P. Grenier

Diagnostic strategy for patients with suspected pulmonary embolism: a prospective multicentre outcome study

BACKGROUND We designed a prospective multicentre outcome study to evaluate a diagnostic strategy based on clinical probability, spiral CT, and venous compression ultrasonography of the legs in patients with suspected pulmonary embolism (PE). The main aim was to assess the safety of withholding anticoagulant treatment in patients with low or intermediate clinical probability of PE and negative findings on spiral CT and ultrasonography. METHODS 1041 consecutive inpatients and outpatients with suspected PE were included. Patients with negative spiral CT and ultrasonography and clinically assessed as having a low or intermediate clinical probability were left untreated. Those with high clinical probability underwent lung scanning, pulmonary angiography, or both. All patients were followed up for 3 months. FINDINGS PE was diagnosed in 360 (34.6%) patients; 55 had positive ultrasonography despite negative spiral CT. Of 601 patients with negative spiral CT and ultrasonography, 76 were clinically assessed as having a high probability of PE; lung scanning or angiography showed PE in four (5.3% [95% CI 1.5-13.1]). The remaining 525 patients were assessed as having low or intermediate clinical probability, and 507 of them were not treated. Of these patients, nine experienced venous thromboembolism during follow-up (1.8% [0.8-3.3]). The diagnostic strategy proved inconclusive in 95 (9.1%) patients, and pulmonary angiography was done in 74 (7.1%). INTERPRETATION Withholding of anticoagulant therapy is safe when the clinical probability of PE is assessed as low or intermediate and spiral CT and ultrasonography are negative.

A combined pulmonary -radiology workshop for visual evaluation of COPD: study design, chest CT findings and concordance with quantitative evaluation

Abstract The purposes of this study were: to describe chest CT findings in normal non-smoking controls and cigarette smokers with and without COPD; to compare the prevalence of CT abnormalities with severity of COPD; and to evaluate concordance between visual and quantitative chest CT (QCT) scoring. Methods: Volumetric inspiratory and expiratory CT scans of 294 subjects, including normal non-smokers, smokers without COPD, and smokers with GOLD Stage I-IV COPD, were scored at a multi-reader workshop using a standardized worksheet. There were 58 observers (33 pulmonologists, 25 radiologists); each scan was scored by 9–11 observers. Interobserver agreement was calculated using kappa statistic. Median score of visual observations was compared with QCT measurements. Results: Interobserver agreement was moderate for the presence or absence of emphysema and for the presence of panlobular emphysema; fair for the presence of centrilobular, paraseptal, and bullous emphysema subtypes and for the presence of bronchial wall thickening; and poor for gas trapping, centrilobular nodularity, mosaic attenuation, and bronchial dilation. Agreement was similar for radiologists and pulmonologists. The prevalence on CT readings of most abnormalities (e.g. emphysema, bronchial wall thickening, mosaic attenuation, expiratory gas trapping) increased significantly with greater COPD severity, while the prevalence of centrilobular nodularity decreased. Concordances between visual scoring and quantitative scoring of emphysema, gas trapping and airway wall thickening were 75%, 87% and 65%, respectively. Conclusions: Despite substantial inter-observer variation, visual assessment of chest CT scans in cigarette smokers provides information regarding lung disease severity; visual scoring may be complementary to quantitative evaluation.

CT-Definable Subtypes of Chronic Obstructive Pulmonary Disease: A Statement of the Fleischner Society

The purpose of this statement is to describe and define the phenotypic abnormalities that can be identified on visual and quantitative evaluation of computed tomographic (CT) images in subjects with chronic obstructive pulmonary disease (COPD), with the goal of contributing to a personalized approach to the treatment of patients with COPD. Quantitative CT is useful for identifying and sequentially evaluating the extent of emphysematous lung destruction, changes in airway walls, and expiratory air trapping. However, visual assessment of CT scans remains important to describe patterns of altered lung structure in COPD. The classification system proposed and illustrated in this article provides a structured approach to visual and quantitative assessment of COPD. Emphysema is classified as centrilobular (subclassified as trace, mild, moderate, confluent, and advanced destructive emphysema), panlobular, and paraseptal (subclassified as mild or substantial). Additional important visual features include airway wall thickening, inflammatory small airways disease, tracheal abnormalities, interstitial lung abnormalities, pulmonary arterial enlargement, and bronchiectasis.

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 bronchi-olitis (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.

Thin-section chest CT findings of primary Sjögren's syndrome: correlation with pulmonary function

Abstract. The purpose of this study was to describe thin-section CT findings of lung involvement in patients with primary Sjögrens syndrome (PSS), and to correlate them with pulmonary function tests (PFT). The chest thin-section CT examinations of 35 patients with proven diagnosis of PSS and respiratory symptoms were retrospectively assessed by two observers, in a first step independently with interobserver evaluation, and in a second step in consensus. The extent of the most frequent CT findings was scored. Correlation was made with PFT in 31 of these patients. Three main CT patterns were identified with good interobserver agreement (kappa coefficient 0.71): 19 of 35 (54%) large and/or small airways disease; 7 of 35 (20%) interstitial lung fibrosis (ILF); and 5 of 35 (14%) suggestive of lymphocytic interstitial pneumonia (LIP). The CT scans were normal in 2 patients (6%) and showed only dilatation of pulmonary vessels due to pulmonary arterial hypertension in two others (6%). Airway disease patients had predominantly obstructive profiles (mean FEV1/FVC ratio 69.7±12.7%, mean MEF25 50.1±22.9%), whereas patients with ILF and LIP had predominantly restrictive profiles and/or a decreased diffusing lung capacity (mean TLC 87.0±26.0 and 64.6±18.6%, mean DLCO 57.4±21.2 and 52.0±8.0%). Significant correlation (p<0.01) was found between the scores of ground-glass attenuation and TLC (r=–0.84) and DLCO (r=–0.70) and between the score of air trapping and FEV1 (r=–1.0). In patients with PSS and respiratory symptoms, thin-section CT may provide characterization of lung involvement which correlates with pulmonary function.

Bronchoarterial ratio on thin section CT : Comparison between high altitude and sea level

PURPOSE Our goal was to measure normal bronchial to accompanying pulmonary arterial diameter ratios and normal bronchial wall thickness on thin section CT at high altitude and at sea level. METHOD Seventeen normal, healthy, nonsmoking subjects living at 1,600 m altitude and 16 living at sea level underwent thin section CT (1.5 to 2.0 mm collimation). All images were photographed at window levels of -450 and -700 HU and window width of 1,500-1,600 HU. Internal diameters of the segmental and subsegmental bronchi were measured and compared with the diameter of the adjacent pulmonary artery. Bronchial wall thickness of each bronchus was measured. Only bronchi and arteries seen in cross section and within 1 mm from each other were included in the analysis. RESULTS Four hundred sixty-seven bronchi (215 at high altitude, 252 at sea level) were assessed. At window level of -450 HU, the bronchoarterial ratio was 0.76 +/- 0.14 (mean +/- SD) at altitude and 0.62 +/- 0.13 at sea level (p < 0.001). Bronchial wall thickness measured 0.92 +/- 0.09 mm (mean +/- SD) at altitude and 1.12 +/- 0.19 mm at sea level (p < 0.001). At window level of -700 HU, there was an artifactual decrease in the bronchoarterial diameter ratios and an increase in bronchial wall thickness. CONCLUSION Bronchoarterial ratio increases and bronchial wall thickness decreases with altitude. These findings are presumably related to hypoxic bronchodilatation and vasoconstriction.

Pulmonary alveolar microlithiasis : CT findings

We present five cases with confirmed diagnosis of pulmonary alveolar microlithiasis that illustrate the appearance of this rare chronic lung disease on conventional and high-resolution CT. Pulmonary alveolar microlithiasis is characterized by widespread intraalveolar calcification of both lungs. Conventional CT confirmed the inferior and posterior predominance of the lesions in four of our cases and showed an exceptionally high concentration of microliths in the subpleural parenchyma and along the bronchovascular bundles. High-resolution CT revealed a perilobular and bronchovascular distribution of the disease process at the level of the secondary pulmonary lobule. This pattern correlated closely with pathologic findings.

Sarcoidosis activity: correlation of HRCT findings with those of 67Ga scanning, bronchoalveolar lavage, and serum angiotensin-converting enzyme assay.

PURPOSE The objective of this study was to correlate the findings of sarcoidosis on high resolution CT (HRCT) with indexes of disease activity as measured with 67Ga scan, bronchoalveolar lavage (BAL), and serum angiotensin-converting enzyme (SACE) assay. METHOD Twenty-nine patients with proven sarcoidosis underwent HRCT scan, 67Ga scan, BAL, and SACE assay within a 1 month period. The extent of parenchymal involvement by nodules, consolidation, ground-glass attenuation, and linear opacities was quantified to the nearest 10% of surface area affected on the CT examination. Whole-lung gallium uptake was quantified and the percentage of BAL-recovered lymphocytes (BAL-%LC) and SACE levels obtained by chart review. CT scores of disease extent were correlated with measured indexes of activity using the Spearman rank correlation coefficient. RESULTS The mean extent of nodules, consolidation, ground-glass attenuation, and linear opacities on HRCT images was 15.1 +/- 16.6, 1.6 +/- 4.0, 17.5 +/- 25.4, and 7.6 +/- 9.6%, respectively. The extent of nodules and consolidation correlated with the intensity of lung gallium uptake (r = 0.46, p < 0.02), BAL-%LC (r = 0.50, p < 0.01), and SACE levels (r = 0.38, p < 0.05). No significant correlation was found between extent of ground-glass attenuation or linear opacities with any indexes of disease activity. CONCLUSION On HRCT scan, nodules and consolidation in sarcoidosis reflect disease activity as measured by 67Ga scan, BAL, and SACE assay.

Congenital anomalies of tracheobronchial branching patterns: spiral CT aspects in adults.

Abstract. Congenital abnormalities of the bronchi have been classically described with chest X-rays, conventional tomography, bronchography, CT and MR imaging. Recently, the capacity of spiral CT to explore a complete volume with no gap and excellent multiplanar reformations has been emphasized. The contribution of this technique to the analysis of congenital anomalies of tracheobronchial branching patterns encountered in adult patients is illustrated. Agenesis, aplasia, and hypoplasia are discussed, followed by bronchial atresia and abnormalities of bronchial divisions. In most cases spiral CT permits a full and correct evaluation of the malformation as well as its associated anomalies. It appears therefore to be the preferable technique for studying such anomalies of the tracheobronchial tree. Moreover, knowledge of CT aspects of the main congenital bronchial abnormalities along with complete visualization of the tracheobronchial tree will probably lead to detection of more incidental anomalies.

Pulmonary hypertension in antisynthetase syndrome: prevalence, aetiology and survival.

Antisynthetase syndrome is characterised by the association of interstitial lung disease and myositis with different anti-tRNA-synthetase antibodies. The occurrence, aetiology and prognosis of pulmonary hypertension have not yet been evaluated. Among 203 consecutive patients, transthoracic echocardiogram and right heart catheterisation results were retrospectively analysed in the light of clinico-biological, morphological and functional parameters. Definitions of pulmonary hypertension were based on the European Society of Cardiology/European Respiratory Society 2009 guidelines, with severe pulmonary hypertension being defined by a mean pulmonary arterial pressure >35 mmHg. Pulmonary hypertension was suspected by transthoracic echocardiogram in 47 (23.2%) cases, corresponding to pulmonary hypertension “possible” (n=27, 13.3%) or “likely” (n=20, 9.9%). Right heart catheterisation was performed in 21 patients, excluding pulmonary hypertension in five and confirming pre-capillary pulmonary hypertension in 16 (7.9%). Although related to interstitial lung disease in all cases, pre-capillary pulmonary hypertension was severe in 13 (81.3%) patients (mean±sd pulmonary arterial pressure 46±9 mmHg), frequently associated with low cardiac index (mean±sd 2.3±0.8 L·min−1·m−2) and high forced vital capacity/diffusing capacity of the lung for carbon monoxide ratio (2.5±0.6). Pulmonary hypertension was significantly associated with a lower survival rate (p<0.001), with a 3-year survival rate of 58%. The occurrence of pulmonary hypertension in antisynthetase syndrome is significant and dramatically worsens the prognosis. Although systematically associated with interstitial lung disease, pulmonary hypertension was usually severe, suggesting a specific pulmonary vascular involvement. PH in antisynthetase syndrome significantly worsens the prognosis, suggesting a specific pulmonary vascular involvement http://ow.ly/okXyG