重建技术在颞骨病变诊断中应用价值的探讨

目的：探讨多层螺旋CT薄层高分辨扫描对颞骨病变的术前诊断价值。方法：对57例颞骨病变患者进行高分辨CT扫描,对原始数剧进行多方住MPR及CPR重建,分析HRCT表现及MPR、CPR重建图像,并与术中所见相比较。结果：C修断胆脂瘤21例,肉芽肿17例,中耳肿瘤9例,颞骨骨折10例。HRCT及MPR、CPR重建表现为：中耳腔扩大伴软组织团块47例（82．4％）,盾板破坏35例（59．6％）,听小骨破坏44倒（77．2％）,面神经骨管破坏33例（57．9％）,半规管破坏11例（19．2％）,鼓室盖破坏7例（12.3％）,骨折线显示10例（100％）,显示骨质改变与术中所见较为接近。结论：通过HRCT轴位图像结合MPR及CPR可以清楚地显示颞骨病变骨质改变及程度,对术前诊断及手术方案制定鼻有指导作用．     

Conversion factors for determining organ doses received by paediatric patients in high-resolution single slice computed tomography with narrow collimation

Estimations of organ doses D_T received during computed tomographic examinations are usually performed by applying conversion factors to basic dose indicators like the computed tomography dose index (CTDI) or the dose-length-product (DLP). In addition to the existing conversion factors for beam apertures of 5 mm or 10 mm, we present new DLP-D_T conversion factors adapted to high-resolution CT (HRCT) examinations of infants and young children with beam apertures of the order of 1 mm and under consideration of bow tie filtration. Calculations are performed on mathematical MIRD phantoms for an age range from 0, 1, 5, 10, 15 up to (for comparison) 30 years by adapting PCXMC, a Monte Carlo algorithm originally developed by STUK (Helsinki, Finland) for dose reconstructions in projection radiography. For this purpose, each single slice CT examination is approximated by a series of corresponding virtual planar radiographies comprising all focus positions. The transformation of CT exposure parameters into exposure parameters of the series of corresponding planar radiographies is performed by a specially developed algorithm called XCT. The DLP values are evaluated using the EGSRay code. The new method is verified at a beam aperture of 10 mm by comparison with formerly published conversion factors. We show that the higher spatial resolution leads to an enhanced DLP-D_T conversion factor if a small organ (e. g. thyroid gland, mammae, uterus, ovaries, testes) is exactly met by the chosen CT slice, while the conversion factor is drastically reduced if the chosen CT slice is positioned above or below the organ. This effect is utilized for dose-saving examinations with only a few single slices instead a full scan, which technique is applied in about 10% of all paediatric chest CT examinations.     

Comparison of endobronchial and transbronchial biopsies with high-resolution CT (HRCIT) in the diagnosis of sarcoidosis

High-resolution computed tomography (HRCT) has been shown to accurately visualise parenchymal infiltrates of sarcoidosis. The aim of this study was to compare the diagnostic yield (DY) of HRCT with that of endobronchial (EBB) and transbronchial (TBB) biopsies in establishing the diagnosis of sarcoidosis. Forty-five patients referred to Helsinki University Central Hospital with a presumptive diagnosis of sarcoidosis underwent fiberoptic bronchoscopy (FOB) with bronchoalveolar lavage (BAL), EBB, TBB and HRCT. Thirty-seven of the patients were diagnosed as having sarcoidosis, 34 of whom showed a parenchymal infiltrate in HRCT. One of the three patients with no parenchymal findings, had positive findings in TBB, and all had lymphocytosis in BAL. The DY for sarcoidosis by EBB and TBB was 24.3% and 50.0%, respectively. The addition of EBB to TBB improved the DY by 8.3%, whereas adding TBB to EBB improved the DY by 30.6%. There were no major complications after the FOB, which was always performed under fluoroscopic control. In conclusion, HRCT is a valuable tool in diagnosing sarcoidosis. However, the HRCT findings cannot be seen in all patients with positive findings in lung biopsy, nor is the parenchymal infiltrate specific for sarcoidosis. Attempting biopsy-proven diagnosis of sarcoidosis is still recommended. Fiberoptic bronchoscopy with EBB and TBB under fluoroscopic control is a safe and well-tolerated procedure.     

Idiopathic Pulmonary Fibrosis: Evolving Concepts

Idiopathic pulmonary fibrosis (IPF) occurs predominantly in middle-aged and older adults and accounts for 20% to 30% of interstitial lung diseases. It is usually progressive, resulting in respiratory failure and death. Diagnostic criteria for IPF have evolved over the years, and IPF is currently defined as a disease characterized by the histopathologic pattern of usual interstitial pneumonia occurring in the absence of an identifiable cause of lung injury. Understanding of the pathogenesis of IPF has shifted away from chronic inflammation and toward dysregulated fibroproliferative repair in response to alveolar epithelial injury. Idiopathic pulmonary fibrosis is likely a heterogeneous disorder caused by various interactions between genetic components and environmental exposures. High-resolution computed tomography can be diagnostic in the presence of typical findings such as bilateral reticular opacities associated with traction bronchiectasis/bronchiolectasis in a predominantly basal and subpleural distribution, along with subpleural honeycombing. In other circumstances, a surgical lung biopsy may be needed. The clinical course of IPF can be unpredictable and may be punctuated by acute deteriorations (acute exacerbation). Although progress continues in unraveling the mechanisms of IPF, effective therapy has remained elusive. Thus, clinicians and patients need to reach informed decisions regarding management options including lung transplant. The findings in this review were based on a literature search of PubMed using the search terms idiopathic pulmonary fibrosis and usual interstitial pneumonia, limited to human studies in the English language published from January 1, 2000, through December 31, 2013, and supplemented by key references published before the year 2000.     

<Emphasis Type="Italic">Pneumocystis</Emphasis> pneumonia in patients with HIV infection: clinical manifestations,laboratory findings,and radiological features

Pneumocystis pneumonia (PCP) remains the most common opportunistic infection in patients with acquired immunodeficiency syndrome (AIDS). Familiarity with the clinical features of PCP is crucial for prompt diagnosis, even if the patient is unaware of their HIV serostatus. We describe herein the clinical features of 34 episodes in 32 patients with AIDS-associated PCP and review the existing literature. As for symptoms, the frequency of fever, cough, and dyspnea was 74%, 74%, and 65%, respectively, and the complete triad was present in only 14 of the 34 episodes on first examination. Median duration from onset of symptoms until diagnosis was 3 weeks, and AIDS-associated PCP tended to take an insidious clinical course. Although laboratory findings were generally nonspecific, measurement of β-D-glucan levels in the serum or plasma was highly useful in the diagnosis of PCP. All but 1 of the patients showed β-D-glucan levels higher than the cutoff value (median, 147 pg/ml; range, 5–6920 pg/ml). Typical radiographic features of PCP are bilateral, symmetrical ground-glass opacities, but a wide variety of radiographic findings were observed. In our patients, high-resolution computed tomography (HRCT) of the lung showed ground-glass opacities sparing the lung periphery (41% of episodes) or displaying a mosaic pattern (29%), or being nearly homogeneous (24%), ground-glass opacities associated with air-space consolidation (21%), associated with cystic formation (21%), associated with linear-reticular opacities (18%), patchily and irregularly distributed (15%), associated with solitary or multiple nodules (9%), and associated with parenchymal cavity lesions (6%).     

放射性肺损伤的高分辨率CT表现

目的：探讨放射性肺损伤的高分辨率ＣＴ（ＨＲＣＴ）特征。材料与方法：５６例经ＨＲＣＴ检查的放射性肺损伤患者,男５２例,女４例,采用双盲法阅片,总结放射性肺损伤ＨＲＣＴ征象,并与临床表现对比,进行回顾性分析。结果：（１）放射性肺损伤的发生与照射剂量成正相关,损伤的部位与照射野一致;（２）放射性肺损伤的临床表现与ＣＴ征角不平行,一般较ＣＴ片象不平行,一般较ＣＴ征象为轻。     

高分辨率CT在评价支气管哮喘患者的气道重塑中的作用

目的运用高分辨率CT（HRCT）观察支气管哮喘患者的气道重塑表现。方法将慢性持续期哮喘患者（37例）和健康人（20名）分列为哮喘组和对照组,运用HRCT观察所有受试者肺部影像学特征,运用PickerPQ6000分析软件测定气道壁厚度（T）、气道壁面积（WA）,采用气道壁厚度/气道外径（T/D）和气道壁面积占气道总面积百分比（WA%）做为标化指标。结果WA轻度哮喘组（12.53±4.19）mm2和中重度哮喘组（14.68±5.96）mm2与健康对照组（9.32±3.78）mm2比较,差异有统计学意义（P〈0.05）;轻度哮喘组和中重度哮喘组差异有统计学意义（P〈0.05）。WA%值轻度哮喘组（70.51±7.04）%和中重度哮喘组（73.50±7.27）%,与对照组（64.80±5.45）%比较,差异有统计学意义（P〈0.05）;轻度哮喘组与中重度哮喘组之间无统计学意义。T、T/D中重度哮喘组较轻度哮喘组和正常对照组差异有统计学意义（P〈0.05）,但轻度哮喘组和正常对照组之间差异无统计学意义（P〉0.05）。结论HRCT可用于评价哮喘患者气道壁增厚和气道壁面积增加等气道重塑表现。     

肺腺癌磨玻璃结节影像特征与EGFR基因突变的相关性分析

目的 磨玻璃结节(ground glass nodule,GGN)的疾病谱包括良性及恶性的病变,有关于GGN的自然生长史目前尚未完全清楚,本研究回顾性定量分析高分辨CT(high-resolution computed tomography,HRCT)表现为纯磨玻璃结节(pure ground glass nodule,pGGN)和实性成分＜5 mm部分实性结节的肺腺癌表皮生长因子受体(epidermal growthfactor receptor,EGFR)基因突变的特点及其与影像表现的关系.方法 2012-04-23 2015 10 30经中国医学科学院肿瘤医院病理确诊为肺腺癌的GGN患者79例.通过测序法检测EGFR基因突变.将患者分为EGFR突变型组及野生型组,分别记录各组患者性别、年龄、病灶位置、大小、相对CT值及薄层CT征象(分叶、毛刺、空泡征、空气支气管征、胸膜牵拉及凹陷征),观察两组GGN影像特征与EGFR基因突变的关系,并进行统计学分析.结果 79例GGN患者中,EGFR突变组41例(51.9％),EGFR野生型组38例(48.1％);EGFR突变组与野生型组之间患者年龄、性别、GGN的位置、分叶、毛刺、空泡及CT空气支气管征、相对CT值差异均无统计学意义,均P＞0.05.突变型组GGN胸膜牵拉或凹陷征发生率高于野生型组,P=0.037.EGFR突变型组的GGN大小、体积及质量均显著高于野生型组(P值分别＜0.001、0.002和0.001).GGN大小、体积、质量预测EGFR突变的最佳临界值分别为10.45 mm、540.6 mm3和0.255 g.结论 在pGGN和实性成分＜5 mm部分实性结节肺腺癌中,HRCT影像特征对于辅助预测EGFR基因突变状态具有一定价值.     

HRCT在感音神经性耳聋伴内耳畸形中的应用研究

目的通过分析感音神经性耳聋患者的HRCT影像学表现,同时在CT工作站对内耳结构进行三维图像重建,进一步分析内耳畸形。探讨HRCT及MPR后处理技术对先天性内耳畸形的诊断价值。方法选取83例临床无明确原因的、表现为重度至极重度感音性聋的患者行颞骨高分辨率多层螺旋CT扫描及多平面重组(MPR),对所得图像进行分析,根据Sennaroglu等提出的新的内耳畸形分类方法进行分类;利用CT工作站对表现清晰的结构如耳蜗高度、前庭、内听道、前庭导水管等进行测量。结果 83例患者中HRCT表现为内耳畸形49例(98耳),其余34例HRCT未见异常。畸形主要表现为前庭导水管扩大24例(48耳),其中单侧扩大27例(50耳),合并其他内耳畸形4例(8耳);Michel畸形4例(6耳);共同腔畸形2例(4耳);耳蜗发育不全1例(2耳);IP-I型l例(2耳);IP-11型(Mondini型)3例(6耳);前庭半规管畸形6例(12耳);内耳道狭窄8例(16耳)。结论 HRCT及MPR后处理可获得内耳畸形的可靠的影像学资料,为临床治疗方法的选择及其预后的评判提供可靠依据。