The significance of diffusion tensor magnetic resonance imaging for patients with nasopharyngeal carcinoma and trigeminal nerve invasion.

To investigate the significance of diffusion tensor imaging (DTI) for patients with nasopharyngeal carcinoma (NPC) and trigeminal nerve invasion.Fifty-two patients with NPC and unilateral infringement and 30 healthy controls were recruited for our study. Routine magnetic resonance imaging (MRI) and DTI were performed for all participants. Within-group and between-group comparisons of DTI metrics, including fractional anisotropy (FA) and the apparent diffusion coefficient (ADC) of the third (V3) branch of the bilateral trigeminal nerves of all participants, were carried out.The FA and ADC values on the affected sides of patients revealed a significant decrease and increase, respectively, when compared with those on the unaffected sides of patients and the healthy controls (P = 0.000 for all), whereas there were no significant differences in DTI metrics between both sides of healthy controls or between the unaffected sides of patients and the healthy controls (P = 0.930, 0.580, 0.095, and 0.360, respectively). The decreasing FA rate on the affected sides of patients correlated negatively with the increasing ADC rate (r = -0.675, P = 0.000).DTI can quantitatively evaluate microstructural abnormalities of the V3 branch of the trigeminal nerve in patients with NPC, which is important for the early detection of trigeminal nerve invasion to achieve a precise T classification, assess prognosis, and guide treatment.

Analysis of nodal size criterion of retropharyngeal lymph node metastasis in nasopharyngeal cancer patients / 中国医学影像技术

Objective To explore the reasonable radiologic nodal size criterion of retropharyngeal lymph node (RLN) metastasis in patients with nasopharyngeal cancer (NPC).Methods Imaging and clinical data of 817 NPC patients were analyzed retrospectively.The patients with RLN metastasis were classified into two groups according to the nodal size of 5 mm or 6 mm as standard in diagnosis.Overall survival (OS),distant metastasis-free survival (DMFS) and the local-relapse-free survival (LRFS) were assessed between the two groups taking 5 mm or 6 mm as standard in diagnosis of RLN.Results No significant difference was found for OS,DMFS,LRFS between nodal size ＜5 mm group and ≥5 mm group.Difference of OS (P＜0.001),DMFS (P=0.001) were significant statistical and difference of LRFS (P=0.380) had no significant statistical between nodal size ＜6 mm group and ≥6 mm group.OS,DMFS,LRFS were not an independent prognostic factor for NPC.Conclusion Using the minimal axial diameter of 6 mm as the nodal size criterion in diagosis of RLN metastasis in patients with NPC may be more reasonable.

Rapid Determination of 25 Kinds of Fungicides in Cereals, Fruits and Vegetables by Solid Phase Extraction and Liquid Chromatography Coupled with Quadrupole-Time of Flight Mass Spectrometry / 分析化学

A method for simultaneous determination of 25 kinds of fungicides in cereals, vegetables and fruits using SPE-LC-Q-TOF/MS technique was developed.The samples were extracted with acetonitrile containing 1% (V/V) acetic acid, purified by solid phase extraction (SPE) with a Crabon/NH2 cartridge, eluted with acetonitrile-toluene(3∶1, V/V), separated by a reversed phase C18 column, gradiently eluted with acetonitrile and 0.1% formic acid solution (Containing 5 mmol/L ammonium acetate), determined by LC-Q-TOF/MS, and quantified by external standard method.A data base of the accurate mass numbers and a library which contains 25 kinds of fungicides were established.The automatic retrieval of detection results was carried on according to the characteristics of the compound, such as accurate mass, retention time, isotope peak distribution, isotopic ratios, and so on.Based on the above results, the qualitative identifications of the 25 new fungicides were accomplished without the contrast of standard substances.The results indicated that 25 fungicides showed good linearity in the range of 0.02-200 μg/L, and the limits of detection (LOD) and the limits of quantification (LOQ) were 0.01-5.00 μg/kg and 0.02-20.00 μg/kg, respectively.The linear relative coefficients were greater than 0.995.The recoveries were in the range 71.8%-114.0% and the relative standard deviations (RSD) were ranged from 0.1% to 21.3% (n=3).The method has some advantages such as simplicity, rapidity and high sensitivity, and is suitable for the rapid determination of the common fungicides in cereals, vegetables and fruits.