Shopify GraphQL: How to know when there is not available product variant image

Question

I need to know with my GraphQL query request when one of the product variants doesn't have the relative image. I have tried to figure it out how to do that but when there is no variant image the image url fallback to the default product image. (Image associated with the product variant. This field falls back to the product image if no image is available.).

https://shopify.dev/api/storefront/2022-04/objects/ProductVariant#fields

  query ($productHandle: String!) {
    product(handle: $productHandle) {
      title
      vendor
      description
      handle
      availableForSale
      images(first: 50) {
        edges {
          node {
            id
            url(transform: { maxWidth: 1100 })
          }
        }
      }
      priceRange {
        maxVariantPrice {
          amount
        }
      }
      variants(first: 100) {
        edges {
          node {
            compareAtPriceV2 {
              amount
            }
            title
            id
            sku
            quantityAvailable
            image {
              id
              url  // this url fallback to the default url when there is no image
              ico: url(transform: { maxWidth: 100 })
              __typename
              altText
            }
          }
        }
      }
    }
  }