1: Figure13_a; Video S2: Figure13_b; Video S3: Figure13_c), the coded images seemed to have better contrast between the myocardial and blood pool and no obvious crosstalk was observed. Figure 10: Beam widths in radial (upper panel) and lateral (lower panel) directions estimated from the point-spread-function (PSF). The red line indicates the value of a non-coded SLT scheme using TT apodization. TT: Tukey (\(\alpha\) = 0.5)-Tukey (\(\alpha\) = 0.5) apodization scheme. Figure 9: Crosstalk evaluation of different MLT schemes. TT: Tukey (\(\alpha\) = 0.5)-Tukey (\(\alpha\) = 0.5) apodization scheme. Figure 11: Tissue phantom images of the 4 MLT and 6 MLT schemes using (**a**,**b**) non-coded; (**c**,**d**) Golay-coded excitation; or (**e**,**f**) chirp-coded excitation. TT apodization was applied on both transmit and receive. TT: Tukey (\(\alpha\) = 0.5)-Tukey (\(\alpha\) = 0.5) apodization scheme. A dynamic range of 55 dB was used. The arrows in panel (**a**) and (**b**) point the areas in which the non-coded MLT schemes started to lose signal-to-noise ratio (SNR). Figure 12: Zoomed in tissue phantom images of the 4 MLT and 6 MLT schemes using (**a,d**) non-coded; (**b,e**) Golay-coded excitation; or (**c,f**) chirp-coded excitation. TT apodization was applied on both transmit and receive. TT: Tukey (\(\alpha\) = 0.5)-Tukey (\(\alpha\) = 0.5) apodization scheme. A dynamic range of 55 dB was used. The arrows in panel (**a**) and (**d**) point the areas in which the non-coded MLT schemes started to lose SNR. Figure 13: In-vivo examples of 4 MLT schemes using (**a**) non-coded excitation, (**b**) Golay coded excitation, and (**c**) chirp coded excitation with TT apodization.