Subclinical hypercortisolism: correlation between biochemical diagnostic criteria and clinical aspects.

OBJECTIVE: Subclinical hypercortisolism (SH) has been associated with increased prevalence of hypertension, type 2 diabetes mellitus, dyslipidaemia, central obesity, osteoporosis and vertebral fractures. We aimed to investigate the accuracy of different SH diagnostic criteria in predicting the presence of complications. DESIGN: This was a retrospective study. PATIENTS: We evaluated data from 231 patients (120 women and 111 men) affected with adrenal incidentalomas (AI). MEASUREMENTS: We studied the accuracy of different SH diagnostic criteria (cortisol after 1 mg overnight dexamethasone suppression test - 1mg-DST - at different cut-off such as 49.7, 82.8, 137.9 nmol/l, elevated urinary free cortisol, reduced adrenal corticotroph hormone (ACTH) levels alone or various combination of these parameters) in predicting the concomitant presence of the following three complications: hypertension, type 2 diabetes and vertebral fractures. RESULTS: The criterion characterized by the presence of two of 1mg-DST >82.8 nmol/l, elevated UFC and reduced ACTH struck the best balance between sensitivity and specificity, reaching a good accuracy in predicting the cluster of complications (61.9%; 77.1% and 75.8%, respectively). The presence of this cluster was associated with this criterion (OR 4.75, 95%CI 1.8-12.7, P = 0.002) regardless of gonadal status, body mass index (BMI) and age. CONCLUSIONS: The SH criterion characterized by the presence of two of 1mg-DST >82.8 nmol/l, elevated UFC and reduced ACTH seems the best in predicting the presence of chronic manifestations of subtle cortisol excess.

Multiple, thin-walled cystic lesions of the lung.

A variety of diseases produces or mimics multiple, thin-walled, air-containing cavities or cysts in the lung. Although some causes of this pattern are common (bullous emphysema, multiple pneumatoceles), others are relatively rare (cystic bronchiectasis, histiocytosis X, tracheobronchial papillomatosis, and lucite ball plombage). To some extent, the radiographic features of these lesions allow their differentiation, but differential diagnosis can be difficult. This paper reviews their principal features.

Accelerated atherosclerosis during maintenance hemodialysis: detection from chest radiographs.

Evidence of accelerated atherosclerosis was studied from chest radiographs of 26 patients on maintenance hemodialysis. The aortic knob was observed for presence of and increase in calcified plaques. At the initiation of hemodialysis, the degree of aortic calcification was no different from that seen in the control group. After periods ranging from one and a half to eight years, the patients on hemodialysis showed a significantly greater amount of aortic calcification and a significantly higher rate of calcification. The degree of calcification correlated with the severity of cardiovascular disease as determined clinically. For patients on maintenance hemodialysis, close scrutiny of serial chest-radiographs may help to identify those who are at greater risk for life-threatening cardiovascular disease.

Chest radiography in intensive care units.

The role chest radiography plays in intensive care units (ICU) is unlike its role elsewhere because in the ICU a patient's underlying disease is usually known. Furthermore, additional diseases that develop in the ICU-such as pneumonia, hemorrhage, edema, lung collapse and effusion-often are radiographically indistinguishable. Nevertheless, an ICU radiograph of the chest is valuable, mainly in identifying such complications as malpositioned intravenous catheters, Swan-Ganz catheters, pacemakers, nasogastric tubes, endotracheal tubes, chest tubes, and mediastinal tubes, and ectopic gas related to mechanical ventilation. Understanding the limitations of the portable ICU chest film in the diagnosis of specific diseases and being alert to possible iatrogenic complications will increase the usefulness of ICU chest radiography.

The right paratracheal stripe in children.

The width of the right paratracheal stripe (RPS) has been established in normal adults but not in normal children. The thymus and great vessels are relatively larger in children than in adults and could obscure or widen the RPS. We found that obscuration does occur and, therefore, the RPS is less often measurable in children than in adults. Widening by the thymus and great vessels, however, does not occur. The width of the RPS in normal children, 0.5 to 3.0 mm, is slightly less than in adults. From this study of normal children and our subsequent experience with pediatric patients, we conclude that in a child an RPS 4 mm or wider is reliable evidence of disease affecting the trachea, mediastinum, or pleura.

The effect of acute pulmonary edema on pulmonary vascular resistance: significance for the interpretation of dilated upper lobe vessels on chest radiographs.

Dilation of upper lobe pulmonary vessels is an important radiographic sign of acute, left heart failure. A prominent theory is that perivascular edema causes increased resistance at the lung bases and inverts the normal perfusion gradient such that upper lobe blood flow exceeds lower lobe flow. This theoretical increase in flow is thought to cause dilatation of upper lobe vessels. Previous experimental studies determined indirectly changes in resistance from changes in the perfusion gradient: Results were contradictory. We measured directly the effect of edema on resistance in isolated canine lungs. Resistance increased linearly with edema. The magnitude of increase was small, however, and insufficient to cause inversion of the perfusion gradient. Our data indicate that interstitial pulmonary edema does not cause significant redistribution of blood flow. We suggest that dilated upper lobe vessels are veins acting as pulmonary venous manometers, reflecting elevated left atrial pressure, not increased blood flow.

The right paratracheal stripe.

The right paratracheal stripe (RPS) is seen on postero-anterior chest radiographs as a thin, water-density stripe between the air column of the trachea and the adjacent right lung. The range of width of the RPS in 1,259 normal subjects was 1 to 4 mm. An RPS width of 5 mm or more is reliable evidence of disease. The differential diagnosis of this finding is lengthy, and best divided into those diseases affecting the (a) trachea; (b) mediastinum; and (c) pleura.