应用胸部CT和血清CYFRA21-1、NSE检测诊断肺癌

目的:探讨胸部CT和血清CYFRA21-1、NSE检测及其联合应用诊断肺癌的价值.方法:选择肺肿瘤患者60例,全部行胸部CT检查和血清CYFRA21-1、NSE 二种肿瘤标志物检测,分别计算二种方法诊断肺癌的灵敏度、特异性和准确性并加以比较.结果:CT诊断肺癌灵敏度为91.3%,特异性为71.4%,准确性为86.7%;CYFRA21-1、NSE诊断肺癌灵敏度为71.7%,特异性为85.7%,准确性为75.0%;CT诊断肺癌具有较高的灵敏度,但特异性较低,而血清CYFRA21-1、NSE诊断肺癌灵敏度较低,但特异性较高.结论:胸部CT和血清CYFRA21-1、NSE检测在肺癌的诊断中具有重要价值,二者联合应用诊断肺癌具有互补作用.     

肝移植术后肝癌复发的超声造影与CT诊断比较

目的探讨超声造影（CEUS）对肝移植术后肝癌复发的诊断价值。方法对肝癌病人肝移植术后常规彩色超声随访发现肝内占位性病变23例，先行超声造影检查，3d内行螺旋CT增强扫描，分别与病理结果比较。结果23例病人经过穿刺活检病理确诊20例，行再次肝移植术经病理确诊3例，CEUS确诊18例，疑诊4例，误诊1例；CT确诊20例，疑诊2例，误诊1例。结论CEUS与CT对原位肝移植术后肝癌复发的诊断均很敏感且价值很高，尤其对不典型病灶的诊断，CT与CEUS结合能提高诊断率。     

CT结肠造影中息肉的自动识别

目的：通过计算机自动识别CT结肠造影中结肠息肉的方法，提高结肠息肉筛查的灵敏度及效率。方法：利用计算CT图像的偏导数得到等值面的几何形态，找到符合息肉特征的体素，通过区域生长及模糊分类完成对息肉的识别与分割，并将识别到的息肉用特殊颜色标记，在其引导下进行虚拟内窥镜重建。结果：自动识别方法对息肉的总体敏感度为58．8％，假阳性率为4．7个，病例，平均检查时间为15．3min。同人工方法相比，检查时间平均缩短40．5％，且对5-10mm息肉的敏感度有明显提高（P=0．046）。结论：本方法具有较高的识别灵敏度，能加快息肉筛查的速度，可作为结肠息肉筛查的辅助手段。     

The reduction of artifacts due to metal hip implants in CT-attenuation corrected PET images from hybrid PET/CT scanners

CT beam hardening artifacts near metal hip implants may erroneously enhance or diminish radiotracer uptake following CT attenuation correction (AC) of PET images. An artifact reduction algorithm (ARA) was developed to reduce metal artifacts in CT-based AC-PET. The algorithm employed a Bayes classifier to identify beam-hardening artifacts, followed by a partial correction of the attenuation map. ARA was implemented on phantom and patient 18F-FDG studies using a clinical PET/CT scanner. In phantom studies ARA successfully removed two artifacts of erroneously elevated uptake near a stainless steel hip prosthesis which were depicted in the standard CT-AC PET. ARA has also identified two targets absent on the scanner PET images. Target-to-background ratios were 1.5-3 times higher for ARA-PET than scanner images. In a patient study, metal artifacts were of lower intensity in ARA-PET as compared to standard images. Potentially, ARA may improve detectability of small lesions located near metal hip implants.     

Mismatch negativity on the cone of confusion

Localization of sounds by the auditory system is based on the analysis of three sources of information: interaural level differences (ILD, caused by an attenuation of the sound as it travels to the more distant ear), interaural time differences (ITD, caused by the additional amount of time it takes for the sound to arrive at the more distant ear), and spectral cues (caused by direction-specific spectral filter properties of the pinnae). Although in a number of psychophysiological studies cortical processes of ITD and ILD analysis were investigated, there is hitherto no evidence on the cortical processing of spectral cues for sound localization. The objective of the present experiment was to test whether it is possible to observe electrophysiological correlates of sound localization based on spectral cues. In an auditory oddball experiment, 80 ms of broadband noise from varying free field locations were presented to inattentive participants. Mismatch negativities (MMNs) were observed for pairs of standards and location deviants located symmetrically with respect to the interaural axis. As interaural time and level differences are identical for such pairs of sounds, the observed MMNs most likely reflect cognitive processes of sound localization utilizing the spectral filter properties of the pinnae. MMN latencies suggest that sound localization based on spectral cues is slower than ITD- or ILD-based localization.     

Integrating micro CT indices,CT imaging and computational modelling to assess the mechanical performance of fluoride treated bone

In this study we evaluate the influence of low-dose fluoride treatment on 23 patient biopsies. Computational finite element (FE) models of each biopsy were subjected to a range of loads including compression, shear and torsion. The modelling framework was validated against three 3D printed models with known material properties subjected to compression till failure using an Instron machine. The primary outcomes from this study were that mechanical strength was not significantly correlated to low-dose (<10 mg/day) of fluoride levels (one-way ANOVA, P-values of 0.78, 0.69 and 0.62 for compression, shear and torsion, respectively). However, when bulk bone material properties were derived from DXA bone mineral density (BMD) from each patient's proximal femur a non-significant linear decline in mechanical strength with increase in fluoride was predicted. When the same material property was used for all bones (to evaluate bone architecture influence) then mechanical strength showed a characteristic concave upwards trend, consistent with the variation of micro CT derived percentage bone volume (BV/TV). The secondary outcomes from this study were that in compression, BV/TV was observed to be a strong surrogate measure for mechanical strength (R² = 0.83), while bone surface density (R² = 0.6), trabecular thickness (R² = 0.5) and intersection surface (R² = 0.6) also explained the variation of mechanical strength well. However, trabecular separation and trabecular number were mildly correlated with mechanical strength (R² of 0.31 and 0.35, respectively). Compression was the loading mode most strongly correlated to micro CT indices. Material properties adapted from the proximal femur reduced the CT index correlations by up to 58% indicating that bulk density from a near proximity is a poor representation of specific localised density. Substituting the 3D micro CT indices with 2D histomorphometric data decreased correlations by at least 33% indicating that structural identification on a plane is not representative of the full 3D architecture necessary for a complete bone strength analysis. The presented computational framework may be used to assess the roles that bone architecture and loading modes play in bone quality, and which micro CT indices are good surrogate measures for mechanical strength.     

Metastasis germinomas of the external acoustic meatus: in a 19-year-boy: a case report

Background: The external acoustic meatus metastasis of germinomas is a rare event. Case presentation: we describe a 19-year-old boy with stuffiness and earplug of the left ear but no other symptoms. The whole body F-18 FDG PET/CT and the brain MRI are performed and demonstrated a germinoma in the pineal gland and vermis cerebellum region and in the right of thalamus. Photomicrograph showing marked infiltration of lymphoplasma cells and macrophages including giant cells. Immunohistochemical analysis results demonstrated the tumor cells are strongly positive for CD117 and PLAP. The final diagnosis was germinoma and all adjuvant therapy was achieved. Conclusion: Although the external acoustic meatus metastasis of germinomas is rare, the diagnosis should be taken into serious consideration in order to improve. In addition, F-18 FDG PET/CT was very useful in diagnosis primary disease and excluding distant metastases. To our knowledge, this is the first published report of this type of case.     

基于灰度共生矩阵和人工神经网络的肺癌CT图像的分类研究

目的研究小细胞肺癌（SCLC）和非小细胞肺癌（NSCLC）的分类问题。方法217例肺癌患者．其中男性165例．殳性52例;年龄35～80岁,平均年龄61．5岁。其中SCLC108例,NSCLC109例。提取患者764幅肺癌CT图像的灰度共生矩阵,选取对比度、熵、能量和逆差矩4个特征值,借助临床确诊结果,利用多层前向（BP）、径向基函数（RBF）人工神经网络对特征进行训练测试。结果BP人工神经网络对10％的78例样本进行测试,SCLC42例预测正确．NSCLC33例预测正确．3例预测失败。RBF神经网络对10％的78例测试样本进行测试,SCLC42例预测正确．NSCLC36例预测正确、类似方法对样本总数的70％进行训练,用30％的230例进行测试;BP人工神经网络有209例预测正确。正确率为90．9％：其中SCLC111例预测正确,正确检出率为88．8％;NSCLC98例预测正确,正确检出率为93.3％。RBF人工神经网络有216例预测正确．正确率为93．9％,其中SCLC117例预测正确,正确率为93．6％;NSCLC99例预测正确,止确检出率为94.3％。可见BP、RBF人1二神经网络对SCLC和NSCLC均具有90％以上的正确率,高于人工诊断结果。结论基于灰度共生矩阵的对比度、熵、能量和逆差矩4个特征值能反映SCLC和NSCLC的有效特征参量．通过人工神经网络能达到分类目的,辅助临床治疗。     

Derailed B cell homeostasis in patients with mixed connective tissue disease

Mixed connective tissue disease (MCTD) is a systemic autoimmune disorder, characterized by the presence of antibodies to U1-RNP protein. We aimed to determine phenotypic abnormalities of peripheral B cell subsets in MCTD. Blood samples were obtained from 46 MCTD patients, and 20 controls. Using anti-CD19, anti-CD27, anti-IgD and anti-CD38 monoclonal antibodies, the following B cell subsets were identified by flow cytometry: (1) transitional B cells (CD19 + CD27-IgD + CD38^high); (2) naive B cells (CD19 + CD27-IgD + CD38^low); (3) non-switched memory B cells (CD19 + CD27 + IgD+); (4) switched memory B cells (CD19 + CD27 + IgD-); (5) double negative (DN) memory B cells (CD19 + CD27-IgD-) and (6) plasma cells (CD19 + CD27^highIgD-). The proportion of transitional B cells, naive B cells and DN B lymphocytes was higher in MCTD than in controls. The DN B cells were positive for CD95 surface marker. This memory B cells population showed a close correlation with disease activity. The number of plasma cells was also increased, and there was an association between the number of plasma cells and the anti-U1RNP levels. Cyclophosphamide, methotrexate, and corticosteroid treatment decreased the number of DN and CD27^high B cells. In conclusion, several abnormalities were found in the peripheral B-cell subsets in MCTD, which reinforces the role of derailed humoral autoimmune processes in the pathogenesis.     

Intraosseous leiomyosarcoma arising in the epiphysis of the distal femur

Herein, we present a rare case of intraosseous leiomyosarcoma arising in the epiphysis of the distal femur and showing unusual radiographic features. A 44-year-old man presented with a pain in the left knee joint. Computed tomography revealed an intraosseous lesion with slightly increased attenuation and a thin marginal sclerotic rim in the femoral medial condyle. The signal of the lesion was hypointense on T1-weighted magnetic resonance (MR) images and hyperintense on fat-suppressed T2-weighted MR images. After gadolinium administration, the signal of the lesion was moderately and diffusely enhanced. The histological diagnosis of leiomyosarcoma was made based on a preoperative core biopsy specimen. Microscopic examination of the resected specimen revealed an ill-defined intraosseous tumor composed of proliferated atypical and mildly pleomorphic smooth muscle cells permeating among the bone trabeculae with only focal destruction of the bone trabeculae and low mitotic activity, indicating low grade leiomyosarcoma. The bone trabeculae at the periphery of the tumor were mildly thickened and anastomosed with a rim of an increased number of osteoblasts. Systemic examination showed no tumorous lesions in other anatomical sites. Leiomyosarcomas rarely present in the bone as a diffuse intertrabecular growth, even in low grade tumors.