Imaging plates were applied to plane-wave x-ray diffraction topography using synchrotron radiation to perform quantitative analysis of minute lattice distortion in as-grown silicon crystals. The lattice distortion was separated into variations in lattice-plane spacing, Delta d/d, and variations in lattice-plane orientation, Delta alpha, by analysis of intensity variations in the digitized topographs. The variations in Delta d/d along the growth direction in magnetic Czochralski (MCZ) silicon were closely correlated with fluctuations in the oxygen concentration. The concentric striation pattern observed in Czochralski silicon crystals was interpreted in terms of the variations in Delta d/d, while the variations in Delta alpha revealed the existence of frozen-in strains. In a ring-shaped area of oxidation-induced stacking faults in another Czochralski silicon crystal, a valley in the variations in Delta d/d was observed, but no valley in the variations in Delta alpha. In floating-zone silicon, Delta d/d increased from an area in which D defects were distributed to an area in which A defects were distributed, and Delta alpha began to decrease at the boundary between the neutral area, in which neither D defects nor A defects were distributed, and the A-defect area.