Magnetic resonance imaging in the evaluation of lung cancer

MRI is used most efficaciously in the evaluation of patients with bronchogenic carcinoma when employed as a tailored examination designed to answer specific questions relevant to patient management. CT continues to be used more generally in staging lung cancer when imaging beyond conventional chest radiography is required. Specific areas in which MRI can provide important and unique information (which may supplement a CT study) include the following: (1) evaluation of the local extent of superior sulcus tumors, and (2) distinction between stage IIIA (resectable) and stage IIIB (unresectable) tumors. Confirmation of tumor invasion of major mediastinal structures is necessary before depriving a patient of potential curative resection. MRI may contribute important information when CT findings are indefinite, particularly with regard to invasion of major cardiovascular structures (eg, superior vena cava, pulmonary artery, pericardium, and heart); invasion of the tracheal carina or bilateral involvement of main bronchi; and the presence of contralateral mediastinal or hilar lymphadenopathy. MRI should be considered as a primary imaging modality to evaluate central tumors in patients for whom intravenous contrast agents are contraindicated, and as a problem-solving modality when CT is inconclusive in the detection of a possible hilar or mediastinal mass. Other specific applications of MRI include the identification of tumor recurrence in the presence of radiation fibrosis, assessment of the extent of chest wall invasion of peripheral lung tumors, and the noninvasive characterization of adrenal masses. The scope of these MRI applications in patients with lung cancer may expand in the future with refinements in motion suppression techniques, implementation of ultrafast MRI (using variations of the echoplanar method), and further development of MRI spectroscopy and MRI contrast agents.     

Pulmonary parenchymal manifestations of mitral valve disease.

Pulmonary parenchymal manifestations of mitral valve disease are the result of either pulmonary venous hypertension in mitral stenosis or abnormal regurgitant flow into pulmonary veins in mitral insufficiency. Typical radiographic findings in mitral stenosis include pulmonary vascular cephalization; interstitial, perivascular, and occasionally alveolar pulmonary edema; diffuse alveolar hemorrhage; hemosiderosis; and pulmonary ossification. Signs of interstitial pulmonary edema are frequently visible and include septal lines. Radiographic findings in diffuse alveolar hemorrhage consist of diffuse, confluent acinar or ground-glass areas of increased opacity, often sparing the peripheral parenchyma and creating the so-called window frame effect. Hemosiderosis is characterized by small, ill-defined nodules or by coarse reticular areas of increased opacity with a bias for the middle and lower lung regions. Ossification manifests as densely calcified, 1-5-mm nodules, mainly in the middle and lower lungs, with a tendency for confluence and the occasional presence of trabeculae. Imaging findings in mitral regurgitation depend on the acuteness of the disease. The most common parenchymal manifestations of acute mitral regurgitation are symmetric alveolar and interstitial pulmonary edema with indistinct, engorged pulmonary vessels and cephalized blood flow. Familiarity with these manifestations can expedite diagnosis, particularly in rare cases of unsuspected mitral valve disease.     

Bronchogenic cyst of the esophagus: clinical and imaging features of seven cases

Seven unusual cases of esophageal bronchogenic cyst (EBC) are presented. Different from mediastinal or pulmonary bronchogenic cysts, EBCs predominately affect young women (six out of seven cases; mean age, 29.9 years), and clinically, such cases were characterized by dysphagia and chest pain, especially during exercise. On radiographs and computed tomographs, EBCs typically appeared as 3- to 4-cm midthoracic cystic masses close abutting to the midthoracic esophagus. Rarely, exophytic lower thoracic EBC may mimic lung nodule. Total cyst excision usually offers satisfactory outcome with no recurrence in long-term follow-up.     

青年肺癌的CT表现与误诊探讨

目的探讨青年肺癌CT表现及误诊分析。方法回顾分析33例病理确诊的40岁以下原发性支气管肺癌的CT表现及临床资料。结果CT表现为肿块13例、结节8例、肺叶实变7例,支气管腔内结节并肺叶不张3例,支气管壁增厚管腔狭窄并阻塞性肺炎,空洞、多中心各1例。8例胸腔积液或合并胸膜结节,7例双肺结节,6例淋巴结肿大,2例骨性胸廓骨质破坏,4例肿瘤直接侵犯纵隔或/和纵隔内血管,胸部转移率为81.8%。初诊时误诊为肺炎6例,结核15例,误诊率63.6%。结论青年肺癌CT主要表现为肿块、结节、肺叶实变,大多数确诊时已为晚期,易误诊为肺结核,误诊率高。     

Unusual radiologic presentations of bronchioloalveolar carcinoma

Bronchioloalveolar carcinoma appears with variable radiologic features. The usual findings include a single nodule, multiple nodules, or areas of consolidation in lung. An air bronchogram in an area of nodular or mass-like density is also a well-known feature. We here report six patients whose disease illustrates interesting or unusual aspects of this neoplasm. The findings include: Minimal radiological signs despite diffuse disease found on CT scan or at surgery (two patients). Thickening of the wall of a preexisting lung cavity: presumed bronchogenic cyst. Expansile lobar consolidation without an air bronchogram simulating pleural disease. An elongated lobulated area of mass-like density resembling mucoid impaction. Homogeneous lobar atelectasis without an air bronchogram. Consideration of these varied features may aid in the radiological diagnosis of bronchioloalveolar carcinoma.     

Pulmonary tuberculosis: CT and pathologic correlation

Typical CT findings of active postprimary pulmonary tuberculosis include centrilobular nodules and branching linear structures (tree-in-bud appearance), lobular consolidation, cavitation, and bronchial wall thickening. The CT findings of inactive pulmonary tuberculosis include calcified nodules or consolidation, irregular linear opacity, parenchymal bands, and pericicatricial emphysema. The typical appearance of primary tuberculosis on CT scans is homogeneous, dense, well-defined segmental or lobar consolidation with enlargement of lymph nodes in the hilum or the mediastinum. Miliary nodules may be seen in primary and postprimary tuberculosis. On CT, tuberculomas appear as a nodule with surrounding satellite nodules and internal cavitation on CT. Atypical radiologic manifestations of tuberculosis, encountered in as many as one third of the cases of adult-onset tuberculosis, are single or multiple nodules or masses, basilar infiltrates, miliary tuberculosis with diffuse bilateral areas of ground-glass opacity, and reversible multiple cysts. Underlying histopathologic findings of typical and atypical CT findings of tuberculosis are caseating granulomas or pneumonia in the active phase and fibrosis and dystrophic calcification in the inactive phase.     

Thoracic sequelae and complications of tuberculosis.

Pulmonary tuberculosis is caused by Mycobacterium tuberculosis when droplet nuclei laden with bacilli are inhaled. In accordance with the virulence of the organism and the defenses of the host, tuberculosis can occur in the lungs and in extrapulmonary organs. A variety of sequelae and complications can occur in the pulmonary and extrapulmonary portions of the thorax in treated or untreated patients. These can be categorized as follows: (a) parenchymal lesions, which include tuberculoma, thin-walled cavity, cicatrization, end-stage lung destruction, aspergilloma, and bronchogenic carcinoma; (b) airway lesions, which include bronchiectasis, tracheobronchial stenosis, and broncholithiasis; (c) vascular lesions, which include pulmonary or bronchial arteritis and thrombosis, bronchial artery dilatation, and Rasmussen aneurysm; (d) mediastinal lesions, which include lymph node calcification and extranodal extension, esophagomediastinal or esophagobronchial fistula, constrictive pericarditis, and fibrosing mediastinitis; (e) pleural lesions, which include chronic empyema, fibrothorax, bronchopleural fistula, and pneumothorax; and (f) chest wall lesions, which include rib tuberculosis, tuberculous spondylitis, and malignancy associated with chronic empyema. These varieties of radiologic manifestations can mimic other disease entities. Therefore, recognition and understanding of the radiologic manifestations of the thoracic sequelae and complications of tuberculosis are important to facilitate diagnosis.     

Coexisting Bronchogenic Carcinoma and Pulmonary Tuberculosis in the Same Lobe: Radiologic Findings and Clinical Significance

Objective

Bronchogenic Carcinoma Can Mimic Or Be Masked By Pulmonary Tuberculosis (Tb), And The Aim Of This Study Was To Describe The Radiologic Findings And Clinical Significance Of Bronchogenic Carcinoma And Pulmonary Tb Which Coexist In The Same Lobe.

Materials and Methods

The findings of 51 patients (48 males and three females, aged 48-79 years) in whom pulmonary TB and bronchogenic carcinoma coexisted in the same lobe were analyzed. The morphologic characteristics of a tumor, such as its diameter and margin, the presence of calcification or cavitation, and mediastinal lymphadenopathy, as seen at CT, were retrospectively assessed, and the clinical stage of the lung cancer was also determined. Using the serial chest radiographs available for 21 patients, the possible causes of delay in the diagnosis of lung cancer were analyzed.

Results

Lung cancers with coexisting pulmonary TB were located predominantly in the upper lobes (82.4%). The mean diameter of the mass was 5.3 cm, and most tumors (n=42, 82.4%) had a lobulated border. Calcification within the tumor was seen in 20 patients (39.2%), and cavitation in five (9.8%). Forty-two (82.4%) had mediastinal lymphadenopathy, and more than half the tumors (60.8%) were at an advanced stage [IIIB (n=11) or IV (n=20)]. The average delay in diagnosing lung cancer was 11.7 (range, 1-24) months, and the causes of this were failure to observe new nodules masked by coexisting stable TB lesions (n=8), misinterpretation of new lesions as aggravation of TB (n=5), misinterpretation of lung cancer as tuberculoma at initial radiography (n=4), masking of the nodule by an active TB lesion (n=3), and subtleness of the lesion (n=1).

Conclusion

Most cancers concurrent with TB are large, lobulated masses with mediastinal lymphadenopathy, indicating that the morphologic characteristics of lung cancer with coexisting pulmonary TB are similar to those of lung cancer without TB. The diagnosis of lung cancer is delayed mainly because of masking by a tuberculous lesion, and this suggests that in patients in whom a predominant or growing nodule is present and who show little improvement of symptoms despite antituberculous or other medical therapy, coexisting cancer should be suspected.     

Bronchioloalveolar carcinoma of the lung

Bronchioloalveolar carcinoma is a histologically distinct form of pulmonary adenocarcinoma representing an estimated 2–10 % of all primary lung cancers. Its varied appearances include focal masses, nodular patterns, and pneumonic and diffuse forms so that bronchioloalveolar carcinoma should be considered in the differential diagnosis of solitary or multiple pulmonary nodules and acute or chronic alveolar diseases. In this article we describe the different radiographic manifestations of bronchioloalveolar carcinoma with particular emphasis on CT findings and those signs that may help in identifying the lesion as bronchioloalveolar carcinoma. Received 15 September 1997; Revision received 17 November 1997; Accepted 17 November 1997     

CT of pulmonary dirofilariasis--differential diagnosis from lung cancer]

We present here four cases of pulmonary dirofilariasis in which histological examination of the surgical specimen showed occlusion of the peripheral pulmonary artery by filariae and formation of a necrotic mass surrounded by reactive inflammation and hemorrhage. Radiological examination showed a solitary pulmonary nodule in three cases and a wedge-shaped consolidation in one case. Although pulmonary nodules in dirofilariasis closely mimic bronchogenic carcinoma on radiographs , it is possible to distinguish them from bronchogenic carcinoma on the basis of the following findings: (1) coexistence of subtle satellite lesions, (2) absence of pleural involvement, (3) fine marginal speculations, and (4) lack of concentric marginal speculations (eccentric speculation). In each case of dirofilariasis, CT showed the peripheral pulmonary artery entering the mass. This finding differentiates this disease from metastatic lung tumor, because in tumor metastasis via the pulmonary arteries, visible vessels are not usually involved.     

肺继发性淋巴瘤的CT多样性

目的：探讨肺继发性淋巴瘤的CT表现特征，以提高诊断正确率。材料和方法：回顾性分析临床或病理证实的26例肺继发淋巴瘤的CT征象，其中15例为非霍奇金淋巴瘤（NHL），11例为霍奇金病（HD）。本研究采用GE Hispeed CT／i，10例平扫，16例直接增强扫描。结果：CT表现多样：肺内毛玻璃样影（NHL 13vs HD6）；单发或多发肿块结节及肿块样实变（NHL 10vs HD8），其中仅HD组肿块中有4例病灶密度不均匀，5例见毛玻璃样晕症；黍粒样结节（NHL1）；支气管血管束增粗（NHL 1vs HD1）；肺门纵隔淋巴结肿大（NHL 9vs HD8）；胸膜侵犯（NHL 5vs HD2）；心包累及（NHL 2vs HD1）；常为多个征象合并出现（NHL 12vs HD5）。可分为以下四个类型：肺炎肺泡型（NHL 3vs HD1），肿块（结节）型（NHL 2vs HD2），黍粒型（NHL1），混合型（NHL 12vs HD5）。结论：多样性为肺继发性淋巴瘤的特点，不均匀的肿块或伴有病灶周围的毛玻璃样晕症多见于HD，对诊断可能有帮助。     

Pulmonary infarction associated with bronchogenic carcinoma

Computed tomography findings of pathologically proven pulmonary infarction associated with bronchogenic carcinoma are reported for two patients. In one case, the infarction was demonstrated as a well-defined pleura-based large nodule in the peripheral portion of the same lobe of the tumor. The nodule had a smooth, convex border and a linear strand from the apex of the lesion toward the hilum. The obstruction of the subsegmental pulmonary artery due to tumor invasion was considered the cause of pulmonary infarction. In the second case, the infarction was demonstrated as a rapidly appeared, pleura-based consolidation in the same lobe of the tumor with a blurred border. Obstruction of the pulmonary vein by a tumor might have played an important role in the development of the pulmonary infarction in association with a large pulmonary artery obstruction. We conclude that pulmonary infarction should be considered as a differential diagnosis when peripheral pulmonary nodules or masses are located in the same lobe as the primary cancer.     

Computed tomography appearances of bronchogenic carcinoma associated with bullous lung disease

Bullous lung disease is known to be a risk factor for developing a bronchogenic carcinoma. In this article, computed tomography appearances of 20 patients with histologically proven bronchogenic carcinoma were reviewed retrospectively. On the basis of the previous literatures and our findings, the computed tomography appearances of bronchogenic carcinoma associated with bullous lung disease could be classified into 3 types; nodule or mass extruding from the bullous wall, nodule or mass confined within the bullous lumen, and soft-tissue density extending along the bullous wall. Attention should be paid in the interpretations for mass or nodule in the wall of the bulla because they frequently lack the characteristic appearances of bronchogenic carcinoma.     

肺弥漫性疾病175例X线分析

目的探讨肺弥漫性疾病的X线诊断。方法回顾性分析175例肺弥漫性疾病的X线表现。结果根据X线征象可将本病归纳为①主质病变征象包括腺泡结节、小片影与大片影、蝶翼征及支气管气相;②间质病变征象包括间质结节、网状影、网结影、间隔线及支气管血管束影增粗等;③主间质病变共有征象包括磨玻璃影、弥漫性钙化、多发肿块影和蜂窝肺。同时,对肺弥漫性疾病的分型及诊断步骤进行了探讨。结论常规胸片仍是目前诊断肺部弥漫性疾病的首选和重要的方法。     

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.     

Nuclear magnetic resonance imaging of the thorax

Nuclear magnetic resonance (NMR) images of the thorax were obtained in ten normal volunteers, nine patients with advanced bronchogenic carcinoma, and three patients with benign thoracic abnormalities. In normal volunteers, mediastinal and hilar structures were seen with equal frequency on NMR images and computed tomographic scans. The hila were especially well displayed on spin-echo images. Spin-echo images showed mediastinal invasion by tumor, vascular and bronchial compression and invasion, and hilar and mediastinal adenopathy. Tumor and benign abnormalities could be separated from mediastinal and hilar fat because of their longer T1 times. Lung masses and nodules as small as 1.5 cm could be seen on the spin-echo images. NMR imaging shows promise for assessment of benign and malignant mediastinal, hilar, and lung abnormalities.     

Metabolic lung disease: imaging and histopathologic findings

Metabolic lung disease includes pulmonary alveolar proteinosis (PAP), pulmonary amyloidosis, metastatic pulmonary calcification, dendritic pulmonary ossification, pulmonary alveolar microlithiasis, and storage diseases. In pulmonary alveolar proteinosis, CT demonstrates air-space consolidation with thickened interlobular septa, producing the so-called "crazy paving" appearance. Pulmonary amyloidosis can appear as parenchymal nodules (nodular parenchymal form), diffuse interstitial deposit (diffuse interstitial form), or submucosal deposits in the airways (tracheobronchial form). Metastatic pulmonary calcification may appear on high-resolution CT as numerous 3- to 10-mm diameter calcified nodules or, more commonly as fluffy and poorly defined nodular opacities. In pulmonary microlithiasis, high-resolution CT demonstrates diffuse punctuate micronodules showing slight perilobular predominance resulting in apparent calcification of interlobular septa. Niemann-Pick disease appears as ground-glass attenuation in the upper lung zone and thickening of the interlobular septa in the lower lung zone. Radiologic study including high-resolution CT will be helpful for the diagnosis and follow-up of these diseases.     

Pathways of tumor spread through the lung: radiologic correlations with anatomy and pathology

The pathways of tumor spread through the lung are described and their significance for radiographic interpretation is illustrated. A key to understanding the spread of bronchogenic carcinoma is the realization that although the normal flow of lymph in the pulmonary lymphatics is centripetal, lymphatic obstruction can cause reversal of flow. As a result, tumor cells are commonly carried centrifugally to the periphery in lymphatics or the connective tissue around them, and remote pleural involvement, secondary parenchymal masses, or satellite nodules may develop. Failure to appreciate peripheral spread of tumor has negative consequences for tumor staging, surgery, and radiotherapy. In the absence of hilar node involvement causing obstruction, long line shadows more than 0.5 inch (1.25 cm) in length proximal to a peripheral mass very infrequently represent tumor.     

Solitary pulmonary nodules in patients with extrapulmonary neoplasms

PURPOSE: To determine the frequency of single lung metastasis, primary lung cancer, and benign lesions in patients with a solitary lung nodule and a primary extrapulmonary neoplasm. MATERIALS AND METHODS: The authors evaluated the electronic charts of 149 patients with an extrapulmonary malignant neoplasm and a solitary pulmonary nodule. The histologic characteristics of the nodule were correlated with those of the extrapulmonary neoplasm and with patient age and smoking history. RESULTS: Patients with carcinomas of the head and neck, bladder, breast, cervix, bile ducts, esophagus, ovary, prostate, or stomach were more likely to have primary bronchogenic carcinoma than lung metastasis (ratio, 25:3 for patients with head and neck cancers; 26:8 for patients with other types of cancer combined). Patients with carcinomas of the salivary glands, adrenal gland, colon, parotid gland, kidney, thyroid gland, thymus, or uterus had fairly even odds (ratio, 13:16). Patients with melanoma, sarcoma, or testicular carcinoma were more likely to have a solitary metastasis than a bronchogenic carcinoma (ratio, 23:9). Thirty patients had a benign nodule. There was substantial overlap in age distribution among the patients with benign disease, lung cancer, and metastasis, although no patient younger than 44 years had a lung cancer. Smokers had a 3.5-fold higher chance of developing lung cancer compared with nonsmokers. CONCLUSION: The likelihood of a primary lung cancer versus a metastasis depends on the histologic characteristics of the extrapulmonary neoplasm and the patient's smoking history.