PATIENT DATA EVALUATION AND RECOMMENDATION: IMAGING STUDIES

Transcription

1 PATIENT DATA EVALUATION AND RECOMMENDATION: IMAGING STUDIES Robert Harwood, MSA, RRT-NPS Objectives At the end of this presentation the student should be able to: Describe the indications of a chest radiograph. Describe the difference between common chest radiographic techniques. Understand how to interpret the quality of the chest radiograph. Describe the various lines, tubes and other findings on a chest radiograph Interpret normal and abnormal findings on a chest radiograph. Identify various causes of changes in the chest radiograph. 1

2 Indication for Chest Radiograph The chest x-ray is performed to evaluate the lungs, heart and chest wall. First imaging test used to help diagnose symptoms such as: Shortness of breath A bad or persistent cough Chest pain or injury Fever Examination to help diagnose or monitor treatment for conditions such as: Pneumonia Heart failure and other heart problems Emphysema Lung cancer Pleural space problems Line and tube placement Other medical conditions Quality of Radiographic Image Dense objects absorb more x- rays- radiopaque Air- filled objects absorb less x- rays- radiolucent BONE SOFT TISSUE FAT AIR OR GAS 2

3 Quality of Radiographic Image RADIOPAQUE RADIOLUCENT NORMAL BONE AIR ABNORMAL CONSOLIDATION, ATELECTASIS PLEURAL SPACE-PNEUMOTHORAX Exposure Exposure Quality Normal-easily visible mid-thoracic intervertebral spaces. Underexposed - loss of mid-thoracic intervertebral spaces Overexposed - darker quality, loose lung detail 3

4 Quality of Radiographic Image RADIOGRAPHIC IMAGE Depth of inspiration NORMAL >8 posterior ribs, >6 anterior ribs above left hemidiaphragm. ABNORMAL Low lung volume: < 8 posterior ribs, < 6 anterior ribs above left hemidiaphragm Rotation Clavicles-spinous process equidistance from clavicle head Rotation- R or L medial end of clavicle overrides spinous process Heart size Heart size < 50% of thoracic diameter Heart size > 50% of thoracic diameter CHF Heart border Clear outline of R and L heart border, cardiophrenic angle RH border obscured-rm lobe pathology LH border obscured-l upper lobe pathology Diaphragm domes Rounded, R dome higher than left Flat-COPD Left higher than right-atelectasis, paralysis Quality of Radiographic Image RADIOGRAPHIC IMAGE NORMAL ABNORMAL Costophrenic angle Gastric air bubble Sharp bilateral angles, radiolucent appearance Bubble-shaped radiolucent appearance under left hemidiaphragm Obscured, radiopaque appearance- Pleural Effusion, interlobar fissures may be visible Bubble-shaped appearance moved toward midline-hiatal hernia Hilum Bones Trachea Similar hilar density on each side, left slightly higher than the right Continuous radiopaque appearance, no breaks, no spinal curvature Should be central, with slight deviation to the right as it crosses the aortic arch Position, size, density change: pulmonary hypertension, mass, pulmonary emboli Ribs-discontinuous radiopaque appearance, breaks or fracture, spine-lateral curvature Right or left shift: pneumothorax, massive atelectasis, effusion 4

5 Posteroanterior (PA) Type of Chest Radiographs Standard, accurate and valid when comparing to previous PA x-rays Able to obtain deep inspiration while standing Can be done while sitting Anteroposterior (AP) Bedside or portable Mediastinum is magnified-larger heart appearance than PA May not be able to take as deep of inhalation as PA Rotation Inferior quality as compared to PA Type of Chest Radiographs Lateral Used along with a PA x-ray to further delineate and localize masses, lesions or consolidation Specifically if the obstruction obscures the heart or diaphragms COPD-increased retrosternal air (in front of the sternum) and retrocardiac (behind the heart) Lateral Decubitus Fluid or air from pneumothorax Expiratory Film Small pneumothorax Inhaled foreign body Apical Lordotic Film Upward angled film to look at the apical lung region Middle lobe 5

6 Lung Scan Type of Chest Radiographs Ventilation/perfusion lung scan (V/P lung scan) Evaluate the circulation of air and blood within a patient's lungs Ventilation part of the test looks at the ability of air to reach all parts of the lungs Perfusion part evaluates how well blood circulates within the lungs Use to detect thromboembolism Pulmonary Angiography Done after uncertain results from a lung scan and CT angiogram Contrast medium injection Use to detect thromboembolism Type of Chest Radiographs Computed Tomography (CT scan) Standard CT scan-slices of body Detection of bronchiectasis, pneumonia, COPD, emphysema High resolution CT scan-thinner body slices Help guide needle aspiration of tissue masses, catheter placement CT angiography-injection of dye Rule out pulmonary embolism, heart disease, lung tumors, pulmonary nodules Magnetic Resonance Imaging Helps evaluate lung cancer and position of tumors Positron Emission Tomography (PET) Used to detect cancer and check blood flow to organs Uses a glucose marker to detect abnormalities 6

7 Lines, Tubes and Other Things Tube, Line, Other Endotracheal tube Tracheostomy tube Nasogastric tube Chest tube Central venous catheter Pulmonary artery catheter Pacemaker Proper Position/Placement 5-7 cm. above carina and below vocal cords (C5-C6) Several cm. above carina,tube lies parallel to the walls of the trachea Within the stomach-10 cm past the gastro-esophageal junction. Within the pleural space to drain air or fluid Within superior vena cava Within main or lobar pulmonary artery Implanted in left thoracic area over pectoralis major muscle Chest Radiographic Findings Pathology Findings Cause Air bronchogram Bronchi surrounded by consolidated alveoli, linear branching air shadows - Radiolucent Pneumonia, pulmonary edema Hyperinflation Flattened diaphragm, elongated heart, increased retrosternal space, intercostal space - Radiolucent COPD atelectasis-obstruction Absent ventilation causes collapse of entire lobes or segments Radiopaque Mucus plugging, aspiration atelectasis-compression Lung collapse from pleural space pathology Radiopaque Pleural effusion, Pneumothorax, Hemothorax 7

8 Chest Radiographic Findings Pathology Findings Cause Silhouette sign Loss of border between structures Radiopaque Pneumonia-loss or heart border or diaphragm border Pneumothorax Pneumomediastinum Air in pleural space, visceral pleura line outlines lung, mediastinum shifted with tension - Radiolucent Radiolucent outline around the heart and mediastinum Trauma, positive pressure, rupture of bleb from coughing Air leak from alveoli, tracheal, esophageal rupture Diffuse shadowing Bilateral and widespread - Radiopaque Consolidation Patchy areas - Radiopaque Pulmonary edema Ground glass appearance, air bronchograms Bilateral ARDS Pneumonia LHF-cardiogenic Pulmonary hypertension Silhouette Sign Loss of right heart border Loss of left heart border Loss of anterior hemidiaphragm Right middle Lobe infiltrates Left upper lobe infiltrates Anterior lower lobe infiltrates 8

9 Chest Radiographic Findings Pathology Findings Cause Pleural effusion Cardiogenic pulmonary edema Non-cardiogenic pulmonary edema Whiting out of costophrenic angle, lower lobes, meniscus sign Radiopaque Kerley s B lines Pleural effusion-right Increased C/T ratio Air bronchograms, ground glass appearance, normal C/T ratio CHF, pneumonia Left heart failure Pulmonary hypertension, aspiration Chest Radiographic Findings Pathology Findings Cause Kirby B lines Diffuse shadowing Lung periphery Radiopaque Bilateral and widespread Radiopaque CHF ARDS Pneumopericardium Radiolucent outline of heart Penetrating trauma, thoracic surgery Subcutaneous emphysema Radiolucent appearance in the neck, face, chest Pneumothorax, barotrauma 9

10 Chest Radiographic Findings Pathology Findings Cause Croup Epiglottis Foreign body aspiration Frontal and lateral neck x-ray: subglottic narrowing below vocal cords church steeple appearance Lateral neck x-ray: inflammation and edema of the epiglottis, overdistention of the hypopharynx, aryepiglottic folds Lateral x-ray: radiopaque object at the laryngeal level. PA x-ray: radiopaque object in lung Lateral x-ray: in front of or behind heart Viral disease-parainfluenza Bacterial disease-haemophilus influenzae Aspiration of food-nuts, hot dog Sample Questions Which of the following would be associated with an underexposed posteroanterior (PA) chest radiograph? a. Lung fields have a more radiopaque appearance b. Loss of mid-thoracic intervertebral spaces c. The heart appears larger than normal d. The stomach gas bubble is more radiopaque 10

11 Sample Question Answer b. Correct When the quality of the chest radiograph is poor, as is the case of underexposure, the mid-thoracic intervertebral spaces are not able to be seen. Sample Question A patient in ICU from a motor vehicle accident is receiving mechanical ventilation. An anteroposterior (AP) chest radiograph shows the left hemidiaphragm higher than the right hemidiaphragm. Which of the following is the result of these findings? a. Left-sided tension pneumothorax b. Right-sided pleural effusion c. Hepatomegaly d. Left-sided atelectasis 11

12 Sample Question Answer d. Correct Left-sided atelectasis causes volume loss resulting in the diaphragm moving upwards. Sample Question An anteroposterior (AP) chest radiograph has returned on an adult, orally intubated patient receiving mechanical ventilation. The respiratory therapist reviewing the chest radiograph notes the tip of the endotracheal tube to be 5 cm above the carina. Based on this finding the respiratory therapist should recommend which of the following? a. Pull the endotracheal tube back 3 cm. b. Insert the endotracheal tube 4 cm. c. Maintain current position d. Insert the endotracheal tube 5 cm. 12

13 Sample Question Answer c. Correct Proper level for endotracheal tube in relationship to the carina within the trachea is 5-7 cm above the carina. Therefore maintaining current position is the best option. Sample Question A 63 year-old female diagnosed with bronchiectasis has been admitted to the hospital for exacerbation of her condition. Posteroanterior (PA) chest radiograph shows infiltrates along the right heart border. The patient has been ordered for therapy including lung drainage. Which of the following areas of the lung should therapy be concentrated? a. Right middle lobe b. Right upper lobe c. Right posterior lower lobed. d. Right anterior lower lobe 13

14 Sample Question Answer a. Correct Infiltrates along the right heart border are in the right middle lobe. This is called the Silhouette Sign that may cause loss of the heart border. Sample Question A frontal neck x-ray of a 4 year-old child shows subglottic narrowing below the vocal cords. Based on this finding the child should be treated for which of the following? a. Tonsillitis b. Epiglottitis c. Asthma d. Croup 14

15 Sample Question Answer d. Correct Frontal neck x-ray is used to determine upper airway narrowing. Subglottic narrowing below the vocal cords is associated with croup and gives the church steeple appearance on frontal neck x-ray. References Clinical Assessment in Respiratory Care, Sixth Edition, Robert L. Wilkins, James R. Dexter, Albert J. Heuer, (2009), The Mosby/Elsevier Company, St. Louis, MO. Egan s Fundamentals of Respiratory Care, Ninth Edition, Robert L. Wilkins, James K. Stoller, Robert M. Kacmarek, (2009), Mosby/Elsevier Company, St. Louis, MO. Perinatal and Pediatric Respiratory Care. Brian K. Walsh, Michael P Czervinske, Robert M. DiBlasi (2010). Saunders Elsevier, St. Louis, MO. Respiratory Care Principles and Practice, Second Edition, Dean R. Hess, Neil R. MacIntyre, Shelley C. Mishoe, William F. Galvin, Alexander B. Adams, (2011), Jones and Bartlett Learning, Sudbury, Mass. The Essentials of Respiratory Care. Robert M. Kacmarek, Steven Dimas, Craig W. Mack (2005). Fourth Edition. Mosby/Elsevier, St. Louis, MO. 15