Hemorrhagic infiltration of the aortopulmonary adventitia: A complication of acute aortic dissection.

BACKGROUND: Hemorrhagic infiltration of the common aortopulmonary adventitia is an infrequent complication of acute aortic dissection, most frequently Stanford type A. The radiological interpretation of this finding may be a diagnostic challenge. The objective of this multicenter case series is to review the radiological and pathological findings of hemorrhagic infiltration of the aortopulmonary adventitia secondary to acute aortic dissection, and to describe the pathophysiology underlying this complication. MATERIAL AND METHODS: The study includes 20 cases of aortic dissection with hemorrhagic infiltration of the aortopulmonary adventitia. These are 17 cases with computed tomography (CT) data obtained from 5 academic centers. Three other cases were retrieved through a search of autopsy reports. Clinical, radiological and pathological data were collected. RESULTS: Linear foci of moderately increased attenuation were seen along the wall of the proximal pulmonary arteries in 4 cases on unenhanced CT. Contrast-enhanced CT showed soft-tissue thickening along these walls in all imaging cases, with some degree of narrowing of the lumen of the pulmonary arteries. Peribronchovascular ground-glass opacities or consolidation were present in 4 cases. CONCLUSION: Hemorrhagic infiltration of the common aortopulmonary adventitia is an infrequent complication of acute type A aortic dissection. The radiologist should be aware of its pathophysiology and imaging findings in order to make a prompt diagnosis in an urgent setting.

Anatomic landmarks to estimate the length of the diaphragm from chest radiographs: effects of emphysema and lung volume reduction surgery.

STUDY OBJECTIVES: To define anatomic landmarks that can be used to predict insertions of the diaphragm on chest radiographs and to estimate diaphragm length. DESIGN: Prospective clinical trial with a parallel group design. SETTING: Laboratory investigations in normal volunteers recruited by advertisement and in emphysema outpatients being evaluated for elective bilateral lung volume reduction surgery (LVRS). PATIENTS: Twenty-six normal subjects classified into young and older age groups, with a third group of 13 emphysema patients matched for age and sex with the older group. MEASUREMENTS: Identification and between-group comparisons were made of anatomic landmarks on anteroposterior and lateral chest radiographs obtained at total lung capacity. Predicted landmarks were generated from normal subjects. Within-subject and between-group comparisons were made of diaphragm length index (DLI) based on observed anatomic landmarks (DLIobs) and diaphragm length index based on predicted anatomic landmarks (DLIpred) at functional residual capacity. RESULTS: Anatomic landmarks were not different between the three groups or between male and female subjects, and were not different before and after LVRS in emphysema patients. No difference was found between DLIobs and DLIpred in normal subjects and emphysema patients, but both were smaller in emphysema patients than in normal subjects and increased after LVRS in emphysema patients. CONCLUSION: This study validates the use of anatomic landmarks to estimate DLI. Using these landmarks simplifies the determination of diaphragmatic lengths and could be a useful tool for the evaluation of the functional capacity of the diaphragm, and possibly as a prognostic indicator of patients who are candidates for LVRS.

Dimethyl sulfoxide affects the selection of splice sites.

Depending on the cell lines and cell types, dimethyl sulfoxide (Me2SO) can induce or block cell differentiation and apoptosis. Although Me2SO treatment alters many levels of gene expression, the molecular processes that are directly affected by Me2SO have not been clearly identified. Here, we report that Me2SO affects splice site selection on model pre-mRNAs incubated in a nuclear extract prepared from HeLa cells. A shift toward the proximal pair of splice sites was observed on pre-mRNAs carrying competing 5'-splice sites or competing 3'-splice sites. Because the activity of recombinant hnRNP A1 protein was similar when added to extracts containing or lacking Me2SO, the activity of endogenous A1 proteins is probably not affected by Me2SO. Notably, in a manner reminiscent of SR proteins, Me2SO activated splicing in a HeLa S100 extract. Moreover, the activity of recombinant SR proteins in splice site selection in vitro was improved by Me2SO. Polar solvents like DMF and formamide similarly modulated splice site selection in vitro but formamide did not activate a HeLa S100 extract. We propose that Me2SO improves ionic interactions between splicing factors that contain RS-domains. The direct impact of Me2SO on alternative splicing may explain, at least in part, the different and sometimes opposite effects of Me2SO on cell differentiation and apoptosis.

Thoracic dimensions at maximum lung inflation in normal subjects and in patients with obstructive and restrictive lung diseases.

OBJECTIVES: To compare the distribution of lung volume at total lung capacity (TLC) among adult men and women known to have normal lung function or chronic obstructive disease or restrictive lung disease (RLD). DESIGN: Five-year retrospective study. SETTING: Review of available clinical pulmonary function testing (PFT) reports and chest radiographs. PATIENTS: Sixty-four patients presenting with normal PFT and chest radiograph findings (normal subjects), 26 patients with severe COPD and increased TLC (COPD group), 29 patients with cystic fibrosis (CF) and increased TLC (CF group), and 19 patients with RLD with a clinical diagnosis of pulmonary fibrosis and a reduced TLC (RLD group). MEASUREMENTS: Average posteroanterior rib cage diameter (PAave), average lateral rib cage diameter (LAave), and average vertical height of the diaphragm (HDIave) were measured using radiography. Normal prediction equations were generated based on stature, body mass index (BMI), age, and sex as independent variables and then used in between-group comparisons. RESULTS: PAave correlated positively with BMI and age but not with height, whereas LAave correlated positively with BMI and height but not with age. HDIave correlated positively with height and age but negatively with BMI. PAave and LAave were smaller and HDIave was greater in women than men having the same stature. In the COPD group and in male CF group patients, BMI was low and only HDIave was greater than in sex-, age-, and height-matched normal subjects, but in female CF group patients, only the rib cage diameters were greater than normal. In the RLD group, PAave and HDIave were smaller than predicted and inversely related to each other, but LAave was normal. CONCLUSION: Variations in maximum lung volume caused by gender, growth, or by lung diseases are nonisotropic and entail substantial changes in chest wall shape.

Abnormalities of the airways and lung parenchyma in asthmatics: CT observations in 50 patients and inter- and intraobserver variability.

The purpose of the study was to evaluate the CT abnormalities of airways and lung parenchyma in asthmatic patients and to assess inter- and intraobserver variability for these abnormalities. The CT scans of 50 asthmatic patients and 10 healthy volunteers were assessed independently by four independent chest radiologists who were masked with respect to the clinical information. Bronchiectasis involving mostly subsegmental and distal bronchi was noted in 28.5% of the asthmatic subjects and none of the non-asthmatics. Bronchial wall thickening, small centrilobular opacities and decreased lung attenuation were observed in 82%, 21% and 31% of asthmatic patients respectively, compared with 7%, 5% and 7% of healthy subjects. The intra- and inter-observer agreements for these four CT abnormalities were measured by the kappa statistic and ranged from 0.60 to 0.79 and from 0.40 to 0.64, respectively. It is concluded that asthmatic patients may exhibit bronchial wall thickening, bronchiectasis and morphological abnormalities suggestive of distal airways disease that can be assessed on CT scans with a clinically acceptable observer variability.

[Radiological changes of talc pleurodesis in cases of effusion]. / Modifications radiologiques du talcage pleural dans les cas d'épanchements.

This study is based on the observations of 86 pleurodesis done by talc insufflation during thoracoscopy in 82 patients suffering from benign (8%) and malignant (92%) pleural effusions. Serial chest films were obtained on every patient. Chest computed tomography was obtained in ten patients. The most frequent finding seen in the early phase and one month later was the appearance of loculations (94%) in selective areas of the thorax. Occasionally they take the appearance of airfluid levels (22%). These loculations are characteristically located in the axillary (60%), intrafissural (30%) and paramediastinal (34%) areas of the chest. In the late phase with a mean evolution time of 6 months, these loculations evolve in 77% of patients in areas of pleural thickening. CT of the chest demonstrates the presence of characteristic pleural thickening in the form of coarse (5/12) and/or fine linear densities (7/12) corresponding to talc deposits, on the pleural surface. These modifications are shown by light microscopy examination of the pleural done at the autopsy.

High-resolution computed tomography of the airways.

High-resolution computed tomography (HRCT) is the imaging modality of choice to evaluate most bronchial tree lesions, especially those affecting small airways. It can confirm the diagnosis of bronchiectasis with high sensitivity and specificity and may contribute to the investigation of bronchiolitis (particularly diffuse panbronchiolitis and bronchiolitis obliterans) and other inflammatory disorders of the airways. HRCT can also reliably detect obstructing bronchial lesions such as tumors or broncholithiasis. It may also provide useful clues to the diagnosis of bronchial fistula, dehiscence, or rupture as well as permit the study of many pulmonary congenital abnormalities. This article describes the CT techniques recommended in each clinical situation and reviews the HRCT findings in diseases of the airway.