  Progress in electromagnetic induction imaging with atomic magnetometers has
brought its domain to the edge of the regime useful for biomedical imaging.
However, a demonstration of imaging below the required 1 Sm$^{-1}$ level is
still missing. In this Letter, we use an $^{87}$Rb radio-frequency atomic
magnetometer operating near room temperature in an unshielded environment to
image calibrated solutions mimicking the electric conductivity of live tissues.
By combining the recently introduced near-resonant imaging technique with a
dual radio-frequency coil excitation scheme, we image 5 mL of solutions down to
0.9 Sm$^{-1}$. We measure a signal-to-noise ratio of 2.7 at 2 MHz for 0.9
Sm$^{-1}$, increased up to 7.2 with offline averaging. Our work is an
improvement of 50 times on previous imaging results, and demonstrates the
sensitivity and stability in unshielded environments required for imaging
biological tissues, in particular for the human heart.
