 title="" class="an ">&ensp;</span>calcium <span  title="" class="an ">&ensp;</span>imaging <span  title="" class="an ">&ensp;</span>has <span  title="" class="an ">&ensp;</span>been <span  title="" class="an ">&ensp;</span>used <span  title="" class="an ">&ensp;</span>to <span  title="" class="an ">&ensp;</span>study <span  title="" class="an ">&ensp;</span>the <span  title="" class="an ">&ensp;</span>effects <span  title="" class="an ">&ensp;</span>of <span  title="" class="an ">&ensp;</span>several <span