Thoughts and Conceiving on the Construction of Medical Supplies Classification and Coding System in China / 中国卫生经济

Through deeply analyzing the classification and coding of medical devices system,as well as existing problems in China,it proposed to build a medical devices classification and coding System,which was unified from state level and a platform for collection as well as surveillance for the information of medical devices,so as to improve the standardized management of the medical devices in China.

Three-dimensional Pseudo-continuous Arterial Spin Label Non-contrast Enhanced Perfusion Imaging of Head and Neck Tumors with High-field MR System / 中国医学科学院学报

<p><b>OBJECTIVE</b>To evaluate the feasibility of three-dimensional pseudo-continuous arterial spin label (3D pCASL) non-contrast enhanced perfusion imaging applied to head and neck tumors in high-field MR and detect the effects of different postlabeling delay (PLD) time on image quality and the reliability of repeated measurements of tumor blood flow (BF) in different 3D pCASL groups.</p><p><b>METHODS</b>In this prospective study,all the 25 patients received neck 3D pCASL non-contrast enhanced perfusion examinations in a 3.0 T MR system by using an 8-channel head and neck joint coil. Conventional T1-weighted (TIWI) and T2-weighted imaging (T2WI) were performed firstly. Finally,three 3D pCASL with different PLD time [ASL1(PLD1=1525 ms),ASL2 (PLD2=2025 ms), ASL3(PLD3=2525 ms)] were acquired. Patients' perfusion-weighted images acquired from different 3D pCASL sequences underwent the analysis of signal to noise ratio (SNR) and contrast noise ratio (CNR) for tumors. Two observers performed the qualitative assessments on spiral artifacts and vascular artifacts of perfusion-weighted images from different 3D pCASL sequences. Blood flow (BF) of tumors from different 3D pCASL sequences were measured by the two observers respectively for the first time and by observer 2 for the second time.</p><p><b>RESULTS</b>Seventeen enrolled patients (age:50.1 ± 12.7 years,M/F=10:7) with histopathologic.</p><p><b>RESULTS</b>underwent the evaluation of image quality and measurements of BF values. The SNRs and CNRs of ASL1,ASL2, and ASL3 showed a descending trendency. SNRs (P=0.011) and CNRs (P=0.009) of ASL1 were significant higher than those of ASL3. There was no significant difference of scores of spiral artifacts among the three ASL groups (P=0.932). The scores of vascular artifacts of ASL1,ASL2,and ASL3 showed a descending trendency,also. And scores of ASL1 was significant higher than that of ASL3(P=0.000). The intraclass correlation coefficient (ICC) of intre-and intraobserver were high (ICC>0.9). Although the BF values of ASL1,ASL2, and ASL3 showed an ascending trendency,there was no significant difference among the three groups (P=0.977).</p><p><b>CONCLUSIONS</b>The 3D pCASL no-contrast enhanced perfusion MR imaging can be used for head and neck tumor. The image quality of perfusion weighted images and reliability of BF measurements were satisfied. The 3D pCASL series with PLD of 1525 ms and 2025 ms have better image quality than PLD of 2525 ms. And BF values do not show significant statistic difference among the three groups. Therefore, 3D pCASL series with PLD of 1525 ms and 2025 ms are more suitable for the perfusion imaging of head and neck tumors</p>

Value of diffusion-weighted imaging in diagnosis of lymph node metastasis in patients with cervical cancer / 中国医学科学院学报

<p><b>OBJECTIVE</b>To investigate the value of diffusion-weighted imaging (DWI) in the differentiation of metastatic lymph nodes from non-metastatic lymph nodes in cervical cancer.</p><p><b>METHODS</b>In 65 patients who underwent lymph node dissection for cervical cancer, conventional MRI and DWI examinations were performed before surgery. Of the 1590 total dissected pelvic lymph nodes, 392 enlarged nodes with a short-axis diameter (S )of 5 mm or greater were included for further analysis. Each of the size-based criteria [i.e., S, long-axis diameter (L), and S/L ratio] and apparent diffusion coefficient(ADC)-based criteria (i.e., ADCmin, ADCmean, rADCmin, rADCmean) were compared between metastatic lymph nodes and non-metastatic lymph nodes.</p><p><b>RESULTS</b>There were statistically significant differences between metastatic and non-metastatic lymph nodes in S, L, S/L ratio, ADCmin, ADCmean, rADCmin, and rADCmean (all P<0.0001). The Az of the ADCmin (0.956) was greater than that of the other ADC-based criteria and all size-based criteria. Using ADCmin=759.0×10(-6) mm(2)/s, the sensitivity and specificity for differentiating metastatic from non-metastatic lymph nodes were 95.2% and 92.1%, respectively.</p><p><b>CONCLUSION</b>DWI, particularly ADCmin, is feasible for differentiating metastatic from non-metastatic pelvic lymph nodes in patients with cervical cancer.</p>