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.     

MR imaging of malignant pleural mesothelioma

The magnetic resonance (MR) findings in three patients with malignant pleural mesothelioma are described. All patients had a circumferential pleural mass surrounding the lung on the affected side. These tumors had a signal of intermediate intensity on T1-weighted images. The T2-weighted images showed a slight increase in signal intensity of the mass, with focal areas of very high signal intensity due to pleural fluid. Adenopathy was demonstrated by CT and MR in two patients. The extent of the tumor and its effects on adjacent structures were well appreciated on the coronal MR images.     

The pathogenesis, radiologic evaluation, and therapy of pleural effusions

Radiology has played a pivotal role in the management of patients with pleural effusions. By confirming the presence of an effusion and providing information regarding the size and distribution of fluid, chest radiography greatly facilitates initial diagnostic thoracentesis. Identification of even small effusions is important because these commonly occur and may have clinical significance. The development of improved antibiotics and a wider range of interventional techniques has increased the reliance on the radiologic imaging of pleural disease in order to plan appropriate therapy. The newer imaging modalities of CT and sonography have proved to be particularly valuable in detecting small effusions and demonstrating single or multiple loculations. Additional features, such as the degree to which a pleural process has become organized and whether there is adjacent lung parenchymal disease, are well assessed on CT. Experience with MR has been limited, but preliminary data suggest that it may be a valuable addition and/or alternative to CT.     

Staging of malignant pleural mesothelioma: comparison of CT and MR imaging

OBJECTIVE: This article compares the accuracy of CT with that of MR imaging in staging of malignant pleural mesothelioma. SUBJECTS AND METHODS: Ninety-five patients were enrolled in a prospective staging protocol based on the International Mesothelioma Interest Group staging system. Sixty-five patients underwent CT and MR imaging and a surgical procedure (excluding percutaneous needle biopsy) to stage and resect the tumor. Receiver operating characteristic analyses were performed. CT and MR scans were interpreted independently by observers who were unaware of the results of the other imaging study; these imaging findings were compared with the results of surgery and pathologic examination. RESULTS: The areas under the receiver operating characteristic curves for eight of 10 features revealed by imaging showed no statistically significant differences between CT and MR imaging. However, MR imaging was superior to CT in revealing invasion of the diaphragm (A(z) = .55 for CT versus .82 for MR imaging) and in revealing invasion of endothoracic fascia or solitary resectable foci of chest wall invasion (A(z) = .46 for CT; A(z) = .69 for MR imaging). Several anatomic regions could not be evaluated because positive findings at surgery were rare. CONCLUSION: CT and MR imaging are of nearly equivalent diagnostic accuracy in staging malignant pleural mesothelioma. MR imaging is superior to CT in revealing solitary foci of chest wall invasion and endothoracic fascia involvement and in showing diaphragmatic muscle invasion; however, this advantage does not affect surgical treatment. For cost reasons, CT should be considered the standard diagnostic study before therapy.     

Evaluation of pleural disease using MR and CT. With special reference to malignant pleural mesothelioma

Purpose: To evaluate MR imaging and CT in differentiating malignant pleural mesothelioma from other malignancies or benign pleural disease.Material and Methods: Thirty-four patients (18 pleural mesotheliomas, 9 other malignancies, 7 benign pleural diseases) were examined using enhanced CT and MR. Two radiologists reviewed the CT and two others the MR images. Comparisons were made between the diagnostic groups and the imaging methods.Results: The abnormalities commonly found in malignant disease, but significantly less frequently in benign pleural disease, were focal thickening and enhancement of interlobar fissures. In mesothelioma, enhancement of interlobar fissures, tumour invasion of the diaphragm, mediastinal soft tissue or chest wall, were significantly more often observed than in other malignancies and MR was the most sensitive method. In other malignancies, invasion of bony structures was a more common finding and was also better shown by MR. The contrast-enhanced T1 fat-suppressed (CET1fs) sequence detected these features better than other MR sequences.Conclusion: MR, especially the CET1fs sequence in three planes, gave more information than enhanced CT. Focal thickening and enhancement of interlobar fissures were early abnormalities indicating malignant pleural disease. MR could be clinically useful for differentiating mesothelioma from other pleural diseases.     

Evaluation of parietal pleural invasion of lung cancers with breathhold inspiration and expiration MRI

The goal of this study was to investigate the feasibility of detecting invasion of the parietal pleura by lung cancer with inspiratory-expiratory magnetic resonance imaging (MRI). Twenty-three patients with lung cancer in contact with pleura were studied with multisectional MRI during deep inspiration and expiration on the axial and coronal planes. Changes in the tumor's relation relative to the chest wall markers, vertebral bodies, or mediastinal structures were noted. Surgical correlation was available for each case. Twelve tumors were located at the right middle and lower lobes. Five patients who had a significant change in the position of the tumor were found not to have pleural invasion at surgery. The remaining seven tumors without change in their position with respiration were surgically found to invade the parietal pleura. Only 1 of the 11 upper lobe and apical segments of the lower lobe-located tumors showed a change in its position, which had no parietal pleural invasion at surgery. The remaining 10 tumors did not show any movement. Four of them had parietal pleural invasion that were surgically proven, and six tumors had no parietal pleural invasion at surgery. In conclusion, MRI performed during deep inspiration and expiration is a complementary method in detecting parietal pleural invasion for the tumors located in the lower and middle lobes.     

MRI在良、恶性胸膜肿瘤鉴别诊断中的价值

目的：探讨磁共振成像在良、恶性胸膜肿瘤鉴别诊断中的作用。方法：对45例胸膜肿瘤患者（良性8例,恶性37例）进行了CT和MRI检查。评估分析良、恶性胸膜肿瘤的CT和MRI形态学特点及其分别在T1WI、T2WI和增强T1WI上的信号特点。结果：在CT图像上,共出现弥漫性胸膜增厚30例（恶性29例,良性1例）,纵隔胸膜受累28例（恶性27例,良性1例）、环绕或不规则胸膜增厚23例（恶性22例,良性1例）,胸壁或膈肌浸润9例（全部为恶性）;在MRI上,共出现弥漫性胸膜增厚32例（恶性31例,良性1例）,纵隔胸膜受累29例（恶性27例,良性2例）、环绕或不规则胸膜增厚24例（恶性23例,良性1例）,胸壁或膈肌浸润1例（全部为恶性）。根据前述形态学特点,CT与MRI对诊断胸膜恶性肿瘤总的敏感性分别为83．8％和86．5％,总特异性均为62．5％。结论形态学及信号特点,MRI对诊断良、恶性肿瘤病变的敏感性为97．3％,特异性为100％。结论：单纯依据其形态学特点,MRI对胸膜肿瘤的发现与诊断价值与CT相仿。但当MR信号与形态学特点结合时,其对良、恶性胸膜肿瘤的鉴别诊断价值则明显优于CT。     

Diagnosis of chest wall invasion by lung cancer: useful criteria for exclusion of the possibility of chest wall invasion with MR imaging

PURPOSE: To compare the accuracy of thin-section CT, conventional static MR imaging (conventional MRI), and breathing dynamic echo planar magnetic resonance imaging (BDEPI) in evaluating lung cancer invasion to the chest wall. MATERIALS AND METHODS: Thin-section CT, conventional MRI, and BDEPI were performed preoperatively in 20 patients suspected of having primary lung cancers adjacent to the chest wall on conventional CT. The results of imaging findings were compared with those of surgical and histopathological findings. RESULTS: All patients were confirmed to have no chest wall invasion after surgery. By thin-section CT, 10 of 20 patients were correctly diagnosed as having no chest wall invasion (50% specificity). Two of the 20 patients were incorrectly diagnosed as having chest wall invasion by conventional MRI and BDEPI (90% specificity). CONCLUSION: When chest wall invasion is suspected on CT scans, static and breathing dynamic MRI are recommended to avoid false positive interpretations.     

Value of MR imaging in the evaluation of chronic infiltrative lung diseases: comparison with CT.

The value of MR imaging was compared with that of high-resolution CT in assessing chronic infiltrative lung disease in 25 patients. The cases included nine patients with usual interstitial pneumonia, six with sarcoidosis, four with hypersensitivity pneumonitis, and six with miscellaneous conditions. The diagnosis was proved by biopsy (n = 17) or by means of clinical, laboratory, and radiologic criteria (n = 8). All patients had 1.5-T MR imaging and CT of the chest. Cardiac-gated T1-, proton density-, and T2-weighted spin-echo sequences were obtained. Initially, the MR images were assessed independently; later they were compared directly with the corresponding CT scans. In six patients, MR images and CT scans were obtained before open lung biopsy, and the images and scans were assessed prospectively. CT was superior to MR imaging in the anatomic assessment of the lung parenchyma and in showing fibrosis. However, areas of air-space opacification (ground-glass opacities) were seen as well on MR as on high-resolution CT. In the six patients who had open lung biopsy, areas of air-space opacification seen on MR and on CT corresponded to areas of active alveolitis or air-space infiltrates pathologically. Follow-up in six patients showed equal degrees of change in the air-space opacification over time on MR and CT. We conclude that, although MR imaging is inferior to high-resolution CT in the assessment of chronic infiltrative lung diseases, it may play a role in the assessment and follow-up of patients with air-space opacification.     

MRI of the thorax during whole-body MRI: evaluation of different MR sequences and comparison to thoracic multidetector computed tomography (MDCT)

PURPOSE: To evaluate the accuracy of four MR sequences used as part of a whole-body MRI protocol to detect pulmonary lesions in cancer patients. MATERIALS AND METHODS: A total of 31 oncology patients were imaged in a 1.5T MR scanner (Magnetom Avanto; Siemens Medical Solutions, Germany) for whole-body staging. MR chest imaging included: axial and coronal T2-weighted (T2w)-short-tau inversion-recovery (STIR), axial T2w turbo spin-echo (TSE), and contrast-enhanced (CE) three-dimensional (3D) volumetric interpolated breathhold examination (VIBE). Multidetector computed tomography (MDCT) of the thorax served as the reference standard. The MDCT and MR images were evaluated independently by two radiologists. Comparative analysis was performed per lesion, per lobe, and per patient. Sensitivity, specificity, and predictive values were determined. RESULTS: Compared to MDCT that detected 268 pulmonary lesions ranging from 2 to 75 mm in diameter, the MR sensitivities were 91.1%, 92.5%, 90.8%, and 87.3% for the coronal STIR, the axial STIR, the axial T2w-TSE, and the axial CE 3D-VIBE, respectively. Undetected pulmonary lesions were either calcified or smaller than 10 mm in the axial diameter. With coronal STIR, six false-positive findings were detected; with axial STIR, 14 were detected; with axial T2w-TSE, 10 were detected; and with 3D-VIBE, seven were detected. CONCLUSION: Pulmonary MRI is feasible as part of a whole-body MRI protocol. In our study, STIR images achieved high accuracy compared to chest MDCT for pulmonary lesions of 3 mm in size or larger.     

MR imaging in the assessment of lung cancer patients: primary lung cancer staging, evaluation of therapeutic effect and diagnosis of recurrent tumor

Magnetic resonance imaging and computed tomography were compared in a prospective study of 137 lung cancer patients proved by surgery or autopsy for determining the staging, evaluation of therapeutic effect and diagnosis of recurrent tumor. 1. Lung cancer staging In peripheral lung cancer, T1 and T2 relaxation times of the tumors before operation have some correlation with those of operated specimens. These relaxation times, however, are of limited nodule characterization. Hilar mass and adjacent pulmonary consolidation (obstructive pneumonia or collapse) can be distinguished on T2-weighted image (77%) and Gd-DTPA enhanced image (80%). Therefore these images help in distinguishing tumor from peripheral lung disease. In the diagnosis of tumor invasion to the heart and great vessels, MRI is superior to CT because MRI can be helpful in distinguishing true mass from heart and great vessels. As for the chest wall, MRI is more useful than CT in detecting tumor invasion especially to the thoracic inlet and superior regions. In the diagnosis of mediastinal and hilar lymphadenopathy, MRI is equivalent or slightly inferior to CT, but MRI can easily demonstrate the lymphadenopathy at subcarinal region on coronal image. 2. Evaluation of therapeutic effect in lung cancer patients treated by radiation and chemotherapy MRI patterns of therapeutic effect was divided into 3 types. It is suggested that there is some correlation between these patterns and histologic types. MRI can easily demonstrate necrotic area on T2-weighted and Gd-DTPA enhanced images. 3. Diagnosis of recurrent tumor in treated lung cancer Concerning detecting recurrent tumor after surgery or irradiation, and delineating tumor from radiation pneumonitis, T2-weighted and Gd-DTPA enhanced images are of clinical value.     

CT未检出原发灶的胸腔积液或肺不张患者18F-FDG显像结果分析

目的评价^18F-脱氧葡萄糖(FDG)符合线路显像(DHTC)寻找CT未能发现原发灶的胸腔积液或肺不张患者的肺癌原发灶，及其对肺癌伴有胸腔积液的患者胸腔积液良恶性鉴别诊断的价值。方法110例CT未发现肺部原发病灶但疑为肺癌及肺癌转移可能的胸腔积液或肺不张患者(其中胸腔积液8．4例，肺不张26例)，进行^18F-FDG DHTC检查。结果38例患者最终确诊为肺癌，其中伴有胸腔积液30例，伴有肺不张8例；另72例为肺部良性病变。^18F-FDG DHTC对CT未能找到原发灶的胸腔积液或肺不张患者肺癌诊断的灵敏度、特异性和准确性分别为97％、78％和85％。30例伴有胸腔积液的肺癌患者中，21例确诊为恶性胸腔积液。^18F-FDG DHTC对良恶性胸腔积液鉴别诊断的灵敏度为86％，特异性为8／9例。结论^18F-FDG DHTC是寻找胸腔积液或肺不张患者肺癌原发灶灵敏可靠的方法，并对良恶性胸腔积液的鉴别诊断有一定的临床价值。     

Assessment of malignant pleural mesothelioma with (18)F-FDG dual-head gamma-camera coincidence imaging: comparison with histopathology.

Malignant pleural mesothelioma is an aggressive primary neoplasm for which early detection and accurate staging are known diagnostic challenges. The role of (18)F-FDG dual-head gamma-camera coincidence imaging ((18)F-FDG-CI) is yet to be defined. The purpose of this study was to evaluate the usefulness of (18)F-FDG-CI in the assessment of malignant pleural mesothelioma using histopathology as the gold standard. METHODS: Fifteen consecutive patients with CT scan evidence of pleural thickening, fluid, plaques, or calcification underwent (18)F-FDG imaging 1.5 h after the intravenous administration of 370 MBq (18)F-FDG. Imaging was performed with a dual-head gamma camera equipped with 2.54-cm-thick NaI crystals operating in coincidence mode. Using an iterative algorithm, whole-body images were reconstructed as transaxial, sagittal, and coronal images. No attenuation correction was applied. The results of (18)F-FDG-CI scans were compared with CT and with histopathologic diagnosis. RESULTS: Eleven of 15 patients had histologically proven malignant mesotheliomas (10 epithelial, 1 sarcomatoid). All 11 primary tumors were detected by (18)F-FDG, and absence of disease was confirmed in the 4 patients who were disease free. Thirty-four lesions were biopsied; among these, 29 were found to be positive for tumor. (18)F-FDG was true-positive in 28 lesions, true-negative in 4, false-negative in 1 (0.5 cm in diameter), and false-positive in 1 (inflammatory pleuritis). The smallest lesion detected was 0.8 cm. For biopsied lesions, overall sensitivity, specificity, and accuracy for (18)F-FDG-CI were 97%, 80%, and 94% respectively, compared with 83%, 80%, and 82% for CT. Twenty-one of 29 positive lesions involved the pleura, lung parenchyma, or chest wall and were all (18)F-FDG avid. In the mediastinum, (18)F-FDG-CI detected 7 of 8 biopsy-positive lesions (88%), whereas CT was positive in 6 of 8 lesions (75%). (18)F-FDG identified extrathoracic metastases in 5 patients, excluding them from surgical therapy. CONCLUSION: These preliminary results suggest that (18)F-FDG-CI appears to be an accurate method to diagnose and to define the extent of disease in patients with diffuse malignant pleural mesothelioma.     

Nodular fasciitis: correlation of MRI findings and histopathology

OBJECTIVE: To compare the histopathology of nodular fasciitis (NF) with the magnetic resonance imaging (MRI) findings in order to evaluate the basis of the MR signal characteristics. DESIGN AND PATIENTS: Ten patients with NF, nine females and 1 male, with an age ranging from 13 to 58 years (mean 26.8 years) were studied. MRI findings, available in all 10 patients, were compared with the histopathology in nine patients, and an area-to-area comparative study of the whole specimen section histopathology and MRI was performed in two patients. RESULTS: On the basis of an excisional biopsy or resection specimen, the nine lesions were classified into myxoid ( n=4), cellular ( n=3) and fibrous ( n=2) subtypes. Four myxoid lesions with a subcutaneous location showed a homogeneous SI comparable with muscle on T1-weighted images, high SI on T2-weighted images, and had homogeneous enhancement. One cellular lesion presented with homogeneous, slightly higher SI than muscle on T1-weighted images and inhomogeneous, high SI on T2-weighted images. Alcian blue stain of the whole specimen section revealed the lesion had two parts corresponding to different enhancement patterns on MRI. The blue-stained myxoid part showed markedly diffuse enhancement, while the non-stained cystic space had only peripheral enhancement. Two other cellular lesions had the same appearance on both T1- and T2-weighted images and showed inhomogeneous, diffuse enhancement. One fibrous subtype lesion presented with inhomogeneous, overall slightly higher SI than muscle on T1-weighted images, lower SI at the periphery and high SI in the center on STIR images and only peripheral enhancement. Microscopy and CD-31 staining of the lesion showed more extracellular matrix, with poor vascularity in the center and more collagenous matrix with higher vascularity at the periphery. CONCLUSION: Although similar findings were found in some lesions, the large histologic variability of NF hampers the definition of a prototype of NF on MRI. However, the MRI appearance of the myxoid subtype is rather characteristic. Histologic findings reflect the different SI characteristics and enhancement pattern on MRI.     

STIR在低场强MRI诊断脊柱转移瘤中的应用价值

目的 探讨低场强磁共振成像(MRI)应用短时反转恢复(STIR)序列对脊柱转移瘤的诊断价值。方法 回顾性分析34例脊柱转移瘤的MRI表现及相关临床资料。结果 (1)34例共检出141个椎体转移。(2)STIR像上5例为等高混杂信号，29例为高信号。结论 STIR在低场强MRI诊断脊柱转移瘤中，对早期发现病灶及了解肿瘤的侵袭范围、脊髓受累情况具有重要的意义。     

Malignant pleural mesothelioma: value of CT and MR imaging in predicting resectability.

OBJECTIVE. Our objective was to determine if CT or MR imaging findings could be used to accurately predict resectability in patients with biopsy-proved malignant pleural mesotheliomas. SUBJECTS AND METHODS. CT and MR findings in 41 consecutive patients with malignant mesotheliomas who were referred to the thoracic surgery clinic for extrapleural pneumonectomy were studied by thoracic radiologists before surgery. Review of radiologic studies focused on local invasion of three separate regions: the diaphragm, chest wall, and mediastinum. Results of all imaging examinations were carefully correlated with intraoperative, gross, and microscopic pathologic findings. RESULTS. After radiologic and clinical evaluation, 34 patients (83%) had thoracotomy; 24 of these had tumors that were resectable. The sensitivity was high (> 90%) for both CT and MR in each region. Specificity, however, was low, probably because of the small number of patients with unresectable tumors. CONCLUSION. CT and MR provided similar information on resectability in most cases. Sensitivity was high for both procedures. Because CT is more widely available and used, we suggest it as the initial study when determining resectability. In difficult cases, important complementary anatomic information can be derived from MR images obtained before surgical intervention.     

STIR turbo SE MR imaging vs. coregistered FDG-PET/CT: quantitative and qualitative assessment of N-stage in non-small-cell lung cancer patients

PURPOSE: To conduct a prospective comparison of the accuracy of short inversion time (TI) inversion-recovery (STIR) turbo spin-echo (SE) imaging and coregistered 2-[fluorine-18] fluoro-2-deoxy-D-glucose (FDG)-positron emission tomography (PET) with computed tomography (CT) (coregistered FDG-PET/CT) to assess the N-stage in non-small-cell lung cancer (NSCLC) patients. MATERIALS AND METHODS: A total of 115 consecutive NSCLC patients prospectively underwent CT, STIR turbo SE imaging, and FDG-PET, as well as surgical and pathological examinations. All STIR turbo SE images were obtained with a 0.9% saline phantom, which was placed alongside the chest wall of each patient, and coregistered FDG-PET/CTs were reconstructed using commercially available software. For quantitative assessments, the ratio of signal intensity (SI) of each lymph node to that of 0.9% saline phantom (lymph node-saline ratio [LSR]) and maximal standardized uptake value (SUV(max)) of each lymph node were calculated. Feasible threshold values were determined by using the receiver operating characteristic (ROC) curve-based positive test, and diagnostic capabilities of N-stage were compared by McNemar's test on a per patient basis. RESULTS: When feasible, threshold values were adopted, quantitative sensitivity (90.1%) and accuracy (92.2%) of STIR turbo SE imaging were significantly higher than those of quantitative and qualitative sensitivities (76.7% and 74.4%) and accuracies (83.5% and 82.6%) of coregistered FDG-PET/CT on a per patient basis (P < 0.05). CONCLUSION: STIR turbo SE imaging is at least as valid as coregistered FDG-PET/CT for quantitative and qualitative assessment of the N-stage for NSCLC patients.     

Presence of local pleural adhesion in CT screening-detected small nodule in the lung periphery suggests noncancerous, inflammatory nature of the lesion

PURPOSE: Differential diagnosis of small nodules in the lung periphery detected by low-dose chest CT screening is important before surgery. The aim of the study was to discriminate between benign and malignant lesions, identified in our preoperative imaging work-up examinations and confirmed during surgery, for nodules detected on CT screening. MATERIALS AND METHODS: This study is based on 106 patients (46 men and 60 women, median age: 61.5 years) with 123 CT screening-detected and histologically confirmed nodules smaller than 30 mm in the lung periphery identified between 2002 and 2005 at Azumi General Hospital, Japan. Lesions were classified into three groups according to histological findings: adenocarcinoma, atypical adenomatous hyperplasia (AAH) and inflammatory focal lesions. We examined the visceral pleura during surgery at a location close to lung nodules. RESULTS: The median diameter of resected lung nodules on high-resolution CT (HRCT) was 9.0 mm. Nodules were nonsolid in 42, partly solid in 51 and solid in 30. Histopathological diagnosis was lung cancer in 69, AAH in 21, other noninflammatory tumours in 6 and inflammatory lesions in 27. Fifty-four lesions were located in the subpleural zone. Eight of 123 nodules showed local pleural adhesions (LPA), while 2 were buried in extensive pleural adhesion. LPA was noted more frequently in inflammatory nodules than in cancer nodules (P<.01). CONCLUSION: The presence of LPA in close proximity to a small nodule is indicative of noncancerous lesion. This feature allows the discrimination of pulmonary peripheral inflammatory lesion from peripheral small cancer on chest low-dose CT screening.     

心脏原发恶性肿瘤CT及MRI表现

目的:了解心脏原发恶性肿瘤的CT、MRI表现,旨在提高诊断及鉴别诊断。材料和方法:12例经病理证实心脏恶性肿瘤的CT及MRI资料进行回顾性分析。其中5例行胸部CT平扫加增强扫描。9例做心脏MR检查,其中7例行动态增强扫描。结果:发生部位以右心房最多见(6/12)。跨心腔生长或累及邻近大血管及心包常见(10/12)。伴有心包和胸腔积液(9/12)。肿瘤多以中度不均匀强化为主,血管肉瘤内见同血管强化一致条状影,横纹肌肉瘤呈后期明显均匀强化。肿瘤MR信号以T1WI等略低信号,T2WI为混杂高信号表现为主,而恶性纤维组织细胞瘤T2WI呈明显低信号较特征。结论:心脏恶性肿瘤具有一般恶性肿瘤侵袭性生长之特点,CT、MRI评价病变范围、组织特征具有优势,有助于诊断及治疗方案实施,进一步组织学定性、鉴别有困难。     

CT and MR imaging of the paranasal sinuses in cystic fibrosis. Correlation with microbiological and histopathological results

PURPOSE: To compare CT and MR findings of the paranasal sinuses in patients with cystic fibrosis (CF) with microbiology and histopathology. Further, to compare microbiology from the maxillary sinuses, nasopharynx and sputum. MATERIAL AND METHODS: CT and MR imaging of the paranasal sinuses were performed in 10 CF patients. Endoscopy and maxillary sinus aspirates were obtained (guided by the MR findings) and analyzed microbiologically and histologically. Samples from the nasopharynx and sputum were analyzed microbiologically. RESULTS: CT and MR were equal in displaying the extent of soft tissue masses, which at CT were homogeneous, while MR showed heterogeneous signals. MR images also demonstrated circumscribed areas with signal void at the STIR sequence with corresponding high to intermediate signal at the T1-weighted sequence. P. aeruginosa was frequently cultured from these areas which we named the "black hole sign". Maxillary sinus cultures revealed the same bacteria as nasopharynx and sputum cultures combined. CONCLUSION: MR images were superior to CT in differentiating soft tissue masses in the paranasal sinuses in CF patients. Bacteria with potential for specialized iron uptake mechanisms were present in areas with signal void at the STIR sequence. Our hypothesis is that the MR "black hole sign" can be explained by paramagnetic properties related to bacterial agents.