Hard-copy versus soft-copy image reading for detection of ureteral stones on abdominal radiography

PURPOSE: The purpose of this study was to compare the usefulness of soft-copy images displayed on a cathode ray tube (CRT) with hard-copy images (film images) for detecting ureteral stones on abdominal radiography. MATERIALS AND METHODS: Five radiologists read images from 50 cases of ureteral stones and 50 normal cases diagnosed on the basis of intravenous urography and CT. For hard-copy reading, 10-bit images at 3,520x4,280 pixels obtained by computed radiography were printed on 14x17-inch films. For soft-copy reading, 8-bit images were displayed on a 17-inch monochrome monitor at 1,024x1,280 pixels. The study items were area under receiver operating characteristics (ROC) curve (Az), ureteral stone detection sensitivity and specificity, and reading time. RESULTS: For soft-copy and hard-copy images, the average Az values were 0.855 and 0.851, sensitivity was 62.8% and 62%, and specificity was 70.8% and 62.4%, respectively. There were no statistically significant differences between these values. Reading time was 106.6 min for soft-copy images, significantly longer than the 71.2 min for hard-copy images (p<0.05). CONCLUSION: Although soft-copy image reading time was longer than hard-copy image reading time, the ability to diagnose ureteral stones on abdominal radiography did not differ for soft- and hard-copy images.     

不同大小和密度肺结节DR摄影:使用和不使用计算机辅助检测的比较

目的:评价DR摄影与计算机辅助检测对肺结节的大小和密度诊断测量的相关性.方法:选取177例(186个结节)经CT证实存在肺小结节的DR胸片和180例正常DR胸片,结节直径5～20mm.应用受试者操作特性曲线(ROC)分析未使用和使用CAD系统对不同大小(D)和密度肺结节检测结果的差异.结果:对于诊断3组不同大小(5 m...     

相同分辨力不同品牌影像诊断显示器对孤立性肺结节识读的影响

目的：通过不同品牌间相同分辨力的影像诊断显示器对胸部数字化X线摄影（DR）肺结节检出准确率的比较,评价品牌之间显示器的诊断效能。方法：从图像存储与传输系统（PACS）数据库中搜寻本院2005年3月～2008年12月胸部DR中发现或可疑有肺结节者行CT检查,CT发现单发、直径≤30mm的结节,列为阳性组;而CT证实无结节者列入阴性组。5位医师分别应用三种品牌显示器用5分法：肯定有、可能有、不确定、可能无、肯定无,独立判断结节有无。利用识读结果绘制ROC曲线,并比较曲线下面积及各品牌显示器之间的诊断效能。结果：5位影像诊断医师在3个品牌显示器中对1～10mm组孤立性肺结节识读的总平均值分别为Az（A）=0.877±0.053,Az（B）=0.895±0.050,Az（C）=0.887±0.051,对10～30mm组孤立性肺结节识读的总平均值分别为Az（A）=0.891±0.045,Az（B）=0.901±0.044,Az（C）=0.892±0.045。所使用的三种显示器中,由于分辨力相同,3百万象素（3MP）,从ROC曲线中可以看出,曲线下的面积Az虽然是有差别的,但都接近于0.9,说明3MP的液晶显示器（LCD）在孤立性肺结节的诊断效能是比较高的,其中品牌B的面积最大。经过统计学检验,P值有所不同。结论：3MP显示器在肺结节识读影像上差异具有统计学意义,但总的诊断效能无明显差异。     

Comparison of observer performance on soft-copy reading of digital chest radiographs: high resolution liquid-crystal display monitors versus cathode-ray tube monitors

The purpose of this study is to compare observer performance for detection of abnormalities on chest radiographs with 5-megapixel resolution liquid-crystal displays (LCD) and 5-megapixel resolution cathode-ray tube (CRT) monitors under bright and subdued ambient light conditions. Six radiologists reviewed a total of 254 digital chest radiographs under four different conditions with a combination of two types of monitors (a 5-megapixel resolution LCD and a 5-megapixel resolution CRT monitor) and with two types of ambient light (460 and 50 lux). The abnormalities analyzed were nodules, pneumothorax and interstitial lung disease. For each reader, the detection performance using 5-megapixel LCD and 5-megapixel CRT monitors under bright and subdued ambient light conditions were compared using multi-case and multi-modality ROC analysis. For each type of ambient light, the average detection performance with the two types of monitors was also compared. For each reader, the observer performance of 5-megapixel LCD and 5-megapixel CRT monitors, under both bright and subdued ambient light conditions, showed no significant statistical differences for detecting nodules, pneumothorax and interstitial lung disease. In addition, there was no significant statistical difference in the average performance when the two monitor displays, under both bright and subdued ambient light conditions, were compared.     

计算机辅助检测肺结节在数字化X线胸片肺癌筛查中的应用价值

目的 评价计算机辅助检测(CAD)肺结节系统在数字化X线胸片上肺癌筛查中的应用价值.方法 由1名放射科医师和CAD肺结节检测系统独立阅读100例连续的数字摄影(DR)X线胸片,CAD系统可以检出最长直径在5～15 mm的肺结节.由2名放射科专家(有15年胸部影像诊断经验)进行回顾性阅读,参照相应的CT图像,两人意见达成一致后标记真结节的个数和位置并保存标记结果,将标记结果作为金标准来比较放射科医师和CAD系统的肺结节检测敏感性和假阳性率.结果 放射科医师共检测到95个结节,CAD系统共检测到304个结节.在回顾性检查中2名放射科专家共标记134个真结节,其中放射科医师检测到82个(61.2%),CAD检测到105个(78.4%),CAD系统检测到而被放射科医师漏诊的结节35个,放射科医师检测到而CAD系统漏诊的结节10个.放射科医师应用CAD系统后检测到112个真结节,检测率提高到83.6%.放射科专家意见一致后认为CAD系统检出199个假阳性结节,平均每张胸片约2.0个.结论 在肺癌筛查中放射科医师和CAD系统必须联合应用才可以识别X线胸片中所有的结节.     

Detection of pulmonary nodules with overlapping vs non-overlapping image reconstruction at spiral CT

The aim of this study was to analyze whether overlapping image reconstruction increases numbers of pulmonary nodules detected at helical CT. Forty-eight helical CT scans (21with a slice thickness of 10 mm; 27 with a slice thickness of 5 mm) of patients with known pulmonary nodules were reconstructed both with overlapping and non-overlapping image reconstruction. Two readers recorded number and size of pulmonary nodules as well as diagnostic confidence. With overlapping image reconstruction each reader diagnosed more pulmonary nodules (slice thickness 10 mm: +24.0 and +26.7 %, both p < 0.01; slice thickness 5 mm: +9.5 and +11.9 %, both not significant) and more “definite” nodules (slice thickness 10 mm: +20.3 %, p < 0.05, and +30.8 %, p < 0.005; slice thickness 5 mm: +18.0 and +17.0 %, both p < 0.05). Nodules diagnosed with overlapping image reconstruction only were almost exclusively smaller than the slice thickness. The increase in number of nodules detected was not associated with a decrease in diagnostic confidence. Overlapping image reconstruction improves detection of pulmonary nodules smaller than the slice thickness at spiral CT. Received: 8 April 1998; Revision received: 16 July 1998; Accepted: 9 September 1998     

Subtle pulmonary nodules: detection and identification with storage phosphor radiographs and conventional chest films

To determine the value of digital storage-phosphor radiography (SR) on the detection and identification of subtle lung nodules, postero-anterior (PA) and lateral (LAT) film-screen (FR) chest radiographs were compared with isodose SR images of 45 patients with metastatic malignancies. The SR postprocessing was done with a particular mode previously optimized for routine chest radiography. Pulmonary metastases were found in 34 patients and were proved or excluded by CT (n = 28) or longterm follow-up FR (n = 17). Chest images were divided into four regions for evaluation of image quality, number of lung nodules per region and marked pulmonary structures by receiver-operating characteristics (ROC) analysis (45 patients; 125 nodules; 2810 observations; five readers). Of the nodules selected for an ROC study 82 % were 0.5–1.0 cm in diameter. Overall image quality was rated better for FR concerning lung fields (PA) and mediastinum/hilum (LAT). More lung-field nodules were detected on FR than on SR chest images (P < 0.05). Use of FR was superior to SR in the general identification of nodules (PA chest), especially concerning intermediate (P < 0.01) and subtle abnormalities (P < 0.05), whereas there was no significant difference for LAT chest images. Our results show, that currently FR still has advantages over SR in the detection and identification of subtle lung nodules in routine clinical radiography. Correspondence to: R. Scheck     

Comparison of low-dose and standard-dose helical CT in the evaluation of pulmonary nodules

The purpose of this study was to investigate the diagnostic accuracy of low-dose helical computed tomography by comparing the number of nodules detected at low- and standard-dose CT. The prospective study included 25 patients who were referred to CT scan for the assessment of pulmonary metastases. All patients underwent CT examinations at both standard- (200 mA, 120 kV, collimation 5 mm, table feed 10 mm per rotation) and low-dose (50 mA, 120 kV, collimation 5 mm, table feed 10 mm per rotation). The number of nodules detected at each protocol was recorded. The size of the nodules was measured electronically and categorized as <3, 3–4.9, 5–6.9, 7–9.9, and ≥10 mm. Finally, the nodules detected at only standard- or low-dose CT were assessed for the underlying causes of discrepancy. In 25 patients, 533 nodules were detected at standard-dose, whereas 518 nodules were observed at low-dose CT. There were no statistically significant differences in the number of nodules detected at standard- or low-dose CT (p>0.05). Four hundred ninety-one (87.7%) nodules were detected at both standard- or low-dose CT, 42 (7.5%) nodules were observed only at standard-dose CT, and 27 (4.8%) nodules were seen only at low-dose CT. The sensitivity of low-dose CT was 92.5% for all nodules, 88.1% for nodules <5 mm, and 97.4% for nodules ≥5 mm. No significant image artifact interfering with nodule detection was observed at low-dose CT. The low-dose CT protocol used in this study provided images of adequate quality; thus, it can be used reliably in the detection or exclusion of pulmonary nodules. Electronic Publication     

数字化体层融合在肺结节探查中的初步应用

目的 探讨数字化体层融合在肺结节探查中的应用价值.方法 30例疑有肺内结节的患者,均先后行胸部X线平片、体层融合和CT检查.将上述影像资料传至后处理工作站,由2名具有3年以上胸部影像诊断经验的医师分别进行双盲法阅片,观察每例患者肺部结节的数量,每个肺结节的部位、大小.然后,2名阅片者再共同阅片,使单独阅片不一致的结果得到统一.以CT结果作为标准,分别计算胸部X线平片和体层融合探查肺结节的敏感性.采用配对四格表资料的X~2检验比较两者的差异性.结果 30例患者,胸部X线平片检查9例阴性,21例阳性,共发现肺结节40个.体层融合检查4例阴性,26例阳性,共发现肺结节89个.CT检查3例阴性,27例阳性,共发现肺结节102个.以CT作为标准对照,胸部X线平片探查肺结节的敏感性为27.4%(28/102),体层融合的敏感性为87.2%(89/102),差异有统计学意义(X~2=4.35,P<0.05).结论 数字化体层融合可显著提高肺结节探查的敏感性,可以作为胸部X线平片良好和必要的补充.     

Quantitative and qualitative assessment of non-contrast-enhanced pulmonary MR imaging for management of pulmonary nodules in 161 subjects

This study aimed at prospectively compared efficacy of non-contrast-enhanced (non-CE) MRI and MDCT for management of pulmonary nodules. A total of 161 patients with 200 nodules underwent MDCT and non-CE MRI (T1WI, T2WI, and STIR) in conjunction with pathological and/or more than 2 years of follow-up examinations. To compare qualitative detection rates between both modalities, all nodules were visually assessed. To compare quantitative and qualitative diagnostic capabilities of MRI, calculation of contrast ratio and visual assessment of probability for malignancy in each nodule were performed. Then, detection rate and diagnostic capability were statistically compared. Although the overall detection rate of each MR sequence (82.5%) was significantly lower than that of MDCT (97.0%, p < 0.05), that of malignant nodules showed no significant difference (p > 0.05). The diagnostic capability of STIR was significantly higher than those of other MR sequences (p < 0.05). Non-CE MR imaging was found to be as useful as MDCT for management of pulmonary nodules.     

Bone suppressed images improve radiologists’ detection performance for pulmonary nodules in chest radiographs

Objectives

To assess the effect of bone suppression imaging on observer performance in detecting lung nodules in chest radiographs.

Materials and methods

Posteroanterior (PA) and lateral digital chest radiographs of 111 (average age 65) patients with a CT proven solitary nodule (median diameter 15 mm), and 189 (average age 63) controls were read by 5 radiologists and 3 residents. Conspicuity of nodules on the radiographs was classified in obvious (n = 32), moderate (n = 32), subtle (n = 29) and very subtle (n = 18). Observers read the PA and lateral chest radiographs without and with an additional PA bone suppressed image (BSI) (ClearRead Bone Suppression 2.4, Riverain Technologies, Ohio) within one reading session. Multi reader multi case (MRMC) receiver operating characteristics (ROC) were used for statistical analysis.

Results

ROC analysis showed improved detection with use of BSI compared to chest radiographs alone (AUC = 0.883 versus 0.855; p = 0.004). Performance also increased at high specificities exceeding 80% (pAUC = 0.136 versus 0.124; p = 0.0007). Operating at a specificity of 90%, sensitivity increased with BSI from 66% to 71% (p = 0.0004). Increase of detection performance was highest for nodules with moderate and subtle conspicuity (p = 0.02; p = 0.03).

Conclusion

Bone suppressed images improve radiologists’ detection performance for pulmonary nodules, especially for those of moderate and subtle conspicuity.     

Computer-aided detection of pulmonary nodules: influence of nodule characteristics on detection performance

AIM: To evaluate prospectively the influence of pulmonary nodule characteristics on detection performances of a computer-aided diagnosis (CAD) tool and experienced chest radiologists using multislice CT (MSCT). MATERIALS AND METHODS: MSCT scans of 20 consecutive patients were evaluated by a CAD system and two independent chest radiologists for presence of pulmonary nodules. Nodule size, position, margin, matrix characteristics, vascular and pleural attachments and reader confidence were recorded and data compared with an independent standard of reference. Statistical analysis for predictors influencing nodule detection or reader performance included chi-squared, retrograde stepwise conditional logistic regression with odds ratios and nodule detection proportion estimates (DPE), and ROC analysis. RESULTS: For 135 nodules, detection rates for CAD and readers were 76.3, 52.6 and 52.6%, respectively; false-positive rates were 0.55, 0.25 and 0.15 per examination, respectively. In consensus with CAD the reader detection rate increased to 93.3%, and the false-positive rate dropped to 0.1/scan. DPEs for nodules < or = 5 mm were significantly higher for ICAD than for the readers (p < 0.05). Absence of vascular attachment was the only significant predictor of nodule detection by CAD (p = 0.0006-0.008). There were no predictors of nodule detection for reader consensus with CAD. In contrast, vascular attachment predicted nodule detection by the readers (p = 0.0001-0.003). Reader sensitivity was higher for nodules with vascular attachment than for unattached nodules (sensitivities 0.768 and 0.369; 95% confidence intervals = 0.651-0.861 and 0.253-0.498, respectively). CONCLUSION: CAD increases nodule detection rates, decreases false-positive rates and compensates for deficient reader performance in detection of smallest lesions and of nodules without vascular attachment.     

CT的分叶征表现在肺内孤立结节影像诊断中的价值

目的探讨CT的分叶征表现在肺内孤立结节影像诊断的价值以及CT多平面重组（MPR）对此征检出的意义。方法观察病理证实的周围型小肺癌137例及良性肺内结节45例，将结节的边缘分为4型。对28例肺癌、22例良性结节行MPR，考察其显示分叶征的作用。引入可能性比值（likelihood ratios，LR）以量化良恶性病变在形态学上存在重叠的表现。结果Ⅰ型边缘结节对良性病变的特异性为83．3％（20／24），敏感性为44．4％（20／45）。Ⅳ型边缘结节对周围型小肺癌的特异性为97．6％（83／85），敏感性为60．7％（83／137）。表明Ⅰ型边缘是良性病变的特点；而Ⅳ型边缘是恶性病变的特征。Ⅳ型边缘的结节恶性病变在MPR重组图像上的检出率为64．3％（18／28），与横断面扫描差异有统计学意义（P〈0．01）。结论分叶征对肺内孤立结节的诊断有价值，MPR配合横断面薄层图像有助于提高该征的检出率。     

不同显示矩阵影像诊断工作站识读肺部小结节的初步研究

目的　评价不同显示矩阵的影像诊断工作站对识读肺部小结节的影响。方法　选取76张计算机摄影 (CR)胸片 ,其中 36张含有CT证实的直径 <2cm的小结节 ,分为 1 0～ 2 0cm及<1 0cm 2组。 3位诊断医师分别在 1K、2K显示器和数字会诊系统的投影屏幕上识读胸片影像 ,用5分法 :肯定有、可能有、不确定、可能没有、肯定没有 ,独立判断结节存在与否。绘制受试者操作特性(ROC)曲线 ,计算每位医师分别在 1K和 2K的影像诊断工作站及数字会诊系统上识读直径 1 0～2 0cm及 <1 0cm 2组肺部小结节的ROC曲线下的面积 (AZ 值 )及标准误 [s x(AZ) ],并进行比较。结果　 3位诊断医师在数字会诊系统、1K及 2K显示器下检测肺部小结节的平均ROC的AZ 值分别为 :直径 1 0～ 2 0cm组 :0 7936、0 82 2 5、0 836 7;<1 0cm组 :0 6 6 98、0 6 998、0 72 32。随着显示器分辨率的提高 ,AZ 值随之提高 ,但是经ROC分析 ,不同观片系统的检测效能差异无显著性意义 (P>0 5 )。结论　用 1K显示器、数字影像会诊系统加用影像后处理 ,特别是放大功能 ,识读肺部直径≥ 1 0cm的小结节是可以的 ,识读肺部 <1 0cm的小结节宜采用 2K× 2K高分辨率工作站。不同显示矩阵的观片系统的合理配置 ,可获得较好的性价比及保证诊断准确性。     

Volumetric measurements of pulmonary nodules at multi-row detector CT: in vivo reproducibility

The aim of this study was to assess the in vivo measurement precision of a software tool for volumetric analysis of pulmonary nodules from two consecutive low-dose multi-row detector CT scans. A total of 151 pulmonary nodules (diameter 2.2–20.5 mm, mean diameter 7.4±4.5 mm) in ten subjects with pulmonary metastases were examined with low-dose four-detector-row CT (120 kVp, 20 mAs (effective), collimation 4×1 mm, normalized pitch 1.75, slice thickness 1.25 mm, reconstruction increment 0.8 mm; Somatom VolumeZoom, Siemens). Two consecutive low-dose scans covering the whole lung were performed within 10 min. Nodule volume was determined for all pulmonary nodules visually detected in both scans using the volumetry tool included in the Siemens LungCare software. The 95% limits of agreement between nodule volume measurements on different scans were calculated using the Bland and Altman method for assessing measurement agreement. Intra- and interobserver agreement of volume measurement were determined using repetitive measurements of 50 randomly selected nodules at the same scan by the same and different observers. Taking into account all 151 nodules, 95% limits of agreement were –20.4 to 21.9% (standard error 1.5%); they were –19.3 to 20.4% (standard error 1.7%) for 105 nodules <10 mm. Limits of agreement were –3.9 to 5.7% for intraobserver and –5.5 to 6.6% for interobserver agreement. Precision of in vivo volumetric analysis of nodules with an automatic volumetry software tool was sufficiently high to allow for detection of clinically relevant growth in small pulmonary nodules.     

The influence of liquid crystal display monitors on observer performance for the detection of interstitial lung markings on both storage phosphor and flat-panel-detector chest radiography

Purpose

To compare observer performance with a flat-panel liquid crystal display (LCD) monitor and with a high-resolution gray-scale cathode ray tube (CRT) monitor in the detection of interstitial lung markings using a silicon flat-panel-detector direct radiography (DR) and storage phosphor computed radiography (CR) in a clinical setting.

Materials and methods

We displayed 39 sets of posteroanterior chest radiographs from the patients who were suspected of interstitial lung disease. Each sets consisted of DR, CR and thin-section CT as the reference standard. Image identities were masked, randomly sorted, and displayed on both five mega pixel (2048 × 2560 × 8 bits) LCD and CRT monitors. Ten radiologists independently rated their confidence in detection for the presence of linear opacities in the four fields of the lungs; right upper, left upper, right lower, and left lower quadrant. Performance of a total 6240 (39 sets × 2 detector systems × 2 monitor system × 4 fields × 10 observers) observations was analyzed by multi-reader multi-case receiver operating characteristic (ROC) analysis. Differences between monitor systems in combinations of detector systems were compared using ANOVA and paired-samples t-test.

Results

Area under curves (AUC) for the presence of linear opacities measured by ROC analysis was higher on the LCDs than CRTs without statistical significance (p = 0.082). AUC was significantly higher on the DR systems than CR systems (p = 0.006). AUC was significantly higher on the LCDs than CRTs for DR systems (p = 0.039) but not different for CR systems (p = 0.301).

Conclusion

In clinical conditions, performance of the LCD monitor appears to be better for detecting interstitial lung markings when interfaced with DR systems.     

Digital skeletal radiography : Reduction of absorbed dose by adaptation of exposure factors and image processing

Purpose: The possibility to reduce the absorbed dose to the patient by increase of tube potential while maintaining the same exposure to the image plate and sufficient image quality in skeletal radiography has been investigated.Material and Methods: Image processing parameters were adjusted to account for an increase in tube potential by 20 kV. Revision of image processing parameters was based on measurements with phantoms constructed to simulate the histogram shape recorded for clinical images. Image quality was evaluated both using image quality criteria and visual grading analysis. Energy imparted was calculated from measurement of the kerma-area-product.Results and Conclusion: Energy imparted was reduced by 20-30% using the modified technique with increased kV. All images were considered of accurate quality for diagnosis and the difference in image quality score was marginal. There was, however, a significant shift towards lower grades for the "high kV" technique using visual grading analysis.     

Detection of pulmonary nodules at spiral CT: comparison of maximum intensity projection sliding slabs and single-image reporting

The aim of this study was to compare numbers of pulmonary nodules detected with maximum intensity projections using a slab thickness of 15 mm (MIP 15) and 30 mm (MIP 30) with single image (SI) presentation of chest CT scans. Two readers reviewed MIP 15, MIP 30, and SI presentations of 10-mm (n = 8) and 5-mm collimation (n = 10) helical CT scans and recorded size, location, and diagnostic confidence (definite, probable) of pulmonary nodules. Readers 1 and 2 recorded more nodules with MIP 15 than with SI: 10-mm collimation, 77/64 and 60/56; 5-mm collimation, 64/60 and 40/36; and more "definite" nodules (10-mm collimation: 68/57 and 51/42; 5-mm collimation: 43/36 and 34/30). MIP 15 also detected more nodules than MIP 30 at 10-mm collimation: 77/72 and 60/50; with no major differences at 5-mm collimation: 64/66 and 40/38; and more "definite" nodules (10-mm collimation: 68/58 and 51/36; 5-mm collimation: 43/39 and 34/29). There were only minor differences between SI and MIP 30. Reading time and image number per study were reduced with MIP presentations by a factor of 1.4-5.3. There were no significant differences in the number of nodules detected with SI, MIP 15, and MIP 30, but MIP presentation reduced reporting time and filming cost when compared with SI reporting. For detection of nodules MIP 15 was slightly superior to MIP 30.     

Detection of masses and calcifications by soft-copy reading: comparison of two postprocessing algorithms for full-field digital mammography

Purpose  The purpose of this study was to determine the effects of a commercially available postprocessing algorithm on the detection of masses and microcalcifications of breast cancer by soft-copy reading. Materials and methods  The study included 64 digital mammograms with 16 histologically proven abnormal findings (eight masses and eight microcalcifications) and 48 normal breasts. Two image-processing algorithms were applied to the digital images, which were acquired using General Electric units. The commercially available advanced and standard postprocessed digital mammograms were evaluated in a localization receiver operating characteristic (ROC) curve experiment involving seven mammography radiographers. Results  The mean area under the ROC curve was 0.921 ± 0.022 for the commercially available advanced postprocessed digital mammograms session and 0.904 ± 0.026 for the standard postprocessed digital mammograms session (P = 0.1953). Observer agreement among the readers was better for the advanced postprocessed digital mammograms than for the standard postprocessed digital mammograms. Conclusion  During soft-copy reading, the interpretation accuracy might be influenced by the postprocessing algorithm.     

计算机辅助检测系统在低剂量CT早期肺癌筛查中的应用研究

目的:评价计算机辅助检测(computed aided detection,CAD)系统在低剂量CT肺癌筛查中的应用价值。方法:120例受检者的胸部低剂量CT图像纳入本研究。采用CAD肺结节自动分析软件(方法 A)、横断面薄层图像结合MIP图像(方法 B)、方法 C(方法 A+B)。方法 B和C由低年资和中年资影像诊断科医师各1名独立完成。以2名高年资影像诊断医师应用方法 C检出的肺结节的一致意见为真结节参照标准。记录检出肺结节的大小、位置和密度,所得数据应用SPSS 16.0软件进行统计学分析。结果:2位高年资医师确定了178个真结节。方法 A检出真结节121个,敏感性为67.98%;低年资和中年资医师应用方法 B检出的真结节数及敏感性分别为97个(54.49%)、142个(79.78%);2位医师应用方法 C检出真结节数及敏感性分别为138个(77.53%)、170个(95.50%)。低年资和中年资医师应用方法 C检出肺结节的敏感性均高于方法B,且差异有统计学意义(P0.001)。低年资和中年资医师应用方法C检出的结节数与参照标准均具有较高的一致性(Kappa=0.718、0.930,P0.001),2位医师之间具有较高的一致性(Kappa=0.784,P0.001)。结论:CAD系统明显提高了影像诊断医师对肺结节的检出能力,具有较高的应用价值。由于CAD系统相对较高的假阴性,在实际工作中尚不能独立应用。