CT assessment of silicosis in exposed workers

For evaluation of the clinical usefulness of CT of the thorax in workers exposed to silica, 58 workers with long-term exposure to silica in the granite and foundry industries of the Eastern Townships of Quebec were examined. CT scans were compared with standard posteroanterior chest radiographs by using the International Labour Office 1980 grading system for silicosis. Six areas of the lung in each patient were assessed by both techniques for profusion (number) of opacities (small nodules), coalescence, and the presence of large opacities. CT scans and chest radiographs yielded similar average scores for detection of opacities. CT identified significantly more coalescence and large opacities in patients with simple silicosis. In patients with complicated silicosis, CT results were comparable with those of chest radiographs. CT of the thorax in workers exposed to silica does not identify more patients with minimal parenchymal disease, but it does detect earlier changes of coalescence.     

Repeated computed tomography during treatment of small cell carcinoma of the lung

Twenty-three patients with small cell carcinoma of the lung were examined with CT and conventional chest radiography before treatment, 19 after 3 courses of chemotherapy, before radiation therapy, and 8 after cessation of chemotherapy and radiation therapy. In most patients high abdominal CT was also employed. CT provided more information about the thoracic involvement than did conventional radiography in more than half of the cases. In 3 cases CT before irradiation demonstrated progression in the thorax, not visible at conventional radiography, and in 4 cases progression of extrathoracic metastases in spite of intrathoracic regression. After therapy, one case of progression in the thorax not seen at conventional radiography was demonstrated. With repeated CT examinations of the thorax and abdomen, progression/regression both intra- and extrathoracically is well demonstrated.     

Radiation dose from volumetric helical perfusion CT of the thorax, abdomen or pelvis

Purpose

To evaluate the radiation doses delivered during volumetric helical perfusion CT of the thorax, abdomen or pelvis.

Materials and methods

The dose-length product (DLP) and CT dose index (CTDIvol) were recorded and effective dose (E) determined for patients undergoing CT (4D adaptive spiral) for tumour evaluation. Image noise and contrast to noise (CNR) at peak enhancement were also assessed for quality.

Results

Forty two consecutive examinations were included: thorax (16), abdomen (10), pelvis (16). Z-axis coverage ranged from 11.4 to 15.7?cm. Mean DLP was 1288.8?mGy.cm (range: 648 to 2456?mGy.cm). Mean CTDIvol was 96.2?mGy (range: 32.3 to 169.4?mGy). Mean effective dose was 19.6?mSv (range: 12.3?mSv to 36.7?mSv). In comparison mean DLP and effective dose was 885.2?mGy.cm (range: 504 to 1633?mGy.cm) and 13.3 mSV (range: 7.8 to 24.5?mSv) respectively for the standard staging CT thorax, abdomen and pelvis. Mean tumour CNR at peak enhancement was 1.87.

Conclusion

The radiation dose imposed by perfusion CT was on average 1.5 times that of a CT thorax, abdomen and pelvis. The dose is not insubstantial, and must be balanced by the potential clinical utility of additional physiologic data. Further efforts towards dose reduction should be encouraged.     

胸部良性神经源性肿瘤的CT诊断

目的 :分析胸部良性神经源性肿瘤的CT表现特点。方法 :搜集 15例经手术病理证实的胸部良性神经源性肿瘤 ,其中神经鞘瘤 8例 ,年龄 2 76 4岁 ,神经纤维瘤 4例 ,年龄 2 444岁 ,节细胞神经瘤 3例 ,年龄 82 0岁。结果 :15例中仅 3例有相关的临床症状 ,CT表现为边界清楚光滑的圆形或椭圆形较均匀稍低密度软组织肿块 ,神经鞘瘤 6例明显不均匀强化 ,2例中度结节状强化 ;神经纤维瘤和节细胞神经瘤呈轻度均匀强化。结论 :胸部良性神经源性肿瘤发病年龄和CT表现对诊断和鉴别诊断有重要的参考价值。     

Thoracic computed tomography in victims of blunt trauma: changes in utilization after the introduction of helical technology

Purpose: In blunt trauma, CT of the thorax is often performed because of the limitations of plain film chest radiography in accurately depicting injuries to the thoracic aorta. The advent of helical CT has allowed the entire chest to be imaged more expeditiously. We will evaluate the extent to which this ability to rapidly obtain additional images of the thorax has increased the utilization of chest CT in blunt trauma. Methods: The radiologic records of all victims of blunt trauma who underwent total body CT (TBCT), which included abdomen, pelvis, and chest images, in the 10 months before and 10 months after our institution acquired helical CT (HCT), were retrospectively evaluated. Results: In the 10 months before we obtained HCT, 520 conventional CT of the abdomen and pelvis were completed, of which only 11 (2.1 %) included images of the full thorax. After HCT was instituted, 684 abdomen and pelvis CT were performed, of which 59 (8.6 %) were ordered with the entire chest. Of the 11 conventional TBCT, 6 (55 %) showed findings in the chest; in 2 of these cases (18 %) the abnormalities were confined exclusively to the thorax. Similarly, of the 59 helical TBCT, 31 (53 %) depicted traumatic abnormalities in the thorax, and in 23 of these cases (39 %) injuries were only within the chest. In 4 of the latter the injuries were mediastinal hematomas, 1 of which (25 %) was confirmed angiographically to represent an aortic laceration. Conclusion: The speed and ease with which additional images can be obtained by HCT has greatly increased utilization of cross-sectional imaging of the thorax after blunt trauma (approximately four-fold). Over half of these depict traumatic injuries.     

应用Mimics软件辅助重建人体胸廓三维有限元模型的研究

目的建立人体胸廓三维有限元模型,为研究人体胸外按压的临床效果与机制提供生物力学仿真基础。方法获取1例20岁男性胸部CT扫描图像,将断层影像输入到Mimics10.1软件,利用Mimics软件的三维模型重建和有限元网格辅助划分功能,在Ansys软件中建立完整的人体胸廓三维有限元模型。结果完整重现了人体胸廓的复杂形态,建立了包括锁骨、肋骨、脊柱等结构在内的鲜明、直观的人体胸廓三维有限元模型,共1 158 085个节点、736 022个单元,并依据CT图像灰度值将胸廓模型从骨皮质到髓核区分为6种材料性质。结论利用Mimics软件辅助建立的人体胸廓三维有限元模型具有较高的真实性和精确度,能够满足人体胸廓生物力学分析的需要,为下一步人体胸廓有限元模型的分析提供了基础。     

Nerves of the thorax: atlas of normal and pathologic findings.

An anatomic and imaging atlas was created to provide detailed information about the six pairs of thoracic nerves (phrenic nerves, vagus nerves, recurrent laryngeal nerves, sympathetic trunks, costal nerves, long thoracic nerves). Serial axial computed tomographic (CT) scans of the normal thorax were obtained and included in the atlas, along with drawings showing the proper location of each nerve relative to adjacent anatomic structures. CT scans obtained in both symptomatic and asymptomatic patients with various thoracic diseases were paired with appropriate drawings and normal CT scans in the atlas. This format was designed to help determine the presence and severity of related disease, including injury from surgery, trauma, or penetrating injury, metastatic disease involvement, and, rarely, primary tumor. Although the nerves of the thorax are rarely identified at cross-sectional imaging, their location can be inferred by localizing easily identified anatomic landmarks. Familiarity with the functional anatomy and clinical significance of the nerves of the thorax is important for the correct interpretation of thoracic images.     

Coronary artery calcification identified by CT in patients over forty years of age

In a study of 100 unselected patients forty years of age or older, routine CT of the thorax demonstrated coronary artery calcification in 41%. Calcification of the left anterior descending was most common, occurring in 34%. For patients 60 years of age and over, clinical evidence of coronary artery disease was 1.7 times more common in those with calcification compared to those without; however, for patients under 60, coronary artery disease was 5.5 times more common in those with calcification than those without. Because of the strong relationship that is known to exist between coronary artery calcification and coronary arteriosclerosis, we believe that the incidental discovery of coronary artery calcification on routine CT of the thorax has significance. All patients under 60 with coronary artery calcification discovered on CT should be investigated for hyperlipidemia if this has not been done, and, if they are not known to have a history of coronary artery disease, they should have a stress test and, if positive, arteriography may be warranted.     

Dose reduction in CT examination of children by an attenuation-based on-line modulation of tube current (CARE Dose)

In a controlled patient study we investigated the potential of attenuation-based on-line modulation of the tube current to reduce milliampere values (mAs) in CT examinations of children without loss of image quality. mAs can be reduced for non-circular patient cross sections without an increase in noise if tube current is reduced at those angular positions where the patient diameter and, consequently, attenuation are small. We investigated a technical approach with an attenuation-based on-line control for the tube current realised as a work-in-progress implementation. The CT projection data are analysed in real time to determine optimal mAs values for each projection angle. We evaluated mAs reduction for 100 spiral CT examinations with attenuation-based on-line modulation of the tube current in a group of children. Two radiologists evaluated image quality by visual interpretation in consensus. We compared the mAs values read from the CT scanner with preset mAs of a standard protocol. Four different scan regions were examined in spiral technique (neck, thorax, abdomen, thorax and abdomen). We found the mAs product to be reduced typically by 10-60% depending on patient geometry and anatomical regions. The mean reduction was 22.3% (neck 20%, thorax 23%, abdomen 23%, thorax and abdomen 22%). In general, no deterioration of image quality was observed. There was no correlation between the age and the mean mAs reduction in the different anatomical regions. By classifying the children respectively to their weight, there is a positive trend between increasing weight and mAs reduction. We conclude that mAs in spiral CT examinations of children can be reduced substantially by attenuation-based on-line modulation of the tube current without deterioration of image quality. Attenuation-based on-line modulation of tube current is efficient and practical for reducing dose exposure to children.     

Intrathoracic goiter in the posterior mediastinum

Several examination methods are now available for diagnosis of intrathoracic goiter; diagnosis of suspicion is made by conventional plain radiography of the thorax, clinical findings being often normal or non-characteristic. If the iodine scintigram shows accumulation in the tumor, we can be practically sure of the diagnosis of an intrathoracic goiter. In case of a negative iodine scan we can obtain pointers to the nature of the tissue via CT or MR, especially if a connection between cervical thyroid tissue and intrathoracic mass can be demonstrated. Furthermore, these two methods (CT and MR) enable exact determination of the extension of the goiter and show the topographical relation to the neighbouring organs or their displacement.     

Multiplanar and three-dimensional multi-detector row CT of thoracic vessels and airways in the pediatric population

Multi-detector row computed tomography (CT) has changed the approach to imaging of thoracic anatomy and disease in the pediatric population. At the author's institution, multi-detector row CT with multiplanar and three-dimensional reconstruction has become an important examination in the evaluation of systemic and pulmonary vasculature and the tracheobronchial tree. In some clinical situations, multi-detector row CT with reformatted images is obviating conventional angiography, which is associated with higher radiation doses and longer sedation times. Although multi-detector row CT with multiplanar and three-dimensional reconstruction is expanding the applications of CT of the thorax, its role as a diagnostic tool still needs to be better defined. The purposes of this article are to describe how to perform multi-detector row CT with multiplanar and three-dimensional reconstruction in young patients, to discuss various reconstruction techniques available, and to discuss applications in the evaluation of vascular and airways diseases.     

99Tcm-MIBI透视三维显示诊断胸部病变的临床价值

评估^99Tc^m－甲氧基异丁基异腈透视三维显示法对胸部恶性病变及其在相邻部位转移灶检出方面较平面及断层显像所具有的优势。方法 回顾性分析54例恶性和6例良性经手术或病理检查证实的胸部病变，并将SPECT透视三维法与X线胸片、CT等对照研究。结果 正常对照组16例均为阴性；恶性病变组中肺癌38例，平面显像阳性率52．6％，断层阳性率78．9％，透视三维法阳性率84．2％；食管癌12例，平面阳性率41．6％，断层阳性率58．3％，透视三维法阳性率75．0％；4例纵隔及腋下恶性病变平面显像和X线无异常，CT阴性，透视三维法阳性。结论 透视三维法检出病灶优于平面和断层显像，与X线胸片、CT、纤支镜比较，灵敏度、特异性相对均衡，准确性高。     

When, why, and how to examine the heart during thoracic CT: Part 1, basic principles

OBJECTIVE: MDCT systems with fast scanning capabilities can acquire images of the thorax with reduced cardiac motion artifacts, enabling improved evaluation of the heart and surrounding structures in the course of routine thoracic CT. This article describes the principles of including an evaluation of the heart in the course of a chest CT examination in terms of both examination technique and image interpretation. In addition, both the normal appearances and some of the most common abnormal appearances of the cardiac structures will be described. CONCLUSION: Details concerning the cardiac structures can inform interpretation of thoracic CT studies and can influence the patient's clinical management. Both unenhanced and contrast-enhanced scans can detect significant cardiac disorders that may otherwise go undetected. In certain situations, a CT examination of the entire chest, complemented by cardiac gating, can provide a more dedicated analysis of the heart and coronary arteries, providing both morphologic and functional information.     

青石棉所致胸膜间皮瘤CT分析

目的分析因环境接触青石棉所致胸膜间皮瘤病例的CT征象。方法对55例经证实的胸膜间皮瘤病例CT表现进行回顾性分析。结果在55例中,局限型胸膜间皮瘤1例并恶变,伴少量胸水;弥漫型胸膜间皮瘤54例,其中无胸水13例,少或中等量胸水30例,大量胸水11例。右下胸膜间皮瘤伴对侧胸水4例。CT表现为胸膜增厚>2cm,呈花边状、结节状或软组织肿块,增强有强化。结论CT对确定胸膜间皮瘤部位、范围及随访方面作用较大。     

Schwierige Diagnose des Boerhaave-Syndroms

Boerhaave??s syndrome presents with a variety of clinical symptoms and the correct diagnosis can often only be found at autopsy. The usefulness of antemortem and postmortem computed tomography (CT) in the diagnostics of Boerhaave??s syndrome is emphasized by presenting two cases. Both autopsies showed a complete rupture of the esophagus and leakage of gastric fluid into the thorax. The first case was accompanied by tension pneumothorax, the second by pneumomalacia. Both cases showed uncommon clinical symptoms with no report of excessive vomiting or matching previous clinical history.     

双源CT在急性胸痛诊断和鉴别诊断中的临床价值

目的：探讨双源CT在急性胸痛诊断和鉴别诊断中的临床价值。方法：51例急性胸痛患者行双源CT心脏及胸部血管检查,对图像进行重组并进行诊断,其中36例患者双源CT结果并与血管造影结果进行对比较。结果：所有患者一次心脏和胸部血管双源CT检查即可快速获得清晰的冠状动脉、肺动脉、胸主动脉及胸部其他结构。双源CT诊断冠状动脉狭窄或闭塞26例,其中5例并发急性心肌梗死,1例合并有冠状动脉夹层;肺动脉栓塞7例,胸主动脉夹层、壁间血肿和动脉瘤分别为6例、2例和2例。冠状动脉及胸主动脉双源CT结果与血管造影结果具有良好的一致性。结论：双源CT可以同时清晰地显示心脏及胸部血管,是急性胸痛病因诊断和鉴别诊断的无创、快速、可靠的检查方法。     

Visual impression of photographic density of lung, thorax, and mediastinum in chest CT images: verification of optical illusion by visual subjective evaluation of medical images

Even if the brain in head CT images is shown physically at the same photographic density, optical illusion (assimilation, contrast, etc.) occurs and practical density can be observed psychologically differently. Therefore, in this study, in order to clarify the visual characteristics of lightness perception in chest CT images, I attempted to compare it with the visual impression of the photographic density of lung, thorax, and mediastinum, using visual subjective evaluation. The results were as follows. (1) In the case of the preferential window setting of lung, both thorax and mediastinum, which surround the lung, are recognized as a wide white frame with contrast, and the photographic density of the lung psychologically seems blackish as a result of the "picture frame effect". (2) In the case of the preferential window setting of thorax and mediastinum, the visual impression of the photographic density varies among observers. (3) In the case of the virtual double window setting of lung, thorax, and mediastinum, under the influence of both high-density and low-density areas in the radiological anatomy of thorax and mediastinum, the photographic density of lung psychologically appears whitish as a result of the "grouping theories" of lightness computation. Further, under the influence of original gray lung, the photographic densities of thorax and mediastinum psychologically appear to be whitish.     

Role of scintigraphy with technetium-99m depreotide in the diagnosis and management of patients with suspected lung cancer

Background: In Sweden, there are over 3000 new lung cancer cases every year. There are still numerous patients with undetermined lesions after routine diagnostic evaluation by clinical examination, chest radiography, computed tomography (CT) of the thorax, and bronchoscopy. An appropriate method for further diagnostic workup is therefore needed.

Purpose: To evaluate the diagnostic value of the somatostatin analogue depreotide in patients with suspected lung cancer, and to determine in which clinical settings it would be beneficial to use ^99mTc-depreotide scintigraphy.

Material and Methods: We included 99 consecutive patients referred to our hospital with suspected lung cancer. A clinical examination, bronchoscopy, chest radiography, CT of the thorax and upper abdomen, and scintigraphy were done. Scintigraphy was performed after injection of 740 MBq ^99mTc depreotide with tomographical imaging of the thorax and whole-body scanning. The diagnostic outcome of the scintigrams was compared to CT, using morphology or clinical outcome as the endpoint.

Results: ^99mTc-depreotide uptake was found in 62 out of 66 malignancies, including 57 of 58 primary lung cancer cases. Two cases of lung metastasis (one from a colon cancer and one from an adenoid cystic carcinoma originating in the palate) and one rib chondrosarcoma did not show depreotide uptake. There were 33 patients with benign lesions, of whom 16 displayed false-positive ^99mTc-depreotide uptake, whereof 11 were pneumonias. Tc-99m-depreotide uptake was absent in 17 patients with benign lesions, including all 10 hamartomas. The sensitivity in detecting malignancy was 94%, and in detecting lung cancer 98%. The specificity was calculated based on two sets of data. When all cases were used, the specificity was 52%. If the 12 pneumonias are excluded, the specificity was 77%.

Conclusion: ^99mTc-depreotide scintigraphy has a high sensitivity in detecting lung cancer. The method is useful in decision-making with respect to surgery.     

9. Assessment of Intrathoracic Metastatic Lung Cancer using FDG-PET and CT of the Thorax

Purpose: The purpose of this study was to assess the accuracy in localizing mediastinal, hilar and intraparenchymal lymphadenopathy in patients with primary lung carcinomas, using FDG-PET and CT of the thorax and to correlate with surgical pathology.Method: Thirty-five patients with primary lung carcinomas and minimal metastatic lymph node involvement, (either N solidus in circle or N1 disease) underwent FDG-PET and CT of the thorax prior to surgical intervention. Both FDG-PET and CT of the thorax were blindly read independent of one another.Results: Histologically, 23 patients had negative lymph nodes (N solidus in circle) and 12 patients had N1 disease. The imaging performance characteristics for FDG-PET and CT of the thorax in N solidus in circle/N1 disease was evaluated and reported in Table 1.Conclusion: This study demonstrates the higher specificity, accuracy, PPV, and NPV of FDG-PET over CT of the thorax in patients with minimal lymph node disease.     

CT容积灌注诊断孤立性肺结节良恶性的临床应用评价

目的评价常规胸部CT结合CT容积灌注(CTVP)诊断孤立性肺结节(SPN)良、恶性的临床应用价值。资料与方法搜集行首过法CTVP的SPN65例,其中恶性43例,良性22例。先通过受试者工作特征(ROC)曲线明确CTVP参数诊断阈值,并通过四格表行2项参数的联合试验。由两名低年资和两名高年资医师回顾性盲法阅常规胸部CT图像,做出诊断(方法A);再阅常规胸部CT及CTVP资料,作出诊断(方法B)。采用ROC曲线比较每名医师采用诊断方法A与B的准确性有无统计学差异。通过组内相关系数(ICC)评价诊断方法A及B的一致性。结果当BF=50ml.100g-1.min-1、BV=3ml/100g、PS=10ml.100g-1.min-1时,CTVP诊断SPN良、恶性的敏感性分别为93%、86%及86%,特异性分别为59%、68%及77%。BF+PS及BV+PS的序列实验联合特异性均为82%。联合运用常规胸部CT和CTVP,四名医师诊断SPN良、恶性的敏感性分别为91%、95%、95%及95%;特异性分别为86%、91%、95%及82%。四名医师方法B的ROC曲线下面积均大于方法A(P均<0.05)。四名医师方法A的ICC=...