PHP header already changed but i get garbage as jpg

I have 2 files:

include_display.php << contains the connection to the database, get the blobData and the blobType. Uses variable blobType to change the header.

$dbQuery = "SELECT blobType, blobData ";
$dbQuery .= "FROM testBlobs ";
$dbQuery .= “WHERE blobId = $blobId”;

$result = mysql_query($dbQuery) or die(“Couldn’t get file list”);

$data = @mysql_fetch_array($result);
if(!empty($data[“blobData”]))
{

// Output the MIME header
header(“Content-Type: $blobType”);
}

else
{
echo “Record doesn’t exist.”;
}

and then I have display.php << its supposed to display the image
but instead of the image, i get bunches of letters, numbers, and symbols. of course, this means the header hasnt been changed.

echo $data[“blobData”];

what am i doing wrong?

Sooo, then a database would not be useful in this case, right?