How to read Chest X-Rays with complete Atlas

by admin on May 30, 2009



General pattern of seeing a X-Ray is described below

Pneumonic to remember headings while describing x-ray to teacher or learning yourself.

PED In O Sonia BA-Tra Hi DiL

Part , exposure and development, inspiratory or expiratory film, orientation, soft tissue shadows, bony cage, trachea and mediastinum, hilar shadow, diaphragm and costophrenic angle, lung fields.

1.First of all describe the part of body in x-ray e.g (chest) look its view i.e A.P or P. A view. P.A view is taken to see lungs and heart while AP view is taken to see posterior lung cage, scapula. PA or AP means the direction from which X-Rays are made to project upon body.

2. See the exposure of film whether overexposed or underexposed.

3. Now describe whether film is taken in expiration or inspiration.

4. Find out the orientation of patient on x-ray : check out orientation of patient on x ray by measuring distances between lateral end of manubrium and medial end of clavicle in case of centrally oriented patient this distance will be equal, to take an x ray in centralized form ask patient to fold both of hands and both of shoulders must touch the plate.

if any of distance is less or shadow is overlapped, patient will have that orientation, that means if patient has removed his left shoulder than right side clavicle will be overlapped with sternum.

5. see soft tissue shadows- like lymphnodes, etc

6. see bony cage- see ribs, cartilages, extra ribs, fracture

7. look for trachea and mediastinum: heart will be explained seperately later in this section.

8. look for hilar shadows

9. Look for diaphragm: look whether diaphragm is flat or curved, its postion, normally lies at 5th -6th ribs

10. look for costophrenic angles, cardiophrenic angle: look whether these angles are obliterated or not, obliterated in case of pleural effusion. But in case of consolidation of lung these angles are not obliterated still you see radio opaque areas, however these consolidation are accompanied by small circular gas filled spot, indicating bronchovascular markings.

11. look for lung fields : looks for homogenous or heterogenous opacity, hypertranslucency, cavity, fibrosis, calcifications, millets etc.

Now look for these heading in details below

  1. Part and View: part i.e chest, view i.e A.P or P.A view, P.A view is taken to see the lung and heart, while AP view is taken to see posterior lung cage, scapula.

Inspiration is done to expand the lung fields, as diaphragm descends down, the principle behind that is that which ever part is closed to X- ray plate is clearly viewed.

PA view is done to minimize bony markings like spine, bony cage, posterior end of ribs are hard so clearly visible in chest x-ray, however anterior part of ribs is fiague, so its shadow becomes light.

  1. Exposure and Development:

Normal Exposure: shadow of vertebral column is faintly visible, intervertebral spaces not clearly visible, and shadow of trachea is normally visible upto the level of clavicle as a translucent shadow.

Over Exposure: vertebral column along with intervertebral spaces will be clearly visible, posterior part that is spine will be clearly visible.

Translucency of trachea is lowered down the level of clavicle may be upto the bifurcation of trachea.

Translucency of the lung field will increase and density and opacity of heart will reduce and heart becomes more central and narrow.

Under Exposed: faint shadow of vertebral column will not be visible at all, translucency of trachea will not be clearly visible, opacity of heart will increase.

  1. Orientation Of the Patient:

What is centrally oriented x – ray?

If the x ray is taken when patient is having hand folded and both of shoulders are touching the plate.

In this case distance between medial end of clavicle and lateral border of vertebrae column will be almost equal in x ray.

Right anterior orientation: only right shoulder touching the plate and left is away, in both left and right orientation there will be overlapping of medial end of clavicle and lateral border of vertebrae.

What is importance of orientation?

In right orientation, trachea will be shifted to left, in x ray, heart will appear to be shifted left or it will show cardiomegaly.

In left orientation heart will appear central, and aortic knuckle, pulmonary conus not visible, tubular appearance of heart in left orientation.

4. Soft tissue shadows:

Abnormalities : abnormality of lymph nodes, calcified (appear dense-more dense than bone) and matted.

Subcutaneous emphysema- vertical linear multiple translucent band like shadow.

5. Bony Cage: cartilages donot have any shadow, from the age of 25 years, cartilages start ossifying, so densly visible.

How to detect cardiomegaly in X ray?

First divide heart shadow in 2 parts from centre by vertical line, now from that line see greatest curves on both left and right side, means there will be to parallel line touching that vertical line, say them (a, b), and say x= a+b

Now measure the transverse diameter of thorax by joining the 2 costophrenic angles and say it to be (y).

If x> y/2 than it is cardiomegaly.

6. Hilar shadows: centre of hilum is place from where vessels originate, it is formed by arteries and viens with small contribution from the walls of the major airways.

The most important vessel in hilum is Basal artery or descending branch of pulmonary artery. On right side it is clearly visible (basal art) width is about 7-19mm when visible on left side it is about 1-2 mm less than right side, generally not visible on left side due to overlapping by heart.

The centre of right hilum is at the level of 3 rd rib anteriorly and 6th rib in the axilla- in a normal inspiratory film.

Ring like shadows around hilum is end of bronchus and solid shadows are blood vessels.

7. Diaphragm and CostophernicAngles: centre of right dome of diaphragm is 5 to 6.5 ant rib in normal insp. Film. Centre of left dome of a diameter is .5 to 2.5 lower than the right.

The curvature of the dome of diaphragm : drop a perpendicular from centre to line coming from angles it is around 1 to 1.5 cm

8. Lung Fields: any lesion should not be defined in reference to lobes but as ZONES.

Upper zone– from 2nd costal cartilage to axilla

Middle zone– between 2nd and 4th costal cartilage.

Lower zone- below 4th costal cartilage.

Horizontal fissure is normally visible in 70% of individual .

Transverse fissure in PA view.

Oblique fissure is not visible in PA view

The level of horizontal fissure in normal inspiratory film is at the level of right hilum, 10 degree inclination or depression is accepted as normal.

Upper zone vessels are less prominent but lower zone vessels are more prominent due to gravitational effects.

In order to look sample X-ray of points described above you need to see x-rays which you can see below in complete atlas…

Complete Atlas of Chest X-Rays by Dr. A. J Chandrasekhar

Some of our readers asked us to tell how to count ribs on chest x ray so your answer is

Ribs counting is done from backward to forward just see the picture which is being attatched red colour indicates the rib which is being counted just compare with other half side of x ray you will see light shadows which are being counted, arrow indicates the direction of ribs counting.

just see the picture below



Also visit self-tutorial for residents and medical students to learn to interpret chest radiographs with confidence at

increase your knowledge with this video presentation of X-Rays

Good videos collection from youtube on understanding and reading chest x-rays

For Further Reading :


{ 18 comments… read them below or add one }

drvikram May 31, 2009 at 4:44 pm
drvikram June 4, 2009 at 2:23 pm

write an article about this site


drvikram June 10, 2009 at 5:13 am

Growing Organs in the Lab by and its video at daily motion link


ginto September 11, 2009 at 3:10 pm

good article


Barrett Ohagan November 25, 2009 at 4:48 am

You made some good points there. I did a search on the topic and found most people will agree with your blog.


dr.mayura December 18, 2009 at 5:10 pm

please mention how to count the rib’s serial no.
also let us know how to see the spine levels.


drvikram December 19, 2009 at 5:20 pm

answer to your question is being updated in this article please see the new x ray attatched


Dr Aamir June 24, 2010 at 7:08 pm

A very good article.specially for undergraduate students..u have explained everything in quite an easy way….thanks


admin June 24, 2010 at 8:40 pm

Thanks Dr Aamir, you can also provide us a good article or surgical video, but it should be your own…with in few days we will be updating some X-rays on which questions are asked in Post Graduate medical examinations

hisham wagdy October 19, 2010 at 2:48 am

thanks for this excellent lecture


rajneesh kumar October 23, 2010 at 4:58 pm

dear sir i want to do job in abroad.and when iwas got the visa then go for the medical laboratary report was ok bt in my xray report dr. wrote the CP ANGLE BLUNT .BT IHAVE NO PROBLEM IN CHEST.SO PLEASE SIR GIVE ME THE RT SUGGGESSION WAT I DO FOR THIS ONE.SIR IWIIL WAIT REPLY FROM U.


admin October 23, 2010 at 5:56 pm

Blunting of costophrenic angle occurs in case of pleural effusion and hyperexpansion, kindly send me your x ray at we will study and tell you what is there.

dr. A dnan A lwan December 17, 2010 at 10:24 am

Good morning sir i get hapiness and pleasure with your scientific production i am allergist
interested in chest disease i hope your help in this field
best regards


admin December 17, 2010 at 12:13 pm

of course you can work with us, you can provide a good case, or picture showing some sign or symptom or a video mail us at our email we will publish that on our site with full credit given to owner of that content.

anoma January 27, 2011 at 10:25 am

what are the causes of honeycomb lung?
is multiple neurofibromatosis a cause?

thank you


admin January 27, 2011 at 12:12 pm

common causes of honey comb lung are
Common Causes
Bullous emphysema of lung
Diffuse interstitial fibrosis of lung
Acute Infections
Herpes zoster (chicken pox)
Tuberculous bronchopneumonia (galloping consumption)
Chronic Diseases
Chronic lipoid pneumonia
Bauxite pneumoconiosis
Other reactive dusts
Granu!omatous Diseases
Chronic tuberculosis
Fungus diseases (chronic)
Wegener’s granulomatosis
Congenita! Diseases
Mickety-Wilson disease (pulmonary dysmaturity)
Co!!agen Diseases
Periarteritis nodosa
Lupus erythematosus (less frequently)
Rheumatoid disease of lung
Ma!ignant Diseases
Lymphangitic spread
Leukemic infiltrates
Lymphoma with spread
Rare Causes
Tuberous sclerosis (muscular cirrhosis of lung)
Myomatosis (“von Recklinghausen’s”)
Leiomyomatosis of lung
Adenomatosis of lung
Giant cell pneumonia
Hamman-Rich syndrome
Storage Diseases
Histiocytoses (histiocytosis X)
Eosinophilic granuloma
Hand-Sch#{252}ller-Christian disease (cholesterol
Letterer-Siwe’s disease (non_lipid histiocytosis)
Niemann-Pick’s disease
Gaucher’s disease

abdulhafeez November 1, 2011 at 7:13 pm

exllent for begners


abdulhafeez November 1, 2011 at 7:18 pm

it is good presentiton

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