Depending on your own interest, both directions are good, one favoring hardware, the other favoring software, both need to chew a lot of hard books and papers. There are no shortcuts.
If you go to grad school later to find a job, or even not to go to grad school, there really isn't much difference. Imaging does image processing, electronics does signal processing. But the undergrad stuff is pretty basic, and you can totally teach yourself if you want to switch later.
Introduction
Biomedical engineering focuses on basic knowledge and skills in life sciences, electronics, computer technology and information science, including biomaterials, artificial organs, biomedical signal processing methods, medical imaging and image processing methods.
For example, the research and development of artificial organs such as artificial hearts and artificial joints, the manipulation and maintenance of medical equipment such as brain CT machines and nuclear magnetic **** vibration machines, and the image processing of ultrasound and nuclear magnetic **** vibration imaging.