Diagnostic imaging of mediastinal tumors. Sensitivity and specificity of sonography in comparison with computed tomography and conventional x-ray diagnosis

The purpose of this prospective study was to evaluate the sensitivity of mediastinal sonography compared to CT and chest radiography in the detection of mediastinal tumors. The sonograms, computed tomograms and chest radiographs of 182 patients were interpreted blindly by three observers and the results of all three procedures were compared. The proportion of diagnostic sonographic examinations varied in the different mediastinal compartments from 85% (subcarinal region) to 96% (supra-aortic region). The sensitivities of sonography and chest radiography (using CT as the gold standard) in the imaging of mediastinal tumors for each compartment were as follows: supra-aortic region: 98% and 67%; paratracheal region: 89% and 69%; aorticopulmonary window: 81% and 62%; prevascular region: 92% and 46%; subcarinal region: 69% and 31%; pericardial region: 100% and 67%; posterior mediastinum: 6% and 6%; paravertebral region: 11% and 44%. These results show that sonography is superior to chest radiography for the diagnosis of mediastinal tumors. In certain mediastinal regions (supra-aortic, pericardial, prevascular and paratracheal region), sonography is so sensitive that CT and MR examinations may be avoided in cases with equivocal radiographic findings.     

纵隔肿瘤影像学特点的探讨(附58例分析)

目的　探讨纵隔肿瘤的影像学特点对定性诊断的价值。方法　结合经手术、病理证实的 5 8例纵隔肿瘤 ,回顾性分析其X线和CT影像学表现 ,再结合文献 ,提出对纵隔肿瘤定性诊断有价值的影像学特点。结果　前纵隔肿瘤 40例 ,包括胸内甲状腺 3 2例 (其中 5例为甲状腺癌 ,1例为甲状腺囊肿 ) ,胸腺瘤 3例 ,畸胎瘤 5例 (其中 1例穿破 ) ;后纵隔肿瘤 18例 ,均为神经原性肿瘤。结论　根据纵隔的分区和X线、CT影像学特点并结合临床 ,能正确做出纵隔肿瘤的定性诊断。     

Indeterminate mediastinal invasion in bronchogenic carcinoma: CT evaluation

The computed tomographic (CT) scans of 80 patients with bronchogenic carcinoma classified as indeterminate for direct mediastinal invasion were retrospectively reviewed after the patients had undergone thoracotomy. Forty-eight (60%) of the masses were resectable, without invasion of the mediastinum, 18 (22%) focally invaded the mediastinum but were technically resectable, and 14 (18%) invaded the mediastinum and were not technically resectable. Although in most circumstances in this relatively small subset of patients CT was not helpful in differentiating masses with and without mediastinal invasion, CT was able to separate a large group of masses that were likely to be technically resectable. Thirty-six (97%) of 37 masses with one or more of these CT findings were considered technically resectable: contact of 3 cm or less with mediastinum, less than 90 degrees of contact with aorta, and mediastinal fat between mass and mediastinal structures. Of these 36 masses, 28 were resectable without mediastinal invasion, and eight were resectable with focal limited mediastinal invasion.     

Adenocarcinomas of unknown primary (ACUP) of the mediastinum mimicking lymphoma: CT findings at diagnosis and follow-up

OBJECTIVE: To describe the computed tomography (CT) features at diagnosis and after treatment of adenocarcinoma of unknown primary (ACUP) mimicking lymphoma of the mediastinum. METHODS: Fifteen patients with pathologically proven ACUP and with primarily mediastinal involvement were initially referred to the Hematologic Department of our institution with a suspected diagnosis of lymphoma, and accounted for our study population. Presenting symptoms and baseline biological values were analyzed. All thoraco-abdominal CT studies were reviewed for the location and size of the mediastinal involvement and associated findings. Follow-up chest CT was performed in 14 patients after radiotherapy, chemotherapy or surgical treatment. RESULTS: The most frequent CT feature was a large anterior and middle mediastinal mass (67%), with no calcification. Associated findings included the presence of lung nodules (40%), compression of large mediastinal vessels (33%) and pleural effusion (27%). Follow-up CT, performed in 14 cases, suggested partial or complete responses in 7 patients (50%) 4 weeks after the treatment onset. CONCLUSIONS: Mediastinal ACUP is a differential diagnosis of large mediastinal masses and is frequently associated with lung nodules and mediastinal vascular compression.     

The anterior mediastinum: anatomy and imaging procedures

The mediastinum is divided into compartments (anterior, middle, posterior) on the basis of lateral chest radiographs. Several anatomical and radiological classifications of the mediastinum are reported in the literature. Most mediastinal abnormalities are initially suspected following chest radiography; the need for further investigation and the most appropriate imaging modality are largely dictated by the tentative diagnosis made on this examination. Although routine chest radiography initiates the evaluation of mediastinal disorders, it is rarely diagnostic: notable exceptions are teeth or bones within a mass, which are diagnostic of a teratoma; air/fluid levels suggest an oesophageal origin, hernia, cyst, or abscess. Chest radiography is followed by spiral computed tomography (sCT). However, even sCT with contrast material is occasionally diagnostic (a confident diagnosis can be made of some lesions such as mature teratoma and mediastinal goiter) but is usually sufficient for preoperative evaluation before mediastinotomy or mediastinoscopy: it is instrumental in planning further diagnostic workup. In certain cases, magnetic resonance imaging (MRI) may be complementary to sCT, but its use is not considered routine. Besides, although the anterior mediastinum is suitable for sonographic examination, the diagnostic value of ultrasonography has not been fully exploited. Thyroid scanning with radioactive iodine is useful in identifying and evaluating masses of suspected thyroid origin. The role of fluorodeoxyglucose positron emission tomography (FDG-PET) in mediastinal diseases continues to be evaluated: it has potential for differentiating between benign and malignant disease and is expected to play a more extensive role in the imaging of mediastinal neoplasms in the future. In this paper, the radiological features of masses located in the anterior mediastinum are discussed, with particular reference to radiographic and CT patterns useful to the clinician's everyday practice.     

Computed tomographic characteristics of the normal thymus gland: Relationship to mediastinal hematoma

Computed tomography (CT) is frequently used in the screening process to determine the need for angiography in patients with possible blunt thoracic aortic injury. Misinterpretation of normal mediastinal structures (particularly the thymus in patients under age 40 years) as mediastinal hematoma may result in a significant number of false-positive scans. During a 20-month period, we reviewed the chest CT examinations of 1247 patients to select two groups of patients: group I, in whom the mediastinum was normal by CT, and group II, in whom the CT identification of a mediastinal hematoma had been proven surgically. Two major mediastinal CT differences were noted between the groups. The first was a normal cleavage plane between the lateral aspect of the aortic arch and the soft tissue density of the thymus seen in 100% of patients with normal mediastinum (group I) and 0% of patients with known mediastinal hematoma (group II). The second difference relates to the anatomic fact that the thymus is normally present only in the anterior mediastinum. Thus, the presence of a soft tissue density throughout the right paratracheal region of the middle mediastinum, which was seen in 100% of group II (mediastinal hematoma) patients and in 0% of group I (normal) patients, represented blood and not thymus tissue. These results demonstrate fundamental differences in appearance between thymic tissue, regardless of its state of involution, and a mediastinal hematoma on unenhanced mediastinal CT (UMCT). It is important that these differences be recognized so that thymic tissue is not confused with a mediastinal hematoma resulting in unnecessary thoracic aortography. Supported in part by the John S. Dunn Research Foundation.     

显微镜下多血管炎胸部CT表现对照分析

目的 探讨胸部CT检查在显微镜下多血管炎(MPA)临床应用巾的价值.方法 搜集66例临床确诊为MPA的临床资料和胸部CT影像资料,将胸部受累患者的CT影像资料根据临床表现分成2组,即疾病活动组和稳定组,对两组数据进行对照统计分析(x2检验).结果 66例MPA患者中胸部CT检查发现异常43例(65.2%),其中活动组32例,稳定组11例.(1)43例MPA胸部CT表现:①肺实变10例(23.2%):均为活动组患者,病变以两中下肺较多见,实变区可见空气支气管征6例.②磨玻璃样改变23例(53.5%):活动组20例、稳定组3例;其巾两肺广泛病变18例(18/23),局限性病变5例(5/23).③磨玻璃样改变和(或)肺实变33例(76.7%):活动组30例,稳定组3例.④散在斑片影19例(44.2%):活动组17例,稳定组2例,分布缺乏特征性.⑤纤维条状及网格影28例(65.1%):活动组19例、稳定组9例,两中下肺及肺外带胸膜下多见.⑥蜂窝状改变6例(14.0%):活动组5例、稳定组1例,以两巾下肺多见.⑦胸腔积液21例(48.8%):活动组20例、稳定组1例.⑧肺大泡8例(18.6%):活动组7例、稳定组1例.⑨纵隔淋巴结肿大25例(58.1%):活动组23例,稳定组2例.(2)MPA活动组与稳定组CT征象对照分析:肺实变、磨玻璃样改变、散在斑片影、纵隔淋巴结肿大及胸腔积液征象在活动组明显多于稳定组,两组差异有统计学意义(x2值分别为4.479、4.083、4.053、9.697、9.345,P值均<0.05).结论 不同时期MPA胸部CT影像表现具有不同特征,胸部CT检查可辅助临床诊断,并对治疗有指导意义.

Abstract：

Objective To evaluate chest CT features of microscopic polyangiitis(MPA).Methods Clinical data and chest CT images of 66 patients diagnosed as MAP had been collected.Depending on clinical manifestations.the 66 cases were divided into the active group and the stable group.The data of two groups were analyzed by x2 test.Results Forty-three of 66(65.2%)CT images were abnormal including 32 of them in active group and 11 in stable group. In these patients,CT images showed ground glass opacities(53.5%),lung consolidations(23.2%),scattered patchy opacities(44.2%),ground glass opacities and/or lung consolidations(76.7%),reticular opacities(65.1%),honeycomb(14.0%),pleural effusions(48.8%),emphysema(18.6%),and mediastinal adenopathies(58.1%).Lung consolidations,ground glass opacities,scattered patchy opacities,mediastinal adenopathies,and pleural effusion in the active group are more common than that in the stable group(X2=4.479,4.083,4.053,9.697,9.345 respectively,P<0.05).Conclusion Chest CT features of in patients with MPA have difference between active and stable periods.The chest CT scan is a useful tool to diagnose MAP in different periods and guide the treatment.     

An anatomo-radiological study of changed tracheal transparency in the pathology of the superior mediastinum. Correlations and integration with mediastinal lines

Twenty cases of mediastinal pathologies were examined with conventional radiology and Computerized Tomography (CT). They all (4 lesions in the superior and 16 in the postero-inferior mediastinum) presented with no significant changes in mediastinal borders. Conventional X-ray pictures were carefully examined for changes in mediastinal shape, and aerial tracheograms for "tracheal dimness"; CT scans were used as anatomical reference material. Mediastinal lines were detectable and evaluable in less cases than tracheal dimness was. The latter proved an useful sign for the evaluation not only of the pathologic condition itself, but also of the therapeutical reduction obtained in previously-diagnosed lesions. The routine study of tracheal dimness on conventional X-ray pictures appears to be an useful addition to the well-known signs of mediastinal pathologic conditions, especially when filters and high voltage are but seldom used.     

Mediastinal tumors: sensitivity of detection with sonography compared with CT and radiography

The purpose of this prospective study was to evaluate the sensitivity of mediastinal sonography compared with computed tomography (CT) and chest radiography in the detection of mediastinal tumors. The sonograms, CT scans, and chest radiographs of 182 patients were interpreted blindly by three observers, and the results were compared. The proportion of diagnostic sonographic examinations varied for the different mediastinal compartments from 85% (subcarinal region) to 96% (supraaortic region). The sensitivities of sonography and chest radiography, respectively, for each compartment, with CT as the reference method, were as follows: supraaortic region, 98% and 67%; paratracheal region, 89% and 69%; aorticopulmonary window, 81% and 62%; prevascular region, 92% and 46%; subcarinal region, 69% and 31%; pericardial region, 100% and 67%; posterior mediastinum, 6% and 6%; and paravertebral region, 11% and 44%. These results show that sonography is superior to chest radiography in the diagnosis of mediastinal tumors. In certain mediastinal regions (supraaortic, pericardial, prevascular, and paratracheal), sonography is so sensitive that CT and magnetic resonance examinations may be obviated in patients with equivocal radiographic findings.     

Gd－DTPA增强MRI对肺癌的分期价值

利用平扫和Ｇｄ－ＤＴＰＡ（二乙二胺五醋酸钆·马根维显）增强ＭＲＩ图像对３８例原发性支气管肺癌的ＴＮＭ分期进行了分析，并与ＣＴ和病理分期结果进行了对照。重点评估了Ｔ因素分期的四项指标：（１）侵犯胸膜；（２）侵入纵隔；（３）与周围肺组织继发性改变（阻塞性肺炎和肺不张）的鉴别；（４）胸内淋巴结转移。结果显示：对侵犯胸膜的显示，ＭＲＩ与ＣＴ相似，其敏感性分别为４０％和７５％，特异性为８６％和９３％，准确性为７４％和８９％；对侵犯纵隔的显示，ＭＲＩ比ＣＴ敏感，特异性和准确性相似。     

纵隔肿块的超声诊断价值

目的　评价超声对纵隔肿块的检查及其声像图特征在诊断中的意义。方法　对 3 2例纵隔肿块进行超声检查 ,并结合胸部X线片及CT资料进行综合分析诊断。结果　在合适声窗的介导下 ,能清楚探查纵隔不同部位肿块的物理性质 ,其中 18例前纵隔肿块中 :囊性 3例 ,实性 10例 ,混合性 5例 ;9例纵隔肿块中 :囊性 6例 ,实性 3例 ;5例后纵隔肿块中 :实性 4例 ,混合性 1例。其回声特点呈均质或不均质 ,回声强度不等。并可显示有些肿块的并发征象及与邻近脏器的关系等。结论　应用超声对纵隔肿块的检查 ,可获取病灶内部及周围的丰富信息 ,对临床诊断治疗提供可靠的依据     

肺源性纵隔气肿的CT表现及解剖学基础(附38例病例)

目的：通过对肺源性纵隔气肿的CT扫描作回顾性分析,探讨轴向肺间质与纵隔的解剖学关系。方法：搜集病例38例。26例先行胸部常规X线检查,后行CT扫描;12例直接进行胸部CT扫描。摄取胸部正侧位片均采用GE公司DR技术,胸部CT扫描采用GE公司16层螺旋CT。结果：38例病例中18例CT片示肺间质气肿与同侧肺门及纵隔相延续,16例CT片仅示纵隔及两肺中外带肺间质气肿,同侧肺门间质气肿未能显示,4例示纵隔气肿及肺门间质气肿。而肺门以外的轴向肺间质未见气肿征象。结论：肺部轴向肺间质与纵隔存在着潜在间隙。     

纵隔肿瘤定性诊断中值得重视的几种X线征象

通过对２１８例经病理学证实的纵隔肿瘤影像学资料（全部有胸部正、侧位片，８９例加作ＣＴ扫描，７例加作ＭＲＩ检查）的分析，讨论了５种对纵隔肿瘤平片定性诊断有价值的Ｘ线征象。立舌征提示胸腺瘤；倒置三角形征提示胸内甲状腺；肺尖圆球征提示后纵隔神经源肿瘤；攀藤征见于前纵隔者提示胸腺瘤，见于中纵隔者提示脉管性肿瘤；蛋壳样钙化征见于前纵隔者提示胸腺瘤，见于纵隔中上区者提示胸内甲状腺。     

Magnetic resonance (MR) imaging of the normal mediastinum

Magnetic Resonance (MR) cross sectional images of the normal mediastinum are presented and discussed. In normal subjects most mediastinal structures visible on Computed Tomography (CT) are also visible using MR. The primary advantages of MR over CT in the evaluation of mediastinum are the greater soft tissues contrast resolution, the multiplanar (axial, coronal and sagittal) display of the mediastinal anatomy and its ability to distinguish vascular from nonvascular structures without injection of contrast media.     

Tumor invasion of the chest wall and mediastinum in lung cancer: evaluation with pneumothorax CT

For preoperative evaluation of chest wall and mediastinal invasion by lung cancer, computed tomography (CT), combined with artificial pneumothorax (pneumothorax CT), was performed in 43 patients with lung cancer in whom conventional CT scans showed that the mass was contiguous to the chest wall (n = 30) and/or mediastinum (n = 25) but without evidence of definite tumor invasion. Invasion was diagnosed on the basis of whether an air space existed between the mass and the adjacent structures. In three patients pneumothorax was not produced. After the procedure, four patients developed symptomatic pneumothorax, and one, subcutaneous emphysema. Comparison of diagnoses based on findings at pneumothorax CT, surgery, and pathologic examination showed that pneumothorax CT is 100% accurate for chest wall invasion and 76% accurate for mediastinal invasion. The authors conclude that this procedure is helpful in accurate evaluation of the T criterion in lung cancer, especially for patients in whom findings at conventional CT suggest tumor invasion of the chest wall and mediastinum.     

巨大纵隔肿瘤的影像诊断及临床意义

目的 :探讨巨大纵隔肿瘤的影像学诊断标准及影像学检查的效能。方法 :从透视胸片、B超、CT及SPECT四个方面分析了 15例病例。结果 :(1)X线纵隔七分区法定位 10例定性正确。 (2 )CT对纵隔肿瘤和它与临近组织的关系显示最好。 (3)B超能清晰分辨实性和囊性肿瘤。 (4)SPECT可助于鉴别肿瘤的良恶性。结论 :巨大纵隔肿瘤的影像学诊断标准为 (1)在侧位胸片上以 7分区法定位 ,肿瘤占据部位超过 1个分区以上。 (2 )肿瘤的平均直径在 6cm以上。     

纵隔囊性病变的CT诊断及鉴别诊断

目的探讨纵隔囊性病变的CT诊断及鉴别诊断.方法本组共12例,均经手术及病理证实,男9例,女3例,年龄17～55岁.12例均行CT平扫,其中5例行CT增强扫描.回顾性分析其CT表现.结果纵隔囊性病变中,胸腺囊肿3例,淋巴管瘤2例,支气管囊肿7例.3例胸腺囊肿中,2例位于前纵隔,1例位于左颈及前纵隔;2例淋巴管瘤,1例位于中纵隔,1例位于左颈及前、中纵隔.7例支气管囊肿,均位于中纵隔气管及支气管右旁区域.结论CT平扫结合增强扫描,不仅准确显示纵隔囊性病变的位置和形态,而且清楚显示其与邻近结构的关系,因此结合临床资料及发病部位,对于纵隔囊性病变一般能够达到术前定性诊断.     

Should mediastinoscopy actually be incorporated into the FDG PET strategy for patients with non-small cell lung carcinoma?

BACKGROUND: Incorporating mediastinoscopy (MS) into the PET-based strategy for non-small cell lung carcinoma (NSCLC) patients might be cost-effective because MS can allow unnecessary thoracotomies to be avoided. The objective of our study was to assess the cost-effectiveness of incorporating MS into a PET strategy for NSCLC patients. METHODS: To determine life expectancy (LE), quality adjusted life years (QALY), and the incremental cost-effectiveness ratio (ICER), a decision-tree sensitivity analysis was designed for histopathologically confirmed NSCLC patients with M0 disease, based on the three competing strategies of chest CT only vs. PET + CT vs. PET + CT + MS. A simulation of 1000 NSCLC patients was created using baselines of other relevant variables in regard to sensitivity, specificity, mortality, LE, utilities and cost from published data. One-way sensitivity analyses were performed to determine the influences of mediastinal metastasis prevalence on LE, QALY and ICER. RESULTS: The LE and QALY per patient in the CT only strategy, PET + CT strategy and PET + CT + MS strategy were 4.79 and 4.35, 5.33 and 4.93 and 5.68 and 5.33 years, respectively, with a 20% prevalence of mediastinal metastasis. The ICERs were 906.6 yen x 10(3) (7555 US dollars)/QALY/patient at a 20% mediastinal metastasis prevalence, and 2194 yen x 10(3) (18,282 US dollars)/QALY/patient at a 50% prevalence, but exceeded 5280 yen x 10(3) (44,000 US dollars)/QALY/ patient at 80%. CONCLUSIONS: Our study quantitatively showed the CT + PET + MS strategy in place of the PET + CT strategy in managing NSCLC patients to be cost-effective. MS should be incorporated into the PET + CT strategy for NSCLC patients except in those highly suspected of having mediastinal disease on chest CT or PET.     

Computerized tomography of the thorax in evaluation of resectability of pulmonary carcinoma]

A group of 49 patients with non-small cell lung carcinoma was investigated at the Clinic of Pulmonary Diseases of the Military Medical Academy in the period 01.01.1995.-01.03.1999. In all patients were performed bronchoscopy, ultrasound of the abdomen and computed tomography (CT) of the thorax. The patients suspected to have locoregionally disseminated disease were selected. The aim of the investigation was to estimate the reliability of CT of the thorax in the evaluation of the possibility for lung carcinoma resection. The findings were confirmed either by invasive diagnostic procedures and/or during thoracotomy. During the evaluation of the direct invasion of mediastinal organs, sensitivity of the method was 48% and specificity was 89%. In the evaluation of the mediastinal lymph node metastases by CT scan, sensitivity of the method was 68.4% and specificity was 81.3%. Reliability of CT of the mediastinum was significantly higher in the detection of lymph nodes suspected to be metastatically altered than in the evaluation of the direct carcinoma invasion into mediastinal organs.     

纵隔囊性病变的CT与MRI诊断

目的：探讨纵隔囊性病变的CT、MRI诊断及鉴别诊断。方法：回顾性总结30例经手术、病理确诊的纵隔囊性病变的CT及MRI表现，包括胸腺囊肿7例，囊性畸胎瘤8例，气管、支气管囊肿9例，食管囊肿4例，囊性淋巴管瘤2例。结果：不同纵隔囊性病变均有其较特定的发病部位。7例胸腺囊肿中6例位于前上纵隔的胸腺区，1例位于前纵隔中下部；8例囊性畸胎瘤主要位于前纵隔中部、大血管起始处；9例气管、支气管囊肿位于中上纵隔，气管、支气管右旁区；4例食管囊肿，其中3例位于后纵隔，1例位于中纵隔；2例囊性淋巴管瘤，其中1例为颈纵隔型，1例为颈一腋纵隔型。结论：纵隔囊性病变虽无明显特征性影像学表现，仔细观察CT与MRI征象特点，结合发病部位，对提高本病的诊断具有重要意义。