This document provides an overview of FAST (Focused Assessment with Sonography in Trauma) exam. It discusses the history and goals of FAST exams. It covers the physics of ultrasound and techniques for performing the exam. The four standard views of the FAST exam are described along with normal anatomy and examples of fluid/injuries. The document notes accuracy rates for FAST and how exam findings can guide trauma management. It discusses advantages and limitations of FAST compared to CT scans. Examples are provided of ultrasound findings for different types of solid organ and vascular injuries.

2. .
Dr. Derhim Alfaqeeh
Radiologist Consultant
HO The Radiology Dept
University Of Science And Technology Hospital - Sana’a
Decimber 17, 2013

3. What does it Mean?
FAST
Focused
Abdominal (Assessment with)
Sonography in
Trauma

4. INTRODUCTION

1980s- US for trauma in Japan, Germany
1990s- US for trauma in North America

The term FAST introduced in 1996


5. Goals of this lecture





Where do I put the probe?
How do I hold the probe?
What am I looking at? - Normal anatomy
What am I looking at? - Abnormal anatomy
What can I tell from the abnormal anatomy?
 Pathologic fluid in the abdomen
 Pathologic fluid in the pericardium , pleura
 Visceral injuries
 Does it make a difference in management?

6. Physics







Ultrasound is a mechanical longitudinal wave
with a frequency exceeding the upper limit of
human hearing (20 KHZ )
Medical ultrasound usually 2MHZ to 16 MHZ
Ultrasound transducers send out ultrasound
waves and then “listen” for returning echoes
Most transducers at this time send out waves
only approximately 1% of the time
Hperechoic (greatest intensity, white) stone, gas
Anechoic (no echoes , black ) fluid
Hypoechoic (intermediate, shades of gray)
tissues, lesions
transducer

8. Technique
 Low frequency probe 2.5 – 5.0 MHz
Tissue penetration
For deep structures
 High frequency probe 5 - 10 MHz
Tissue penetration
For superficial structures
Remember: Probe marker almost ALWAYS
facing either patient’s right or patient’s head

9. FAST: Applications

Indications





Acute blunt or penetrating torso trauma (stable or unstable patient )
Trauma in pregnancy
Pediatric trauma
Subacute torso trauma(unexplained hypotension)
Goal: To identify fluid in a location where it does not normally
belong and detect visceral injury.

10. Where can I see FF?



Free fluid usually appears anechoic by US (black )
Accumulation in area of injury
Overflows into dependent areas (pouch of Douglas,
Morrison’s pouch) via rivers (paracolic gutters)

11. FAST: Anatomy
7 Dependent Sites
1.
2.
3.
4.
5.
6.
7.
Right Supramesocolic
(Morison’s pouch)
Left Supramesocolic
(Splenorenal rescess)
Right Pericolic gutter
Right Inframesocolic
Left Inframesocolic
Left Pericolic gutter
Pelvic cul-de-sac

12. FAST: Technical Considerations
1
4
2
• Standerded views (standerded FAST ):
1- Subxiphoid/Subcostal: Pericardium
2- RUQ: Morrison’s Pouch
3-Pelvis: Pelvic Cul-de-sac (Douglas )
Transverse
Longitudinal
4- LUQ: Splenorenal & perisplenic spaces
3
Supine patient
• Extended views (E-FAST) :For pleural effusion
Remember: Probe marker almost ALWAYS facing
either patient’s right or patient’s head

14. 1) Subxiphoid exam

Probe placed




Transversally
Midline plane
Just below subxiphoid region
Probe facing towards patient’s right

15. FAST: Subxiphoid exam
Anterior



Right
Left
Posterior
Normal Anatomy
Liver at very top of screen
Epicardial fat vs. effusion
 Thin layer anterior to
RV
 Not present posterior
to LV

16. Normal Subxiphoid exam

17. FAST: Subxiphoid exam
Pericardial Effusion

18. Pericardial Effusion

19. Types of pericardial effusions, subxiphoid cardiac view.
Left image: typical effusion, middle image: clotted effusion , right image : with cardiac tamponade
.

20. 2)FAST: RUQ exam

Probe placed




Probe facing


Perpendicular
Mid-coronal plane
Just superior to the iliac crest
Toward patient’s head
Evaluating


Hepatorenal interface
Possibility of fluid in Morison’s
pouch ( Right Supramesocolic
space)

21. FAST: RUQ exam

Anterior

Morison’s
Pouch
Inferior
Superior
Posterior
Normal Anatomy
In the supine patient, the
hepatorenal space
(Morison’s Pouch) is the
most dependent space

22. FAST: RUQ exam

23. FAST: RUQ exam
FF
L
K
RS
D

24. FAST: RUQ exam
L
FF
K

25. 3)FAST: Pelvis exam





Pelvis: Longitudinally and Transvers Axis.
Probe placed
 Transeversally than Longitudinally
 Midline 2 cm superior to the symphysis pubis
 “aimed” caudally into the pelvis (prostate )
Probe facing
 Toward patient’s head and right side.
Best with some urine in bladder(acoustic window)
Evaluating
 Bladder ,Uterus in female ,and Prostate in
male
 The potential spaces are Pouch of
Douglas (Cul de sac ) in female and
retrovesicle space in male

26. FAST: Pelvis exam
Anterior



Superior
Inferior
Posterior
Longitudinal
Pelvis: Longitudinal Axis
Normal Anatomy
In the erect patient, the pouch of Douglas
(retrovesicle space ) is the most
dependent space

27. retrovesicle space
Pouch of Douglas
(Cul de sac )

28. Mild fluid in pouch of Douglas
Longitudinal

30. FAST: Pelvis exam
Anterior

Pelvis: Transverse Axis

Left
Right

Evaluating Bladder


Posterior
Transverse
Normal Anatomy
Well cirucumscribed
Contains fluid that
appears anechoic

31. Pouch of Douglas
Transverse
Retrovesicle space

32. Transverse

33. FAST: Pelvis exam - Pathology
Transverse

34. Bladder
FF
Transverse

35. 4)FAST: LUQ exam

Probe placed




Probe facing


Perpendicular
Mid - coronal plane
Just superior to the iliac crest
Towards patient’s head
Evaluating


Spleno-renal interface
Possibility of fluid in splenorenal recess
and presplenic /subphrenic space( most
common space for fluid collection in
LUQ)

36. FAST: LUQ exam
Anterior

Presplenic space


Splenorenal
Recess

Superior
between kidney and spleen
Inferior

Posterior
Normal Anatomy
More difficult to evaluate than RUQ (do
not have liver as acoustic window)
Left kidney more superior than right
Splenorenal Recess , Potential space
Presplenic /subphrenic space between
spleen and diaphragm ( most common
space for fluid collection in LUQ)

37. FAST: LUQ exam

39. FF

40. FF
Spleen
Diaphragm
Kidney

41. Don’t mistake

42. Don’t mistake

43. Don’t mistake

45. FAST Demo

46. FAST
Focused Abdominal Sonography In Trauma
Reliability
 accuracy
86 - 97 %
 sensitivity
88 - 91.7 %
 specificity
94.7 - 99 %
Can detect 70 ml fluid (by linear probe can detect as
little as 10 ml or less)

47. How To Interpret FAST

Positive:
 Fluid

Negative:
 No

in pericardium or any 1 of 4 abdominal windows
fluid in any windows
Indeterminate:
 If
any one of the 4 windows is inadequately visualized

48. Does FAST Make a Difference In Trauma Management?

During primary or secondary survey
FAST
Indeterminate
Positive
unstable
stable
unstable
OR
CT
OR
DPL
Negative
stable
CT
DPL
Serial exam
Repeat US/ CT
Adapted from: Rozycki GS, et al. J Trauma, 1996

49. Pearls

Lack of FF ≠ no injury




Not enough to see (?too early)
You missed it
Hard-to-see places
FF may not be blood
Urine, lavage fluid, ascites,
amniotic fluid, bowel contents, ruptured cyst


50. Advantages
 Easy & Early to Diagnose in
Resuscitation/Emergency room
 Rapid(1 – 2.5 min)
 Repeatable
 Non-invasi
 Low cost.

51. Disadvantages
 Difficult to distinguish
 Type of fluid
 Site of bleeding ,
 Solid organ injury
 Cannot evaluate retroperitoneum
 Difficult in the obese patient , subcutaneous emphysema
 Examiner Dependent.
 Bowel gas interposition
 False –Negative : retroperitoneal & Hollow viscus injury

52. Pitfalls and limits
•
•
•
•
-Pre-exsiting fluid collection ( Ascites , dialysis )
-Pelvic fluid collection (female ) .
-Fluid filled bowel loops .
-Contained injury (hollow viscus, bowel wall
contusion, pancreatic trauma and renal pedicle injury)
• -Echogenic clot.
The scan should be repeated during the secondary survey and
also if the patient demonstrates clinical deterioration, since free
fluid may have accumulated in the intervening time .
The quality of images obtained may also be a limiting factor with
patient obesity , gas in the bowel leading to degradation in image
quality , subcutaneous emphysema , non-mobile patient and
pnetrating injury.

53. Does FAST replace CT?


Unstable patient, (+) FAST  OR
Stable patient, low force injury, (-) FAST  consider observing patient.
CT is far more sensitive than FAST for detecting and characterizing abdominal injury in
trauma. The gold standard for characterizing intraparenchymal injury.
“Death begins with a CT.” Never send an unstable patient to CT. FAST, however, can be
performed during resuscitation.
FAST
Positive
Negative
Indeterminate
unstable
stable
unstable
stable
OR
CT
OR
CT
DPL
DPL
Serial exam Repeat US/
CT

55. ?
Is Pneumoperitoneum Can Be Detected By US?
YES

56. Pneumoperitoneum

57. Extended FAST (E-FAST)
RUQ, LUQ views:
 Check above diaphragm for hemothorax

CXR = US in detection of hemothorax
Ma and Mateer. Ann Emerg Med, 1997


50-175cc vs. 20cc or less
US does not replace CXR
Suprapubic view:

Check uterus for pregnancy

58. Hemothorax
D
SP
FF
KD

59. Pleural Fluid

60. Right pleural effusion, transverse subxiphoid view

61. Don’t mistake

62. Lung Scanning for Pneumothorax
Comet tails sign
and sliding lung

64. Loss of comet tail and lung
sliding movement

66. Abdominal Organ Injury
Hollow
Organs
Solid
Organs
Vascular
Injury
Stomach
Gall bladder
Intestines
Ureters, Bladder
Liver
Spleen
Kidney
Pancreas
Aorta
Vena Cava
Major Branches

67. Blunt Injury
Abdominal Trauma



Spleen
25%
Liver
15%
Hollow viscus
15%


Ileum
Sigmoid

Kidney

Retroperitoneal

Mesentery




12%
13%
5%
Compression / deceleration
Crushing
Shearing
Avulsion

68. Solid-Organ Injuries (sonographic patterns)
I.
Contusion : patchy ill defined non-linear echogenic area .
II. Subcapsular hematoma : under capsule.
III. Intra-parenchymal hematoma : well defined rounded hyperechoic area .
IV. Laceration : linear well defined hper / hypoechoic area.
V. Multiple lacerations/vascular injury (organic fracture ,disorganization )

70. Liver laceration and hematoma

71. Subcapsular Liver hematoma

72. Liver laceration and hematoma

73. Splenic laceration

74. Spleen hematoma
Subcapsular spleen hematoma

75. Splenic laceration

76. Preinephric and renal
hematoma
Renal laceration

77. Subcapsular renal hematoma

78. References
Vicki E Nobil , Manual of emergency and critical care ultrasound , Cabridge
university 2007
Rosen, C. Ultrasound in Emergency Medicine. Emergency Medicine Clinics of
North America. August 2004. Volume 22. Number 3.
O. John Ma and James R. Mateer. Emergency Ultrasound. McGraw-Hill. Medical
Publishing Division. 2003.
Simon, B. Ultrasound in Emergency and Ambulatory Medicine. Mosby. 1997
Temkin, BB. Ultrasound Scanning: Principles and Protocols. WB Saunders.
1993.

80. Questions?