cxr revised 24 11-91
DESCRIPTION
normal chest X-rayTRANSCRIPT
CXR Normal Anatomy
A. Almasi MDIran University of Medical Science
Department of Radiology
PA CXR
• Quality Control• Trachea• Mediastinum& Heart• Diaphragms• Pleural space including fissures• Lungs• Hidden Areas of the Lungs• Hila• Below Diaphragm• Bones
PA view
Quality Control
• Inspiration:• Ant. end of 5th - 6th or post. end of 10th rib above the
diaphragm
• Centering: • Medial end of the clavicles equidistant from T4-5
spinous process
• Exposure:• Vertebral bodies and disc spaces behind the heart must
be barely visible and bronchovascular marking should be visible through the heart
PA view
Rotation Effect• Anterior structures (e.g. heart) shift to the side farther from the film• The lung farther from the film appears more lucent and the ipsilateral
hemithorax appears wider• In this rotated film skin folds can be mistaken for a tension
pneumothorax (blue arrows)
Expiratory Film• Increased heart size• More prominent bronchovascular markings• Basal opacities• Tracheal deviation to the right
Expiratory Film• Increased heart size• More prominent bronchovascular markings• Basal opacities• Tracheal deviation to the right
inspiration expiration
Respiration and Rotation Effect
Inspiration Expiration& Leftwards Rotation
Improper ExposureUnderexposed Overexposed
Trachea
• Exact midline in the upper part& deviating to the right around the aortic knob
• Even diameter up to M:25mm F:21mm• Right paratracheal stripe <4-5mm• Azygos vein at the anlge between the RMB&
trachea (less than 10mm in diameter)• Carina at T6-7 angle: 60-75°
Trachea in Superior Mediastinum• Left side of the trachea is not border forming on
CXR it is not surrounded by aerated lung
Normal PA Viewright paratracheal stripe
SVC
right brachiocephalic artery
carina
Right Paratracheal Stripe
Normal after Radiotherapy
Hodjkin’s Disease
Wide Carinain Mitral Malady
left atrial appendage
cephalization
left atrium
The Heart
• 1/3(1/5-1/2) to the right& 2/3 to the left of midline
• CT ratio 50% on PA and 60% on AP view• Diameter up to F:14.5cm M:15.5cm• 1-1.5cm increase on two consecutive films
is significant• Enlarges in expiration& when diaphragm is
high
Cardiothoracic (CT) Ratio
Normal PA View
Mediastinal BordersRight Superior
Brachiocephalic A&VSVCTortuous or dilated
ascending aorta may contribute
InferiorRt atriumIVC (probable)
LeftSubclavian AAortic knobPulmonary ALt atrial appendageLt ventricle
1.1MediastinalBorders
1.1.BraciocephalicA&V1.SVC2.RA3.SubclavianA4.Aortic Knob5.Descending Aorta6.Pulmonary Trunk7.LA Auricle8.LV
Normal PA View
ProminentPulmonaryTrunk
Is normal in young women& children
Tortuous Aorta& Prominent LtCardiophrenicAngle Fat Pad
Ascending A
Fat Pad
CardiophrenicAngle Fat Pad on LateralCXR
Tortuous Aorta& Brachiocephalic Aneurysm
PA CXR• Quality Control• Trachea• Mediastinum& Heart• Diaphragms• Pleural space including fissures• Lungs• Hidden Areas of the Lungs• Hila• Below Diaphragm• Bones
Diaphragm
• Right hemidiaphragm is usually higher• More than 3cm difference between heights
of the hemidiaphragms may be abnormal• Dome of the hemidiaphragms is usually
posteriorly located but on the right it may be anterior 40% of the times
• Contour should be sharp except where heart lies on the diaphragm
PA view
Anterior right diaphragm dome
High Hemidiaphragm DDx
• Normal esp. when there is much gas in the bowel, normal motion on fluoroscopy or sonography
• Diaphragmatic Paralysis esp. after thoracic surgery, paradoxical motion of the diaphragm
• Eventration usu.paradoxical motion on fluoroscopy
High Hemidiaphragm
DiaphragmaticScalloping
DiaphragmaticSlipping in flatdiaphragms
• Athletes• Emphysema
Hump of Diaphragm
Hump
Sonography rules outsubdiaphragmatic mass
Pleural Space
• Lateral Costophrenic Angles should be acute, blunting indicate effusion (250ml at least), flattening or thickening
• Posterior Costophrenic Angles can become blunted by as little as 75ml fluid on lateral view
• Fissures are double layered pleura separating lobes
Fissures
• Oblique (major) visible only on lateral view
From T4-5 to just posterior to costophrenic angel on the right and 5cm posterior on the left
• Horizontal (minor) visible on both PA& lateral views
From right hilum to the 6th rib at axillary line
Fissures
Fluid-filled fissures• The patient below has a pleural effusion extending into the fissure. Which fissure is
which? • What is the bright loop near the center of the films?
Segmental Lung Anatomy
•Lung lobes are separated by fissures which are composed of two adjacent layers of parietal pleura•A lung segment is the lung parenchyma surrounding a segmental bronchus
Lobar& Segmental Anatomy of the Lungs
Lobar& segmental anatomy
Minor FissureFrom right hilum to the 6th rib at axillaryline
MinorFissure
Major FissuresFrom T4-5 crossing the hilum and terminating behind costophrenic angel on the right and 5cm more posteriorly on the left
Fissuresminor
left major
right major
The Lungs
• Opacity• Symmetry in marking& lucency• Vasculature
– Inferior vessels are more prominent– No vessel>3mm in diameter in the 1st anterior intercostal space– Concave lateral border of Rt descending pulmonary A
• Hidden Areas– Apex– Posterior Recess– Areas superimposed by mediastinum, hila& bones
Normal PA View
Lung Hila• Left hilum higher 97%• Symmetric in size and density• Concave lateral border• Contour made up of superior pulmonary vein&
descending branch of main pulmonary artery • Descending branch of main pulmonary artery on
the Rt has concave lateral contour and measures less than 16mm in diameter
• Normal LNs not visible
Hilar Anatomy
Hila on PA View
Hila on Lateral View
Hila on Lateral
View
* Lt Sup Bronchus
* Rt Sup Bronchus
Rt MainPul. A
Lt Main Pul. A
Hilar Adenopathy
HilarAdenopathy
ProminentHila-Vascular(Pulmonary Venous HTN)
ProminentHilaPulmonary ArterialHTN
ProminentHilaPulmonary ArterialHTN
Hilar Enlargement Vascular vs Adenopathy
Below diaplragm, Soft tissue& Bones
• Gas shadows (stomach, bowel, surgical emphysema, etc.)
• Symmetric axillary lines, Mastectomy• Bone lesions
Normal PA View
Normal PA
Prominent skin fold vs pneumothorax
Calcified Costal Cartilage
Hypertrophied 1st Costochondral Junction
Hypertrophied 1st Costochondral Junction
Lateral CXR
• Clear Spaces• Vretebral
Translucency• Diaphragm Outline• The fissures• The lung Hila• The Trachea& Upper
Lobe Bronchi• The Sternum
Clear Spaces& Vertebral Translucency
• Ant. Clear Space– Ant. medistinal masses, LNs& aortic aneurysm
may fill this space– In emphysema it widens (>3cm)
• Post. Clear Space– Vertebral translucency increases progressively
downward in this space
CXR Lateral View
PE on lateral view(effect on vertebral translucency)
PE
Fissuresminor
left major
right major
Hila on Lateral
View
* Rt Sup Bronchus
* Lt Sup Bronchus
Rt MainPul. A
Lt Main Pul. A
HilarAdenopathy
LLL Consolidation
Lateral Decubitus Films
• To differentiate pleural effusion from thickening in case of a blunt costophrenic angle
• To assess the volume of pleural effusion• Demonstrates whether a pleural effusion is mobile or loculated• Detection of a pneumothorax in the nondependent hemithorax in a patient
who could not be examined erect• The dependant lung should increase in density due to atelectasis from the
weight of the mediastinum putting pressure on it. Failure to do so indicates air trapping
PA versus AP CXR
PA versus AP CXR
Recommended order of reading a CXR
•It is recommended to start from the regions of least radiologic interest to decrease the likelihood of missing details. 1- Abdomen
2- Thorax (soft tissues and bones)
3- Mediastinum
4- Lung-unilateral
5- Lungs-bilateral
This order can be memorized by the breviation ATMLL
Abdomen
• The recommended path is shown, beginning at the right lower corner.
Thorax (soft tissues and bones)
• The path again starts from the right lower corner of the x-ray
Mediastinum• Mediastinum can be assessed in two consecutive runs
one for the trachea And bronchi and the other for the soft-tissue structures and pulmonary hila
Lung
• It is recommended to look at the lungs one by one at first and then a look that compares the two lungs
Lateral Film• The same order that was mentioned (ATMLL) is
applicable to lateral films too
Proposed reading order for a CXR
• Turn off stray lights, optimize room lighting, view images in order• Patient Data (name history #, age, sex, old films)• Routine Technique: AP/PA, exposure, rotation, supine or erect• Trachea: midline or deviated, caliber, mass• Lungs: abnormal shadowing or lucency• Pulmonary vessels: artery or vein enlargement• Hila: masses, lymphadenopathy• Heart: thorax: heart width > 2:1 ? Cardiac configuration?• Mediastinal contour: width? mass?• Pleura: effusion, thickening, calcification• Bones: lesions or fractures• Soft tissues: don’t miss a mastectomy• ICU Films: identify tubes first and look for pneumothorax
Atelectasis vs Lobar Pneumonia
Atelectasis•
Volume Loss Associated Ipsilateral Shift
• Linear, Wedge-Shaped• Apex at Hilum
Pneumonia• Normal or Increased Volume
No Shift, or if Present Contralateral
• Consolidation, Air Space Process
• Not Centered at Hilum