A 38.88 MHz time-stretch line-scan imaging system with parallel interleaving detection is experimentally demonstrated. Since only half-chromatic dispersion is used to stretch optical pulses for wavelength-to-time mapping, the power efficiency is significantly improved by 6.5 dB. Furthermore, the theoretical analysis indicates that the power loss can be efficiently reduced for scan rates less than 100 MHz. In addition, a mathematical model for signal-to-noise evaluation is derived, including amplified spontaneous emission noise in the power compensation. Thanks to the improvement of the power efficiency by using parallel interleaving detection, the signal quality is enhanced.