Role of Imaging in Abdominal Trauma. # Imaging #Trauma #Abdomen #FAST #eFAST #CT #USG

1. Role of Imaging in
Abdominal Trauma
• Dr. Sachin Sharma
• JR-1, Dept. of Radio-Diagnosis

2. Introduction
• Blunt trauma is a major cause of abdominal trauma and usually occurs
due to road traffic accidents or falls, with resulting compression and
deceleration injuries often associated with injuries to the head, spine
and limbs.
• In this situation, abdominal injuries can be missed, with up to 70% of
patients having either neurological impairment or a distracting injury.
• Although less common, penetrating trauma is also on the increase,
particularly in urban areas.

3. • Simultaneous therapeutic and diagnostic measures need to be
instituted.
• Plain abdominal radiographs have no role in assessment of blunt
abdominal trauma but may be useful in penetrating injury to
demonstrate bullets or fragments.
• FAST scanning can be performed rapidly and concurrently with other
procedures to look for free intraperitoneal or intrathoracic free fluid
and can triage a hemodynamically unstable patient to surgery.
• However, it is insufficiently sensitive to exclude solid organ,
mesenteric or retroperitoneal injury.

7. FAST
(FOCUSED ASSESSMENT WITH SONOGRAPHY IN TRAUMA)
• A focused, goal directed, sonographic examination of the abdomen.
• Goal is to see the presence of hemoperitoneum or hemopericardium.
• An extension of clinical examination.
• Part of the Primary Survey of any patient with signs of shock or
suspicion of abdominal injury.

9. • FAST examines four areas for free fluid:
oPerihepatic & hepato-renal space.
oPeri-splenic.
oPelvic.
oPericardial.

10. The Peri-hepatic Space

11. The Peri-splenic Space

12. The Pelvis Scan
• The pelvic examination visualizes :
• The cul-de-sac: the Pouch of Douglas in female sand the rectovesical
pouch in the male.
• Bladder
• Uterus and prostrate

13. A B

14. The pericardial scan
• The pericardial examination screens for fluid between the fibrous
pericardium and the heart.
• The transducer is placed just to the left of the xiphisternum and
angled upwards under the costal margin.

16. • FAST can detect between 100-250ml
• 0.5 cm in Morison's Pouch = 500ml
• 1 cm in Morison's Pouch = 1000ml
• CT can detect volumes of free fluid as low as 100ml
Some Important Points about FAST

17. Extended FAST (eFAST)
• Evaluation of pneumothorax and hemothorax in addition to
intraperitoneal injuries.
• Hemothorax:
Ultrasound is much more sensitive for detecting pleural fluid and
can identify as little as 20mL in the pleural space
• Pneumothorax :
M-MODE USG is used to detect pneumothorax.

18. eFAST: Anterior Thoracic Views
• Probe is usually placed on the anterior chest in the 3-4th intercostal
space and midclavicular line.
• When "Sliding sign" (seashore sign){NORMAL} is not present, a
pneumothorax is suspected.
• Comparing one side of the chest to the other may be helpful.

20. MDCT SCAN
• The mainstay of imaging following abdominal trauma is MDCT.
• CT should be done in all hemodynamically stable patients with
evidence of abdominal trauma (including a positive FAST scan).
• MDCT has a high accuracy (over 95%) for significant abdominopelvic
injury and is one of the major factors responsible for the increased
use of non-operative management in trauma patients.

21. MDCT PROTOCOLS
• Abdominal images are usually obtained around 60–65s after an
intravenous bolus injection of iodinated contrast
• The 60–65 s delay represents the portal venous phase of imaging and
gives an optimal trade-off between vascular opacification and solid
organ enhancement.
• The CT raw data are then reconstructed on
• A soft tissue algorithm.
• Bony algorithm

22. • A soft tissue algorithm at 1.5, 5-mm sections and multiplanar reformats
(MPRs) are also routinely reconstructed at 5 mm sections in the coronal
plane. MPRs are useful in assessment of disruption in the cephalocaudal
plane, e.g.- diaphragmatic rupture.
• Bony algorithm :- axial images should also be obtained and may be
used to provide coronal and sagittal MPRs of the spine and pelvis.
• Thin-section sagittal or coronal MPRs, MIPs are useful for CT
angiography and 3D reformats such as volume-rendered images, can be
subsequently generated.
• Delayed scans 5–10min after contrast are not performed routinely, can
be useful to differentiate
• Active bleeding from contained vascular injury, and
• To assess the integrity of the urinary tract, which should be opacified with
contrast on delayed images.

23. CT findings of shock
• Collapse of inferior vena cava
• Small aorta
• Persistent nephrogram without excretion
• Hypodense spleen, without enhancement and normal vascular pedicle
• Increased enhancement of the small bowel wall
• Increased enhancement of the adrenal glands
• Sometimes findings of right cardiac insufficiency with reflux into the
hepatic veins

25. ABDOMINAL WALL TRAUMA
• Stranding of the fat planes deep to the site of injury is suggestive of
possible peritoneal injury. trauma to the abdominal wall itself can be
associated with significant haematoma formation
• Shearing forces, can cause the development of an acute wall tear with
hernia formation.

26. A B

27. Spleen
• The spleen is the most commonly injured solid organ following
abdominal trauma.
• Several types of splenic injury can occur:
oIntraparenchymal hematoma
oSubcapsular haematoma,
oLaceration,
oActive extravasation,
oContained vascular injury
oInfarction.

28. Intraparenchymal splenic haematoma

29. SPLENIC LACERATION AND PERI-SPLENIC HEMATOMA

31. Splenic infarct.

32. American Association
for the Surgery of
Trauma (AAST) organ
injury severity scale
grading system for
splenic injury

33. LIVER
• The liver is the second most commonly injured organ in abdominal
trauma.
• Between 70 and 90% of hepatic injuries are minor, with the right lobe
most commonly affected.
• The liver is prone to the same array of injuries as the spleen, including
intraparenchymal and subcapsular hematoma lacerations, infarcts,
active extravasation and contained vascular injury.

34. • Lacerations near the major hepatic veins or IVC can be a/w injury to
these vessels resulting in catastrophic bleeding leading to high
mortality.
• Laceration occurring in the “bare area” of the liver, posteriorly in the
right lobe can lead to hemorrhage into the retroperitoneum, which is
frequently a/w injury to right adrenal and kidney.
• FAST can be falsely negative in retroperitoneal hemorrhage.
• Lacerations involving the porta hepatis – a/w a tear in the central
biliary tree, which can lead to biloma development manifesting as an
enlarging perihepatic fluid collection.

40. (a) (b)
(c)

41. GENITOURINARY TRACT
• The kidney is the most injured urologic organ following trauma.
• 80% of injuries are minor and heal spontaneously.
• The kidney is prone to the same range of injuries as the spleen and
liver, namely
• Contusions,
• Subcapsular and peri-nephric hematoma,
• Lacerations,
• Active extravasation,
• Contained vascular injury and
• Infarcts.

42. • Clinical indicator is the presence of hematuria, which is present in
95% of significant renal injuries, but can be absent in renal vascular
injuries, or injury to the PUJ or ureter.
• Contusions account for 80% of injuries.
• Subcapsular hematomas are rare, due to the strong attachment of the renal
capsule, but if large can compress the kidney sufficiently to cause excessive
renin secretion and hypertension – the “Page kidney”.
• Perinephric hematomas lie between the kidney and Gerota’s fascia and are
commoner than subcapsular hematomas.
• Lacerations are linear or branching low-density areas and if they reach the
hilum of the kidney, delayed scanning is indicated to look for a urine leak.

43. PAGE’S KIDNEY

46. • Ureteric injury - rare and typically occurs at the PUJ.
• Complete or
• Partial tear (partial) - Contrast is seen in distal ureter on delayed scans.
• Bladder injury – can be limited to wall contusion or hematoma, but
bladder rupture can also occur, which may be either
• Intraperitoneal - due to a direct blow to a distended bladder
• Extra peritoneal - due to laceration of the bladder wall from pelvic fracture
fragments
• Bladder rupture can be diagnosed with either conventional
cystography or CT cystography, where dilute contrast is instilled into
the bladder via a Foley catheter.

49. GASTROINTESTINAL TRACT TRAUMA
• Free intra-abdominal fluid in the absence of solid organ injury is
suggestive of injury to the bowel or mesentery.
1.Gastric trauma
• Blunt trauma to the stomach is relatively rare, and most commonly
involves the fundus.
• Full-thickness injury can lead to gastric rupture with
pneumoperitoneum.
• Gastric trauma may be associated with diaphragmatic rupture which
can predispose to intrathoracic gastric migration with possible
volvulus and strangulation.

51. 2.Bowel injury
• The small bowel is most commonly injured, particularly where it is
relatively fixed at the ligament of Treitz and distal ileum
• Resulting in a wall contusion, serosal tear or full-thickness tear. Which may
manifest as a focal area of bowel wall thickening.
• Mesenteric injury on CT shows as mesenteric fat stranding or haematoma.
• Mesenteric vascular injury includes abrupt vessel termination and
vascular beading
• Mesenteric tear can give rise to a subsequent internal hernia.
• Hypovolaemic shock complex: diffuse small bowel wall thickening small,
bowel mucosal hyperenhancement, peripancreatic fluid, hyper enhancing
adrenal glands and flattening of the IVC.

52. Traumatic Duodenal Laceration
A B

55. A B

56. PANCREATIC TRAUMA
• Pancreatic trauma is rare but can lead to significant complications
such as
• abscess or pseudocyst formation,
• pancreatitis or pancreatic fistula.
• The key issue in pancreatic trauma is the integrity of the pancreatic
duct. On CT, signs of injury can be subtle which most commonly
demonstrates peripancreatic fluid and fat stranding.
• Peripancreatic changes can also be due to fluid resuscitation.
• Contusion to the gland can cause diffuse swelling, while a laceration
is manifested as a linear low-attenuation defect.

57. • Laceration >50% of the AP diameter of the gland is an increased risk
for ductal injury (Figure 4.22).
• Complete pancreatic transection may occur, but this can be difficult
to detect unless there is fluid or blood between the transected edges.
• Duct rupture can be diagnosed non-invasively with MRCP, which also
allows visualization of the ducts upstream from a disruption;
• ERCP however, offers the opportunity both for diagnosis and
treatment via covered stent placement.

58. Pancreatic Trauma

59. Gallbladder and Extrahepatic Bile Duct Injury
• Gallbladder injuries include contusion, laceration, perforation
and avulsion.
• CT signs include :
oPericholecystic fluid,
oGallbladder wall thickening and
oLoss of clarity,
oGallbladder wall tear active extravasation into the lumen.

60. Extrahepatic & Intrahepatic Bile Duct
Injury
• Acute deceleration with compression of the duct against the spine can
cause ductal transection, and elevation of the liver.
• As in intrahepatic bile duct injury, biloma may ensue, manifesting as a
perihepatic fluid collection on CT.

61. DIAPHRAGM
• Diaphragmatic rupture is rare and common on the left.
• Several signs of diaphragmatic rupture are:
oFocal diaphragmatic discontinuity and thickening.
oLoss of diaphragmatic clarity.
o Visceral herniation into the chest k/as the “collar”sign.
oDependent viscera sign: a tear causes the solid organs of the upper
abdomen to lie against the posterior chest wall in the supine position.

62. Diaphragmatic rupture

63. Dependent viscera sign