PDM和AON在临床化学质控中的应用

统计了20个项目近三个月的病人每日检验结果均值（PDM）和每日正常结果均值（AON），与同期定值质控结果比较。可以看出AON优于低值定值质控结果，PDM不如高值定值质控结果，PDM和AON结果与定值质控血清联合应用将更有利于做好质控工作。     

老年高尿酸血症与糖尿病前期及胰岛素抵抗的相关性研究

目的：探讨老年患者高尿酸血症与糖尿病前期以及胰岛素抵抗之间的关系。方法：84例高尿酸血症糖尿病前期老年患者作为观察组,64例血尿酸水平正常糖尿病前期老年患者作为对照组,并将观察组根据血糖水平再次分为空腹血糖受损组（A组,n=48）与糖耐量异常组（B组,n=36）,分别检测所有患者空腹血糖（FPG）、空腹胰岛素（FINS）、糖耐量试验,并计算胰岛素抵抗指数（HOMA-IR）、胰岛素敏感指数（ISI）,在各组之间进行对比分析。结果：观察组血尿酸、FPG、HOMA-IR均显著高于对照组,而ISI则显著低于对照组;A组患者血尿酸、FPG、2hPG、FINS、HOMA-IR均显著高于B组,而IFG组ISI则显著低于B组;观察组血尿酸水平与FPG、2hPG、FINS均呈显著正相关,而血尿酸水平与ISI则呈显著负相关。结论：HUA患者较容易合并IFG及IGT,且胰岛素抵抗状态与HUA有密切关系,良好的控制血尿酸水平将对PMD的预防具有重要意义。     

Robust GRAPPA reconstruction and its evaluation with the perceptual difference model

PURPOSE: To develop and optimize a new modification of GRAPPA (generalized autocalibrating partially parallel acquisitions) MR reconstruction algorithm named "Robust GRAPPA." MATERIALS AND METHODS: In Robust GRAPPA, k-space data points were weighted before the reconstruction. Small or zero weights were assigned to "outliers" in k-space. We implemented a Slow Robust GRAPPA method, which iteratively reweighted the k-space data. It was compared to an ad hoc Fast Robust GRAPPA method, which eliminated (assigned zero weights to) a fixed percentage of k-space "outliers" following an initial estimation procedure. In comprehensive experiments the new algorithms were evaluated using the perceptual difference model (PDM), whereby image quality was quantitatively compared to the reference image. Independent variables included algorithm type, total reduction factor, outlier ratio, center filling options, and noise across multiple image datasets, providing 10,800 test images for evaluation. RESULTS: The Fast Robust GRAPPA method gave results very similar to Slow Robust GRAPPA, and showed significant improvements as compared to regular GRAPPA. Fast Robust GRAPPA added little computation time compared with regular GRAPPA. CONCLUSION: Robust GRAPPA was proposed and proved useful for improving the reconstructed image quality. PDM was helpful in designing and optimizing the MR reconstruction algorithms.     

吸烟与肥胖对糖尿病前期患病的交互作用

目的 分析40～79岁人群吸烟与肥胖对糖尿病前期（prediabetes mellitus, PDM）患病的交互作用。方法 采用多阶段随机抽样的方法,在荣昌区21个街道或镇开展调查,每个调查点随机抽取3～5个村或社区,每个村或社区随机抽取20～50名符合条件的调查对象,调查包括问卷调查、体格检查和血生化检测。PDM影响因素及吸烟与肥胖对PDM患病的交互作用采用软件R 4.1.1进行多因素logistic回归分析。结果 3 017例调查对象中,PDM患病率为38.98%。调整混杂因素后,吸烟（OR=1.570,95%CI:1.303～1.892）、肥胖（OR=1.391,95%CI:1.113～1.737）与PDM患病高风险相关。相乘交互作用分析发现,吸烟×肥胖对PDM存在相乘交互作用（OR=2.122,95%CI:1.251～3.601）;相加交互作用分析发现,吸烟且肥胖风险高于不吸烟且不肥胖者（OR=3.978,95%CI:2.543～6.224）,相加作用评价指标RERI、AP和SI分别为2.200(0.444～3.956)(P>0.05)、0.553(0.336～0.770...     

Optimizing Staff Dose in Fluoroscopy-Guided Interventions by Comparing Clinical Data with Phantom Experiments

PurposeTo evaluate conditions for minimizing staff dose in interventional radiology, and to provide an achievable level for radiation exposure reduction.Materials and MethodsComprehensive phantom experiments were performed in an angiography suite to evaluate the effects of several parameters on operator dose, such as patient body part, radiation shielding, x-ray tube angulation, and acquisition type. Phantom data were compared with operator dose data from clinical procedures (n = 281), which were prospectively acquired with the use of electronic real-time personal dosimeters (PDMs) combined with an automatic dose-tracking system (DoseWise Portal; Philips, Best, The Netherlands). A reference PDM was installed on the C-arm to measure scattered radiation. Operator exposure was calculated relative to this scatter dose.ResultsIn phantom experiments and clinical procedures, median operator dose relative to the dose-area product (DAP) was reduced by 81% and 79% in cerebral procedures and abdominal procedures, respectively. The use of radiation shielding decreased operator exposure up to 97% in phantom experiments; however, operator dose data show that this reduction was not fully achieved in clinical practice. Both phantom experiments and clinical procedures showed that the largest contribution to relative operator dose originated from left-anterior-oblique C-arm angulations (59%–75% of clinical operator exposure). Of the various x-ray acquisition types used, fluoroscopy was the main contributor to procedural DAP (49%) and operator dose in clinical procedures (82%).ConclusionsAchievable levels for radiation exposure reduction were determined and compared with real-life clinical practice. This generated evidence-based advice on the conditions required for optimal radiation safety.     

2D-3D shape reconstruction of the distal femur from stereo X-ray imaging using statistical shape models

Three-dimensional patient specific bone models are required in a range of medical applications, such as pre-operative surgery planning and improved guidance during surgery, modeling and simulation, and in vivo bone motion tracking. Shape reconstruction from a small number of X-ray images is desired as it lowers both the acquisition costs and the radiation dose compared to CT. We propose a method for pose estimation and shape reconstruction of 3D bone surfaces from two (or more) calibrated X-ray images using a statistical shape model (SSM). User interaction is limited to manual initialization of the mean shape. The proposed method combines a 3D distance based objective function with automatic edge selection on a Canny edge map. Landmark-edge correspondences are weighted based on the orientation difference of the projected silhouette and the corresponding image edge. The method was evaluated by rigid pose estimation of ground truth shapes as well as 3D shape estimation using a SSM of the whole femur, from stereo cadaver X-rays, in vivo biplane fluoroscopy image-pairs, and an in vivo biplane fluoroscopic sequence. Ground truth shapes for all experiments were available in the form of CT segmentations. Rigid registration of the ground truth shape to the biplane fluoroscopy achieved sub-millimeter accuracy (0.68 mm) measured as root mean squared (RMS) point-to-surface (P2S) distance. The non-rigid reconstruction from the biplane fluoroscopy using the SSM also showed promising results (1.68 mm RMS P2S). A feasibility study on one fluoroscopic time series illustrates the potential of the method for motion and shape estimation from fluoroscopic sequences with minimal user interaction.     

Absence of a differentiation defect in muscle satellite cells from DM2 patients

Myotonic dystrophy type 1 (DM1) and type II (DM2) are dominantly inherited multisystemic disorders. DM1 is triggered by the pathological expansion of a (CTG)_n triplet repeat in the DMPK gene, whereas a (CCTG)_n tetranucleotide repeat expansion in the ZNF9 gene causes DM2. Both forms of the disease share several features, even though the causative mutations and the loci involved differ. Important distinctions exist, such as the lack of a congenital form of DM2. The reason for these disparities is unknown. In this study, we characterized skeletal muscle satellite cells from adult DM2 patients to provide an in vitro model for the disease. We used muscle cells from DM1 biopsies as a comparison tool. Our main finding is that DM2 satellite cells differentiate normally in vitro. Myotube formation was similar to unaffected controls. In contrast, fetal DM1 cells were deficient in that ability. Consistent with this observation, the myogenic program in DM2 was intact but is compromised in fetal DM1 cells. Although expression of the ZNF9 gene was enhanced in DM2 during differentiation, the levels of the ZNF9 protein were substantially reduced. This suggests that the presence of a large CCTG tract impairs the translation of the ZNF9 mRNA. Additionally, DM2 muscle biopsies displayed the altered splicing of the insulin receptor mRNA, correlating with insulin resistance in the patients. Finally, CUGBP1 steady-state protein levels were unchanged in DM2 cultured muscle cells and in DM2 muscle biopsies relative to controls, whereas they are increased in DM1 muscle cells. Our findings suggest that the myogenic program throughout muscle development and tissue regeneration is intact in DM2.