Differentiation of pulmonary parenchymal consolidation from pleural disease using the sonographic fluid bronchogram

The nature of pleural-based thoracic collections may be sonographically confusing. To help lessen this confusion, the fluid bronchogram, a useful sonographic sign of pulmonary parenchymal consolidation, is described. Bronchi containing fluid in consolidated lung can be identified using ultrasound.     

Real-time sonography of pleural opacities

Fifty patients with radiographic pleural or pleural-based opacities were examined with high resolution real-time sonographic sector scanning. In 90% of cases selected for thoracentesis, fluid sufficient for diagnosis was obtained. Complex, septated pleural loculations contained an exudative effusion in 74% of the patients, while anechoic areas yielded exudative and transudative effusions with almost equal frequency. The use of real-time scanning is stressed because of greater flexibility and shorter examination time compared to compound scanning, and its utility for portable scanning on critically ill patients.     

CT findings of pulmonary tuberculosis presenting as segmental consolidation.

PURPOSE: The purpose of our study was to determine specific CT findings of tuberculous pneumonia presenting as segmental or lobar consolidation along with a pathologic review of specimens with similar radiographic patterns. METHOD: CT findings of 45 cases of proven tuberculous pneumonia and 21 proven nontuberculous pneumonia were compared. Pathologic findings of five surgically resected tuberculous pneumonia cases were also investigated. The presence of fluid bronchogram (linear, branching shadow of fluid attenuation) and inner low attenuation/cavitation in the area of consolidation, luminal dilatation, and wall thickening of proximal bronchi were the main points sought on CT scan. In addition, the presence of bronchogenic dissemination, lymph node enlargement, and pleural lesions was also checked for in the unaffected area of both lungs. RESULTS: The following bronchial changes were seen in the tuberculous pneumonia and nontuberculous pneumonia groups, respectively: fluid bronchogram in 68.9 and 23.8% (p < 0.05), bronchial luminal dilatation in 60.0 and 23.8% (p < 0.05), and bronchial wall thickening of the proximal airway leading to the area of consolidation in 52.8 and 7% (p < 0.05). Bronchogenic dissemination outside the consolidation appeared in 88.9 and 52.4% (p < 0.05), respectively. In the tuberculous pneumonia group, lymph node enlargement and pleural reaction were seen in 55.6 and 35.6%, respectively, but in 42.9 and 57.1% in the nontuberculous pneumonia group (p > 0.05). Histologically, tuberculous pneumonia showed either bronchioles containing inflammatory exudates and submucosal granuloma or alveoli containing aggregates of alveolar macrophages or cellular debris. CONCLUSION: Fluid bronchogram in the area of homogeneous consolidation, bronchial luminal dilatation, and bronchial wall thickening of the proximal airway were the bronchial changes more significantly prominent in the tuberculous pneumonia group. We suspect that these findings may represent tuberculous bronchitis in small airways.     

Fluid within preexisting pulmonary air-spaces: a potential pitfall in the CT differentiation of pleural from parenchymal disease

There have been many reports of the ability of CT to distinguish between parenchymal and pleural disease. The purpose of this report is to describe the appearance of seven cases of intraparenchymal fluid-filled air-spaces (bullae or lung cysts) in which the CT findings may resemble those of pleural disease and, thus, cast doubt on the specificity of the established criteria.     

Hydrocolonic sonography for evaluating inflammatory bowel disease.

OBJECTIVE: The purpose of our study was to compare the usefulness of hydrocolonic sonography and (99m)Tc-hexamethylpropyleneamine oxime (HMPAO)--labeled leukocyte scintigraphy in the examination of patients with inflammatory bowel disease, using precise sonographic criteria of bowel involvement. SUBJECTS AND METHODS: Sixty-eight consecutive patients with active inflammatory bowel disease (34 ulcerative colitis and 34 Crohn's disease), 12 with inactive inflammatory bowel disease, and 10 control subjects were prospectively studied. Patients with active disease underwent clinical assessment, hydrocolonic sonography, scintigraphy, and colonoscopy within 72 hr, whereas patients with inactive disease and control subjects underwent clinical examination and hydrocolonic sonography. RESULTS: Involvement of a colonic segment by active inflammatory bowel disease was best defined by mucosal thickness greater than 1.5 mm, bowel wall thickness greater than 4 mm, mucosal irregularity, or the absence of haustra; and involvement of the terminal ileum by bowel wall thickness greater than 4 mm. Using these criteria, hydrocolonic sonography had 100% sensitivity for identifying patients with active inflammatory bowel disease and a greater overall accuracy (87%) than scintigraphy (77%) in the assessment of disease extension. In addition, strong correlation was shown between a hydrocolonic sonography activity index and clinical and endoscopic activity indexes. CONCLUSION: This prospective study provides precise sonographic criteria for the definition of bowel involvement by active inflammatory bowel disease. Hydrocolonic sonography has a greater accuracy than scintigraphy for assessing disease extension and activity. Therefore, hydrocolonic sonography should be considered a first-choice technique to complete the study of inflammatory bowel disease after confirmation of the diagnosis by histology.     

CT fluid bronchogram: observation in postobstructive pulmonary consolidation.

Twelve patients with bronchial obstruction secondary to either cancer or broncholith were evaluated with chest radiography and computed tomography (CT). Chest radiography showed nonspecific lobar consolidation (12 cases), bulging fissure (6 cases), and air bronchogram (1 case). CT revealed air bronchogram, CT angiogram sign, bulging fissure, and fluid bronchogram in all six cases with partial bronchial obstruction (except for absence of air bronchogram in one case). CT fluid bronchograms were also present in the remaining six cases with total bronchial obstruction. Because of the lobar atelectasis, bulging fissure was absent in all six of these patients. CT angiogram signs and air bronchograms were observed in only half of the patients. CT is, therefore, very useful in detailed evaluation of postobstructive pulmonary consolidation. We particularly stress that the term "CT fluid bronchogram" should be applied when the bronchi are filled with fluid instead of air.     

Transcutaneous contrast-enhanced sonography of pleural-based pulmonary lesions

OBJECTIVE: Transcutaneous ultrasound enables visualization of pleural-based lesions but with a poor correlation to specific pathology. Ultrasound contrast agents in conjunction with contrast-specific imaging techniques are increasingly accepted in clinical use. Based on the dual arterial supply of the lung, this organ is suited for evaluation of arterial vascularity by contrast-enhanced sonography (CES). This review will present first data about practise and clinical use of CES in patient with peripheral lung lesions. METHODS: This review is based on the experience of transcutaneous CES in 350 patients with chest pathology diagnosed by B-mode sonography at an internal medicine center. CES studies were performed with a contrast-devoted unit (Acuson, Sequoia, Siemens medical solution) that had contrast-specific, continuous-mode software. A low mechanical index was used. A sulfur hexafluoride-based microbubble contrast medium (Sonovue, Bracco SpA, Milan, Italy) was injected. Pulmonary lesions were characterized by CES regarding time to enhancement (TE) and extend of enhancement (EE). RESULTS: CES in peripheral lung lesions is feasible and depending on underlying diseases lesions may show a variable TE and EE. CES enables to distinguish pulmonary arterial supply from bronchial arterial supply by TE. First experiences with CES have shown that various peripheral lung lesions do have a characteristic CES pattern regarding TE and EE. First clinical data show that there are clinical conditions, which may show a diagnostic advantage of CES in comparison to B-mode US. CES may be helpful (1) to confirm diagnosis of pleurisy, (2) to confirm diagnosis peripheral pulmonary embolism, (3) to characterize lung opafication to atelectasis, pneumonia, and tumor, and (4) to assist in interventional procedures. CONCLUSION: : CES of the chest is limited to pleural-based lesions. CES enables to characterize lung lesions regarding TE and EE. The clinical benefit is yet unclear, but first results are encouraging.     

Value of sonography in determining the nature of pleural effusion: analysis of 320 cases.

To assess the value of sonography in determining the nature of pleural effusions, we prospectively analyzed the sonographic findings in 320 patients with pleural effusion of various causes (224 with exudates and 96 with transudates). The nature of the effusions was established on the basis of chemical, bacteriologic, and cytologic examination of pleural fluid; pleural biopsy; and clinical follow-up. All patients had high-frequency, real-time sonography performed by one of three sonographers who had no clinical information concerning the patients. The sonographer evaluated the images for internal echogenicity of the effusion, thickness of the pleura, and associated parenchymal lesions of the lung. The images were also printed out and interpreted a second time by the other two sonographers to reach a consensus. Our results showed that the two types of effusions could be distinguished on the basis of sonographic findings. Transudates were anechoic, whereas an anechoic effusion could be either a transudate or an exudate. Pleural effusions with complex septated, complex nonseptated, or homogeneously echogenic patterns were always exudates (p less than .01). Sonographic findings of thickened pleura and associated parenchymal lesions in the lung also were indicative of an exudate (p less than .01). Homogenous echogenic effusions were due to hemorrhagic effusion or empyema. Sonographic evidence of a pleural nodule was a specific finding in patients with a malignant effusion. We conclude that sonography is useful in determining the nature of pleural effusion.     

Differentiation of radiation-induced fibrosis from recurrent pulmonary neoplasm by CT

We describe and compare the computed tomographic (CT) manifestations of radiation fibrosis and recurrent neoplasm and consider the potential application of CT in the follow-up of patients after radiotherapy for bronchogenic carcinoma. Thirty-one patients were evaluated in this retrospective study. The CT findings in 20 patients with radiation fibrosis were compared with those in 11 patients with recurrent tumor. In 19 of the 20 patients with radiation fibrosis, CT allowed demonstration of consolidation, with a straight lateral margin and containing ectatic air-containing bronchi. In 9 of the 11 patients with recurrent tumor, CT showed a soft tissue mass with a convex lateral border and without air-containing bronchi. Twenty of the 31 patients had a suspected recurrence on plain chest radiographs. CT permitted accurate differentiation between radiation fibrosis and recurrent tumor in all patients, with the exception of two who had large pleural effusions. Because of its great specificity, CT appears useful in complementing chest radiographs in the follow-up of patients after radiotherapy.     

Multifocal osteosarcoma with extensive pleural metastatic disease.

An eighteen year old female presented with multifocal synchronous osteosarcoma, with multiple skeletal foci of tumour in long bones, pelvis and spine. The radiographically dominant lesion was in the right ilium, and this was considered to be the primary site. There was an extensive osseous pleural plaque and there were also metastases to lungs, peritoneum, abdominal wall, adrenal gland and lymph nodes. A review of the literature reveals that multifocal osteosarcoma is an uncommon condition and is probably due to metastatic disease and not multiple primary lesions. Pleural metastatic disease in osteosarcoma has been seldom reported.     

Pulmonary MRA: Differentiation of pulmonary embolism from truncation artefact

Purpose

Truncation artefact (Gibbs ringing) causes central signal drop within vessels in pulmonary magnetic resonance angiography (MRA) that can be mistaken for emboli, reducing diagnostic accuracy for pulmonary embolism (PE). We propose a quantitative approach to differentiate truncation artefact from PE.

Methods

Twenty-eight patients who underwent pulmonary computed tomography angiography (CTA) for suspected PE were recruited for pulmonary MRA. Signal intensity drops within pulmonary arteries that persisted on both arterial-phase and delayed-phase MRA were identified. The percent signal loss between the vessel lumen and central drop was measured. CTA served as the reference standard for presence of pulmonary emboli.

Results

A total of 65 signal intensity drops were identified on MRA. Of these, 48 (74 %) were artefacts and 17 (26 %) were PE, as confirmed by CTA. Truncation artefacts had a significantly lower median signal drop than PE on both arterial-phase (26 % [range 12–58 %] vs. 85 % [range 53–91 %]) and delayed-phase MRA (26 % [range 11–55 %] vs. 77 % [range 47–89 %]), p?<?0.0001 for both. Receiver operating characteristic (ROC) analyses revealed a threshold value of 51 % (arterial phase) and 47 % signal drop (delayed phase) to differentiate between truncation artefact and PE with 100 % sensitivity and greater than 90 % specificity.

Conclusion

Quantitative signal drop is an objective tool to help differentiate truncation artefact and pulmonary embolism in pulmonary MRA.

Key points

? Inexperienced readers may mistake truncation artefacts for emboli on pulmonary MRA ? Pulmonary emboli have non-uniform signal drop ? 51 % (arterial phase) and 47 % (delayed phase) cut-off differentiates truncation artefact from PE ? Quantitative signal drop measurement enables more accurate pulmonary embolism diagnosis with MRA     

Symposium on Nonpulmonary Aspects in Chest Radiology. The pulmonary ligament

The pulmonary ligament forms an important attachment of the lower lobe to the mediastinum and therefore influences the ultimate configuration of pneumothorax, lower-lobe atelectasis, and mediastinal pleural effusions. Since the ligament consists of a double pleural sheath, under certain circumstances fluid, air, and so on can collect within it, producing a lesion of triangular configuration. The latter must be differentiated from an air cyst or atelectasis.     

Perthes' disease. Accuracy potentials and the value of sonography

During a 2-year period 59 patients underwent sonography, 33 of them with confirmed Legg-Perthes disease and 26 in whom clinical examination had given rise to suspicion of this disorder. An intraarticular effusion was found in 53% (n = 26) of the patients and characteristic sonographic findings could be detected in 84% (n = 41). The special examination technique and the diagnostic criteria and their validity and correlation to radiologic abnormalities are discussed.