Figure 2

RISHA imaging of blood phantoms. (a–c) Imaging of polyethylene tubes (ϕ3 mm) filled with vegetable oil, an aqueous solution of anticoagulant EDTA, mouse blood containing the same EDTA concentration as the aqueous solution, or 0.9% NaCl. (a) Photograph of the tubes. The blue box indicates the scanned region. (b) Co-registered RISHA (red) and US (green) images. The dashed brown box is analyzed in Supplementary Fig. S2. The yellowish color is a result of adding red with green showing the overlapping area of the two contrasts. (c) Average of signals from panel b along y-axis (40 rows/measurements) showing relative amplitudes of RF absorption (solid red) and US echo (dashed green) in x-axis. The shaded color patches that is surrounding the average signal show the standard deviation of the measurements. (d–g) Imaging of a synthetic phantom containing a tube of mouse blood (B) overlaid on side-by-side pieces of porcine fat (F) and muscle (M). (d) Photograph of the phantom. (e) RISHA image. The dashed blue box indicates the region analyzed in panel g. (f) Co-registered RISHA and US images. The yellowish color is a result of adding red with green showing the overlapping area of the two contrasts. (g) Average of RISHA signals in the dashed box in panel e, along the y-axis. The resulting projection along the x-axis shows two-fold higher RF absorption (TBR 6 dB) by blood than by muscle. (h–k) Imaging of ex-vivo chicken tissue containing a blood vessel and muscle. Arrows indicate blood vessel. (h) Photograph of the tissue. (i) RISHA image. The dashed arrow indicates a line profile analyzed in panel k. (j) Co-registered RISHA and US images. (k) Line profile of RISHA signals along the dashed arrow in panel i showing two-fold higher RF absorption by blood than by muscle. Scale bars are 2 mm.