Quantum dots,as nanometer-sized semiconductor crystals,are widely used in life sciences for their excellent optical characteristics.This article introduces the unique optical characteristics of quantum dots and their application in labeling cancer cells and tumor markers as well as in the targeting and imaging of tumor vasculature.

The dual source computed tomography is equipped with two X-ray tubes and two corresponding detectors.With its 83 ms-temporal resolution of single segment reconstruction,high quality coronary artery CT angiography can be acquired without heart rate control.Dual energy output by two x-ray tubes improves the differentiation of body tissues,clinical application and lesion diagnostic accuracy of CT.

Objective To discuss the construction and principal of dual-source CT,as well as its superiorities in imaging of heart coronary artery and the clinical application of dual energy technique.Methods The structure of Siemens 64-slice CT was analyzed.The superiorities of dual-source CT in imaging of heart coronary artery were compared with conventional multi-slice CT,and the clinical value of dual energy technique was discussed.Results The dual-source computed tomography had high temporal resolution superiority,and high quality coronary artery CT angiography could be acquired without heart rate control.Dual energy technique could be applied to differentiate tissue component,display given tissue,evaluate the content of iodine in tissue.Conclusion Dual-source CT can not only enhance the diagnosis veracity of pathological changes of heart coronary artery but improve the ability of CT in tissue differentiation.

The low sensibility of MR molecular imaging to signals makes signal amplification exceptionally important.This paper reviews the strategy of the reporter gene signal amplification in MR molecular imaging.

Argon-helium cryosurgical system has been widely used in the treatment of solid tumors.The basic mechanism of this technique is that the ultra low temperature(below 140℃ ) can act on the diseased tissues, resulting in the formation of ice crystals both inside and outside of the cells and causing the rupture of the cells, which will further produce a series of physical and chemical changes and finally bring about the necrosis of tumor cells.This paper aims to introduce the argon-helium cryosurgical system, focusing on its guiding mode, freezing extent and time, freezing immunity, curative effect and combination of treatments.

Atypical teratoid/rhabdoid tumor of the central nervous system has aggressive growth with high potential CSF dissemination and frequently affects very young children.The tumor contains rhabdoid cells and primitive neuroectodermal,malignant mesenchymal and epithelial elements.Immunohistochemistry is helpful in differentiating atypical teratoid/rhabdoid tumor from primitive neuroectodermal tumor/medulloblastoma.Atypical teratoid/rhabdoid tumor is cytogenetically characterized by monosomy 22 or deletion of chromosome band 22q11.2.Intensified therapy combined with surgical resection has been suggested for its treatment.Due to the secondary cystic/necrotic changes and hemorrhage,the imaging features of the tumor are variable.

This article is to review the basic principles of renal perfusion in CT and MR,imaging method and perfusion characteristics in kidney diseases.It shows that in addition to the morphologic information,perfusion imaging can also provide functional and metabolic information about the renal neoplasms,which is very helpful for not only the differential diagnosis,but also the evaluation of tumor biological behaviors,it will have a bright future in clinical application.

Objective To evaluate the value of multi-slice spiral CT in nasal endoscopic surgery.Methods The multi-slice spiral CT data of 232 patients who were scanned prior to nasal endosopic surgery were analyzed.Results The nasal and sinus disease could be diagnosed correctly with multi-slice spiral CT.The ostiomeatal complex and the channels of the frontal sinus' drainage could be showed clearly.All the manifestation of the multi-slice spiral CT was in correspondence with the endoscopy showed in the surgery.Conclusion The multi-slice CT has the advantages of short scan time,less radiation dosage and multiplanar reconstruction.So it can display the nasal and sinus structures in detail,and has a great value in guiding the nasal endoscopic surgery.

Objective:To investigate the value of ultrasonography in the diagnosis of cystic renal cell carcinoma(CRCC).Methods:To review and analyze 32 cases confirmed by histological examination with the complete data and to sum up their characteristic features of ultrasonographic appearance,and then compared with the results of CT.Results:The sensitivity of ultrasonography in the diagnosis of cystic renal cell carcinoma was 75.00%(24/32),CT was 87.50%(28/32),therefore there was no obvious statistical difference between them.Conclusion:Color Doppler ultrasonography has diagnostic value in cystic renal cell carcinoma.

Objective To investigate the occurrence of p16 gene methylation in the population chronically exposed to arsenic in Inner Mongolia,and to study the molecular mechanisms of carcinogenesis associated with arsenic exposure.Methods The study group was composed of 40 cases of typical arseniasis selected from the epidemic area,and the two control groups consisting respectively of 40 non-arseniasis cases selected from the same epidemic area,and 40 healthy persons enrolled from non-epidemic area.Methylation of p16 gene in the blood specimens were analyzed for all the subjects with MS-PCR techniques,and statistical analysis was performed using chi square test.Results The positive rates of p16 hypermethylation in blood specimens were 65.0%,47.5% and 20.0% respectively in study group and two control groups,and the rate of hypermethylation increased with the increase in arsenic exposure with drinking water in epidemic areas.The positive rate of p16 hypermethylation showed significant differences(P