Computed tomography findings in 66 patients with malignant pleural mesothelioma due to environmental exposure to asbestos

We aimed to investigate the computed tomography (CT) findings of malignant pleural mesothelioma (MPM) caused by environmental asbestos exposure. We retrospectively reviewed CT scans of 66 patients, which were performed before any invasive procedure was done. Pleural effusion (80.3%), pleural thickening (77.2%), volume contraction (37.9%), involvement of mediastinal pleura (31.8%) and interlobar fissure (28.8%) were the most common CT findings of MPM. Although none of these findings are pathognomonic for MPM, they may provide valuable clues for the differential diagnosis, at least in patients with a history of asbestos exposure.     

Malignant pleural mesothelioma: CT manifestations in 50 cases

Malignant pleural mesothelioma, a rare and usually fatal neoplasm that is associated with asbestos exposure, is being encountered with increasing frequency. Pretreatment CT findings from 50 patients with malignant pleural mesothelioma are illustrated. Pleural thickening was found in 46 (92%) of the 50 patients, thickening of the pleural surfaces of the interlobar fissures in 43 (86%), pleural calcifications in 10 (20%), and pleural effusions in 37 (74%). The volume of the involved hemithorax varied appreciably. Contractions of the involved hemithorax was noted in 21 (42%) of 50 patients and contralateral mediastinal shift in seven (14%). Disease beyond the parietal pleura was found in the chest wall (nine patients), mediastinum, lymph nodes, and diaphragm.     

Malignant pleural disease

The vast majority of pleural neoplasms invade the pleura secondarily and can be seen in patients with bronchogenic carcinoma, breast cancer, lymphoma, and ovarian or gastric carcinoma. Primary pleural neoplasms are less common, although they have developed notoriety since the up-surge of malignant mesothelioma and the knowledge of its connection to asbestos exposure. Other malignant primary tumors include localized fibrous tumor and pleural liposarcoma. In most patients with diffuse malignant pleural disease the chest radiograph shows pleural effusion with or without pleural thickening. Computed tomography (CT) usually provides precise localization and extent of the disease and may be of value in assessing chest wall and mediastinal involvement. In specific situations, magnetic resonance (MR) may be useful as a problem-solving tool when CT findings of chest wall or diaphragmatic invasion are equivocal or in patients with contraindication to intravenous administration of ionic contrast material.     

良、恶性胸腔积液的CT鉴别诊断

目的评价良、恶性胸腔积液的CT特征性表现.资料与方法回顾性分析38例恶性胸腔积液和56例良性胸腔积液的CT征象.结果良性积液中,双侧占41.1%,胸膜增厚占19.6%,呈弥漫均匀增厚,纵隔胸膜受累占10.7%,胸膜外脂肪层明确显示占71.4%,厚度＞3 mm占41.1%,平均厚度5.7 mm;恶性积液中,双侧占15.8%,胸膜增厚占57.9%,主要呈不规则弥漫或局限性增厚,累及纵隔胸膜占36.8%,胸膜外脂肪层显示占60.5%,＞3 mm占26.3%,平均2.9 mm.结论单侧、大量积液且张力高,胸膜不规则增厚,纵隔胸膜受累对恶性诊断有特异性;而胸膜无或轻度弥漫规则增厚,胸膜外脂肪层增厚多提示良性.     

Malignant pleural mesothelioma: the spectrum of manifestations on CT in 70 cases.

AIM: The aim of this pictorial review is to illustrate the spectrum of manifestations on computed tomography (CT) of malignant pleural mesothelioma. Malignant pleural mesothelioma is the most common primary neoplasm of the pleura, but nevertheless is a rare tumour. It has a strong association with previous occupational exposure to asbestos and has a bleak prognosis. MATERIALS AND METHODS: The pre-treatment CT findings of 70 patients at our institution, and the subsequent findings of the 35 patients who had follow-up CT, have been reviewed by three observers by consensus. 16 patients had surgical resections. RESULTS: The most common pre-treatment findings were pleural thickening (94%) and pleural effusions (76%). Both contraction (27%) and enlargement (10%) of the ipsilateral hemithorax were identified. Extension of disease to the chest wall, mediastinum, thoracic lymph nodes, and below the diaphragm were identified. Concurrent bilateral pleural calcification and plaques indicative of previous asbestos exposure were identified in 16% of patients. CT failed to identify chest wall and mediastinal invasion in a number of patients who underwent surgical resections. CONCLUSION: CT plays an important role in the diagnosis, assessment, and evaluation of treatment response of this tumour, although it has some limitations in specific areas in evaluating patients for surgical resection.     

Asbestos-related pleural disease: value of dedicated magnetic resonance imaging techniques

OBJECTIVES: We sought to compare respiratory-gated high-spatial resolution magnetic resonance imaging (MRI) and radial MRI with ultra-short echo times with computed tomography (CT) in the diagnosis of asbestos-related pleural disease. METHODS: Twenty-one patients with confirmed long-term asbestos exposure were examined with a CT and a 1.5-T MR unit. High-resolution respiratory-gated T2w turbo-spin-echo (TSE), breath-hold T1w TSE, and contrast-enhanced fat-suppressed breath-hold T1w TSE images with an inplane resolution of less than 1 mm were acquired. To visualize pleural plaques with a short T2* time, a pulse sequence with radial k-space-sampling was used (TE = 0.5 milliseconds) before and after administration of Gd-DTPA. CT and MR images were assessed by 4 readers for the number and calcification of plaques, extension of pleural fibrosis, extrapleural fat, detection of mesothelioma and its infiltration into adjacent tissues, and detection of pleural effusion. Observer agreement was studied with the use of kappa statistics. RESULTS: The MRI protocol allowed for differentiation between normal pleura and pleura with plaques. Interobserver agreement was comparable for MRI and CT in detecting pleural plaques (median kappa = 0.72 for MRI and 0.73 for CT) and significantly higher with CT than with MRI for detection of plaque calcification (median kappa 0.86 for CT and 0.72 for MRI; P = 0.03). Median sensitivity of MRI was 88% for detection of plaque calcification compared with CT. For assessment of pleural thickening, pleural effusion, and extrapleural fat, interobserver agreement with MRI was significantly higher than with CT (median kappa 0.71 and 0.23 for pleural thickening, 0.87 and 0.62 for pleural effusion, and 0.7 and 0.56 for extrapleural fat, respectively; P < 0.05). For detection of mesothelioma, median kappa was 0.63 for MRI and 0.58 for CT. CONCLUSION: High-resolution MR sequences and radial MRI achieve a comparable interobserver agreement in detecting pleural plaques and even a higher interobserver agreement in assessing pleural thickening, pleural effusion, and extrapleural fat when compared with CT.     

Fatal pleural mesothelioma in Japan (2003–2008): evaluation of computed tomography findings

Purpose

The purpose of this study was to clarify the characteristic findings of mesothelioma at the time of diagnosis, and determine precautions and guidelines for diagnosing mesothelioma early in imaging studies.

Materials and methods

Overall, 327 patients with pleural mesothelioma were selected from 6030 patients who died of mesothelioma between 2003 and 2008 in Japan. Their imaging findings were examined retrospectively.

Results

Plaques were found in 35 % of computed tomography (CT) scans. Asbestosis, diffuse pleural thickening, and rounded atelectasis were found in only seven (2 %), five (2 %), and two cases (1 %), respectively. Pleural thickening findings on CT scans were classified into four stages: no irregularity, mild irregularity, high irregularity, and mass formation. Overall, 18 % of cases did not show a clear irregularity. Localized thickening was observed in the mediastinal (77 %) and basal (76 %) pleura and in the interlobar fissure (49 %). Eight percent of cases did not have any thickening in these three areas.

Conclusions

Upon examination of the CT scans at diagnosis, 18 % of mesothelioma cases did not show a clear irregularity. When diagnosing pleural effusion of unknown etiology, it is necessary to consider the possibility of mesothelioma even when no plaque and pleural irregularity are observed.

     

实验性大鼠恶性胸膜间皮瘤的CT表现

目的探讨大鼠恶性胸膜间皮瘤(MPM)特征性CT征象。方法W istar大鼠100只,右侧胸膜腔闭式染尘法注入石棉纤维混悬液,每月1次,每次20 mg/m l,连续2月,石棉总剂量为40 mg,对照组用同样方法注入灭菌生理盐水,大鼠垂死时或死亡后立即CT扫描及尸解病理检查。整个动物实验历时2年。结果得到实验组MPM 66例,胸膜增生14例,阴性12例。对照组4只胸膜增生,10只阴性,无胸膜间皮瘤。根据病理改变分为MPM组66例,非MPM组26例,对照组非MPM组14例。胸膜增厚的形态、厚度在实验组MPM组与实验非MPM组及对照组均有差异,结节状胸膜增厚只出现在MPM组,其它组无,特异性为100%。胸膜的平均CT值MPM组其它两组无差异。MPM组胸腔肿块发生率达94.5%,可为肿瘤、脓肿或包裹性积液,其中肿瘤性肿块62.5%。MPM的纵隔改变包括纵隔增宽,纵隔胸膜增厚、不规则及纵隔的移位,以纵隔不规则增宽、纵隔胸膜的改变与非MPM组比较差异有显著性。胸水与临床及尸解相比少见。未见胸内淋巴结肿大。结论大鼠MPM具有一些较特征性的CT征象。     

The CT appearance of pleural and extrapleural disease in lymphoma.

OBJECTIVE: Pleural effusions in patients with lymphoma that are assumed to be related to malignancy are attributed to either lymphatic obstruction by tumour with resultant decreased clearance of pleural fluid, or direct tumour involvement of the pleura. The purpose of our study was to determine how often pleural or extrapleural disease was detected by computed tomography (CT) of patients with pleural effusions and primary or recurrent lymphoma. METHODS AND MATERIALS: We reviewed CT examinations showing evidence of pleural effusion in 61 patients with a diagnosis of primary or recurrent lymphoma and no history of other systemic disorders, including infection. The study population consisted of patients with non-Hodgkin's lymphoma (n = 44) or Hodgkin's disease (n = 17); both primary disease (n = 11) and recurrent disease (n = 50) were represented. Each CT examination was evaluated for the presence of disease involving the visceral and parietal pleura and extrapleural space, mediastinal adenopathy, and pulmonary parenchymal disease. RESULTS: Fourteen patients (23%) (nine with non-Hodgkin's lymphoma and five with Hodgkin's disease) had parietal pleural disease (thickening or nodules). Eighteen patients (30%) (14 with non-Hodgkin's lymphoma, four with Hodgkin's disease) had tumour or enlarged lymph nodes in the extrapleural space. Forty-three patients (70%) had mediastinal lymphadenopathy. Patients who received intravenous contrast did not have evidence of visceral pleural abnormalities or underlying pulmonary parenchymal disease. CONCLUSION: Forty-one percent of the patients with lymphoma and pleural effusions had CT evidence of pleural and/or extrapleural disease. The majority of the patients with extrapleural disease had adjacent posterior mediastinal disease.     

HRCT鉴别诊断结核性和癌性胸水的价值

目的 :探讨高分辨力CT(HRCT)对结核性与癌性胸水影像表现及其鉴别诊断价值。材料和方法 :回顾性分析 86例经病理证实的结核性与癌性胸水HRCT表现并进行总结。结果 :5 2例结核性胸水均为少量到中等量 ,并 3 9例出现包裹 ,无 1例纵隔胸膜受累。在 3 4例癌性胸水中 ,无 1例出现包裹 ,2 1例出现大量胸水 ,13例为少到中等量胸水 ,19例出现纵隔胸膜受累。结论 :在HRCT上对结核性与癌性胸水的鉴别诊断中 ,纵隔胸膜受累对于确定癌性胸水具有重大的临床意义。     

Pleural disease in silicosis: pleural thickening, effusion, and invagination

PURPOSE: To retrospectively evaluate pleural disease on images from patients with autopsy-proved silicosis. MATERIALS AND METHODS: The study had institutional review board approval, and informed consent from relatives of diseased subjects was waived. Lung specimens were obtained at autopsy in 110 men (mean age, 72 years) who had been followed up radiologically for a mean of 14.8 years. Computed tomographic (CT) scans obtained within 2 years before death were examined for presence of pleural thickening; shape, composition, size, and subpleural location of progressive massive fibrosis (PMF); and pleural invagination (bandlike structure between lesion and pleura). Lung specimens were reviewed and compared with CT findings. Serial chest radiographs and CT scans were reviewed for presence of pleural effusion. Association between radiographic findings and pleural invagination was analyzed with chi2 and Student t tests. Multiple logistic regression analysis was used to find predictive variables for pleural invagination. RESULTS: Pleural effusion was found in 12 (11%) patients at chest radiography and CT, and thickening was found in 64 (58%) patients at CT; the latter finding was significantly more frequent with complicated silicosis (P < .001). At CT, 128 PMF lesions were seen, 39 (30%) of which showed pleural invagination; CT scans showed pleural thickening in 36 (92%) of these 39 lesions. In 17 (44%) PMF lesions, CT scans depicted a bandlike structure that was pathologically confirmed to represent invaginated pleura in all cases. Pathologic presence of invagination was significantly associated with pleural thickening (P < .001), ipsilateral pleural effusion (P < .01), interstitial fibrosis (P < .05), and the nearness of PMF to the pleura (P < .005). Multiple logistic regression analysis showed that pleural thickening (odds ratio, 62.51; 95% confidence interval [CI]: 5.564, 70.2) and pleural effusion (odds ratio, 25.865; 95% CI: 1.992, 335.8) were significant CT variables associated with presence of pathologic pleural invagination (P = .001 and .013, respectively). Five PMF lesions had radiographic features of rounded atelectasis. CONCLUSION: Various pleural abnormalities can occur in silicosis, especially in advanced disease.     

CT appearances of talc pleurodesis

AIM: To report the computed tomography (CT) appearances of talc pleurodesis in the management of patients with pleural effusions and spontaneous pneumothorax. MATERIALS AND METHODS: The post-pleurodesis CT studies of 16 patients obtained over a 5-year period were reviewed. The mean age was 63 years (range 41-79 years). Ten patients were male. After pleurodesis, nine patients underwent a single chest CT examination and seven patients underwent more than one. RESULTS: The characteristic finding observed in all patients, except one, was the presence of high-density deposits in the posterior basal regions of the pleural space. These were typically linear in seven patients, nodular in two, and a combination of linear and nodular in six. In five patients talc deposits were present on both the visceral and parietal pleura separated by an effusion (a variant of the split pleura sign). Talc deposits extended into an interlobar fissure with associated fissural thickening in five patients. In patients who underwent more than one CT study, the appearances remained stable. CONCLUSIONS: The typical finding was the presence of high attenuation areas in the posterior basal regions of the pleural space. Two new appearances were observed: extension of talc deposits into the fissure and the presence of a variant of the split pleura sign. It is important to recognize these CT appearances so as not to confuse them with other conditions such as asbestos exposure.     

纵隔原发性精原细胞瘤的CT表现与病理对照

目的探讨纵隔内原发性精原细胞瘤的CT表现。方法回顾性分析7例经病理证实的纵隔内原发性精原细胞瘤的CT表现。结果肿瘤均位于前中上纵隔,呈类圆形结节、不规则形肿块、斑片状影,病灶大小不一,大部分较大,肿瘤密度不均,内出现散在坏死灶5例,未见钙化病例,增强后肿瘤不均匀轻一中度强化,坏死灶无强化。边界清楚2例,周边浸润5例,累及心包致心包增厚1例,上腔静脉综合征3例;1例侵及邻近胸膜;无肺部及心腔侵犯病例。所有病例均未发现肿大淋巴结,无心包积液、胸腔积液产生。结论原发性纵隔精原细胞瘤的CT表现有一定的特征性,但缺乏特异性,明确诊断仍需依靠实验室检查及病理。     

Pleural granulocytic sarcoma: CT characteristics

The CT findings in a case of granulocytic sarcoma of the pleura are presented and correlated with pathology sections. CT features included diffuse, circumferential pleural thickening, multiple pleural fluid locules and mediastinal adenopathy. Similarities with the appearance of mesothelioma and metastatic pleural disease are discussed and the literature reviewed.     

恶性胸膜间皮瘤的CT评价

目的：主要分析恶性胸膜问皮瘤的CT征象，评价CT对本病的诊断价值。方法：回顾性分析12例经组织学证实的恶性胸膜问皮瘤的CT征象。结果：10例弥漫性恶性胸膜问皮瘤患者中，8例胸膜增厚大于10mm，占67％，胸膜增厚呈结节或肿块状7例，占58％，环状胸膜增厚6例，占50％，纵隔胸膜及叶间膜受侵8例，占67％，8例有半侧胸腔体积缩小，2例表现为单发结节，4例有纵隔淋巴结转移，1例有远处转移，侵犯颈椎。结论：CT在确定恶性胸膜间皮瘤的侵犯范围和程度方面具有重要作用，但本病的最终确诊仍需要病理组织学的证实。     

CT在恶性胸膜间皮瘤诊断中的价值

目的探讨CT在恶性胸膜间皮瘤诊断中的价值。资料与方法回顾分析9年来我院经手术或/和病理证实的42例恶性胸膜间皮瘤患者的CT资料,并与12例手术所见作比较。结果结节状或肿块状胸膜增厚(97.6%)是胸膜间皮瘤最常见的CT表现,有诊断性的表现为胸膜增厚>1cm(59.5%),环状胸膜增厚(41.5%),病变累及纵隔胸膜(92.9%)或叶间裂(69.0%),病变侵犯周围胸壁或/和肋骨、纵隔、心包、膈肌等邻近组织或器官(65.9%),1例呈胸内巨大肿块,42.9%病例可见纵隔或/和肺门淋巴结肿大。在CT和手术所见的比较中,CT准确检出了13处(65%)对周围组织或器官的侵犯,漏诊7处(35%)。结论CT在恶性胸膜间皮瘤的诊断、分期上有重要价值,是治疗前的标准诊断方法。     

ANCA阳性小血管炎的胸部高分辨率CT表现

目的：探讨ANCA阳性小血管炎（ANCA-associated small vessel vasculitis,AASV）的肺部高分辨率CT（HRCT）的影像学表现。方法：搜集26例经临床证实的ANCA阳性小血管炎的胸部HRCT资料,对其HRCT表现进行回顾性分析。结果：AASV的主要表现包括：①间质性改变：主要为网状改变,不规则网状改变17例（65.4%）、结节状网状改变3例（11.5%）,在不规则网状改变中,树冠征阳性较具特点,共7例;其它有小叶间隔增厚22例（84.6%）、磨玻璃影22例（84.6%）、支气管扩张9例（34.6%）、胸膜下线7例（26.9%）。囊状改变：葡萄串样2例（7.7%）、串珠样13例（50%）、蜂窝样9例（34.6%）,囊内小叶核心征阳性较具特点,共13例（50%）;②肺泡改变：其中弥漫渗出较具特点,共8例（30.8%）,局部渗出1例（3.8%）、空气捕捉征3例（11.5%）、树芽征1例（3.8%）、实变灶3例（11.5%）;③结节改变：均为散发,共10例（38.5%）;④其它影像学改变：包括条索影22例（84.6%）,斑片影12例（46.1%）、钙化灶（近胸膜下）3例（11.5%）、胸膜增厚17例（65.4%）,结节状叶间胸膜增厚较具特点,共5例（19.2%）,肺不张4例（15.4%）、纵隔、腋下淋巴结显示25例（96.2%）;肿大4例（15.4%）、胸腔积液7例（26.9%）、心包积液4例（15.4%）、肺动脉高压3例（11.5%）;⑤10位患者随访结果：无变化3例、加重5例,减轻2例。结论：HRCT可提供ANCA阳性小血管炎胸部病变的众多信息,对ANCA阳性小血管炎诊疗有重要参考价值。     

Computed tomography features of primary pulmonary non-Hodgkin's lymphoma.

AIM: To characterize computed tomography (CT) features of primary pulmonary lymphoma (PPL). METHODS: The CT films of six patients (five men, one woman; 63.2 +/- 14.5 years) with low grade non-Hodgkins PPL were evaluated for alveolar opacities (lobar consolidation, masses or nodules, and ill-defined consolidations), peribronchial disease or bronchial wall thickening, mediastinal nodes and pleural effusion. RESULTS: Multilobar bilateral, multilobar unilateral, and unilobar unilateral involvement were present in three, one and two cases respectively. CT features were: ill-defined mainly subpleural consolidations (n = 4), mass-like consolidation (n = 1), lobar consolidation (n = 1), and pleural effusion (n = 1). Minor peribronchial disease was seen in two patients, heterogeneous enhancement in four patients, and CT-angiogram sign in one patient. There were no lymphadenopathy or lung nodules. Although the pleura were inseparable from subpleural disease, pleural enhancement was noted on magnetic resonance imaging (MRI) of a patient with lobar lymphoma. CONCLUSION: PPL is characterized by ill-defined alveolar opacities that are usually multifocal. Peribronchial disease, proximal bronchiectasis and positive CT-angiogram sign are ancillary features. MRI may be useful in further evaluation with respect to pleural or chest wall involvement.     

Rounded atelectasis of the lung: diagnosis on conventional radiology and CT

Rounded atelectasis is a radiological diagnosis and has to be differentiated from other mass-like opacities in the dorso (basal) part of the chest. Differential diagnosis must first be made with malignant pleural and pulmonary tumors. Specific radiological features such as irregular pleural thickening and the "comet-tail" sign help to make the diagnosis and to avoid unnecessary surgery. CT may be very helpful but frontal or sagittal conventional tomography will often be more diagnostic.     

Diffuse pleural thickening in an asbestos-exposed population: prevalence and causes

Two types of pleural reaction have been described in association with asbestos exposure: pleural plaques and diffuse pleural thickening. This study was undertaken to determine the prevalence and causes of diffuse thickening in asbestos-exposed persons. Serial chest radiographs in 1373 exposed individuals and 717 controls were interpreted according to the ILO scheme by two B readers. Diffuse pleural thickening was defined as a smooth, noninterrupted pleural density extending over at least one-fourth of the chest wall, with or without costophrenic angle obliteration. Among the exposed group, plaques and diffuse thickening occurred with almost equal frequency, 16.5% and 13.5%, respectively. Of the 185 cases with diffuse thickening, the radiographic appearance was most often due to the residual of a benign asbestos effusion (31.3%) or confluent plaques (25.4%). The most commonly held explanation of diffuse thickening, an extension of pulmonary fibrosis to the visceral and parietal pleura, was actually infrequent (10.2%). Among the group with diffuse thickening without asbestosis, the forced vital capacity and single-breath diffusing capacity were significantly lower than those of comparable normal persons and those with confluent plaques.