We can definitely get local imaging with X-Ray and ultrasound - we use bedside machines that can be used and interpreted quickly.
X-Ray has limitations though - most of our emergencies aren't as easy to diagnose as bullets or pneumonia. CT, CTA, and to a lesser extent MRI are really critical in the emergency department, and you definitely need four years of training to interpret them, and a computer to let you view the scan layer-by-layer. For many smaller hospitals they may not have radiology on-site and instead use a remote radiology service that handles multiple hospitals. It's hard to get doctors who want to live near or commute to more rural hospitals, so easier for a radiologist to remotely support several.
X-Ray has limitations though - most of our emergencies aren't as easy to diagnose as bullets or pneumonia. CT, CTA, and to a lesser extent MRI are really critical in the emergency department, and you definitely need four years of training to interpret them, and a computer to let you view the scan layer-by-layer. For many smaller hospitals they may not have radiology on-site and instead use a remote radiology service that handles multiple hospitals. It's hard to get doctors who want to live near or commute to more rural hospitals, so easier for a radiologist to remotely support several.