the basics of cxr interpretation - amazon s3of+chest+x-ray... · the basics of cxr interpretation...

THE BASICS OF CXR

INTERPRETATION

Mir M. Alikhan, MDPulmonary & Critical Care Medicine

drbeen.com

Disclosures● None

● All sources and credits for images will be provided at the end of this presentation

Introduction

● CXR is probably the most common imaging test

● Few providers (including MDs) are comfortable interpreting

their own films

● Clinical decisions are too often made based on reports

from non-clinicians

● Having a systematic and repetitive approach is the key

Objectives

● By the end of this lecture, the learner will be able to:

○ Develop an understanding of the normal CXR appearance

○ Assess the technical quality of a CXR

○ Utilize a systematic and reliable approach in CXR evaluation

○ Identify common CXR findings

○ Correlate basic CXR findings with clinical evaluation in order

to reach a diagnosis

Understanding the Normal CXR

Is this a normal CXR?

● Develop confidence with the

normal appearance

● Type of CXR will have an

impact on what is

considered “normal”

● Absence/aberration of

normal findings should raise

red flags

● Know which structures

should be present or absent

Different Types of CXR

Postero-anterior (PA; standard)

Patient is usually standing with anterior chest against the x-ray plate

X-ray beam originates from 5-6 feet behind the patient

Beam penetrates from posterior to anterior chest

Antero-posterior (AP; portable)

Patient is usually in bed and leaning with back against the x-ray plate

X-ray beam originates from 2-4 feet in front of the patient

Beam penetrates from anterior to posterior chest

Heart

Diaphragm

Trachea

Gastric air bubble

Aortic knob

Right PA/hilumLeft PA/hilum

Carina

Utilizing a Systematic Approach

RIP - ABCDE - LUNGS

Assessing Technical Quality

● R - rotation● I - inspiration● P - penetration

Rotation

● Ideally CXR beam should be transmitted perpendicular to

the chest

● Abnormal angles will distort the image by creating an

oblique view

● Clavicular heads should be equidistant from vertebral

spinous processes

Inspiration

● Assessment of inspiratory effort and lung volumes

● Ideally 7-9 ribs should be visible

● < 7 suggests poor effort by the patient and/or low lung

volumes (restrictive lung disease, atelectasis, etc.)

● 10 or more ribs typically suggests hyperinflation (COPD,

asthma, bronchiectasis)

Penetration

● Exposure quality of the film

● Over-penetration will make structures more radiolucent

which could lessen significance of opacities

● Under-penetration will make structures more radioopaque

which may lead to “over-calling” certain findings

Evaluation of Structures

● A - airway● B - bones (and soft tissues)● C - cardiac silhouette● D - diaphragm● E - everything else (hardware)

Airway● Trachea

○ Deviation

○ Caliber

● Carina

○ Typical angle

○ Splaying

● Mainstem and lobar bronchi

○ Right mainstem is more straightly aligned with trachea

Bones (and soft tissues)● Scan all bony structures

○ Fractures

○ Pins/rods/staples/wires

○ Thoracic cage deformities (scoliosis, etc.)

● Look for foreign bodies

Cardiac ● Evaluate the size and shape of the cardiac silhouette

○ Cardiomegaly - width of the silhouette is greater than ½ the thoracic cage width

■ Can be exaggerated or “over-called” on AP (portable) films

○ Aortic knob

○ Left atrium

○ Pulmonary arteries

○ Shift of mediastinal structures

○ Cardiac borders

○ Pericardial effusion

Diaphragm● Diaphragmatic line should be clearly demarcated

● Evaluate costophrenic and cardiophrenic angles

● Retrocardiac space

● Elevation or flattening of the hemidiaphragms

● Also look at structures immediately beneath diaphragm (liver, gastric bubble,

free air in the abdomen)

● Things that obscure the diaphragm:

○ Pleural effusion

○ Atelectasis

○ Lower lobe infiltrates or mass

Everything Else (Hardware) ● Endotracheal tube

○ Tip should be 2-4 cm from the carina

● Central line

○ Tip of catheter should lie in the cavo-atrial junction

● Pacemaker or defibrillator

○ Know how to tell the difference

○ Leads can be placed in the atria or ventricles

● Chest tubes

○ Always identify the “sentinel” hole to make sure it is within the pleural space

Lungs

● Make a conscious effort to evaluate the lung parenchyma

last!!

● Look at each side independently and then compare the

two sides

● Point out features that seem abnormal

● Always describe before diagnosing!

Lungs● Common descriptive terms

○ Opacities/Infiltrates

○ Mass/Nodule

● Defining the descriptions

○ Consolidation

○ Effusion

○ Atelectasis

○ Edema

○ Fibrosis

Lungs

● Opacities

○ Something which appears relatively radio-opaque compared to normal lung

○ Alveolar opacity

○ Interstitial opacity

● Mass/Nodule

○ Discrete appearance with apparent borders

○ Nodule < 3 cm

○ Can be pleural-based or parenchymal

Lungs● Consolidation

○ Focal confluence of alveolar opacities○ Air bronchograms○ Obliteration of vessels

● Atelectasis vs. Effusion○ Look for discrete lines or lobar distribution for atelectasis○ Effusions are usually dependent which causes gradation from base upwards

● Edema○ Alveolar vs. Interstitial patterns

● Fibrosis○ Septal thickening○ Honeycombing

Clinical Correlations

A Common Radiology Report ...

● “The lung fields demonstrate non-specific hazy, discrete interstitial and alveolar infiltrates or opacities that could represent any of the following: consolidation, effusion, atelectasis, or mass. These findings could suggest pneumonia, lung malignancy, or absolutely nothing. Please correlate clinically.”

Case #1

60 y/o M with recent pneumonia returns with severe shortness of breath and cough. Also complains of L-sided chest pain when taking a breath.

T 101.3 HR 115 BP 120/70 RR 30 O2Sat 87%

Exam: tachypneic, diminished breath sounds in L hemithorax

Labs: WBC 21.2 BUN 28 Cr 1.4

Case #1What is the most likely diagnosis?

A) Recurrent pneumonia

B) Mucus plugging leading to atelectasis

C) Parapneumonic pleural effusion

D) Hemothorax

E) Tension pneumothorax

Case #2

68 y/o male with history of smoking presents with intermittent night sweats, weight loss, and hemoptysis.

T 99.0 HR 96 BP 118/80 RR 18 O2Sat 98%

Exam: no distress; breath sounds clear bilaterally

Labs: WBC 11.5 Hgb 9.5


A) Aspergilloma

B) Tuberculosis

C) Lung adenocarcinoma

D) Sarcoidosis

Case #3

42 y/o male with history of CAD presents with sudden onset of chest pain and severe shortness of breath. The pain radiates to the back and he finds it hard to take a deep breath. He also was in a car accident 2 days ago and has been under a lot of stress.

T 98.0 HR 130 BP 85/50 RR 35 O2Sat 80%

Exam: severe resp distress, diminished breath sounds, mild tracheal deviation

Labs: WBC 14.5

EKG: sinus tachycardia, T wave inversions


A) Aspiration pneumonia

B) Myocardial infarction

C) Aortic dissection

D) Hemothorax

E) Tension pneumothorax

Case #4What do you think of this CXR?

A) Lobar pneumonia

B) Atelectasis

C) Pleural effusion

D) Cardiomegaly

Case #5

40 y/o male with recent influenza infection presenting with shortness of breath, recurrent fever, cough, and yellow-green sputum production.

T 102.3 HR 110 BP 105/65 RR 24 O2Sat 93%

Exam: diminished breath sounds and some scattered crackles/rhonchi

Labs: WBC 22.5 BUN 30 Cr 1.6 BNP 45


A) Pleural effusion

B) Pulmonary edema

C) Multifocal pneumonia

D) Atelectasis due to mucus plugging

E) Interstitial lung disease

Case #6

70 y/o male with history of ETOH abuse is admitted with acute pancreatitis. He is admitted to the hospital for aggressive IV fluid resuscitation and pain control. Over the next 24 hours he develops worsening respiratory distress?

T 100.2 HR 120 BP 160/95 RR 35 O2Sat 86%

Exam: diaphoretic, tachypneic, inspiratory crackles in lower lung fields


A) Hospital-acquired pneumonia

B) ARDS

C) Myocardial infarction leading to pulmonary edema

D) Aspiration pneumonitis

Summary

● Look at all your films - even the “normal” ones

● Use a repetitive & reliable system to avoid missing details

● RIP - ABCDE - LUNGS

● Describe findings first before considering a diagnosis

● Clinical correlation is ALWAYS necessary to arrive at a

diagnosis

Sources

● By Frank Gaillard - http://images.radiopaedia.org/images/4195/5e7cfb6d90bbcf70e73493819e691a.jpg, CC BY-SA 3.0, https://commons.wikimedia.org/w/index.php?curid=14698169

● By The original uploader was Pabloes at Spanish Wikipedia - Transferred from es.wikipedia to Commons., CC BY-SA 3.0, https://commons.wikimedia.org/w/index.php?curid=1753377

● By James Heilman, MD - Own work, CC BY-SA 3.0, https://commons.wikimedia.org/w/index.php?curid=4639778● By Hellerhoff - Own work, CC BY-SA 3.0, https://commons.wikimedia.org/w/index.php?curid=17766964● By James Heilman, MD - Own work, CC BY-SA 3.0, https://commons.wikimedia.org/w/index.php?curid=4646165● By Samir 04:51, 17 September 2007 (UTC). Modified by Delldot 07:55, 28 April 2008 (UTC) - http://en.wikipedia.

org/wiki/Image:Noncardiogenic_pulmonary_edema.JPG, CC BY-SA 3.0, https://commons.wikimedia.org/w/index.php?curid=3954240

● By Photographed by User Clinical Cases 00:42, 7 November 2006 - Originally from tension pneumthorax page on clinicalcases.orgTransferred from en.wikipedia to Commons.; description page is/was here; uploader to en Wiki was Clinical Cases at en.wikipedia, CC BY-SA 2.5, https://commons.wikimedia.org/w/index.php?curid=2235891

https://commons.wikimedia.org/w/index.php?curid=1753377








Sources

● By Clinical_Cases: I made the photo myself, licensed under Creative Commons license. - http://en.wikipedia.org/wiki/Image:Left-sided_Pleural_Effusion.jpg originally http://clinicalcases.blogspot.com/2004/02/massive-left-sided-pleural-effusion.html, CC BY-SA 2.5, https://commons.wikimedia.org/w/index.php?curid=2294191

● By James Heilman, MD - Own work, CC BY-SA 3.0, https://commons.wikimedia.org/w/index.php?curid=18076955● By Gregory Marcus, MD, MAS, FACC - http://knol.google.com/k/-/-/hCjLTV2A/bdmV3w/ICD.CXR.jpg , embedded in

http://knol.google.com/k/gregory-marcus-md-mas-facc/implantable-cardioverter-defibrillators/hCjLTV2A/qeyBbw?domain=knol.google.com&locale=en#, CC BY 3.0, https://commons.wikimedia.org/w/index.php?curid=5857447

● By Christaras A - Converted from anonymized dicom image, CC BY 2.5, https://commons.wikimedia.org/w/index.php?curid=1247722

● By Jtechr - Own work, CC BY-SA 3.0, https://commons.wikimedia.org/w/index.php?curid=17385153● By James Heilman, MD - Own work, CC BY-SA 3.0, https://commons.wikimedia.org/w/index.php?curid=11110205








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