Figure 4.

EPR imaging of a phantom of the charcoal spin probe. The phantom consists of two conical centrifuge tubes. (A) Photograph of the phantom; (B) 3D spatial image; (C) 2D spectral–spatial image. The imaging parameters for 3D spatial imaging were a 746-MHz microwave frequency; 1,024 projections; a 15-G/cm gradient; a 5-s projection acquisition time; a 0.4-G modulation amplitude; and a 40-mm spatial window (field of view). The parameters for 2D spectral–spatial image were a 5-G spectral window; a 40-mm spatial window; a 5-s base projection acquisition time; and a 5-min total acquisition time. Microwave power of 60 mW was used.