Investigations

Investigations
1- Chest Imaging
Imaging includes use of x-rays, MRI, nuclear scanning, and ultrasonography. There are no absolute contraindications to undergoing noninvasive imaging procedures except for MRI where the presence of metallic objects in the patient s eye or brain precludes the test.
X-Ray Techniques
X-ray techniques that are used to image the chest include plain x-rays, fluoroscopy, high-resolution and helical (spiral) CT, and CT angiography.
Plain CXR: They are usually the initial test done to evaluate the lungs. The standard chest x-ray is taken in the inspiratory phase from back to front (posteroanterior view) to minimize x-ray scatter that could artifactually enlarge the cardiac silhouette and from the side of the thorax (lateral view). Lordotic or oblique views can be obtained to evaluate pulmonary nodules or to clarify abnormalities that may be due to superimposed structures, although chest CT provides more information and has largely superseded these views. Lateral decubitus views may be used to distinguish free-flowing from loculated pleural effusion, but CT or ultrasonography can provide more information. End-expiratory views can be used to detect small pneumothoraxes.