INTERACTIVE CASE DISCUSSIONS

Medical ClerkshipDepartment of Radiological Sciences

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(+) cough (+) difficulty of breathing (-) fever

Persistence.

VS HR 120/80 HR 96 RR 28 T 36.4°C in respiratory distress, supraclavicular,

intercostal and subcostal retractions symmetric chest expansion, BS left lower

lung, (+) coarse crackles & rhonchi, L

1 wk PTC

Consult.

30/F CC: cough

CH

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-RAY AP SUPINE LEFT LAT DECUBITUS

CLERK’S GUIDE: Discuss first the basics of a normal chest x-ray.

CC: Cough

action of the body takes to get rid of substances that are irritating the air passages

occurs when mechanical or chemical afferent nerves get irritated and trigger a chain of events

Air in lungs is forced out under high pressure.

Analysis

Cough › Acute < 3weeks› Persistent >3weeks› Chronic >8weeks

› Acute cough Infectious Non infectious

Acute Cough

Acute Cough – signs and symptoms

Infectious Non infectious

Fever, chills, body aches, sore throat vomiting, headache, sinus

pressure, runny nose, night sweats, and postnasal drip.

sputum, or phlegm,

exposure to certain chemicals or irritants in the environment,

coughs that may improve with inhalers or allergy medications

Indications for a Chest X-ray

For patient with acute cough Abnormal vital signs Chest examination suggestive of

pneumonia

Patient: RR 28 › in respiratory distress, supraclavicular,

intercostal and subcostal retractions› symmetric chest expansion, BS left lower

lung, (+) coarse crackles & rhonchi, L

AP supine

if px can’t assume upright position, though

can’t critically evaluate the size of the heart because of hypoventilation, diaphragmatic elevation pushing the base of the heart upwards.

Lateral Decubitus position

px lies on right or left side; the beam traverses the body in horizontal position

px w/pleural effusion, pneumothorax – presence of fluid gravitates to dependent portions

demonstrate fluid levels in cavities

Normal Chest X-ray

Chest anatomy: Evaluation

Ribs› Anterior ribs

obliquely placed wider intercostals

spaces› Posterior ribs

horizontally placed narrower intercostals

spaces› Intercostal Spaces

Chest anatomy: Evaluation

Diaphragm: right and left› middle segment partially

obscured› Normal level

10th post rib / 5th ant rib right higher than the left

(liver)› dome-shaped

Costophrenic angle / sinus and Cardiophrenic angle› Sharp, well defined and

not blunted

Chest anatomy: Evaluation

Trachea and mediastinum› radioluscent: means it

has an air› bifurcates at T5

(carina) into right and left bronchus

› normal: midline› right bronchus: shorter

and more vertical› left bronchus: longer

and more horizontal

Chest anatomy: Evaluation

Hila, bronchovascular markings› pulmonary artery and vein› bronchial artery and vein› bronchus› lymph nodes

Normal: › left hilum higher than the

right› pulmonary artery crosses

above the left and below the right bronchus

› size of hilum varies depending on pulmonary blood flow

Chest anatomy: Evaluation

Lungs› Radiolucent

Inner, middle, outer zones› Inner zone: from

sternoclavicular joint draw a vertical line following contour of the chest, big blood vessels are located

› middle zone: medium blood vessels are located

› outer zone: junction of the clavicle and 1st rib draw a vertical line; small blood vessels are located

Chest anatomy: Evaluation

Upper, middle, lower lung fields› landmarks: 2nd and

4th anterior ribs› upper lung field:

further subdivided by the clavicle into supraclavicular (apex) and infraclavicular

› significance: for localization of the lesions

Chest anatomy: Evaluation

Lobar anatomy› right lobe

major fissure: divides lower lobe from upper and middle

minor fissure: divides upper and middle› left lobe

for upper and lower lobes only

Chest anatomy: Evaluation

Heart shadow› Superior mediastinum

draw a line from the sternal angle to the 4th vertebra

› Anterior mediastinum bounded by posterior

surface of the sternum and anterior surface of the heart

› Posterior mediastinum bounded by posterior part

of the heart and anterior spinal muscle

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Chest anatomy: Evaluation

Size› Cardiothoracic ratio› Easiest gross determination› Compare size of the heart with the

thorax› Normal 2:1› Get the widest transverse

diameter of the heart compare with the widestinternal transverse diameter of the thorax

Shape› Variable› neonate: globular

Chest anatomy: Evaluation

Right border› Superior vena cava› Right atrium› Inferior vena cava

Chest anatomy: Evaluation

Right border› Superior vena cava› Right atrium› Inferior vena cava

Left border› Aortic knob› Main pulmonary trunk› Left ventricle

Lateral View

Left atriumLeft ventricleRight ventricle

AORTA

Main Pulmonary Artery

trachea

RC

RS

Patients Chest X-ray

CH

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-RAY AP SUPINE LEFT LAT DECUBITUS

CLERK’S GUIDE: Discuss first the basics of a normal chest x-ray.

Patient’s chest xray

Obscured diagphragmatic sulci at the left

Narrow intercostal space No shifting of the mediastinal

structures Cardiac shadow not appreciated

Hyperluscency of the right lung Homogenous opacification of the left

lung

Radiographic Differentials

Consolidation Atelectasis Pleural effusion Mass lesions

Mass Consolidation

Pleural effusion Atelectasis

Duration Chronic Sub acute to chronic

Sub acute to chronic Acute to sub acute

A-abdomen and thorax, costophrenc and cardiophrenic sulci, diaphragm

May be affected depending on the location of the mass

Blunted/ normal

Blunting of costrophrenic sulcus, nor visualization of hemidiaphragm, due to presence of fluid

Hemidiaphragm may be affected depending on the size of atelectasis

T-thoracic cage

normal Normal +/- widenend interspaces on affected side

Narrowed interspaces on affected side with compensatory widening on opposite side

M-mediastinum

+/- shifting depends on the size and location

Normal +/- shifting contralaterally

+/- shifting ipsilaterally

LL- Lung comparison

Solitary , calcificied, ildefined, spiculations, irreguar, cavitations, hilar enlargement, effusions

Air bronchogram

Homogenous opacification with a lateral upward curve(meniscus sign)Lat decubitus view- free fluid within the pleural space +layering oon the dependent part

Homogenous opacification of affected side

Atelectasis

means “lack of stretch” refers to collapse or loss of lung

volume 2 types: Obstructive or Non obstructive

Atelectasis

Obstructive› blockage of an airway › Air retained distal to the occlusion is then

resorbed from nonventilated alveoli› affected regions become totally airless

Non obstructive› caused by loss of contact between the

parietal and visceral pleurae, parenchymal compression, loss of surfactant, or replacement of lung tissue by scarring or infiltrative disease.

Direct signs › displacement of fissures › increased opacification of the airless lobe.

Indirect signs › displacement of hilar structures, › cardiomediastinal shift toward the side of

collapse, › narrowing of ipsilateral intercostal spaces, › elevation of the ipsilateral hemidiaphragm,

compensatory hyperinflation and hyperlucency of the remaining aerated parts of the lung, and

› obscuring of structures adjacent to the collapsed lung, such as the diaphragm, heart, or pulmonary vessels.

ROLE OF MAGNETIC RESONANCE IMAGING

can distinguish between obstructive and nonobstructive atelectasis

Obstructive atelectasis › displays high signal intensity on T2-weighted images due

to proton-rich mucus accumulation. Nonobstructive atelectasis

› low signal intensity on T1 and T2 weighted spin-echo images, since the residual alveolar gas has a low proton concentration, and magnetic susceptibility effects between alveolar walls lead to a decrease in signal.

The use of MRI in diagnosing atelectasis is still experimental, and more experience needs to be accrued

Treatment

Continuous positive airway pressure (CPAP)

Fiberoptic bronchoscopy for the extraction of secretions

Mucolytic therapy 

NORMAL CHEST X RAY