Presaturation Power Adjusted Pulsed CEST: A Method to Increase Independence of Target CEST Signals

Figure 3

Percent change in the total CEST signal at each frequency when the concentration is reduced in any one substance relative to the signal in the 4-high z-spectra. Each signal is lowered when its own concentration is reduced (meshed-column) and when the concentration of most other substances is reduced. Compared to asymmetry analysis (a–d), the effect of CEST interference from neighboring signals was magnified in the fitting analysis (e–h). The results were obtained using a 2.3 µT/5 s presaturation pulse at 37°C. (a) Nicotinamide at 3.5 ppm. (b) Glutamate at 3.0 ppm. (c) Creatine at 2.0 ppm. (d) Glucose at 1.0 ppm. (e) Nicotinamide at 3.5 ppm. (f) Glutamate at 3.0 ppm. (g) Creatine at 2.0 ppm. (h) Glucose at 1.0 ppm.

(a)

(b)

(c)

(d)

(e)

(f)

(g)

(h)