Chiara Moroni

Comparison of spirometric-gated and -ungated HRCT in COPD.

Purpose: The purpose of this work was to evaluate feasibility of spirometric‐gated high‐resolution computed tomography (HRCT) in patients with chronic obstructive pulmonary disease (COPD) and to compare the lung density CT measurements obtained with and without spirometric control of lung volume. Method: Twenty‐nine patients with COPD underwent pulmonary function tests and spirometric‐gated (3 slices at 10% and 90% of vital capacity) and ‐ungated (12 slices at maximum expiration and inspiration) HRCT in the same day. Four lung density measurements (inspiratory pixel index, expiratory pixel index, inspiratory and expiratory mean lung density) derived from gated and ungated acquisitions were compared using the nonparametric Wilcoxon test, the line of equality, and the Bland and Altman test. Results: The vital capacity measured at pulmonary function tests and on the CT table showed a substantial agreement. All but one patient completed the gated and ungated examination, but only 8 (28%) of 28 patients reached the expiratory and inspiratory gating level for CT acquisitions at the first attempt. Only the inspiratory mean lung density derived from the 3 gated and 12 ungated slices showed borderline agreement. Other CT measurements, and notably all those from the 3 gated and ungated scans, acquired at the same anatomic level, did not agree. Conclusions: Although the procedure can be difficult for individual patients, spirometric gating significantly influences the lung density CT measurements and might improve standardization of CT evaluation of COPD. Index Terms: high‐resolution computed tomography, chronic obstructive pulmonary disease, spirometric gating

Spirometric-gated computed tomography quantitative evaluation of lung emphysema in chronic obstructive pulmonary disease: A comparison of 3 techniques

Objective: To compare the quantitative assessment of pulmonary emphysema with spirometric-gated computed tomography (gated CT) using 3 different acquisition techniques and to determine if low-current spiral CT could be used effectively to quantitate emphysema. Methods: Eleven patients with chronic obstructive pulmonary disease (COPD) underwent gated CT and pulmonary function tests (PFTs). Spiral whole-lung 10-mm collimation acquisitions at standard (146 mAs) and low (43 mAs) current and sequential 3-slice 1-mm collimation high-resolution computed tomography (HRCT) acquisitions at standard current were obtained at 90% of the patient’s vital capacity. The mean lung density (MLD) and the pixel index (PI) derived from the 3 data sets were compared using one-way analysis of variance and correlated with PFTs using linear regression. Moreover, the radiation dose associated with each technique was measured. Results: The MLDs were not significantly different. The PIs calculated from the standard- and low-current spiral acquisitions were similar, and both were significantly different from that of HRCT. The MLDs correlated with the PFTs in standard-current spiral and HRCT but not in low-current spiral acquisitions, whereas the PIs correlated with the PFTs in all 3 techniques. High-resolution computed tomography implied the lowest dose (0.08 mSv) compared with low-current (1.2 mSv) and standard-current (4 mSv) spiral techniques. Conclusions: Low- and standard-dose spiral CT provides similar lung density data in COPD. The combination of low-dose whole-lung spiral CT and 3-slice HRCT represents the best compromise between the amount of information provided and radiation exposure to the patient and could be substituted for standard-dose spiral CT for quantitative evaluation of COPD.

Lung/Pleural Injuries

Thoracic trauma account for about 25% of all trauma deaths and may produce injuries to endothoracic organs that play a vital role in normal physiology and homeostasis; some injuries to the chest and its contents, if unrecognized or untreated, may produce death within minutes. In the diagnostic algorithm of thoracic trauma, clinical data are of extreme importance and must be well recognized by the emergency physician. But, because of the low specificity of most of them consisting mainly in dyspnea, cough, hemoptysis, chest pain and, in very critical cases, in severe hypoxia or shock, imaging plays an essential role in the diagnostic work-up of these events permitting in most cases a fast and definite diagnosis and, therefore, a prompt adequate treatment. In an emergency context, three imaging modalities are helpful in the diagnosis of a thoracic trauma: chest X-ray, ultrasound (US) examination, and multidetector computed tomography (MDCT). Chest plain film and US examination play an important role in the initial emergency work-up of post-traumatic thoracic injuries as they are cheap and bedside available. Actually, MDCT has established itself as the preferred imaging method for the evaluation of polytrauma patients. This chapter will consider the main pleural and lung lesions and the injuries caused by open trauma.

Radiological Patterns of Lung Involvement in Inflammatory Bowel Disease

Inflammatory bowel disease (IBD) is a form of chronic inflammation of the gastrointestinal tract, including two major entities: ulcerative colitis and Crohns disease. Although intestinal imaging of IBD is well known, imaging of extraintestinal manifestations is not extensively covered. In particular, the spectrum of IBD-associated or related changes in the chest is broad and may mimic other conditions. The common embryonic origin of intestine and lungs from the foregut, autoimmunity, smoking, and bacterial translocation from the colon may all be involved in the pathogenesis of these manifestations in IBD patients. Chest involvement in IBD can present concomitant with or years after the onset of the bowel disease even postcolectomy and can affect more than one thoracic structure. The purpose of the present paper is to present the different radiological spectrum of IBD-related chest manifestations, including lung parenchyma, airways, serosal surfaces, and pulmonary vasculature. The most prevalent and distinctive pattern of respiratory involvement is large airway inflammation, followed by lung alterations. Pulmonary manifestations are mainly detected by pulmonary function tests and high-resolution computed tomography (HRCT). It is desirable that radiologists know the various radiological patterns of possible respiratory involvement in such patients, especially at HRCT. It is essential for radiologists to work in multidisciplinary teams in order to establish the correct diagnosis and treatment, which rests on corticosteroids at variance with any other form of bronchiectasis.