How update programmatically node entity with empty field_image? i need to make an import from one mysql table in my base.

I create node with : 

$value= array(
                'type' =&gt; strtolower($typeProduit),
                'field_1'=&gt;"test",
                'title'=&gt;"test",
                'body' =&gt; array(
                    'value' =&gt; "test",
                    'format' =&gt; 'full_html',
                ),
                'field_2'=&gt;"",
                'field_3'=&gt;"",
                'field_4'=&gt;"",                
            );

 $nodeEntity=\Drupal::entityTypeManager()
        -&gt;getStorage('node')
        -&gt;create($value);

    $nodeEntity-&gt;save();


All node are create and if i have an image, i add it to my $value before save() : 

$value['field_image_video']=array(
                    'target_id' =&gt; $fileImageVideo-&gt;id(),
                    'alt' =&gt; $catalogue-&gt;titreVideo,
                    'title' =&gt; $catalogue-&gt;titreVideo,
                );


if i have no image, i do nothing for this field.

I need to update some node programmatically after this first step.

And when i just try to change the title like this :

     $nodeEntityUpdate = \Drupal::entityTypeManager()
                    -&gt;getStorage('node')                
                    -&gt;load(273);

     $nodeEntityUpdate-&gt;title="blabla";
     $nodeEntityUpdate-&gt;save();


if node don"t have image field set, i got this error :


  PHP Fatal error:  Call to a member function getFileUri()


If node has image, update work.

How can i set my image_field to null ?

i try to set my image field like that on creation : 

$value['field_image_video']=array();


But that didn't work.

this image field is set to unlimited values
i got it in the update :

i set my image_field in the update:

  $nodeEntityUpdate = \Drupal::entityTypeManager()
                    -&gt;getStorage('node')                
                    -&gt;load(273);

     $nodeEntityUpdate-&gt;title="blabla";
     $nodeEntityUpdate-&gt;field_image_video =array();
     $nodeEntityUpdate-&gt;save();


I try to set this field in the create, but that change nothing.

As i can see, we need to set image field in the update if she is empty at the creation.