HOW TO READ:

CHEST X-RAY
ABDOMINAL X-RAY
HEAD CT-SCAN
REAGAN RESADITA
CHEST X-RAY

• PA view : standart view for chest xray

• AP View : another view when the patient can stand (eg.
ICU, multiple Trauma, CHF NYHA IV)
 SYSTEMATIC CXR
INTERPRETATION
TECHNIQUE, cont.
• Projection or Quality of the film:

• First determine is the film a PA or AP view.

• PA- the x-rays penetrate through the back of the patient on to the film.

• AP-the x-rays penetrate through the front of the patient on to the film.
The width of heart & mediastinum larger on AP film.

• All x-rays in the ICU are portable and are AP view

SYSTEMATIC CXR
INTERPRETATION
• Untuk mengetahui kondisi pulmo cukup atau tidak ada 2 hal ayng dinilai
• Melihat lusensi udara (hitam) yang terdapat di luar tubuh (Pembanding )
• Kondisi cukup (PA) : tampak VTh I-IV
• Kondisi Kurang (PA): hanya tampak VTh 1
• Untuk mengetahui kondisi Costae cukup atau tidak ada 2 hal yang dinilai (pada kondisi
keras, infiltrate paru tidak tampak) bandingkan densitas pulmo dan jaringan lunak
• Proyeksi Keras (PA) : tampak VTh V-VI
• Proyeksi Lunak (PA): tampak VT I-XII
• Inspirasi
• Cukup: diafragma setinggi VT X(expirasi setinggi VT VII-VIII), costae 6 anterior memotong
dome diafragma
• Kurang : coracan bronkovascular meningkat, ukuran jantung dan mediastinum meningkat
(lebih sering salah interpretasi)
SYSTEMATIC CXR
INTERPRETATION

―Rotation
• Determine by observing the equal distance between the
medial clavicular head and the spinous process of the
thoracic vertebral body.
• The distance between Sternoclavicular right and left to the
median line had an equal distance
HOW TO READ CHEST X RAY

• The simple way is Using ABDCE

• A: Airway (check for deviation, or ETT)
• B: Broncovascular, Bone
• C: Cardiac (check for CTR, enlargement, ect)
• D : Diafragm ( Costodiafragm angle, free air below)
• E: Enviroment and Edge of lung (subcutan emphysema, corpus alienum)
TENSION PNEUMOTHORAX
AIR UNDER THE DIAPHRAGM
ABDOMINAL X-
RAY
LIGHTBULB MOMENT
a moment of sudden inspiration, revelation, or recognition
APPROACH TO ABDOMINAL X-RAY

• Bowel gas pattern

• Extraluminal air
• Soft tissue masses
• Calcifications
NORMAL AXR
Liver Gas in
stomach Splenic flexure
11th rib T12

Psoas margin
Left kidney

Hepatic flexure
Transverse colon

Iliac crest
Gas in sigmoid
Sacrum

Gas in caecum
SI joint

Bladder
Femoral head
GAS PATTERN
What is normal?
• Stomach
• Almost always air in stomach
• Small bowel
• Usually small amount of air in
2 or 3 loops
• Large bowel
• Almost always air in rectum
and sigmoid
• Varying amount of gas in rest of large bowel
NORMAL FLUID LEVELS
• Stomach
• Always (upright, decub)
• Small bowel
• Two or three levels
acceptable (upright, decub)
• Large bowel
• None normally
(functions to remove fluid)
LARGE VS SMALL BOWEL

• Large bowel
• Peripheral (except RUQ occupied by liver)
• Haustral markings don’t extend from wall to wall
• Small bowel
• Central
• Valvulae conniventes extend across lumen and are spaced closer together
 RADIOGRAPHIC PRINCIPLES

Series of films for acute abdomen

• Obstruction series/ Acute abdominal series/ Complete abdominal
series
– Supine (almost always)
– Upright or left decubitus (almost always)
– Prone or lateral rectum (variable)
– Chest, upright or supine (variable)
ACUTE ABDOMINAL SERIES
WHAT TO LOOK FOR
VIEW LOOK FOR

SUPINE ABDOMEN Bowel gas pattern

Calcifications
Masses

PRONE ABDOMEN Gas in rectosigmoid

Gas in ascending and
descending colon
UPRIGHT ABDOMEN Free air, air-fluid levels

UPRIGHT CHEST Free air, lung pathology

secondary to intraabdominal
process

Substitutes: Prone Lateral rectum

Upright Left lateral decub
Upright chest Supine chest
COLON IN LOOP
• Define as radiographic exam using contrast (single or double)
• Preparation : Colon Preparation
• One day before patient only eating “bubur kecap”
• Last meal at 08.00 pm
• At 10.00 pm patient start to fasting and eating MgSO4 or Laxative
• Reduce or stop talking and smoking to reduce bowel air
• Using Catheter contrast fill the Colon, max in Caecum (with some kind of maneuver), wait for 2 minute
(single contrast)
• For double contrast fill the colon slowly with air (it can caused vagal reflex or perforate bowel)
ABNORMAL GAS PATTERNS

• Functional ileus
• One or more bowel loops become aperistaltic usually due to local irritation or
inflammation
• Localised “sentinel loops” (one or two loops)
• Generalised (all loops of large and small bowel)

• Mechanical obstruction
• Intraluminal or extraluminal
• Small bowel obstruction
• Large bowel obstruction
LOCALISED ILEUS
KEY FEATURES
• One or two persistently dilated
loops of small or large bowel
(multiple views)
• Often air-fluid levels in sentinel
loops
• Local irritation, ileus in same
anatomical region as pathology
• Gas in rectum or sigmoid
• May resemble early SBO
CAUSES OF LOCALISED ILEUS
BY LOCATION

SITE OF DILATED LOOPS CAUSE

Right upper quadrant Cholecystitis
Left upper quadrant Pancreatitis
Right lower quadrant Appendicitis
Left lower quadrant Diverticulitis
Mid-abdomen Ulcer or kidney/ureteric calculi
COLON CUT OFF SIGN
Abrupt cutoff of colonic gas column at the splenic flexure (arrow). The colon is
usually decompressed beyond this point.

Explanation:

Inflammatory exudate in acute

pancreatitis extends into the
phrenicocolic ligament via lateral
attachment of the transverse
mesocolon

Infiltration of the phrenicocolic

ligament results in functional
spasm and/or mechanical
narrowing of the splenic flexure at
the level where the colon returns
to the retroperitoneum.
GENERALISED ILEUS
KEY FEATURES
• Entire bowel aperistaltic/hypoperistaltic
• Dilated small bowel and large bowel to rectum (with LBO no gas in
rectum/sigmoid)
• Long air-fluid levels

CAUSE REMARK

*Postoperative Usually abdominal surgery

Electrolyte imbalance Diabetic ketoacidosis

* almost always
GENERALISED ADYNAMIC ILEUS
The large and
small bowel are extensively airfilled but not
dilated.

The large and

small bowel "look the same".
MECHANICAL SMALL BOWEL OBSTRUCTION
(SBO)

• Dilated small bowel

• Fighting loops (visible loops, lying transversely, with air-fluid levels
at different levels)
• Little gas in colon, especially rectum
SBO ERECT SBO Supine

Air fluid levels

CAUSES OF MECHANICAL SBO
Adhesions
Hernia*
Malignancy
Gallstone ileus*
Intussesception
Inflammatory bowel disease

* May be visible on AXR

STEP LADDER APPEARANCE

• Loops arrange
themselves from left
upper to right lower
quadrant in distal SBO
COIL SPRING SIGN
 STRING OF PEARLS SIGN

Considered diagnostic of obstruction (as opposed to ileus)

and is caused by small bubbles of air trapped in the
valvulae of the small bowel.
STRETCH/SLIT SIGN

Slit of air caught in a

valvulae, characteristic
of SBO
CRESCENT SIGN

Caused by:

LUQ Soft tissue mass

OR

Head of intussusception
in distal transverse colon
 DOUBLE BUBBLE SIGN

Duodenal Atresia
MECHANICAL LARGE BOWEL
OBSTRUCTION (LBO)
• Colon dilates from point
of obstruction
backwards

• Little/no air fluid levels

(colon reabsorbs water)

• Little or no air in
rectum/sigmoid
LARGE BOWEL OBSTRUCTION
Bowel loops tend not to
overlap therefore
possible to identify site
of obstruction

Little or no gas in small

bowel if ileocaecal valve
remains competent*

* If incompetent, large bowel

decompresses into small bowel, may
look like SBO
 CLOSED LOOP OBSTRUCTION

• Two points of same loop of bowel obstructed at a single

location
• Forms a C or a U shape
• Term applies to small bowel, usually caused by adhesions
• Large bowel, called a volvulus
NOTE ON VOLVULUS

• Sigmoid colon has its own mesentry therefore prone

to twisting

• Caecum usually retroperitoneal and not prone to

twisting; 20% people have defect in peritoneum that
covers the caecum resulting in a mobile caecum
VOLVULUS
A volvulus always extends away from the area of twist.Sigmoid volvulus can only
move upwards and usually
goes to the right upper quadrant. Caecal volvulus
can go almost anywhere.
COFFEE BEAN SIGN
SIGMOID VOLVULUS

Massively
dilated
sigmoid loop
APPLE CORE SIGN

• Radiologic manifestation of a
focal stricture of the bowel
usually at contrast material
enema examination. The
stricture demonstrates
shouldered margins and
resembles the core of an apple
that has been partially eaten.
The most common cause is an
annular carcinoma of the colon.
LEAD PIPE
COLON

• Shortening of colon
secondary to fibrosis
• Loss of haustration
• Ulcerative colitis
EXTRALUMINAL AIR
• TYPES
– Pneumoperitoneum/free air/intraperitoneal air
– Retroperintoneal air
– Air in the bowel wall (pneumatosis intestinalis)
– Air in the biliary system (pneumobilia)
UPRIGHT FILM BEST

• The patient should be positioned sitting upright for 10-20 minutes prior to
acquiring the erect chest X-ray image.

• This allows any free intra-abdominal gas to rise up, forming a crescent
beneath the diaphragm. It is said that as little as 1ml of gas can be detected in
this way.
FREE AIR
CAUSES

• Rupture of a hollow viscus

• Perforated peptic ulcer
• Trauma
• Perforated diverticulitis (usually seals off)
• Perforated carcinoma

• Post-op 5-7 days normal, should get less with successive

studies *NOT ruptured appendix (seals off)
SIGNS OF FREE AIR
• Crescent sign
• Chilaiditis sign
• Riglers (and False Rigler’s)
• Football sign
• Falciform ligament sign
• Triangle sign
• Cupola sign
• Lesser sac sign
CRESCENT SIGN II

Free air under the diaphragm

Best demonstrated on upright chest x rays
or left lat decub

Easier to see under right diaphragm

CHILAIDITIS SIGN
• May mimic air under
the diaphragm
• Look for haustral folds
• Get left lat decub to confirm

In patients who have cirrhosis

or flattened diaphragms due to
lung hyperinflation, a void is
created within the upper
abdomen above the liver. This
space may be filled by bowel. If
this bowel is air filled then it
may mimic free gas.
RIGLER’S SIGN
Bowel wall visualised on both sides due to intra and extraluminal air
Usually large amounts of free air
May be confused with overlapping loops of bowel, confirm with upright view
FALSE RIGLER’S SIGN

• The Rigler sign can sometimes be simulated by contiguous loops of bowel,

whereby intraluminal air in one loop of bowel may appear to outline the wall
of an adjacent loop, which results in a misdiagnosis of free air.

• Measure distance of interface if unsure

 FOOTBALL SIGN

Seen with massive

pneumoperitoneum

Most often in children with

necrotising enterocolitis
In supine position air
collects anterior to
abdominal viscera

Paediatric Adult
FALCIFORM LIGAMENT SIGN
Normally invisible.

Supine film, free air

rises over anterior
surface of liver
OTHER PATTERNS OF AIR AROUND LIVER

Doge’s Cap Sign

INVERTED V SIGN

• On the supine radiograph, an inverted "V" may be seen over the pelvis in a
patient with pneumoperitoneum.

• While in infants this is produced by the umbilical arteries, in adults it appears

to be created by the inferior epigastric vessels
 CONTINUOUS DIAPHRAGM SIGN

Sufficient free air, left and

right hemi- diaphragms
appear continous
LESSER SAC SIGN CUPOLA SIGN
Cupola
Lesser sac
sign
sign(black
– (white arrows)
arrows)

The lesser sac is Air superior to left

positioned posterior to lobe of liver
the stomach and is
usually a potential space.
There is free connection
between the lesser sac
and the greater sac
through the foramen of
Winslow

Double Bubble Sign

TRIANGLE SIGN
• The triangle sign refers to
small triangles of free gas
that can typically be
positioned between the
large bowel and the flank
RETROPERITONEAL AIR
• Recognised by:
– Streaky, linear appearance outlining retroperitoneal structures
– Mottled, blotchy appearance
– Relatively fixed position
• May outline:
– Psoas muscles
– Kidneys, ureters, bladder
– Aorta or IVC
– Subphrenic spaces
CAUSES OF RETROPERITONEAL AIR

• Bowel perforation (appendix, ileum, colon)

• Trauma (blunt or penetrating)
• Iatrogenic
• Foreign body
• Gas producing infection
PNEUMORETROPERITONEUM
• This patient has free air in the
retroperitoneal space. The air is
seen surrounding the lateral border
of the right kidney (white arrow).
There is other evidence of free gas
including Rigler's sign.

• If you are not confident that the

appearance is
pneumoretroperitoneum, you can
try an erect and decubitus view to
see if the gas moves. If the gas is
seen to move, it's not in the
retroperitoneum.
AIR IN THE BOWEL WALL

• Signs
– Best seen in profile producing a linear lucency that parallels the
bowel
– Air en face has a mottled appearance resembling gas mixed
with faeculent material
CAUSES OF AIR IN BOWEL WALL
• Primary Pneumatosis cystoides intestinalis (rare)
• usually affects left colon
• Produces cyst-like collections of air in the submucosa or serosa
• Secondary
• Diseases with bowel wall necrosis
• Obstructing lesions of the bowel that raise intraluminal pressure
• Complications
• Rupture into peritoneal cavity
• Dissection of air into portal venous system
PNEUMATOSIS
INTESTINALIS
• Intramural air, best
appreciated in
profile
AIR IN THE BILIARY TREE
• One or two tube-like branching
lucencies in the RUQ, conform to
location of major bile ducts
CAUSES
• “Normal” if Sphincter of Oddi incompetence
• Previous surgery including sphincterotomy or transplantation of CBD

• Pathology (uncommon)
• Gallstone ileus: gallstone erodes through wall of GB into the duodenum
producing a fistula between the bowel and the biliary system.
• Stone impacts in small bowel = mechanical SBO. “ileus” misnomer
BILIARY VS PORTAL VENOUS AIR

• Portal venous air usually

associated with bowel
necrosis

• Air is peripheral rather

than central

• Numerous branching
structures
HEAD CT SCAN
HEAD CT
GENERAL PRINCIPLES OF THE CT

• CT is basically a specialized X-Ray

• We talk about “density” or “attenuation”
• The image is a measure of absorption of X-rays through different angles
through a given tissue and then transformed mathematically
WHAT IS HYPERDENSE VS HYPODENSE ON
CT?

• Bone (dense calcium) (1000 HU)

• Metal
• Acute (but not hyperacute) blood (56-76 HU)
• Thrombosis
• Grey matter>white matter (30, 20 HU)
• CSF (0 HU)
• Fat (-30-100 HU)
• Air (-1000)
BRAIN VS BONE WINDOW
BLOOD CAN BE VERY BAD
• B: blood
• look for EDH, SDH, ICH, IVH, SAH and extra cranial hemorrhage
• C: cisterns
• look for the presence of blood, effacement and asymmetry in four key cisterns
• B: brain
• look for asymmetry or effacement of the sulcal pattern, gray-white matter differentiation (including the
 insular ribbon sign), structural shifts and abnormal hypo (e.g. air, edema) or hyperdensities (e.g. blood,
calcification)
• V: ventricles
• look for intraventricular hemorrhage, ventricular effacement or shift and for hydrocephalus
• B: bone
• look for skull fractures (especially basal) on bone windows (soft tissue swelling, mastoid air cells and 
paranasal sinuses fluid in the setting of trauma should raise the possibility of a skull fracture; intracranial air
means that the skull and the dura have been violated somewhere)
EPIDURAL HEMATOMA

• Biconvex shape (lens shaped)

• Does not cross suture
• Most case are caused by injury of meningeal artery
• Low mortality if treated prior to unconsciousness (<20%)
SUBDURAL HEMATOMA
• Sickle shape (crescent shape) dekat tabula internadapat menyebrag sutura
• Crosses suture but doesn’t cross midline
• Acute subdural is marker for severity head injury
• Chronic subdural usually caused by slow venous bled and well tolerated

Acute Sub acute (3-14) days Chronic (>14 days)

(<3 Days)
SUBARACHNOID
HEMORRHAGE

• Blood fill subarachnoid space, it can be seen full

fill the sulci and gyri of brain, cistern and ventricle
• Occurrs in setting of aneurysm rupture or artery
venous malformation
• Thunderclap headache is the typical sign (worst
headache ever)
 REFERENCES

• http://www.wikiradiography.com
• http://www.radiopaedia.org
• http://www.imagingconsult.com
• http://www.swansea-radiology.co.uk Radiology Teaching Site. Introduction to abdominal
radiography
• Mussin, R. Postgrad Med J 2011: 87:274-287. Gas patterns on plain abdominal radiographs
• http://www.radiologymasterclass.co.uk/tutorials/abdo/abdo_x-ray_abnormalities
• Ghazali M.R, 2006, Radiologi Diagnostik edisi ke-6., Marvell incorporation. Yogyakarta.