Approach to CXR. Terminology. 1.Identification. Greg Blecher SCH Respir Fellow. Correct patient Correct date and time Correct examination

Transcription

1 Approach to CXR Greg Blecher SCH Respir Fellow From Rob Posteraro ; Approach to viewing Chest x-ray Basics - A.J. Chandrasekhar Terminology 1.Identification Xray - opacity (white or light)/ lucency (dark) CT - density MRI - signal insensity Correct patient Correct date and time Correct examination

2 2. Technique Complete examination Are all the requested views included? Is the entire anatomical area included on the films? Position - erect/ supine/ decubitus PA or AP Rotation medial ends clavicles, midline Penetration - under/ over Is this film centered? Difficult to evaluate the position of mediastinum if the film is not centered.

3 Is this film centered? Inspiration - good inspiration 5 ½ ant ribs, 9 post In older infants and children, 6th anterior rib ends intersect the domes of the diaphragm. Is this a PA or AP film?

4 Is this a PA or AP film? Is the exposure appropriate?

5 Is the exposure appropriate? Expiratory Is this a good inspiration film?

6 Posterior Anterior How do you number ribs?

7 Identify hilum. Identify costophrenic angles

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9 3. Interpretation 1. Extraneous material 2. Soft tissues 3. Bones 4. Diaphragms and below 5. Lung fields 6. Heart 7. Mediastinum 8. Hila 9. Pulmonary vascularity 10.Interstitial markings 1. Extraneous material: 2. Soft tissues ingested or injected contrast material, lines, tubes, surgical clips, prostheses, etc.» i.always note location of lines and tubes tips eg level T5. Not sufficient to just mention line or tube present.» The important information is whether line or tube properly located. Look for i. asymmetry in soft tissues may be result of surgery, trauma, atrophy or hypertrophy of tissues or a mass. ii.soft tissue calcifications eg old haematoma, neuroblastoma. iii. Air leaks eg surgical emphysema

10 3. Bones Examine all bones (prox humeri, scapulae, ribs, vertebrae, visible portion of the mandible). Make sure all bones present eg hemivertebrae Examine each pair of ribs in sequence (right vs left), first through tenth or eleventh. It s very easy to miss an absent rib. Then examine each posterior rib, each anterior rib, and finally, lateral aspects of each rib. Rib fractures/ skeletal metastasis most frequently along lateral aspects of the ribs, easy to miss! Look for rib splaying - mediastinal mass Rib notching eg neuroblastoma 4. Diaphragms and below right hemidiaphragm normally higher than left by up to 1.5 cm. Abnormal elevation of either diaphragm may indicate atelectasis in the lower lobe of the ipsilateral lung phrenic paralysis on that side subpulmonic or subdiaphragmatic fluid, mass, abcess or organomegaly (hepatomegaly or splenomegaly). Can the whole of diaphragm be seen (ant 1/3 Lt) Check abdominal situs Situs Situs inversus with dextrocardia not associated with congenital heart disease Dextrocardia with normal visceral situs is associated with congenital heart diseases Look below the diaphragms free intraperitoneal air: recent abdominal surgery, trauma or possibly ruptured bowel? dilated loops of bowel - ileus or obstruction.

11 5. Lung fields Now can examine the lungs. Trachea usually to Rt of midline Compare the lung tissue in each interspace with lung tissue in the corresponding interspace on opposite side. asymmetry density may indicate a lung lesion. Lung parenchyma should become darker (lucent) as go down Check retrocardiac space 6. Heart Normally 2/3 lies to Lt of midline Note size and shape Aortic arch check tissue around trachea. Side with more tissue = arch CTR Normal Cardio-Thoracic Ratio CTR i. First few months accept 0.6 ii. 3 5 yr old 0.5 to 0.55 iii.then < 0.5 iv. The transthoracic diameter is measured from the inner aspect of the ribs cage. This rough rule of thumb for cardiac size is valid only on an erect chest filmwith the patient having taken a properly deep inspiration.

12 7. Mediastinum Thymus prominent up to 5 yr of age max (see below) no rough rule of thumb for normal width of mediastinum. Only experience will teach you what is normal and what is not. Certainly, any obvious mass distorting contour of the mediastinum should be noted. How do you assess position of Mediastinum? 8. Hila hila should be concave in shape. If convex, suspect a hilar mass, adenopathy, or pulmonary vessel enlargement.

13 Identify hilum. 9. Pulmonary vascularity pulmonary vessels should be sharply defined taper from the hila to the periphery of lung fields. On an erect film, vessels to upper lobes should be narrower in diameter than the pulmonary vessels to the lower lobes at a comparable distance from the hila. If upper lobe vessels > in diameter than the corresponding lower lobe vessels, consider pulmonary vascular engorgement.

14 10. Interstitial markings interstitial markings should be very fine (almost invisible). Lobes Do you know where each lobe projects?

15 Identify left and right diaphragm

16 Imaging Findings ABC approach: A-Abdomen, check for: bowel gas pattern (ileus or obstruction), free intraperitoneal air, abnormal calcification, abdominal situs, diaphragm position. B-Bone, check for: fractures, splaying of ribs, lytic or blastic lesions, metabolic bone diseases,. C Chest midline trachea mediastinum, abnormal mediastinal and cardiac contours, position of the aortic arch, pleural effusions, pulmonary vascularity, pneumomediastinum, pneumothorax, pneumopericardium, infiltrates, atelectasis.