High resolution CT (HRCT) of the lung in adults. Defining the limits between normal and pathologic findings.

Under normal conditions, HRCT shows secondary lobule structures and allows for a precise evaluation, with inspiratory and expiratory scans, of central airways dimensions, lung area and parenchymal density. Frequently, asymptomatic smokers with normal lung function tests, present with mild abnormalities not visible at chest X-ray: bronchial thickening, bronchiolectasis, respiratory bronchiolitis and centrilobular or paraseptal emphysema. In the elderly, HRCT studies often show borderline findings such as age-related tracheo-bronchial calcifications and emphasise the progressive increase in the bronchoarterial ratio. Another frequent finding is expiratory air trapping, which can be associated with a variety of lung diseases, but can also represent a physiologic and temporary finding, during an episode of sub-clinical bronchospasm or related to local variation of bronchiolar dynamic compliance. The knowledge of the boundaries between normality and pathology is an essential prerequisite for the correct interpretation HRCT findings.

Differential diagnosis between usual interstitial pneumonia (UIP) and nonspecific interstitial pneumonia (NSIP) assessed by high-resolution computed tomography (HRCT).

PURPOSE: The aim of this study was to assess the accuracy of high-resolution CT in the differential diagnosis between UIP and NSIP, and the correlations with histological and functional findings. MATERIALS AND METHODS: Patients underwent thin-collimation spiral CT (1 mm), with 10-mm interval. Pulmonary function was assessed with a pneumotacograph and body plethysmograph connected with a computer for data analysis. Three pathologists, blinded to the clinical and functional data, provided a histological diagnosis based on established criteria reported in the literature. The study group only included patients with a histological diagnosis of either UIP or NSIP. RESULTS: We achieved a correct diagnosis of NSIP in 86.6% of cases (76.4% sensitivity; 84.6% specificity), whereas UIP was correctly diagnosed in 73.3% of cases (84.6% sensitivity; 76.5% specificity). An 80% agreement was achieved between the HRCT and histological findings in the whole case series (73% sensitivity, 87% specificity, p<0.01). CONCLUSIONS: The most important finding of our study was that a ground glass appearance equal to or greater than 15% is highly suggestive of NSIP. Therefore, our results could be useful to confirm a suggested diagnosis of NSIP.

Early smoking-induced lung lesions in asymptomatic subjects. Correlations between high resolution dynamic CT and pulmonary function testing.

PURPOSE: To evaluate the prevalence and significance of the pathological effects of cigarette smoking on the lung and the sensitivity of high-resolution CT (HRCT) in the recognition of early smoking-induced lesions in asymptomatic former or current smokers. MATERIALS AND METHODS: We performed a prospective and consecutive analysis of 36 volunteers (16 males, 20 females), 10 non-smokers (3 males; 7 females) and 26 smokers (13 males; 13 females / 17 current smokers; 9 former smokers), all asymptomatic and with normal respiratory flows. These subjects underwent lung function testing and HRCT, after providing written informed consent for the study. The HRCT scans were obtained at three pre-selected levels (aortic arch, tracheal carina and venous hilum). The same scans were obtained in post-expiration phase. At the level of the apical segmental bronchus of the right upper lobe, we measured on the monitor wall thickening, and the total and internal diameters using the techniques reported in literature. Each study was independently evaluated by two radiologists that were blinded to all clinical and functional data; they also evaluated the presence, prevalence and type of emphysema, areas of patchy hyperlucency and oligoemia in the inspiration phase and areas of expiratory air trapping. The extension was evaluated with the visual score method. The data obtained were analysed with the Windows SPSS package for statistical analysis. RESULTS: The two groups (non smokers and smokers) showed significant differences in some functional tests such as FEV1 (p<0.005) and Tiffeneau index (p<0.005), which were lower in current-smokers or former-smokers, although still within the normal range. The HRCT study did not show areas of emphysema or air trapping in non smokers. In the smokers' group, air trapping was observed in 30.7% of cases: 33.3% former-smokers and 29.4% current smokers (mean extension was 21.36% in former smokers and 9.48% in current smokers). Mean extension in the smokers' group was 13.94%. Pulmonary emphysema was found in 34.6% of cases in the smokers' group: 33.3% former-smokers and 35.2% current-smokers. Emphysema was prevalent in the upper lobes (88.8%). Mean extension was 8.76% in the former smokers group and 18.81% in current-smokers, with a total mean extension of 15.47% in the smokers' group. Statistically, there was a significant difference between non-smokers and smokers as regards emphysema extension and expiratory air trapping (p=0.034 and p=0.050, respectively). The smokers' group had a significantly wider diameter of the apical segmental bronchus of the right upper lobe than the controls. There was no significant statistical correlation between this dilatation and the emphysema score (r=0.051; p=0.81). The entity of smoking history did not correlate with emphysema extension or air trapping or with the size of the apical segmental bronchus of the right upper lobe. CONCLUSIONS: Our study demonstrates that HRCT is more sensitive and specific than commonly-used functional tests for the evaluation of initial emphysema in asymptomatic smokers. We observed expiratory air trapping only in the smokers' group, and only of the lobular type, without evidence of disease in inspiratory scans. Among the smokers and former-smokers, air trapping was found in 30.7% of subjects, with a mean extension lower than 10%. Our results therefore suggest that, even in asymptomatic subjects, expiratory air trapping is probably pathological and, once bronchial asthma has been excluded, it may be related to cigarette smoking and indicate early inflammatory bronchiolar damage. HRCT may therefore be regarded as a useful tool in the early diagnosis of smoking-related lung disease.

Traumatic injuries: imaging of thoracic injuries.

Chest trauma is one of the most important causes of death, in particular in individuals under the age of 40 years. The mortality rate for chest trauma, often related to motor vehicle accidents, is approximately 15.5%; it increases dramatically to 77% with associated shock and head injury (Glasgow scores of 3-4). The accurate diagnosis of pathologies consequent to blunt chest trauma depends on a complete knowledge of the different clinical and radiological manifestations. The first diagnostic approach is classically based on chest X-ray often carried out on supine position at the hospital admission. A CT study must then be performed in all chest trauma patients in whom there is even the smallest diagnostic doubt on plain film. In particular, spiral CT (SCT) assumes a fundamental role in the demonstration of mediastinal hemorrhage and direct signs of aortic lesions. At present, SCT is routinely part of a diagnostic evaluation which also includes scans of the brain and the abdomen in polytraumatized patients. Magnetic resonance is the ideal method for visualizing diaphragmatic lesions. Furthermore, recent reports have demonstrated the high diagnostic value of MR in evaluating aortic injuries. The purpose of this article is to review the most common radiological patterns related to chest trauma.

[Role of videofluorography in the study of esophageal motility disorders]. / Ruolo della videofluorografia nello studio dei disordini della motilità esofagea.

PURPOSE: To repropose the importance of videofluoroscopy in the study of esophageal motor disorders, comparing the radiologic and manometric results; the manometric results are considered the reference parameters. MATERIAL AND METHODS: From 1996 to 1999, 76 patients (42 males and 34 females), were studied first using manometry and then videofluoroscopy. The patients had symptoms like dysphagia, thoracic pain or both. The manometric study was performed with a perfusional system equipped with 6 tips (4 radial for the study of the esophageal sphincters and 2 placed longitudinally for the study of the esophageal peristalsis). With the patient in a supine position we analysed 5-10 deglutitions with 5 ml water bolus at 20-25 degrees C, administered using a graduated syringe. The radiologic study was performed with a remote-control digital television system, connected to a video recorder. Three 7.5 ml bolues of high density barium suspension (250% weight/volume) were injected orally in the upright position and other three were injected in the prone position following the passage from the oral cavity to the stomach. RESULTS: The comparison of the manometric and videofluoroscopic results suggests that the total sensitivity of the radiological study in the detection of esophageal motor disorders was 92%. In particular dynamic radiologic investigation diagnosed the normal esophageal functionality in 100% of the cases, nonspecific esophageal motility disorders in 89.6%, diffuse esophageal spasm in 100% of the cases, the presence of achalasia in 90%, whereas "nutcraker esophagus" only in 50%. Videofluoroscopy therefore showed high sensitivity in four groups of the five considered. It has some limitations in the diagnosis of initial achalasia, and is not sufficiently sensitive in the diagnosis of "nutcracker esophagus". CONCLUSIONS: Videofluoroscopy is a simple method which presents high sensitivity and specificity in the detection of motility disorders of the esophagus and could therefore be proposed as the first diagnostic method in patients with specific symptoms.

Magnetic resonance imaging evaluation of aortic elastic properties as early expression of Marfan syndrome.

In Marfan syndrome, early identification and treatment of aortic involvement could improve prognosis, but clinical diagnosis may be difficult at a young age, before aortic dilation occurs. The aim of this study was to evaluate biomechanical aortic properties in Marfan patients and in their relatives to identify an early index of aortic involvement. A magnetic resonance imaging (MRI) morphologic and functional study of the thoracic aorta was performed in 20 Marfan patients, 15 family members, and 14 healthy volunteers as a control group. The aorta was imaged in the oblique sagittal plane by spin-echo sequence. A high-resolution gradient-echo sequence was then applied in the axial plane at the level of ascending supravalvular aorta to evaluate aortic distensibility. Aortic distensibility (mm Hg(-1) was significantly different in the three groups (ANOVA, p = 0.0001). Aortic distensibility was sensibly reduced in Marfan patients (0.0085 +/- 0.006 vs. 0.025 +/- 0.006 control group, p < 0.05). No significant correlation was found between aortic area and distensibility. Aortic distensibility was reduced also in family members (0.016 +/- 0.011 vs. 0.025 +/- 0.006 control group, p < 0.05). Among them, 4 subjects showed aortic diameters to the upper limit of the normal range, whereas the other 11 presented normal aortic diameters. Intraobserver and interobserver reproducibility for diastolic measurement was 1.2% and 0.4%, respectively, and 1.1% and 0.3%, respectively, for systolic measurement. MRI is an accurate technique in detecting abnormal aortic elastic properties in Marfan patients. Abnormal ascending aorta distensibility may constitute an index of early aortic involvement before dilation occurs.

[Endovascular treatment in diseases of the thoracic aorta]. / Il trattamento endovascolare nelle malattie dell'aorta toracica.

PURPOSE: To determine whether endovascular treatment of thoracic aorta conditions can be an effective alternative approach to surgical repair. MATERIAL AND METHODS: July 1997 to February 1999, eighteen patients (16 men and 2 women; 58.6 +/- 14.8 years) presenting with different kinds of descending aorta conditions were selected for the endovascular treatment. All patients exhibited severe comorbid pulmonary and/or cardiovascular medical conditions which increased surgical risk. All implants were performed in the operating room under fluoroscopic and TEE guidance. Clinical and imaging follow-up was performed 1, 3, 6 and 12 months later. RESULTS: The endovascular treatment was successful in 17 cases. No deaths or major complications occurred. No leakage was evident at post-procedure angiography. The patients were discharged after 6 +/- 4 days. MRI or CT study performed before hospital discharge showed aneurysms exclusion in 16 patients. In the four cases of dissection, thrombosis of the false lumen was evident since the first follow-up study. In the group of patients (11 cases) with 6 months follow-up, the diameters of stented aortic segments decreased. No late leakage was observed and thrombosis was complete in all cases. DISCUSSION: The natural history of aortic aneurysms and dissection is progressive toward dilation and aortic rupture. Surgery of descending thoracic aorta is burdened with a mortality of 8-12% in elective cases and over 50% in emergency cases or aortic dissection. The endovascular treatment of aortic conditions was introduced in clinical practice in 1991 and literature data show that it is effective, with lower mortality and morbidity rates than surgical treatment. CONCLUSION: Our results stress the feasibility and effectiveness of endovascular procedure in the treatment of complex thoracic aorta conditions even in high risk patients. Thus, endovascular treatment of thoracic aorta can be considered an effective alternative approach to conventional surgery.