Replace array inside array with PHP

The goal

Replace this:

(
    [0] => 'Header'
    [1] => 'Body'
)

For this:

['Header'] => Array
    (
        [0] => Hello!
    )

['Body'] => Array
    (
        [0] => This is the body
    )

The problem

I'm missing the logic and I think this is happening because I doesn't know the syntax.

The scenario

Follow the original array (preview):

Array
(
    [Title] => 'Hello!'
    [Layout] => 'Shared/_Master'
    [Section] => Array
        (
            [0] => 'Header'
            [1] => 'Body'
        )    
)

Code:

<?php 

$array = [
    'Title' => 'Hello', 
    'Layout' => 'Shared/_Master',
    'Section' => ['Header', 'Body']
    ];

$mineredSection = ['Header' => ['Hello!'], 'Body' => ['This is the body.']];

What did I already tried

I already tried this:

foreach ($array['Section'] as $index => $section) {
    $t[$section] = [array_values(array_filter($mineredSection))[$index]];
}

$a = array_replace($array['Section'], $t);

print_r($a);

The result is:

Array
(
    [0] => 'Header'
    [1] => 'Body'
    ['Header'] => Array
        (
            [0] => Hello!
        )

    ['Body'] => Array
        (
            [0] => This is the body
        )

)

Can someone give me an idea?