Split a 2d array into flat arrays and add a prefix to each associative key

I need to split single array in to multiple arrays.

For example:

Array
(
    [0] => Array
        (
            [pageviews] => 26
            [visits] => 20
        )

    [1] => Array
        (
            [pageviews] => 9
            [visits] => 4
        )

    [2] => Array
        (
            [pageviews] => 18
            [visits] => 9
        )
)

I need to split the array like below:

Array
(

            [ga:pageviews] => 26
            [ga:visits] => 20
)

Array
(
            [ga:pageviews] => 9
            [ga:visits] => 4
)

Array
(
            [ga:pageviews] => 18
            [ga:visits] => 9
)

Ok, so using foreach:

foreach ( $original as $item ) {
    var_dump( array(
        'ga:pageviews' => $item['pageviews'],
        'ga:visits' => $item['visits'],
    ) );
}