Biomedical subjects

Peiping Zhu

Publications and source records attributed to Peiping Zhu.

4 recordsLinked to original sources

PubMed2006

Evaluation of x-ray diffraction enhanced imaging in the diagnosis of breast cancer.

The significance of the x-ray diffraction enhanced imaging (DEI) technique in the diagnosis of breast cancer and its feasibility in clinical medical imaging are evaluated. Different massive specimens including normal breast tissues, benign breast tumour tissues and malignant breast tumour tissues are imaged with the DEI method. The images are recorded respectively by CCD or x-ray film at different positions of the rocking curve and processed with a pixel-by-pixel algorithm. The characteristics of the DEI images about the normal and diseased tissues are compared. The rocking curves of a double-crystal diffractometer with various tissues are also studied. The differences in DEI images and their rocking curves are evaluated for early diagnosis of breast cancers.

Absorption↗

PubMed2006

A micro-tomography method based on X-ray diffraction enhanced imaging for the visualization of micro-organs and soft tissues.

Diffraction enhanced imaging (DEI) is one of the phase contrast imaging methods using the monochromatic X-ray from synchrotron, which provides information on the out-of-plane angular deviation of X-ray. DEI allows the investigation of micro-structures inside weakly absorbing samples at high spatial resolution without serious radiation exposure. Tomographic techniques can be applied readily to phase contrast images. The combination of DEI and tomography allows for a reconstruction of refractive index gradient distribution inside weakly absorbing samples with micrometer resolution, particularly suited for the 3D observation of micro-organisms and tissues. The existing phase contrast tomography methods based on DEI use phase contrast images as projections, such images contain not only the phase information, but also the absorption information. A novel method (DEI in the tomography mode) was developed to greatly increase the proportion of refraction information in phase contrast images by computing the difference between the two sets of images acquired at different angles of the rocking curve to adopt the projections with a complete set (2pi) for reconstruction. The reconstructed images of cochlea of a guinea pig showed the spatial structures and the micro-features inside the samples. The new method reveals higher spatial resolution compared to the conventional phase contrast tomography methods and is more suitable to the investigation of micro-structures of micro-organisms and tissue materials.

Algorithms↗

PubMed2006

Reconstruction of the refractive index gradient by x-ray diffraction enhanced computed tomography.

The computed tomography technique cannot easily be extended to diffraction enhanced imaging (DEI) because, while from DEI we may extract the refractive index gradient in one dimension, from the conventional CT reconstruction algorithm we may reconstruct only a scalar quantity. However, recently we showed that changing the direction of the scan axis, and collecting a set of data related to the three-dimensional distribution of the refractive index gradient of the sample, a CT image was obtained. The algorithm we used is based on the conventional CT algorithm but with a specific pre-processing of the projection data. The mathematical framework of the procedure and a simple CT experiment are presented and discussed.

Algorithms↗

PubMed2005

X-ray diffraction-enhanced imaging of uterine leiomyomas.

BACKGROUND: The purpose of this study was to investigate the microstructures of a uterine leiomyoma using a synchrotron-based imaging technique. MATERIAL/METHODS: The tissues of different regions of a uterine leiomyoma were imaged using X-ray diffraction-enhanced imaging. RESULTS: Compared with optical microscopy and conventional X-ray, X-ray diffraction-enhanced imaging can show not only the surface, but also the internal structure of organs or soft tissues with better contrast. Internal hyaline degeneration and the cavum of liquefied uterine leiomyomas are shown very clearly. Some microstructures, such as the myomatous burble, rupture and conglomeration of muscle fiber, and the cavum resulting from red degeneration, can be displayed in X-ray diffraction-enhanced images. These microstructures can show the developmental progress of necrosis in uterine leiomyomas and indicate their potential canceration. CONCLUSIONS: X-ray diffraction-enhanced imaging can clearly show internal microstructures of uterine leiomyomas, making the complex procedure of doing this with a large number of pathology slices avoidable.

Female↗