How to echo image Thumbnail size ?

Hi,

i use code show my imagae by category

<?php $url = categoryCustomFields_GetCategoryCustomField($get_id, 'dimg'); ?>
<?php $url = explode('@',$url[0]->field_value); ?>
<?php $url = $url[0]; ?>
<img src="<?php echo $url; ?>">

How to echo image as Thumbnail Sizes:

the_post_thumbnail();                  // without parameter -> Thumbnail

the_post_thumbnail('thumbnail');       // Thumbnail (default 150px x 150px max)
the_post_thumbnail('medium');          // Medium resolution (default 300px x 300px max)
the_post_thumbnail('large');           // Large resolution (default 640px x 640px max)
the_post_thumbnail('full');            // Original image resolution (unmodified)

the_post_thumbnail( array(100,100) );  // Other resolutions

Thanks

https://wordpress.org/plugins/categorycustomfields/