1. A method for tomosynthesis image quality control for a tomosynthesis imaging system, the method addressing the measurement of in-plane resolution and slice thickness, via the measurement of modulation transfer function (MTF), the method comprising: positioning a phantom having an edge of predetermined sharpness at a predetermined angle relative to an imaging plane of an x-ray detector; performing tomosynthesis acquisition and generating one or more slice images using one or more three-dimensional reconstruction algorithms; selecting a slice image to be measured from the one or more slice images; identifying a sharpest edge in the slice image to be measured, wherein the sharpest edge in the slice image to be measured comprises the in-focus portion of the phantom; inputting the slice image to be measured and coordinates of the sharpest edge in the slice image to be measured into an MTF algorithm; and using the MTF algorithm, calculating the in-plane resolution and slice thickness of the slice image to be measured.