C are calcifications in the normal breast tissues because of calcium salt deposited in the ageing breast tissue. The fibres of benign tumour breast tissue are in disorder and make up anomaly masses(see figure 6(B), which means the high density tumour tissues get together and form anomalous conglomerations. The sizes of the conglomerations are different and have a random distribution. For those specimens tested in this work, the maximum one is about 2 mm and the minimum one is 0.5 mm. The cavity formed due to liquid degeneration appears obviously in figure 6(B), denoted by the white arrow. Their average size is 0.5 mm. There are some microstructures found in the malignant tumour, such as fibre fortification(see figure 6(C) These fortifications result from uniform or asymmetric encroachment of the malignant cell along the breast duct. At the same time the calcifications also distribute along the fibre fortification and form the stick or Y-shaped assembly as shown in figure 6(C). In addition some breast ducts are expanded(the black arrow in figure 6(C). These irregular structures and pecial symptoms of the tissue can play very important roles in distinguishing the malignant Id benign tumours. 4.4. Rocking curve The rocking curve which can be used to study the dynamic processes of x-ray diffraction is related to the absorption, the extinction, the mosaic domain in crystals, and so on. In DEl experiments, the shape of the rocking curve is decided by the analyser Si(111crystal and the experimental specimen(see figure 7). As listed in table 1, the peak remains in the same position but in general the sample affects the broadening of the rocking curve and also the d intensity. Due to the differences between the absorption and refraction of the specimens, the DEl images let us see various microstructures clearly. The integrated intensities of the rocking curve are obviously different for different kinds of breast tissues, although its peak position nd the width stay almost unchanged. The difference of integrated intensity mainly results from the differences in absorption of breast tissues under test. Because of the compactness and the relatively high density of healthy tissues, the integrated intensity for normal breast tissue is the lowest, which reflects a strong absorption. For the tumour tissues, the formation of cavities in benign tumours will increase the transmittance and result in a growth of the integrated intensity of the rocking curve. In contrast the assembling of calcified spots in the progression to cancer of diseased tissue will increase the absorption and then lead to a fall of the rocking curve. This general trend is in accordance with our earlier work in which the infrared absorption of healthy or diseased human tissues was studied (Liu et al 2006). we found that the IR absorption spectrum varies from abundantly featured to faint from normal breast tissue to benign tumours: while it develops from a relatively smooth spectrum to a much more complicated one in progressing to cancer of the diseased tissue. The reason for these changes is the variation of the absorption of different breast tissues in the IR region. However, the change of integrated intensity of rocking curves among different breast tissues is due to their different absorptions in the x-ray region. 5. Conclusions DEl images can disclose the inside microstructures of various breast tissues without the need of large numbers of pathology slices. The refraction images can show the microstructures of normal, benign and malignant breast tissues with the best clarity and highest contrast in all kinds of DEl images. The peak images have higher contrast than the apparent absorption images and can show microstructures inside the breast tissues as well. there are more426 C Liu et al are calcifications in the normal breast tissues because of calcium salt deposited in the ageing breast tissue. The fibres of benign tumour breast tissue are in disorder and make up anomaly masses (see figure 6(B)), which means the high density tumour tissues get together and form anomalous conglomerations. The sizes of the conglomerations are different and have a random distribution. For those specimens tested in this work, the maximum one is about 2 mm and the minimum one is 0.5 mm. The cavity formed due to liquid degeneration appears obviously in figure 6(B), denoted by the white arrow. Their average size is 0.5 mm. There are some microstructures found in the malignant tumour, such as fibre fortification (see figure 6(C)). These fortifications result from uniform or asymmetric encroachment of the malignant cell along the breast duct. At the same time, the calcifications also distribute along the fibre fortification and form the stick or Y-shaped assembly as shown in figure 6(C). In addition, some breast ducts are expanded (the black arrow in figure 6(C)). These irregular structures and special symptoms of the tissue can play very important roles in distinguishing the malignant and benign tumours. 4.4. Rocking curve The rocking curve which can be used to study the dynamic processes of x-ray diffraction is related to the absorption, the extinction, the mosaic domain in crystals, and so on. In DEI experiments, the shape of the rocking curve is decided by the analyser Si (1 1 1) crystal and the experimental specimen (see figure 7). As listed in table 1, the peak remains in the same position but in general the sample affects the broadening of the rocking curve and also the integrated intensity. Due to the differences between the absorption and refraction of the specimens, the DEI images let us see various microstructures clearly. The integrated intensities of the rocking curve are obviously different for different kinds of breast tissues, although its peak position and the width stay almost unchanged. The difference of integrated intensity mainly results from the differences in absorption of breast tissues under test. Because of the compactness and the relatively high density of healthy tissues, the integrated intensity for normal breast tissue is the lowest, which reflects a strong absorption. For the tumour tissues, the formation of cavities in benign tumours will increase the transmittance and result in a growth of the integrated intensity of the rocking curve. In contrast the assembling of calcified spots in the progression to cancer of diseased tissue will increase the absorption and then lead to a fall of the rocking curve. This general trend is in accordance with our earlier work in which the infrared absorption of healthy or diseased human tissues was studied (Liu et al 2006). We found that the IR absorption spectrum varies from abundantly featured to faint from normal breast tissue to benign tumours; while it develops from a relatively smooth spectrum to a much more complicated one in progressing to cancer of the diseased tissue. The reason for these changes is the variation of the absorption of different breast tissues in the IR region. However, the change of integrated intensity of rocking curves among different breast tissues is due to their different absorptions in the x-ray region. 5. Conclusions DEI images can disclose the inside microstructures of various breast tissues without the need of large numbers of pathology slices. The refraction images can show the microstructures of normal, benign and malignant breast tissues with the best clarity and highest contrast in all kinds of DEI images. The peak images have higher contrast than the apparent absorption images and can show microstructures inside the breast tissues as well. There are more