Mostly no. Foreign doctors can't legally practice medicine on US patients. Those third-world doctors are mostly used for things like insurance case review. Some radiologists also perform interventional procedures, which requires being physically present (at least until teleoperated surgical robots become common).
We have multidisciplinary case conferences every day which can't be outsourced and perhaps most importantly you also want to know who your radiologist is.
Reporting of anything remotely complex (e.g. oncological studies, inflammatory bowel disease, interstitial lung disease) isn't black/white and is adjusted to local practice environments/treatments options with feedback from clinicians continuously adjusting how we report.
Every center I've worked at in US & Canada won't even accept an outside report from another North American academic institution for oncological studies and will request a formal second opinion even if the scan and report came from MGH/Mayo/Hopkins.
Some of this is medicolegal risk but it's apparently backed up by research/quality improvement studies although I'm not familiar with the literature.
The stuff that's outsourced to licensed physicians (within continental US or abroad) is the easy stuff like ER/acute care.