A case of adenocarcinoma with mixed subtypes displaying ground-glass opacity on high-resolution CT

We report a case of adenocarcinoma with mixed subtypes with pleural dissemination and lymphatic permeation, although the CT results showed ground-glass opacity that led to the diagnosis of bronchioloalveolar carcinoma without foci of active fibroblastic proliferation.     

Localized pure ground-glass opacity on high-resolution CT: histologic characteristics

PURPOSE: The aim of this study is to assess the histologic characteristics in cases of localized pure ground-glass opacity (LPGGO) that do not exhibit consolidation on high-resolution CT (HRCT) images. METHOD: Twenty surgically resected lesions from 20 consecutive cases were retrospectively investigated. Each of the 20 lesions had exhibited LPGGO on HRCT images. The HRCT images and histopathologic findings were examined for correlations. RESULTS: The areas of LPGGO had a maximum diameter of 2.0-24 mm on the HRCT images. Histopathology of the LPGGO lesions resulted in diagnosis of fibrosis (n = 3; 15%), atypical adenomatous hyperplasia (n = 5; 25%), bronchioloalveolar carcinoma (n = 10; 50%), and adenocarcinoma with stromal invasion (n = 2; 10%). Nonaerogenous components corresponding to solid components without normal alveolar septal destruction were pathologically observed in 15 of the 20 lesions. The diameter of the nonaerogenous components varied between 0.2 and 2.0 mm. CONCLUSION: Because 10% of LPGGO lesions include invasive disease, patients with LPGGO should undergo pathologic examination for confirmation.     

Voxel dimensions required for micromorphologic evaluation of ground-glass opacity on lung high-resolution CT

PURPOSE: To clarify the appropriate voxel dimensions required for pathologic evaluation of areas with ground-glass opacity on lung high-resolution computed tomography (HRCT). MATERIALS AND METHODS: Synchrotron radiation CT (SRCT) images of autopsied lung speci-mens (n=25) that showed ground-glass opacity on HRCT were reconstructed with 12 different voxel dimensions ranging from 0.006 to 0.6 mm. The specimens were micromorphologically categorized into one of three pathologic groups: alveolar, interstitial, and mixed abnormalities. Each SRCT image was independently diagnosed as one of three pathologic groups by six chest radiologists. The diagnostic accuracy required to estimate the appropriate voxel dimensions was compared among different voxel dimensions by means of the Tukey test. RESULTS: Diagnostic accuracy with voxel dimensions less than or equal to 0.06 mm was significantly higher than that with voxel dimensions of 0.18 mm or more (p<0.01). There was, however, no significance of difference in diagnostic accuracy with voxel dimensions of less than or equal to 0.06 mm. In addition, no significant difference in diagnostic accuracy was found with voxel dimensions of 0.18 mm or more. CONCLUSION: The appropriate voxel dimensions are approximately 0.06 mm for pathologic differentiation of areas with ground-glass opacity on HRCT.     

Fibrosing alveolitis: prognostic implication of ground-glass attenuation at high-resolution CT.

To evaluate the prognostic implication of ground-glass attenuation at high-resolution computed tomography (HRCT) in assessing response to treatment in fibrosing alveolitis, the authors correlated HRCT findings with the improvement in pulmonary function, as represented by the increase in percentage predicted values on pulmonary function tests after corticosteroid therapy. Nineteen patients underwent HRCT before treatment and pulmonary function testing before and after treatment. The HRCT scans were reviewed by two independent observers. Areas of ground-glass attenuation were quantified subjectively by using a 0%-100% scale with 10% increments. The extent of ground-glass attenuation at HRCT was significantly correlated with improvement in diffusing capacity for carbon monoxide (r = .67, P = .0019), forced vital capacity (r = .71, P = .0007), and forced expiratory volume in 1 second (r = .64, P = .0034) after steroid treatment. These results suggest that ground-glass attenuation at HRCT is a good predictor of response to treatment in fibrosing alveolitis.     

Focal area of ground-glass opacity and ground-glass opacity predominance on thin-section CT: discrimination between neoplastic and non-neoplastic lesions

AIM: To reveal differences in thin-section computed tomography (CT) findings between lung neoplastic lesions and non-neoplastic lesions, which showed a focal area of ground-glass opacity or ground-glass opacity predominance. MATERIALS AND METHODS: A total of 82 focal areas of ground-glass opacity and ground-glass opacity predominance, consisting of 38 neoplastic and 44 non-neoplastic lesions, were assessed retrospectively regarding their thin-section CT findings. RESULTS: The frequency of wholly well-defined margin (p=0.001), spiculation (p=0.019), pleural indentation (p=0.016), air bronchograms (p=0.027), air-containing space (p=0.004) was significantly higher in neoplastic lesions than in non-neoplastic lesions. Thirty-four of 38 (89%) neoplastic lesions were well-defined in more than 50% of the circumference, of which nine had an air-containing space other than air bronchogram, whereas only one non-neoplastic lesion had these features. CONCLUSION: A focal area of ground-glass opacity or ground-glass opacity predominance with a well-defined margin and air-containing space is more likely to be a neoplasm.     

Computer-aided diagnosis of localized ground-glass opacity in the lung at CT: initial experience

The purpose of this study was to develop an automated scheme to facilitate detection of localized ground-glass opacity (GGO) in the lung at computed tomography (CT). Institutional review board approval and informed consent were not required. Two radiologists reviewed CT images from 14 patients (five men, nine women) who had lung cancer or metastasis and whose malignancy was classified as GGO. The lung region was sampled and completely covered with contiguous, 50% overlapping regions of interest (ROIs) measuring 30 x 30 pixels in size. The lung area within each ROI was analyzed to compute texture features and gaussian curve fitting features. Performance of the artificial neural networks (ANNs) measured by using the area under the receiver operating characteristic curve was 0.92. With a threshold of 0.9, the sensitivity of the ANN for detecting GGO ROIs was 94.3% (280 of 297 ROIs), and the positive predictive value was 29.1% (280 of 963 ROIs). A computerized scheme may hold promise in facilitating detection of localized GGO at CT.     

Ground-glass opacity on thin-section CT: value in differentiating subtypes of adenocarcinoma of the lung.

OBJECTIVE: The purpose of this study was to determine whether thin-section CT could be used to differentiate small localized bronchioloalveolar carcinoma from peripheral adenocarcinoma having a bronchioloalveolar (replacement) growth pattern of alveolar lining cells and from adenocarcinoma not having a replacement growth pattern on the basis of the extent of ground-glass opacity revealed by thin-section CT. MATERIALS AND METHODS: One hundred twenty-four small, surgically resected, peripheral adenocarcinomas from 119 patients (67 men and 52 women; mean age, 60 years) were studied. Lesion diameters were 0.4-2.0 cm (median, 1.5 cm). The extent of ground-glass opacity within lesions on preoperative thin-section CT was reviewed retrospectively by three thoracic radiologists. On the basis of replacement growth of alveolar lining cells, small adenocarcinomas were classified histologically as localized bronchioloalveolar carcinomas (n = 42) or as adenocarcinomas with (n = 53) or without (n = 29) a replacement growth pattern of alveolar lining cells. RESULTS: The percentage of lesions that had ground-glass opacity was significantly greater in localized bronchioloalveolar carcinomas (mean, 56.7%+/-33.0%) than in adenocarcinomas with a replacement growth pattern (mean, 26.3%+/-25.3%, p < .001) or in adenocarcinomas without a replacement growth pattern (mean, 8.3%+/-4.7%, p < .001). CONCLUSION: Determination of the ground-glass opacity area in each tumor as revealed on thin-section CT was useful for differentiating small localized bronchioloalveolar carcinomas from small adenocarcinomas not having a replacement growth pattern.     

HRCT对周围型小肺癌的诊断价值

目的:评价HRCT对周围型小肺癌的诊断价值.方法:回顾分析43例确诊为周围型小肺癌的胸部HRCT表现,观察病变的分布特点,影像特征及增强后的特征.结果:病灶呈"小结节堆积征"23例(53.4%),病灶呈分叶34例(79%).边缘毛刺33例(76.7%),血管纠集6例(13.9%),"胸膜凹陷征"20例(56.5%).病灶以双肺下野外周分布为主.HRCY病灶增强表现:腺癌24例,病灶强化程度为26～58HU,平均为(48±16.8)HU;细支气管肺泡癌9例,增强范围为17～54HU,平均为(41.6±19.1)HU;鳞癌10例,增强后CT值为31～35.9HU,平均为(35.6±13.5)HU.结论:周围型小肺癌的肺部病变HRCT平扫及增强表现的认识对早期发现,早期治疗,提高存活率有重要的意义.HRCT是评价周围型小肺癌的肺部病变的敏感方法,为临床提供了更可靠的诊断依据.     

磨玻璃密度小肺癌CT表现与病理类型相关性研究

目的：探讨磨玻璃密度（GCO）小肺癌的CT表现与病理类型相关性。方法：搜集43例（45个）表现为纯磨玻璃密度（pGGO）或混合磨玻璃密度（mGGO）的周围型小肺癌,根据GGO占整个病灶比例的不同分三型,分别与病理对照。并有12个小肺癌术前行中长期动态观察。结果：I型（GGO成分占91％-100％）11个,病理均为细支气管肺泡癌（BAC）;II型（GGO成分占51％。90％）21个,BAC11,BAC伴高分化腺癌4个,高分化腺癌4个,中分化腺癌2个;Ⅲ型（GGO成分占≤50％）13个,BAC3个,中分化腺癌5个,低分化腺癌3个,低分化鳞癌2个;通过三型间比较发现GGO所占比例越高,小肺癌的病理分化越好,GGO成分占≥50％时,病理多数为BAC（22／32）;同时对部分小肺癌术前中长期动态观察及术后随访,发现肿瘤生长缓慢、预后良好。结论：局限性GGO不仅是周围型肺癌的重要征象之一,而且通过半定量分析GGO所占比例的多少,能一定程度上预测其病理类型、分化程度、倍增时间及预后。     

Computer-aided diagnosis of lung cancer: definition and detection of ground-glass opacity type of nodules by high-resolution computed tomography

Purpose  The ground-glass opacity (GGO) of lung cancer is identified only subjectively on computed tomography (CT) images as no quantitative characteristic has been defined for GGOs. We sought to define GGOs quantitatively and to differentiate between GGOs and solid-type lung cancers semiautomatically with a computer-aided diagnosis (CAD). Methods and materials  High-resolution CT images of 100 pulmonary nodules (all peripheral lung cancers) were collected from our clinical records. Two radiologists traced the contours of nodules and distinguished GGOs from solid areas. The CT attenuation value of each area was measured. Differentiation between cancer types was assessed by a receiver-operating characteristic (ROC) analysis. Results  The mean CT attenuation of the GGO areas was −618.4 ± 212.2 HU, whereas that of solid areas was −68.1 ± 230.3 HU. CAD differentiated between solidand GGO-type lung cancers with a sensitivity of 86.0% and specificity of 96.5% when the threshold value was −370 HU. Four nodules of mixed GGOs were incorrectly classified as the solid type. CAD detected 96.3% of GGO areas when the threshold between GGO and solid areas was 194 HU. Conclusion  Objective definition of GGO area by CT attenuation is feasible. This method is useful for semiautomatic differentiation between GGOs and solid types of lung cancer.     

Centrilobular lesions of the lung: demonstration by high-resolution CT and pathologic correlation

To determine the value of high-resolution computed tomography (HRCT) in the diagnosis of diffuse pulmonary diseases, a direct HRCT-pathologic correlative study was performed using four inflated and fixed lungs from autopsy. In normal lungs, the smallest pulmonary artery resolved by HRCT was 200 microns in diameter; the artery was accompanied by the terminal bronchiole and the first-order respiratory bronchiole. The distance from the vessel to the corresponding lobular border ranged from 3 to 5 mm. These results suggest that the centrilobular area or the area around the terminal or respiratory bronchioles can be recognized with HRCT. In addition, the authors confirmed that centrilobular emphysema and centrilobular tuberculous nodules can be diagnosed with HRCT. Thus, HRCT can demonstrate the location of pathologic changes within a lobule and may be helpful in the differential diagnosis of diffuse pulmonary diseases.     

毛玻璃样密度肺结节的CT诊断和鉴别诊断

由于CT的普及、高分辨力CT的广泛应用以及利用CT进行早期肺癌的筛查,使隐蔽的结节状毛玻璃样密度(nodular ground-glass opacity, NGGO)和局灶性毛玻璃样密度(focal ground-glass opacity, FGGO)影的发现率逐渐升高,有关其定性诊断问题也日益引起外科和放射科医师的关注.     

毛玻璃样密度肺结节的CT诊断和鉴别诊断

由于CT的普及、高分辨力CT的广泛应用以及利用CT进行早期肺癌的筛查,使隐蔽的结节状毛玻璃样密度(nodular ground-glass opacity,NGGO)和局灶性毛玻璃样密度(focal ground-glass opacity,FGGO)影的发现率逐渐升高,有关其定性诊断问题也日益引起外科和放射科医师的关注。本文就毛玻璃样密度肺结节的定义、病理基础、CT检查的技术要求以及CT诊断和鉴别诊断征象予以介绍。     

Identification and characterization of focal ground-glass opacity in the lungs by high-resolution CT using thin-section multidetector helical CT: experimental study using a chest CT phantom

Purpose The aim of this study was to investigate how much the radiation dose can be reduced for the identification and characterization of focal ground-glass opacities (GGOs) by high resolution computed tomography (HRCT). Materials and methods A chest CT phantom including GGO nodules was scanned with a 40-detector CT scanner. The scanning parameters were as follows: tube voltage 120 kVp; beam collimation 32 × 1.25 mm; thickness and intervals 1.25 mm; tube current and rotation time 180, 150, 120, 90, 60, and 30 mA. 180 mA was the standard. Using a three-point scale at different currents, we visually evaluated image quality. Furthermore, we carried out observer performance tests using receiver operating characteristic (ROC) analysis to evaluate the ability to identify GGO nodules at each current. Results By visual analysis, the scores for all particulars were significantly lower on images obtained at less than 120 mA than at 180 mA (Steel’s test, P < 0.05). There was no statistically significant difference in any particulars other than artifact on images obtained at 180, 150, and 120 mA. By ROC analysis there was no statistical difference in the Az value to identify GGO nodules on images obtained at 180, 150, 120, 90, or 60 mA. However, the Az value at 30 mA was significantly lower than at 180 mA (Dunnett’s test, P < 0.01). Conclusion The minimum current necessary for the characterization of GGO nodules on HRCT was 120 mA, although their identification was possible at currents of >30 mA.     

Small peripheral carcinomas of the lung: thin-section CT and pathologic correlation

The aim of this study was to clarify the thin-section CT features of small peripheral carcinomas of the lung on the basis of pathologic findings of tumor growth patterns. Thin-section CT and pathologic correlation was evaluated in 19 patients with surgically verified small peripheral carcinomas of the lung ( < 20 mm in size) that had been detected in a screening trial for lung cancer using spiral CT. Four thin-section CT types of nodules were observed: (a) type L1 (4 of 19, 21 %), a fairly well-defined nodule with ground-glass attenuation, corresponding to tumor lepidic growth without alveolar collapse; (b) type L2 (4 of 19, 21 %), a partly lobulated nodule with a low but inhomogeneous attenuation, corresponding to tumor lepidic growth with scattered foci of alveolar collapse; (c) type L3 (4 of 19, 21 %), an ill-defined nodule with an irregularly shaped higher-density central zone in a ground-glass attenuation peripheral zone, accompanied by convergence of the bronchovascular structures from the surrounding lung parenchyma, which corresponded to desmoplastic response in the central zone and to tumor lepidic growth in the peripheral zone; and (d) type H (7 of 19, 37 %), a well-defined nodule with a solid homogeneous attenuation, corresponding to tumor hilic growth. Thin-section CT features of small peripheral carcinomas of the lung can be classified into four types, based on the density distribution of the tumor, which reflect the histologic findings. Received: 4 September 1998; Revised: 25 November 1998; Accepted: 17 March 1999     

Detection of lung cancer on chest radiographs: analysis on the basis of size and extent of ground-glass opacity at thin-section CT

PURPOSE: To evaluate the detection of small peripheral lung tumors on chest radiographs on the basis of the size of the tumor and its extent of ground-glass opacity (GGO) at thin-section computed tomography (CT). MATERIALS AND METHODS: Chest radiographs of 75 patients with peripheral carcinomas 20 mm in diameter or smaller (26 localized bronchioloalveolar carcinomas [BACs], 49 other carcinomas) and 60 normal chest radiographs were retrospectively reviewed individually by 10 radiologists. The extent of GGO within the lesions at thin-section CT was reviewed retrospectively. The detection rates for localized BAC and other carcinomas on chest radiographs were calculated and were correlated with tumor size and extent of GGO. RESULTS: The mean sensitivity for detection of small peripheral carcinomas was 58.5% +/- 8.8 (standard error) for localized BAC and was 78.6% +/- 5.1 for other carcinomas (P =.024). Lesions that were smaller than 15 mm in diameter and had an extent of GGO of 70% or greater at thin-section CT were more difficult to detect than tumors that had larger diameters or less extensive GGO (chi(2) = 8.13, df = 1, P =.004). CONCLUSION: The detection of small peripheral carcinomas on chest radiographs is influenced by tumor size and extent of GGO as seen at thin-section CT.     

表现为局灶性纯磨玻璃密度影的肺癌:影像与病理对照分析

目的:分析HRCT上表现为局灶性纯磨玻璃密度影(pGGO)的细支气管肺泡癌(BAC)的影像表现、复查进展,旨在提高对pGGO、BAC的认识.方法:回顾性分析由手术及病理证实的8例BAC,其中1例为同一病灶内BAC合并AAH的影像表现,将影像学结果与病理学结果进行对照分析.结果:8例在HRCT上均表现为pGGO,其中右上叶4例,右中叶1例,右下叶1例,左上叶2例.术前6例首次及末次CT大小增加而密度无改变3例,大小及密度均增加3例,肿瘤倍增时间为384.4天～2372.2天,平均(864.9±757.6)天.结论:HRCT偶然发现的、长期存在的pGGO提示BAC、AAH;HRCT上表现为pGGO的BAC为早期(ⅠA)肺癌,肿瘤倍增时间长,生长缓慢;HRCT上AAH与BAC形态方面鉴别困难,AAH较BAC密度低,可帮助鉴别.     

Integrated PET/CT and the dry pleural dissemination of peripheral adenocarcinoma of the lung: diagnostic implications

OBJECTIVE: The aim of this study was to describe retrospectively the CT findings of dry pleural dissemination of peripheral lung adenocarcinoma, and to compare the mutual roles of PET and CT components of integrated PET/CT in the diagnosis of the disease. METHODS: The authors analyzed retrospectively the CT findings of pathologically proved dry pleural dissemination in 8 of 172 patients with peripheral adenocarcinoma of the lung. Subsequently, one radiologist and one nuclear medicine physician (unaware of the CT and pathologic results) evaluated together in a random order the integrated PET/CT of 172 adenocarcinoma patients (8 with dry pleural dissemination and 164 without). They recorded the presence of pleural dissemination using PET images only and using both PET and CT images. The diagnostic accuracies with respect to the presence of pleural dissemination were evaluated. RESULTS: The CT findings of dry pleural dissemination were pleural small nodules (n=8, 100%) (>or=6 in number in all patients; 198/204 nodules were <5 mm in diameter and 6/204 were 5-10 mm) and uneven (n=4, 50%) or band-like (n=3, 38%) fissural thickening. By PET only, the sensitivity, specificity, and accuracy of dry pleural dissemination were 25% (2/8), 90% (147/164), and 87% (149/172), respectively; by PET plus CT these were 100% (8/8), 100% (164/164), and 100% (172/172), respectively. CONCLUSIONS: The CT findings of dry pleural dissemination are multiple small pleural nodules and uneven pleural thickening. Dry pleural dissemination should be diagnosed using CT findings at integrated PET/CT because lesions causing pleural dissemination without pleural effusion are usually beyond PET resolution.