Chest Radiology

3B2010

Subject: Radiology

Topic: Chest Radiology

Date: June 13, 2008

Lecturer: Dra. Irene Bandong

CHEST RADIOLOGY  The cornerstone of radiologic diagnosis is the CHEST RADIOGRAPH.  The most satisfactory basic or routine radiographic views evaluation of the chest are: o Posterioranterior and o Left lateral projections  The optimal chest radiograph is obtained o In the posterior-anterior (AP) view o At a target-to-film distance of 72 inches o With the patient in the upright position o At maximum inspiration  ADEQUATE PENETRATION BY RADIATION o Thoracic spine should be barely seen thru the heart o Bronchovascular structures can usually be seen thru the heart o Spine appears to be darker caudally. This is due to more air in lung in the lower lobes and less chest wall o Sternum should be seen edge on o Posteriorly there should be two sets of ribs Non-standard chest radiography  Lordotic Projection It is advocated in 3 situations: 1. For improving visibility of the lung apices, superior mediastinum and thoracic outlet 2. For locating a lesion by parallax 3. For identifying the minor fissure in these suspected cases of atelectasis of the right middle lobe  Lateral Decubitus -particularly helpful for the identification of small pleural effusions -useful to demonstrate a change in position of an air fluid level in a cavity -to ascertain whether a structure that forms part of a cavity represents a freely mowing intracavitary loose body (fungus ball)  Oblique Projection -useful in locating a disease process (pleural plaque)

Trans Group: Riz, Alphe, AM

Special Radiographic Techniques: 1. Inspiratory-Expiratory radiography -main indication is the investigation of air trapping either general or local  General air trapping- exemplified by asthma or emphysema  Local air trapping- there is bronchial obstruction, or lobar emphysema nd -2 indication= when pneumothorax is suspected and the visceral pleural pleural line is not visible 2. Valsalva and Muller maneuvers -may aid in determining the vascular or solid nature of intrathoracic mass 3. Bedside radiography -in patients who are too ill to stand, anteroposterior (AP) upright or supine projections offer an alternative COMPUTED TOMOGRAPHY Most common indication for the use of CT scan 1. Evaluation of suspected mediastinal abnormalities identified on standard chest radiograph 2. Search for occult thymic lesions 3. Determination of the presence and extent of neoplastic 4. Search for diffuse or central calcification in a pulmonary nodule Miscellaneous indications: 1. Assisting in the percutaneous biopsy of a lesion such as mediastinal, pleural or pulmonary masses 2. Localization of loculated collections of fluid within the pleural space 3. Assessment of the size and configuration of the thoracic aorta Main indication for the use of HRCT 1. Diagnosis of bronchiectasis 2. Detection of parenchymal lung disease ATELECTASIS -state of incomplete expansion of lung or any portion of it -loss of lung volume Causes of Collapse

 Intrinsic mass -primary or metastatic neoplasms or eroding lymph nodes  Intrinsic stenosis -TB, inflammatory processes, fracture of a bronchus  Extrinsic pressure -enlarged LN, mediastinal tumor, aortic aneurysm, cardiac enlargement  Bronchial plugging -FB or mucus accumulation Types 1. Resorption/ obstructive atelectasis -occurs when communication between the trachea and alveoli is obstructed -may be intrinsic, caused by a tumor, foreign body, inflammatory disease, heavy secretions -extrinsic pressure on bronchi caused by tumor or enlarged nodes or bronchial constriction secondary to inflammatory disease 2. Passive atelectasis -intrapleural abnormalities -caused by space occupying process that can compress the lung -pneumothorax, pleural fluid, diaphragmatic elevation, herniation of the abnormalities viscera into the thorax, large intrathoracic tumors 3. Compressive atelectasis -intrapulmonary abnormalities -is a secondary effect of compression of normal lung by a primary, spaceoccupying abnormality -bullous emphysema, lobar emphysema 4. Adhesive atelectasis -occurs when the luminal surfaces of the alveolar walls stick together -hyaline membrane disease, pulmonary embolism, acute radiation pneumonitis, uremia 5. Cicatrization atelectasis -is primarily the result of fibrosis and scar tissue formation in the interalveolar space -classic cause: TB