The cardiac CT and Nuke "certifications" are not certifications in the sense of an ABMS certification. They are not "specialties." The nuclear cardiology board, in fact, can be taken by a nuclear medicine resident while still in training - and it gives no special recognition above what the sloppy ABNM certification does for the interpretation of nuclear cardiac studies. The same is the case for cardiac CT. A hospital where cardiologists rule cardiac CT is not going to hire a nuclear medicine physician (unless, that is, they have an insane volume and would hire you as an em,employee for less than what a nurse practitioner makes and no partnership - LOL. Radiologists doing cardiac CT need someone who can cover any radiology subspecialty.
Finally, ACR MRI cardiac is again, not even required. Just training and experience with cardiac MRI with ABR certification. And so on and so forth with vascular.
Nuclear medicine physicians without a background in diagnostic radiology keep fighting the cold hard reality with meaningless papers. It's not about what paper you have - it's about the training, experience and expertise. A nuclear radiologist can do everything a nuclear medicine physician can do much better period.
Just do a diagnostic radiology residency like hundreds of excellent candidates do every year.
The situation of pure nuclear medicine without rqadiology has been a known facts for over 25-30 years now. This is now on the intellectual level of history denialism.
P.S. If you'd like to keep throwing good money after bad don't forget to get your "DEXA interpretation credentials!"