Densitometric CT evaluation of acute and chronic thromboembolic filling defects of the pulmonary arteries before and after contrast injection.

PURPOSE: The aim of this study was to assess the baseline computed tomography (CT) attenuation of acute and chronic pulmonary thromboemboli, their contrast enhancement (CE), correlation with haematocrit (Ht) levels and the presence of hypertrophic bronchial arteries. MATERIALS AND METHODS: From January 2006 to October 2009, we measured the baseline and postcontrast attenuation values of acute pulmonary thrombi emboli on CT angiograms of 86 patients with acute pulmonary embolism (PE) and those of chronic thrombi in 29 patients with pulmonary hypertension of various origins. The attenuation of acute thrombi was correlated with Ht and CE of chronic thrombi with the presence of hypertrophic bronchial arteries. RESULTS: Acute emboli had a mean baseline attenuation of 54.9 Hounsfield units (HU) and showed no CE. The attenuation of acute thrombi was not dependent on Ht. Chronic thrombi had a mean baseline attenuation of 33.8 HU, and 54% of thrombi showed significant CE. In 57% of cases, a collateral circulation had developed. In 76.5% of cases, CE and hypertrophic bronchial arteries coexisted (p=0.026). Neither thrombotic CE nor bronchial artery hypertrophy predominated in any one of the diseases associated with chronic thrombosis. CONCLUSIONS: Before contrast administration, acute emboli coare prevalently hyperattenuating and therefore more conspicuous. Only chronic thrombi exhibit CE, and CE is significantly associated with the development of collateral circulation, which may be involved in the process of thrombotic recanalisation.

Post-ARDS pulmonary fibrosis in patients with H1N1 pneumonia: role of follow-up CT.

PURPOSE: Our aim was to evaluate the evolution of 20 patients with H1N1 pneumonia, focusing our attention on patients with severe clinical and radiological findings who developed post-acute respiratory distress syndrome (post-ARDS) pulmonary fibrosis. MATERIALS AND METHODS: Twenty adult patients (nine women and 11 men; mean age 43.5 ± 16.4 years) with a diagnosis of H1N1 infection confirmed by pharyngeal swab came to our attention from September to November 2009 and were followed up until September 2010. All patients were hospitalised in consideration of the severity of clinical findings, and all underwent chest X-ray. Twelve of them underwent at least one computed tomography (CT) scan of the chest. RESULTS: In 75% of cases (15/20), there was complete resolution of the clinical and radiological findings. Twenty-five percent of patients (5/20) developed acute respiratory distress syndrome (ARDS), which progressed to predominantly peripheral pulmonary fibrosis in 10% (2/20; one died and one had late-onset pulmonary fibrosis, documented on day 68). Moreover, in one patient with a CT diagnosis of pulmonary fibrosis, we observed progressive regression of radiological findings over 4 months of follow-up. CONCLUSIONS: In patients with H1N1 pneumonia, post-ARDS pulmonary fibrosis is not a rare complication. Therefore, a CT scan should be performed in all patients with severe clinical findings. Our study demonstrated that in these patients, fibrosis could present a different spatial distribution and a different temporal trend, with delayed late onset; moreover, in one case, the signs of interstitial lung disease partially regressed over time. Therefore, CT should be considered not only in the diagnostic stage, but also during the follow-up.

Application of a new pulmonary artery obstruction score in the prognostic evaluation of acute pulmonary embolism: comparison with clinical and haemodynamic parameters.

PURPOSE: Evaluation of computed tomography (CT) pulmonary angiography parameters revealing pulmonary embolism (PE) severity with particular attention to pulmonary obstruction indexes. Comparison with clinical and hemodynamic data and determination of predictive role in the development of chronic pulmonary heart disease. MATERIALS AND METHODS: This retrospective study analyzes 45 not consecutive patients from November 2007 to December 2008 with CT angiography diagnosis of acute PE. Included in the study are patients at the first documented episode of acute PE, with 6 month follow-up. Patients with severe pre-existent cardiopulmonary pathology or neoplastic diseases were excluded from the study. CT angiography evaluated right ventricular (RV)/left ventricular (LV) ratio, obstruction index according to Qanadli and Total Clot Burden (Ghanima score). PE indexes were compared with Troponin I measurement and echocardiography result; at last hospitalization and intensive care time were reported. RESULTS: A significant association was found between Ghanima and Qanadli score: the two indexes are equivalent in quantification of pulmonary arterial obstruction (p<0.001). Among others CT parameters, the new Ghanima score evidenced the best accuracy to detect patients evolving to chronic pulmonary heart disease (76%). This value is higher than that of echocardiography (71%). Troponins showed highest accuracy (82%). CONCLUSIONS: Ghanima score can be used in emergency CT angiography diagnosis as prognostic marker for a quickly risk stratification of pulmonary heart disease or death in patients with acute PE. This approach allows to obtain, with just one test, both the diagnosis and a rather accurate acute PE risk stratification.

Contrast-enhanced US evaluation in patients with blunt abdominal trauma().

INTRODUCTION: To evaluate the use of contrast-enhanced ultrasonography (CEUS) in patients with blunt abdominal trauma. MATERIALS AND METHODS: A total of 133 hemodynamically stable patients were evaluated using ultrasonography (US), CEUS and multislice Computer Tomography (CT) da eliminare. RESULTS: In 133 patients, CT identified 84 lesions: 48 cases of splenic injury, 21 of liver injury, 13 of kidney or adrenal gland injury and 2 of pancreatic injury. US identified free fluid or parenchymal abnormalities in 59/84 patients positive at CT and free fluid in 20/49 patients negative at CT. CEUS revealed 81/84 traumatic injuries identified at CT and ruled out traumatic injuries in 48/49 negative at CT. Sensitivity, specificity, positive and negative predictive values for US were 70.2%, 59.2%, 74.7% and 53.7%, respectively; for CEUS the values were 96.4%, 98%, 98.8% and 94.1%, respectively. CONCLUSIONS: The study showed that CEUS is more accurate than US and nearly as accurate as CT, and CEUS can therefore be proposed for the initial evaluation of patients with blunt abdominal trauma.