低场MRI与超声对诊断子宫腺肌症的比较

目的探讨低场（0．23T）MRI与超声对子宫腺肌症的诊断价值。方法由手术和病理证实的子宫腺肌症45例和对照组子宫肌瘤36例术前均行超声（经腹、经阴道途径）、MRI检查。比较各种方法的诊断敏感性、特异性、准确性、阳性预测值及阴性预测值。结果MRI柃查对子宫腺肌症的诊断敏感性为95．56％,特异性为100％,准确性97．53％,阳性预测值为100．00％,阴性预测值为97．74;经阴道超声分别为80．0％、88．89％、83．95％、90．00％、78．05％;经腹部超声分别为68．89％、83．33％、75.31％、83．78％、68．18％。结论对于子宫腺肌症的诊断,低场MRI为最有价值的检查手段,而经阴道超声又优于经腹部超声。     

二维超声、三维彩超与超声弹性成像诊断乳腺肿物性质的对比研究

目的探讨二维超声、三维彩超与超声弹性成像在诊断乳腺肿物性质的敏感性、特异性和准确率,以判断它们的临床应用价值。方法对120例（共178个肿物）患者分别进行对照,分析其敏感性、特异性及准确率。结果二维超声诊断乳腺恶性肿物的敏感性、特异性和准确率分别为76．8％（43／56）、86．9％（106／122）、83．7％（149／178）;三维彩超诊断乳腺恶性肿物的敏感性、特异性和准确率分别为89．3％（49／56）、92．6％（113／122）、91．0％（162／178）;超声弹性成像诊断乳腺恶性肿物的敏感性、特异性和准确率分别为94．6％（53／56）、95．1％（118／122）、96．7％（171／178）。超声弹性成像与二维超声及三维彩超对乳腺肿物性质的诊断结果进行比较,差异均具有统计学意义（P〈0．05）。结论在诊断乳腺肿物性质中,超声弹性成像具有重要临床应用价值,其敏感性、特异性及准确率均优于二维超声及三维彩超。     

GM、G试验及真菌培养鉴定对肺部侵袭性真菌感染的诊断价值

目的：检测疑诊为肺部侵袭性真菌感染（IFI）患者的支气管肺泡灌洗液（BALF）和血清半乳甘露聚糖（galacto-mannan,GM）、血清（1,3）-β-D葡聚糖[（1,3）-beta-D-glucan,G test]并对BALF进行真菌培养鉴定,评估上述实验诊断方法对临床深部真菌感染的诊断效率。方法回顾性分析148例IFI疑诊患者,总结血清／BALF GM、血清G试验和真菌培养结果,分别评估其敏感性、特异性、阳性预测值、阴性预测值和联合检测对IFI的诊断价值。结果148例病例中临床诊断为IFI有48例,临床排除100例,在48例IFI患者中,血清GM阳性3例,BALF GM阳性25例,G试验阳性31例,真菌培养阳性30例。联合检测敏感性91．6％、特异性70．0％、阳性预测值59．5％、阴性预测值94．6％,联合检测大幅度提高了其诊断敏感性。结论联合检测GM、G试验和真菌培养鉴定能提高IFI诊断敏感性,对肺部IFI具有较好的诊断价值。     

CT图像纹理分析在鉴别良恶性肺结节中的价值

目的 评价CT纹理分析在鉴别肺良恶性结节中的价值.方法 回顾性分析110例孤立性肺结节(SPNs)(恶性55例,良性55例)的CT平扫图像,所有结节均经组织病理学或临床随访证实.提取肺结节CT平扫图像的对比度、能量、熵、相关以及一致性等5个灰度共生矩阵纹理参数进行分析.使用t检验比较良恶性结节纹理特征的差异.使用受试者工作特征曲线(ROC)分析确定各参数的最佳临界值,并评价各参数诊断肺良恶性结节的敏感性、特异性、准确性、阳性及阴性预测值.结果 5个纹理特征中,能量、一致性和熵的ROC曲线下面积(AUC)分别为0.997、0.918、0.976.恶性结节的能量、一致性小于良性结节,熵大于良性结节(P＜0.001).使用最佳临界值标准,能量、一致性和熵的敏感性分别为0.982,0.818,1.000,特异性分别为0.964,0.909,0.910,准确性为0.973,0.864,0.945,阳性预测值为0.964,0.9,0.915,阴性预测值为0.981,0.833,0.980.结论 CT纹理特征定量分析是一种有前景的能够准确鉴别良恶性肺结节的手段.     

多层螺旋CT和正电子发射计算机体层成像-CT评价乳腺癌腋窝淋巴结状态的对照研究

目的探讨多层螺旋CT（MSCT）、正电子发射计算机体层成像-CT（PET-CT）评价乳腺癌腋窝淋巴结转移的价值。方法手术病理证实的乳腺癌患者40例均行MSCT增强扫描，其中的13例行^18F脱氧葡萄糖（^18F-FDG）PET—CT检查。3名医师分别采用5分评价法对CT图像中淋巴结进行综合评分，≥3分时该淋巴结记录为阳性（淋巴结有转移），〈3分时记录为阴性。采用目测法和半定量分析法相结合分析PET—CT图像所显示的淋巴结，分别作阴、阳性记数。将PET-CT、增强MSCT对腋窝淋巴结的检出结果与手术病理结果进行对照。用精确概率法对结果进行统计学分析。结果40例患者行MSCT检查共检出腋窝淋巴结158枚，其中CT阳性计数91枚，阴性计数67枚；术后病理阳性99枚，阴性59枚。13例行PET-CT检查者共检出腋窝淋巴57枚，PET-CT显像阳性39枚，阴性18枚；术后病理阳性39枚，阴性18枚。CT对腋窝淋巴结转移定性的敏感性、特异性、准确性、阳性预测值和阴性预测值分别为88．89％、94．91％、91．14％、96．70％和83．58％；PET-CT分别为97．44％、94．44％、96．49％、97．44％和94．44％。CT与PET-CT对腋窝淋巴结转移定性的敏感性、特异性、准确性和阳性预测值差异无统计学意义（P〉0．05）；但PET-CT的阴性预测值高于MSCT，二者之间差异有统计学意义（P〈0．05）。结论CT、PET-CT都能准确评价乳腺癌腋窝淋巴结的状态，但PET-CT检测腋窝淋巴结的阴性预测值高于MSCT，PET-CT能在术前更准确评价乳腺癌患者腋窝淋巴结状态。     

^99Tcm-depreotide显像对肺部病灶的鉴别诊断价值

Depreotide是一种人工合成的十肽生长抑素类似物,含生长抑素受体结合序列和^99Tcm配位序列。通过荟萃分析肺部病灶的^99Tcm-depreotide显像资料显示,^99Tcm-depreotide鉴别肺部病灶良恶性的灵敏度为94．2％（95％可信区间：90．5％,97．9％）,特异度为61．2％（95％可信区间：50．7％,71．7％）,诊断准确率为81．6％,阳性预测值为81．1％,阴性预测值为83．2％;对于1．5cm以下的孤立性肺结节（SPN）,^99Tcm-depreotide显像特异性极高,显像阳性是手术治疗的适应证;对于1．5cm以上的SPN,因其灵敏度高,^99Tcm-depreotide显像阴性者可进行系列CT扫描随访观察。     

PET/CT鉴别诊断孤立性肺结节的优势与限度

目的：探讨PET/CT在孤立性肺结节（SPNs）鉴别诊断中的价值。方法：经病理证实的58例SPNs均行PET/CT扫描,结合结节的PET的代谢特点及CT的形态学特点综合判定SPNs的性质。结果：恶性SPNs的最大标准摄取值SUVmax（均值7.03±4.75）明显高于良性SPNs（均值2.06±1.06）,差异有统计学意义（t=6.40,P〈0.001）。PET/CT诊断恶性SPNs的敏感度、符合率、阴性预测值（100%、96.6%、100%）均较单独利用CT（88.2%、87.9%、50.0%）和单独利用PET（86.3%、84.5%、41.7%）高。结论：PET/CT可以提高诊断孤立肺结节的敏感度、符合率及阴性预测值。     

MRI在胎盘侵犯术前诊断中的价值

目的：研究 MRI 在胎盘侵犯术前诊断中的价值。方法：回顾性分析产前疑似胎盘侵犯的46例孕妇 MRI 图像,两位阅片者分别记录最佳 MRI 序列、方位、图像质量、诊断信心、有无侵犯、侵犯深度以及特异性 MRI 征象;并对两者的结果进行一致性检验。以术后病理或手术记录作为金标准,分别计算 MRI 诊断胎盘侵犯、侵犯深度以及各个 MRI 征象的敏感性、特异性、阳性预测值和阴性预测值。结果：两者术前诊断达到中度至高度的一致性（κ值为0．478～0．739）。单次激发闭气序列（SSFSE）及矢状面是最佳的 MRI 序列和观察方位。MRI 诊断胎盘侵犯的敏感度和特异度为79．4％和66．7％;诊断胎盘粘连、植入和穿透的敏感度分别为28．4％,70．6％和33．3％。胎盘与肌层间低信号带缺失在胎盘侵犯中的出现率明显高于无胎盘侵犯（P ＝0．027）,其胎盘侵犯的阳性预测值为83．95％,敏感度为76．5％。胎盘与肌层间低信号带缺失和 T2 WI 上结节状低信号带同时出现的阳性预测值达到92．3％,但敏感度仅为35．3％。胎盘与肌层间低信号带缺失和子宫下段膨隆同时出现的阳性预测值是100％,但敏感性仅为23．5％。结论：MRI 判断有无胎盘侵犯具有较高的敏感性和特异性。判断侵犯深度（粘连、植入和穿透）时敏感性偏低。MRI 征象判断胎盘植入具有较高的阳性预测值,但是敏感性偏低。     

非对比增强MRA诊断轻中度肾功能不全合并肺栓塞

目的：探讨空间标记多反转脉冲序列（SLEEK）非增强 MR 血管成像对轻中度肾功能不全合并肺栓塞（PE）的诊断准确性。方法：16例经CT肺动脉血管成像诊断为肺栓塞的轻中度肾功能不全患者,于CTPA检查48小时内行非增强SLEEK MRA检查。由2位放射诊断医师对图像进行分析,以CTPA作为参考标准,分别计算基于肺血管分区（8个分区）和每个栓子,非增强SLEEK MRA诊断肺栓子的敏感性、特异性、阳性预测值以及阴性预测值,并对2位医师诊断结果的一致性进行统计学分析。结果：按栓子的肺血管分区来统计,非增强SLEEK MRA 诊断肺栓子的敏感度为84．5％,特异度100％,阳性预测值为100％,阴性预测值88．6％;基于每个栓子来进行分析,敏感度为78．0％,特异度99．7％,阳性预测值98．9％,阴性预测值92．7％。两位阅片者间诊断结果的一致性较好（Kappa＝0．76）。结论：CTPA 和（非增强） SLEEK MRA诊断肺栓塞的准确性无明显差异,但非增强SLEEK MRA无需使用对比剂,有利于肾功能不全怀疑肺栓塞患者的诊断。     

肺灌注显像结合Wells评分及D-二聚体检查对急性肺血栓栓塞症的诊断价值

目的评价肺灌注显像结合Wells评分及D-二聚体检查对急性肺血栓栓塞症（APE）的诊断价值。方法选择2006年1月至2008年12月连续121例疑诊APE的初诊患者,所有患者均进行Wells评分、D-二聚体检查、胸部X线检查及核素肺灌注显像。分别计算肺灌注显像结合x线胸片（Q／X显像）、Q／X显像结合Wells评分或（和）D-二聚体检查用于诊断APE的灵敏度、特异性、阳性预测值和阴性预测值。结果全部121例患者中,41．3％（50／121）的患者最终诊断为APE;58．7％（71／121）最终排除了APE。Q／X显像示APE阳性者49例（40．5％）。Q／X显像的诊断灵敏度、特异性、阳性预测值、阴性预测值分别为86．O％（43／50）、91．5％（65／71）、87．8％（43／49）和90．3％（65／72）。Q／x显像对于Wells评分〉4且D-二聚体阳性（≥0．5mg／L）的患者,其APE阳性预测值为100．0％（29／29）;Q／X显像对Wells评分≤4且D-二聚体阴性（〈0．5mg／L）的患者,其APE阴性预测值亦为100．0％（41／41）。结论Q／X显像结合Wells评分及D-二聚体检查可以有效提高Q／X显像诊断APE的阳性预测值和阴性预测值,从而更准确地诊断APE。     

Solitary pulmonary nodule on helical dynamic CT scans: analysis of the enhancement patterns using a computer-aided diagnosis (CAD) system

OBJECTIVE: We wanted to investigate the usefulness of a computer-aided diagnosis (CAD) system in assisting radiologists to diagnosis malignant solitary pulmonary nodules (SPNs), as compared with diagnosing SPNs with using direct personal drawing. MATERIALS AND METHODS: Forty patients with SPNs were analyzed. After the pre-contrast scan was performed, an additional ten series of post-contrast images were obtained at 20-second intervals. Two investigators measured the attenuation values of the SPNs: a radiologist who drew the regions of interest (ROIs), and a technician who used a CAD system. The Bland and Altman plots were used to compare the net enhancement between a CAD system and direct personal drawing. The diagnostic characteristics of the malignant SPNs were calculated by considering the CAD and direct personal drawing and with using Fisher's exact test. RESULTS: On the Bland and Altman plot, the net enhancement difference between the CAD system and direct personal drawing was not significant (within +/- 2 standard deriation). The sensitivity, specificity, positive predictive value (PPV), negative predictive value (NPV) and accuracy of diagnosing malignant SPNs using CAD was 92%, 85%, 75%, 96% and 88%, respectively. The sensitivity, specificity, PPV, NPV and accuracy of diagnosing malignant SPNs using direct drawing was 92%, 89%, 79%, 92% and 88%, respectively. CONCLUSION: The CAD system was a useful tool for diagnosing malignant SPNs.     

~(18)F-FDG PET-CT和双源CT的LungCare软件在评估孤立性肺结节中的比较研究

目的 探讨18-氟-脱氧葡萄糖(~(18)F-FDG)PET/CT显像及Siemens双源CT的LungCare软件对孤立性肺结节(SPN)的辅助诊断能力及适用范围.方法 回顾分析经病理证实的24例SPN患者的PET-CT图像资料,并与利用双源CT的LungCare软件分析SPN进行比较研究.用χ~2检验对2种检查方法的评价结果进行统计学分析,以P<0.05作为差异有显著意义.结果 在24例SPN中,恶性结节15例,良性结节9例.LungCare软件评估其良恶性的准确性、敏感性、特异性、阳性预测值、阴性预测值分别为83.3%、80.0%、88.8%、92.3%、72.7%,PET-CT评估其良恶性的准确性、敏感性、特异性、阳性预测值、阴性预测值分别为87.5%、93.3%、77.7%,87.5%、87.5%.LungCare软件和PET/CT定性SPN的准确性相当,两者之间并不存在明显的差异(P>0.05).PET/CT的敏感性、阴性预测值明显高于LungCare软件,但其特异性、阳性预测值明显低于LungCare软件(P<0.05).结论 ~(18)F-FDG PET-CT对肺结节的诊断有一定辅助作用,适用于对孤立性肺结节的良恶性鉴别诊断.PET/CT密切结合LungCare软件,可进一步提高诊断正确率.     

18F-FDG PET/CT结合高分辨率CT对孤立性肺结节的

 目的 探讨18F-FDG PET/CT显像结合高分辨率CT(high resolution CT,HRCT)对孤立性肺结节(solitary pulmonary nodule,SPN)的诊断价值。方法 回顾性分析124例SPN患者的18F-FDG PET/CT检查资料,其中76例加做HRCT扫描,所有病例经病理或临床随访证实。18F-FDG PET/CT通过目测法和半定量法判断病灶的代谢情况,结合CT或HRCT病灶的形态学特征判断良、恶性。结果 48例仅行18F-FDG PET/CT检查的SPN患者,正确诊断32例为恶性,8例为良性,假阳性与假阴性各4例。76例加做HRCT的患者,正确诊断62例恶性与8例良性,假阳性与假阴性分别为2例和4例。18F-FDG PET/CT 结合HRCT与单纯18F-FDG PET/CT诊断SPN的灵敏度、特异性及准确率分别为94%、80%、90%与89%、67%、83%。结论 18F-FDG PET/CT协同HRCT可提高对SPN性质判断的灵敏度、特异性及准确率。     

Integrated multislice CT and Tc–99m Sestamibi SPECT–CT evaluation of solitary pulmonary nodules

PURPOSE: The purpose of this study was to evaluate efficacy of multislice computed tomography (MSCT) and single photon emission computed tomography (SPECT)-CT with Tc-99m Sestamibi in the assessment of solitary pulmonary nodules of uncertain significance. Scintigraphy was performed using a 'hybrid' g-camera that allows simultaneous acquisition of SPECT and CT images, with interesting results in diagnostic oncology. MATERIALS AND METHODS: Between September 2003 and August 2004, 23 patients with a solitary pulmonary nodule detected on CT underwent SPECT-CT using Tc-99m Sestamibi as a radiotracer. Nodules with positive scintigraphy were immediately subjected to biopsy or surgical resection. Nodules with negative scintigraphy were followed up after 3-4 months by MSCT with automatic segmentation software (Advanced Lung Analysis, ALA) and histological characterisation. RESULTS: Of the 23 nodules (size range 0.8-2 cm) discovered with MSCT, 11 showed intense uptake of Tc-99m Sestamibi. Ten lesions were true positive: seven adenocarcinomas, one squamous cell carcinoma, one large cell carcinoma and one metastasis. The only false positive was histologically classified as a large cell granuloma. Twelve lesions had negative scintigraphy: five fibrous lesions, three hamartomas, three granulomas and one adenocarcinoma (false negative). Benign nodules without tracer uptake underwent another CT scan 3-4 months later, which confirmed stability of the nodule size. Correlation of Sestamibi SPECT with histology showed sensitivity (Se) of 90.9 %, specificity (Sp) of 91.6 %, diagnostic accuracy of 91.3 %, positive predictive value (PPV) of 90.9% and negative predictive value (NPV) of 91.6 %. CONCLUSIONS: The integrated use of MSCT and Tc-99m Sestamibi SPECT-CT could be very useful in the management of solitary pulmonary nodules (SPNs). In particular, in our preliminary study, scintigraphy provided significant diagnostic information to differentiate benign from suspicious pulmonary nodules. The use of scintigraphy could be helpful to anticipate histological assessment and surgical treatment of SPNs identified at CT.     

99Tcm-MIBI显像与钼靶X线对乳腺癌诊断的比较研究

目的 比较99Tcm-MIBI SPECT/CT显像和钼靶X线对女性乳腺癌的诊断价值。 方法 女性患者83例, 先行99Tcm-MIBI胸部SPECT/CT早期显像和延迟显像, 并以延迟显像阳性为判定标准, 再行乳腺钼靶X线摄影, 并与最终的病理结果进行对照。 结果 延迟显像的阳性患者为52例(T/NT值>3.33), 阳性与阴性病灶的早期、延迟显像分别比较, 差异均有统计学意义, 且以延时2 h结果更为显著, 最终病理结果证实45例为恶性病灶。99Tcm-MIBI显像结果的灵敏度为93.33%、特异度为73.68%、阳性预测值为80.77%、阴性预测值为90.32%;而钼靶X线对于相同病灶的灵敏度、特异度分别为64.44%、73.68%, 阳性、阴性预测值分别为74.36%、63.63%。99Tcm-MIBI显像对乳腺癌诊断价值优于钼靶X线(χ2=4.11, P < 0.05), 但两种方法的一致性较差(Kappa=0.217, P < 0.05)。 结论 99Tcm-MIBI显像较之钼靶X线的结果判定更为客观, 而两种方法同时运用则能提高乳腺癌的检出率, 显著提高影像学对于乳腺癌的早期诊断。     

Optimization of the scanning technique and diagnosis of pulmonary nodules with first-pass 64-detector-row perfusion VCT

ObjectiveThe aims of this study were to optimize the scanning technique of first-pass 64-detector-row perfusion volume computed tomography imaging, to evaluate the effectiveness and stability of this scan protocol, and lastly to evaluate the differential diagnosis ability of perfusion imaging in solitary pulmonary nodules (SPNs).MethodsA total of 144 patients with SPNs underwent perfusion scan with 64-slice spiral CT scanner. The CT perfusion imaging was analyzed for time–density curve, perfusion parametric maps, and the respective perfusion parameters. We then analyzed the main factors concerning the imaging quality and evaluated the effectiveness of scan protocol by determining the receiver operating characteristic (ROC) curve, diagnostic efficacy, and odds ratio as well as the stability of scan protocol by consistency analysis. Immunohistochemical findings of microvessel density measurement and vascular endothelial growth factor expression were evaluated.ResultsThe total sensitivity, specificity, accuracy, positive predictive value, negative predictive value, likelihood ratio, and the area under ROC curve during 5–45-s scan period were 78.95%, 82.4%, 80.6%, 83.3%, 77.8%, 4.620, 0.280, and 0.840, respectively, and Kappa value was 0.894. The diagnostic efficacy of CT pulmonary perfusion was significantly higher than during 0–40-s scan period. The parameter values in different nodules were different.ConclusionThe optimized 5–45-s scan period of CT pulmonary perfusion imaging is effective in pathologic diagnosis and has good stability, worthy of being popularized. Lung perfusion CT could be a promising and feasible method for differentiation of SPNs.     

Solitary pulmonary nodules: morphological and metabolic characterisation by FDG-PET-MDCT

PURPOSE: This study was done to analyse the additional morphological and functional information provided by the integration of [18F]-2-fluoro-2-deoxy-D-glucose positron emission tomography ([18F]-FDG-PET) with contrast-enhanced multidetector computed tomography (MDCT) in the characterisation of indeterminate solitary pulmonary nodules (SPNs). MATERIALS AND METHODS: Fifty-six SPNs, previously classified as indeterminate, were evaluated using a Discovery ST16 PET/CT system (GE Medical Systems) with nonionic iodinated contrast material and [18F]-FDG as a positron emitter. Images were evaluated on a dedicated workstation. Semiquantitative parameters of [18F]-FDG uptake and morphological, volumetric and densitometric parameters before and after contrast administration were analysed. Results were correlated with the histological and follow-up findings. RESULTS: Twenty-six SPNs were malignant and 30 were benign. Malignant lesions at both PET/CT and histology had a mean diameter of 1.8+/-1.2 cm, a volume doubling time (DT) of 222 days, a mean standardized uptake value (SUV) of 4.7 versus 1.08 in benign lesions and a mean postcontrast enhancement of 44.8 HU as opposed to 4.8 HU in benign nodules. Malignant lesions had a significantly shorter doubling time and significantly greater postcontrast enhancement compared with benign nodules. Based on the SUV and using a cut-off value of >2.5, PET/CT had a sensitivity of 76.9%, specificity of 100%, diagnostic accuracy of 89.2%, positive predictive value (PPV) of 100% and negative predictive value (NPV) of 83.3%. Based on doubling time (cut off<400 days), it had a sensitivity of 76.9%, specificity of 93.3%, accuracy of 85.7%, PPV of 90.9% and NPV of 82.3%. Based on postcontrast enhancement (cut off>15 HU), it had a sensitivity of 92.3%, specificity of 100%, accuracy of 96.4%, PPV of 100% and NPV of 93.7%. CONCLUSION: PET/CT allows accurate analysis of anatomical/morphological and metabolic/functional correlations of SPN, providing useful data for identifying and locating the disease, for differentiating between malignant and benign nodules and for establishing the aggressiveness and degree of vascularity of pulmonary lesions. Therefore, partly in view of the considerable reduction in time and cost of the single examinations, we believe that PET/CT will gain an increasingly dominant role in the diagnostic and therapeutic approach to lung cancer, especially in the preclinical phase.     

Differential diagnosis of solitary pulmonary nodules based on 99mTc-EDDA/HYNIC-TOC scintigraphy: the effect of tumour size on the optimal method of image assessment

Purpose The aim of the study was to determine an optimal method for the evaluation of scintigrams obtained with ^99mTc-EDDA/HYNIC-TOC for the purpose of differential diagnosis of solitary pulmonary nodules (SPNs) and to assess the diagnostic value of the method. Methods Eighty-five patients (48 males and 37 females, mean age 57 years, range 34–78 years) were enrolled in the study. Patients underwent ^99mTc-EDDA/HYNIC-TOC scintigraphy for the purpose of differential diagnosis of SPNs (size between 1 and 4 cm). Images of all patients were evaluated visually in a prospective manner. Results Positive scintigraphic results were found in 37 out of 40 (93%) patients with malignant SPNs including 34 out of 35 (97%) patients with primary lung carcinoma. Two remaining false negative cases turned out to be metastatic lesions of malignant melanoma and leiomyosarcoma. Among 45 benign tumours, negative results were obtained in 31 cases (69%) and positive results in 14. The accuracy of the method was 80%. Analysis of the results of the visual assessment of scintigrams revealed a significantly higher frequency of false positive results among larger nodules (diameter at least 1.4 cm). Uptake of the tracer in those nodules was therefore assessed semi-quantitatively (using the tumour-to-background ratio), in expectation of an improvement in the low specificity of the visual method. The semi-quantitative assessment reduced the total number of false positive results in a subgroup of larger nodules from 13 to six, while preserving the high sensitivity of the method. Conclusion The combination of visual analysis (for lesions smaller than 1.4 cm in diameter) and semi-quantitative assessment (for larger lesions) provided a high sensitivity of the method and significantly improved its specificity (84%) and accuracy (88%) in comparison with visual analysis (p<0.05).     

PET/CT诊断孤立性肺结节的价值

目的 评价PET/CT在鉴别诊断孤立性肺结节（SPNs）的价值.方法 经病理或临床随访证实的143例SPNs均行PET/CT扫描,根据结节PET的代谢特点进行PET诊断,根据CT的形态学特点进行CT诊断,PET/CT则结合PET的代谢特点及CT的形态学特点进行综合判定SPNs的性质.结果 恶性SPNs的最大标准摄取值（SUV-max）（mean 6.08±4.57,n=120）明显高于良性结节（mean 2.73±2.16,n=23）,并且有统计学意义（t＇=5.45,P＜0.001）.低分化、中分化恶性肿瘤的SUVmax（mean 8.46±4.29,5.67士4.57）均明显高于高分化恶性肿瘤（mean 3.22±4.58）,并且有统计学意义（t＇=6.16,P＜0.001;t＇=2.86,P＜0.01）;低分化恶性肿瘤的SUVmax（mean 8.46±4.29）明显高于中分化恶性肿瘤（mean 5.67±4.57）,并且有统计学意义（t＇=3.01,P＜0.01）.PET/CT诊断恶性SPNs的敏感度、特异度、准确度、阳性预测值、阴性预测值（96.7％、73.9％、93％、95.1％、81％）均较单独利用CT（86％、72.7％、83.9％、94.5％、48.5％）和单独利用PET（80.8％、52.2％、76.2％、89.8％、34.3％）高.结论 PET/CT可以提高诊断孤立肺结节的准确度及把握度.     

Clinical results of CsI-detector-based dual-exposure dual energy in chest radiography

The aim of this study was to compare the sensitivity and specificity of digital chest radiography alone with digital chest radiography combined with dual-energy chest radiography in the detection of small non-calcified pulmonary nodules. Standard and dual-energy radiographs were obtained with a flat-panel digital chest system. Four radiologists reviewed digital posteroanterior chest radiographs in random order either alone or in conjunction with dual-energy soft tissue and bone images. Twenty patients with a total of 59 pulmonary nodules (median 0.5 cm, range 0.3 – 2.5 cm) confirmed by computed tomography (HU 100) were included. A level of confidence for each diagnosis was documented using a rating scale of 1–5. Brunner and Langer's test was performed for statistical analysis. Subgroup analysis was performed for nodules greater than 1 cm, 1–0.5 cm, and <0.5 cm. For posteroanterior chest radiography, sensitivity was 33%, positive predictive value 83%, specificity 81%, and negative predictive value 30%. Review in conjunction with dual-energy images resulted in a sensitivity of 42%, positive predictive value 88%, specificity 85%, and negative predictive value 34%. The increase of nodule detection overall as well as for different size categories was significant (p<0.05). The increase of the confidence level rating was also significant (p<0.001). Dual energy added to standard posteroanterior chest radiography significantly improves the sensitivity, specificity, and confidence in detection of small non-calcified pulmonary nodules.