What are the two noninvasive diagnostic procedures commonly used in the clinical setting?

X-Rays, CTs, MRI, FMRI, ultrasound scans, EEG, and EKG would be considered non-invasive imaging and studies as they don't require surgery, or any invasive procedures.

Some procedures such as PET Scans or Angiography would be minimally invasive as contrasts and dyes are injected. A colonoscopy might also fall into that category.