Insert image in caption

Question

I manage to use graphical images in both text and tables as if they were letters:

\documentclass{article}
\usepackage{graphicx}
\newcommand{\inspictext}{  \includegraphics[width=0.04\textwidth]{example-image-b}}
\begin{document}
Some text \inspictext
\begin{table}
  \newcommand{\inspic}{  \includegraphics[width=0.04\textwidth]{example-image-a}}
  \begin{tabular}{llc}
    A &\inspic \
    B &\inspic \
  \end{tabular}
  %  \caption{the symbol \inspictext is ..}

\end{table}
\end{document}

This is confirmed in the output:

I would like to use an image also in the table caption. Therefore, I uncomment the line

   %  \caption{the symbol \inspictext is ..}   

I get an error:

! Argument of \@caption has an extra }.
<inserted text> 
                \par 
l.14     \caption{the symbol \inspictext is ..}

How to fix?