Radiologic Examination of the Chest Chapter 8  Radiologic Examination of the Chest

Fundamentals of Radiography

Standard Positions and Techniques of Chest Radiography Posteroanterior radiograph Anteroposterior radiograph Lateral radiograph Lateral decubitus radiograph

  Figure 8-1. Standard PA chest radiograph with the patient’s lungs in full inspiration.

Figure 8-2. A PA chest radiograph of the same patient shown in Figure 8-1 during expiration.

Figure 8-3. Compared with the PA chest radiograph, the heart is significantly magnified in the AP chest radiograph. In the PA radiograph the ratio of the width of the heart to the thorax is normally less than 1:2.

  Figure 8-4. AP chest radiograph. The diaphragms are elevated, the lower lung lobes appear hazy, the ratio of the width of the heart to the thorax is greater than 2:1, and extraneous lines are apparent on the patient’s left side.

Figure 8-5. Lateral radiograph.   Figure 8-5. Lateral radiograph.

  Figure 8-6. Subpulmonic pleural effusion. Right lateral decubitus view. Subdiaphragmatic fluid has run up the lateral chest wall, producing a band of soft tissue density. The medial curvilinear shadow (arrow) indicates fluid in the lips of the major fissure.

Inspecting the Chest Radiograph

  Figure 8-7. Normal PA chest radiograph. 1, Trachea (note vertebral column in middle of trachea); 2, carina; 3, right main stem bronchus; 4, left main stem bronchus; 5, right atrium; 6, left ventricle; 7, hilar vasculature; 8, aortic knob; 9, diaphragm; 10, costophrenic angles; 11, breast shadows; 12, gastric air bubble; 13, clavicle; 14, rib.

  Figure 8-8. Normal lateral chest radiograph. 1, Manubrium; 2, sternum; 3, cardiac shadow; 4, retrosternal air space in the lung; 5, trachea; 6, bronchus, on end; 7, aortic arch (ascending and descending); 8, scapulae; 9, vertebral column; 10, diaphragm; 11, breast shadow.

Table 8-1 Common Radiologic Terms Air cyst Bleb Bulla Bronchogram Cavity Consolidation Homogeneous density Honeycombing Infiltrate

Table 8-1 Common Radiologic Terms, cont. Interstitial density Lesion Opacity Pleural density Pulmonary mass Pulmonary nodule Radiodensity Radiolucency Translucent

Selected Examples of Common Radiologic Terms

Cavity Lung with TB cavities Radiograph of cavity Figure 17-1, C. Figure 17-2; From Armstrong P et al: Imaging of diseases of the chest, ed 2, St. Louis, 1995, Mosby.

Consolidation or Opacity (Caused by a Right Lung Pneumonia) Figure 15-1. Figure 15-5.

Bronchogram Figure 15-6. Air bronchogram. (From Armstrong P et al: Imaging of diseases of the chest, ed 2, St. Louis, 1995, Mosby.)

Bronchogram Shown in chest CT Scan Figure 15-7. (From Armstrong P et al: Imaging of diseases of the chest, ed 2, St. Louis, 1995, Mosby.)

Honeycombing (as shown in interstitial pulmonary fibrosis)   Figure 28-4. (From Armstrong P et al: Imaging of diseases of the chest, ed 2, St. Louis, 1995, Mosby.)

Infiltrate (As shown in patient with ARDS—general term) Figure 27-2.

Pleural Density   Figure 28-3. (From Armstrong P et al: Imaging of diseases of the chest, ed 2, St. Louis, 1995, Mosby.)

Pulmonary Mass   Figure 26-3. (From Rau JL, Pearce DJ: Understanding chest radiographs, Denver, 1984, Multi-Media Publishing.)

Radiodensity (Caused by a Right Lung Pneumonia) Figure 15-1. Figure 15-5.

Translucency or Radiolucency (Caused by a Right Pneumothorax) Figure 22-1. Figure 22-10, B.

Translucency or Radiolucency (Caused by a Chronic Emphysema) Figure 12-3. Figure 12-2.

Technical Quality of the Radiograph Exposure quality Level of inspiration

First Technical Quality Was the patient in the correct position? Check the medial ends of the clavicles to the vertebral column Even a small degree of patient rotation can create a false image Erroneously suggesting tracheal deviation, cardiac displacement, or cardiac enlargement

Second Exposure Quality Normal exposure is verified by determining whether the spinal processes of the vertebrae are visible to the 5th or 6th thoracic level Compare the relative densities of the heart and lungs Overexposure: heart and lungs more radiolucent Underexposure: heart and lungs more dense or whiter

Third Level of Inspiration When Radiograph Was Taken At full inspiration, the diaphragmatic domes should be at the level of the 9th to 11th ribs posteriorly At expiration, the lungs appear denser, the diaphragm is elevated, and the heart appears wider and enlarged

Sequence of Examination Mediastinum Trachea Heart Hilar region Lung tissue Pleura Diaphragm Gastric air bubble Bony thorax and soft tissues

    Figure 8-7. Normal PA chest radiograph. 1, Trachea (note vertebral column in middle of trachea); 2, carina; 3, right main stem bronchus; 4, left main stem bronchus; 5, right atrium; 6, left ventricle; 7, hilar vasculature; 8, aortic knob; 9, diaphragm; 10, costophrenic angles; 11, breast shadows; 12, gastric air bubble; 13, clavicle; 14, rib.

Structure Abnormal Position Causes Mediastinum Leftward shift Trachea Carina Heart Major vessels Abnormal Position Leftward shift Causes Pulled left by upper lobe tuberculosis, atelectasis, or fibrosis Pushed left by right upper lobe emphysematous bulla, fluid, gas, or tumor Table 8-2. Examples of Factors That Pull or Push Anatomic Structures Out of Their Normal Position in the Chest Radiograph.

Structure Abnormal Position Causes Left diaphragm Upward shift Pulled up by left lower lobe atelectasis or fibrosis Pushed up by distended gastric air bubble Table 8-2. Examples of Factors That Pull or Push Anatomic Structures Out of Their Normal Position in the Chest Radiograph, cont.

Structure Abnormal Position Causes Horizontal fissure Downward shift Right lung Right hilum Abnormal Position Downward shift Causes Pulled down by right middle lobe or right lower lobe atelectasis Pushed down by right upper lobe neoplasm Table 8-2. Examples of Factors That Pull or Push Anatomic Structures Out of Their Normal Position in the Chest Radiograph, cont.

Structure Abnormal Position Causes Left lung Rightward shift Pulled right by right lung collapse, atelectasis, or fibrosis Pushed right by left-sided tension pneumothorax or hemothorax Table 8-2. Examples of Factors That Pull or Push Anatomic Structures Out of Their Normal Position in the Chest Radiograph, cont.

Other Radiologic Techniques Computed tomography (CT) CT scan Position emission tomography (PET) PET scan Magnetic resonance imaging Pulmonary angiography Ventilation-perfusion scan Fluoroscopy Bronchography

Normal CT Scan Lung Window Figure 8-9. Overview of normal lung window CT scan. The apex appears in the two views in the upper right hand corner of this figure; the diaphragm at the base of the lungs appears in the lower right hand view.

Example of Several Normal CT Scan Lung Window Slices

Normal CT Scan Lung Window B Figure 8-10. Close-up of a normal lung window CT scan. A, The portion of the chest the CT scan is taken. Figure 8-9 B. The actual cross-sectional slice, or axial view of the chest.

Normal CT Scan Lung Window Figures 8-10, A, and 8-9, C.

Normal CT Scan Lung Window Figures 8-10, A, and 8-9, D.

Normal CT Scan Lung Window Figures 8-10, A, and 8-9, E.

Normal CT Scan Lung Window Figures 8-10, A, and 8-9, F.

Normal CT Scan Lung Window Figures 8-10, A, and 8-9, G.

Normal CT Scan Lung Window Figures 8-10, A, and 8-9, H.

Normal CT Scan Lung Window Figures 8-10, A, and 8-9, I.

Normal CT Scan Lung Window Figures 8-10, A, and 8-9, J.

Normal CT Scan Lung Window Figures 8-10, A, and 8-9, K.

Normal CT Scan Lung Window Figures 8-10, A, and 8-9, L.

Example of Several Normal CT Scan Mediastinal Window

Normal CT Mediastinal Window

Normal CT Mediastinal Window

Normal CT Mediastinal Window

Normal CT Mediastinal Window

Normal CT Mediastinal Window

Normal CT Mediastinal Window Figures 8-11. Close up of normal CT mediastinal window. A, The portion of the chest the CT scan is taken. B, The actual cross-sectional slice, or axial view of the chest. Note that the lungs are overexposed and appear mostly black. The bone and mediastinal organs appear mostly white.

Normal CT Mediastinal Window

Normal CT Mediastinal Window

Normal CT Mediastinal Window

Normal CT Mediastinal Window

Normal CT Mediastinal Window

Positron Emission Tomography PET Scan

A B Figure 8-12. Chest radiograph identifying two suspicious findings: in the right upper lobe (A) and in the left lower lobe (B), just behind the heart (see white arrows).

CT scan, upper right lobe Chest radiograph CT scan, left lower lobe Figure 8-13. Same chest radiograph as shown in Figure 8-12. Note the CT scan also identifies the suspicious nodules and their precise location.

Coronal View Figure 8-14. PET scan: coronal views. The last three views show a “hot spot” in left lower lung lobe.

Figure 8-15. PET scan: sagittal views Figure 8-15. PET scan: sagittal views. The encircled images show a “hot spot” in the lower left lobe.

Axial View Figure 8-16. PET scan: axial view. A “hot spot” is further confirmed in left lower lung lobe.

Axial View No hot spot seen Figure 8-17. PET scan: axial view. This image confirms that the small nodule identified in the upper right lobe in the chest radiograph and CT scan is benign (i.e., no “hot spot” is evident).

PET Scan and CT Scan

CT Scan CT/PET Fusion PET Scan Axial View Coronal View Figure 8-18. CT/PET scan (center). CT scan, CT/PET fusion, and PET scan, all showing the same malignant nodule in right upper lobe (see white arrow). Note: The CT/PET fusion is normally presented in color (e.g., red, blue, yellow).

Magnetic Resonance Imaging

  Figure 8-19. Anatomy of mediastinum on MRI. A, LBCV, Left brachiocephalic vein; RBCV, right brachiocephalic vein; Ao A, aortic arch; T, trachea; Es, esophagus. B, RV, Right ventricle; LV, left ventricle; RA, right atrium; LA, left atrium; D Ao, descending aorta; Es, esophagus; Az V, azygos vein. (From Armstrong P, Wilson AG, Dee P: Imaging of diseases of the chest, St. Louis, 1990, Mosby.)

Pulmonary Angiography

  Figure 8-20. Abnormal pulmonary angiogram. Radiopaque material injected into the blood is prevented from flowing into the left lung past the pulmonary embolism (arrow). No vascular structures are seen distal to the obstruction.

Bronchography

  Figure 8-21. Bronchogram obtained using contrast medium in a patient with a history of bronchiectasis. Arrows indicate the carina and the bronchi leading to the posterior basilar segment of the left lower lobe. (From Rau JL, Jr, Pearce DJ: Understanding chest radiographs, Denver, 1984, Multi-Media Publishing.)