ct of trauma
DESCRIPTION
ct in traumaTRANSCRIPT
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1CT OF TRAUMA
Myron A. Pozniak, MDUniversity of WisconsinDepartment of RadiologyDepartment of Radiology
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2Life has changed
General facts regarding trauma
Leading cause of death in the first four Leading cause of death in the first four decades of life.
150,000 deaths/year in U.S.
2,000,000 nonfatal injuries in the U.S./year.
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3General facts regarding trauma
Injuries due to violence make up 14% of Injuries due to violence make up 14% of injuries
Unintentional fall - 52%
Evaluation of the trauma patient
Obtain the maximum information in the Obtain the maximum information in the shortest possible time.
Critically unstable patients belong in the operating room.
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4Routine ER x-rays
AP chest AP chest Lateral cervical
spine AP pelvis Cross table lateral
T and L spine
Indication for emergency trauma imaging
Unexplained drop in hematocrit
Confusing physical exam
Hemodynamically stable patient
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5Choices for emergency trauma imaging
Diagnostic peritoneal lavage (DPL) Diagnostic peritoneal lavage (DPL)
Ultrasound (US)
Computed Tomography (CT)
Diagnostic peritoneal lavage (DPL)
Advantages Disadvantages Quick Inexpensive
Invasive No idea which organ is injured No information about retroperitoneumretroperitoneum Does not allow non-operative management
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6FAST UltrasoundAdvantages Disadvantages
Variable sensitivity and specificity (operator dependent)
Absence of free fluid with retroperitoneal injury or non-capsule disrupting injury
Performed at bedside Noninvasive Relatively inexpensive No IV contrast
p p g j y Poor at identifying acute
parenchymal organ injury Very low sensitivity for bowel
and renal injuries
Computed Tomography(CT) Advantages Disadvantages Non-invasive Organ specific Highly accurate Allows non-operative
management
Time consuming Relatively expensive Intravenous iodinated contrast risk Poor for bowel and pancreasPoor for bowel and pancreas injuries
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7CT vs. DPL vs. Ultrasound - Which one?
Patient selection
Trauma managers preference
Quality / availability / experience of the various services
Ultrasound has replaced DPL for the detectionUltrasound has replaced DPL for the detection of free intraperitoneal fluid
CT provides much more information and allows for non operative managementallows for non-operative management
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8Trauma CT technique
Proximity to the emergency room Proximity to the emergency room Sub-second rotation time Multi-detector system High heat capacity tube Power injector Remote patient monitoring
Trauma CT technique (cont.)
Patient Preparation Sedation
Alcohol/drugs/head injury Oral contrast
Two cups if toleratedJ i i Just prior to scanning
Clamp the Foley catheter Minimize artifacts
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9Minimize artifacts
EKG lead artifact
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Arms at side
Metal Bar Artifact
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Not all metal is necessarily Artifact
Carpenters nail gun
Trauma CT technique (cont.)
Intravenous ContrastIntravenous Contrast Low osmolar contrast 150 cc or 100 cc with a 50 cc saline chaser 4 cc/sec Bolus tracking (cardiac contusion)
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Contrast enhancement key to determination of organ integrity
Non-contrast After IV contrast
Trauma CT technique (cont.)Scan Sequence Chest - diaphragm to apexp g p
1.25 mm collimation High speed (15 table feed) .625 mm reconstruction
Abdomen/pelvis 2.5 mm collimation High speed table feed 2.5 mm reconstruction Extremity run off - if indicated
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Trauma CT technique (cont.)
Delayed sequence (7 minutes) Kidneys through bladder 5 mm collimation
Consider filling the bladder retrograde (CT cystogram)( y g )
Targeted reformatting of bony anatomy Obviates the need for a re-scan
Several critical observations:
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Look at the box
Surface findings indicateSurface findings indicate point of impact
Fractures Localized hematoma Seat belt injury Seat belt injury
Look at the box
Surface findings indicateSurface findings indicate point of impact
Fractures Localized hematoma Seat belt injury Seat belt injury
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Always check the bone windows -especially the vertebral column
Cine evaluation Cine evaluation Lateral scout view
Free intraperitoneal fluid
Very useful finding but not after DPLVery useful finding but not after DPL Blood Urine Bile Intestinal contents
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The subtle nondisplaced rib fracture must not be ignored
Active bleeding
appears as an enlarging puddle of contrastpp g g p
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If in doubt get that delayed scan
7 minutes later
The size of the potential space is a key determinant of survival
Liters Gallons
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So what do you do with this patient
Go to the OR Observe
Aortic injury
16% of all deaths from MVA 16% of all deaths from MVA
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Timing of death with aortic injury
Within 1 hour in 94% Within 1 hour in 94% Within 24 hours in 99%
Ann Thorac Surg 1994;57(3):726-730
Aortic injury
Variable confidence level for exclusion of tear Variable confidence level for exclusion of tear
A small collection of mediastinal blood even if periaortic rarely correlates with a significant
i i jaortic injury
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How many of you would dictate:
Cant rule out aortic injury.?
Increasing the frequency of post-traumatic angiography because of mediastinal blood on CT negates the advantage of this tool.
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54 y/o female unrestrained passenger
Focal Dissection Raised Intimal Flap
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A Media I
The ability of CTA to identify aortic injury exceeds the treatment threshold.
Traumatic Aortic Injury
We are in a period of transition We are in a period of transition - the stakes are high - definitive supporting literature is just
appearing
Subjective assessment is very good at predicting aortic injury but not the CXR
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A normal CXR does NOT exclude aortic injury
A normal CXR does NOT exclude aortic injury
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A normal CXR does NOT exclude aortic injury
Traumatic Aortic Injury
Endovascular repair of aortic injury Endovascular repair of aortic injury
Mortality of emergent aortic surgery is very high - 54%
Indications for stenting evolving
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Small Intimal Tear
Natural history of arterial injuries diagnosed with arteriography.Hoffer EK, Sclafani SJ, et al.Hoffer EK, Sclafani SJ, et al.
The natural history variable and unpredictable. Nonocclusive "minimal" injuries rarely cause
ischemic or hemorrhagic complications. Cl f ll i i l if i Close follow-up is essential if a non-operative approach is chosen.
J Vasc Interv Radiol. 1997 Jan-Feb;8(1 Pt 1):43-53
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Acute Aortic Pseudoaneurysm
Delayed diagnosis of the intimal tear
Chronic pseudoaneurysm rate 5% Chronic pseudoaneurysm rate - 5%
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The isolated mediastinal hematoma is not as serious a finding as previously thought.
Cannot R/O aortic injury Cannot R/O aortic injury If the CTA is normal leave it alone We lack a large study to confirm this.
Angio the not-so-gold standard
Positives are slam dunks Positives are slam-dunks Small intimal tears are
easily overlooked
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Post-traumatic Dissection
Not all aortic injuries are at the arch
18 y/o in a stolen car tried to outrun the police
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Not all aortic injuries are at the arch
Not all aortic injuries are at the arch
Post traumatic pseudoaneurysm
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Traumatic Aortic Injury
Look carefully for aberrant great vessels Look carefully for aberrant great vessels -may affect the ability to cross clamp the aorta at surgery
If theres a lower extremity fracture
Include the leg in the CTA run Include the leg in the CTA run.
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Splenic injuries Most commonly injured
abdominal organ (46%) 30-60% have associated
abdominal injuries Isolated injuries have better
prognosis
SPLEEN INJURY SCALE
I. Hematoma 3 cm
IV. Laceration with >25% devascularizationV. Completed shattered or devascularized spleen
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With rapid scan acquisition during the l h f h t lti livascular phase of enhancement a multislice
scanner can go past a slow active bleeder before it has time to accumulate a significant amount of extraluminal contrast.
Maintain a low threshold for delayed scan.
27 y/o Hispanic male3 f ll 3 story fall
Comatose Stable hematocrit CT abdomen/pelvis at the same time as the C abdo e /pe v s at t e sa e t e as t e
head CT
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24 y/o male MVA Splenic laceration
Scanned 4 days later, after a drop in hematocrit
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62 y/o female MVA Initial CT showed a splenic
lacerationlaceration Follow-up CT scan 8 days later
Inhomogeneous enhancement of the spleen Artifact of rapid dynamic enhancement
Arterial phase Venous phase
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No role for non- contrast CT in trauma
Lacerations can be missed Lacerations can be missed
Non-contrast After IV contrast
Liver injuries
2nd most commonly injured organ in blunt 2nd most commonly injured organ in blunt trauma
Most common in penetrating trauma Right lobe injuries are most common
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LIVER INJURY SCALEI. Hematoma
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Concept of the Stress riser
UW Quarterback fell on the football
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Active bleeding appears as a puddle of contrast opacified blood
Active bleed hepatic segment 4B
Active bleeding appears as a puddle of contrast opacified blood
If its more than a puddle Go to the OR
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CT detected acute trauma bleeds
Only 4 out of 5 require OR Only 4 out of 5 require OR the higher the attenuation the closer the
focus of the bleed Yao & Jeffrey
Renal Trauma
Mechanisms of InjuryMechanisms of Injury Direct blow Laceration by rib or foreign body Tear from rapid deceleration
Stress riser
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Clinical signs of renal trauma
Gross hematuria Gross hematuria 25% have significant injury
Microhematuria 1-2% have significant injury (usually severe
pedicle injury with vascular avulsion)
Renal injury
95% are managed non operatively 95% are managed non-operatively Focal contusion Superficial laceration Segmental infarction Perinephric hematoma Subcapsular hematoma
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Renal injuries requiring surgery
Parenchymal fragmentation (maybe) Parenchymal fragmentation (maybe) Ureteral avulsion Major hemorrhage (maybe)
Grading of Renal Injury
American Association for the Surgery of American Association for the Surgery of Trauma (AAST)
Grades 1-5 Not consistently used
Often used by surgeons for research purposes Hard for us to remember!
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Grade I
80% of all injuries 80% of all injuries Contusions, nonexpanding subcapsular
hematomas, hematuria with negative imaging
C i i d fi d hi f Contusion is defined as geographic area of decreased enhancement (sharp or diffuse margins)
Grade 1: Contusion
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Grade I: Subcapsular Hematoma
The hilum is spared The hilum is spared
Grade I: Subcapsular Hematoma
Appearance varies Appearance varies with maturity Most are post-
lithotripsy
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Grade 2
Nonexpanding perinephric retroperitoneal Nonexpanding, perinephric, retroperitoneal hematomas
Superficial cortical lacerations
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Grade 3
Renal lacerations >1cm in depth Renal lacerations >1cm in depth These do not involve the collecting system
Grade 4
Lacerations extending to collecting system Lacerations extending to collecting system Extravasation of contrast on delayed images
Contained main renal artery/vein injury Segmental infarction without laceration
Wedge-shaped areas of non-enhancementWedge shaped areas of non enhancement Caused by dissection, thrombosis or laceration of
segmental arteries
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Grade 4: Collecting System Extravasation
Initial spiral sequence must be followed by a delayed scan
The problem with IV contrast and trauma
S ti i l l i t i ll k dl l t d Serum creatinine level is typically markedly elevated with urine extravasation.
High creatinine should not preclude the use of IV contrast in a trauma patient
Dont bother with Cr levels in severe traumaDon t bother with Cr levels in severe trauma It takes too long You wont give contrast to the pt. that needs it most
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Grade 4: Vascular injury (contained)
Traumatic renal artery dissection/intimal tear Traumatic renal artery dissection/intimal tear Can be treated with stent
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Grade 4: Vascular injury (contained)
Grade 4: Segmental Infarcts
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Grade 5
Shattered kidney Shattered kidney Devascularized kidney
Non-enhancement may be only sign of injury no hematoma or urinoma
UPJ avulsion Little or no hematuria
Grade 5: Shattered Kidney
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Grade 5: Devascularization
Grade 5: Devascularization
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Grade 5: Devascularization
Grade 5: UPJ avulsion
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Grade 5: UPJ avulsion
Bottom Line
Kidney is salvaged 85 90% Kidney is salvaged 85-90% Conservative management Grades 1-3 Even most Grades 4-5 are conservatively
managed Indications for surgery: large devitalized Indications for surgery: large devitalized
areas, major arterial injury, UPJ avulsion, unstable patient with active extravasation.
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Remember the stress riser
Is it a tear of the collecting system?
Persistent Active Extravasation
This finding may require intervention no This finding may require intervention no matter what the AAST grade
Either surgery, or catheter embolization
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but Active Extravasation may slow as the compartment fills.
The Horseshoe Kidney especially prone to injury
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Bladder Trauma
10% f ll GU 10% of all GU trauma involves the bladder
Intraperitoneal Seat belt injury Seat belt injury
Extraperitoneal Pelvic fracture
Grading: 5 Types
Type I: Mucosal tear most common no imaging findingsType I: Mucosal tear, most common, no imaging findingsType II: Intraperitoneal, 10-20% of major injuries, caused
by blow to distended organ, dome ruptureType III: Interstitial rupture, CT cystography, contrast in
bladder wall. Blunt or penetrating injuryT IV E t it l 80 90% f j i j iType IV: Extraperitoneal, 80-90% of major injuries,
contrast in prevesicular space, tracking along fascia to thigh, scrotum
Type V: Combined intra- and extraperitoneal, ~5%
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Intraperitoneal Extraperitoneal
Intraperitoneal Extraperitoneal
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Which Test?
CT cystography is just as accurate as CT cystography is just as accurate as retrograde cystography if bladder is distended with 300-400ml of contrast
CT cystography gives the advantage of evaluating the remainder of the abdomenevaluating the remainder of the abdomen and pelvis
Overall cost and time savings
CT cystogram
6% contrast via Foley 6% contrast via Foley catheter (50 cc of 60% contrast in 500 cc of saline)
Warm to body temperaturetemperature
5 mm collimation
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Is it urine or is it blood?
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Urethral Injury
Typically at urogenital Typically at urogenital diaphragm
Best imaging retrograde urethrogram (pre attempted Foley(pre-attempted Foley cath insertion)
Urethral Injury
Typically at urogenital Typically at urogenital diaphragm
Best imaging retrograde urethrogram (pre attempted Foley(pre-attempted Foley cath insertion)
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Urethral Injury
Adrenal bleed
Most commonly seen after: Most commonly seen after: Direct iatrogenic insult
Liver transplant Childbirth
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Adrenal bleed
smallsmall
medium
large
Super-sized with an active bleeder
early late
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Intestinal injury
Accuracy of CT is quite Accuracy of CT is quite variable
Most frequently affects duodenum and terminal ileum
Oral contrast or not?
Takes too long Takes too long Post-traumatic
ileus
But when it extravasates
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Duodenal Contusion
Duodenal Bleed It appears we may no longer need oral contrast
Intramural Intraluminal
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Traumatic duodenal perforation
Retroperitoneal Retroperitoneal air and blood
Anterior pararenal space
CT is good at detecting perforation Free air Free fluid Free fluid
CT is poor at detecting: Contusion Mesenteric hemorrhageg Ischemic Serosal tear
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Body habitus makes a big difference
Mesenteric hematoma
Body habitus makes a big difference
Active bleeder
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Body habitus makes a big difference
Bowel wall hematoma
Bowel wall hematoma
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GI Perforation
Inter loop fluid / triangular configuration = bowel perforationBut not quite as certain in ovulating females
Few perforation cases actually have free air
Focal jejunal perforation at surgery.
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Shock BowelProfound HypotensionReperfusion after injuryReperfusion after injuryHyperdense bowel
Pancreas injury
Changes of post-traumatic pancreatitis are time Changes of post-traumatic pancreatitis are time dependent
Initial scan - limited findings
Delayed scan Phlegmon Pseudocyst Etc.
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Pancreatic fracture/contusionOften with steering wheel injury
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2 k l2 weeks later
Traumatic rupture of the diaphragm
Incidence: 4 6% of MVA cases Incidence: 4 6% of MVA cases
Mortality rate of missed tear approaches 30%.
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Traumatic rupture of the diaphragm
The diaphragm is the weakest link of the The diaphragm is the weakest link of the abdominal cavity enclosure, especially at the transition between the central tendon and the muscular portion.
Traumatic rupture of the diaphragm
Radiographic identification of the tear hinges on the presence of herniation.
Delayed if patient on Positive Pressure VentilationVentilation
Up to 70% of diaphragmatic tears are initially missed.
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Liver Herniation
CT diagnosis limited CT diagnosis limited in the absence of herniation
Omental Herniation
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Gastric Herniation
Miscellaneous findings in trauma
Flat inferior vena cavaFlat inferior vena cava
Hypovolemia
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Malpositioned chest tube
Quiz cases
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MVAhematuria
Renal Artery Laceration with Brisk Active Bleed
MVAdropping hematocrit
Active hemorrhage from Inferior Epigastric Artery
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MVAunresponsivewide mediastinum on CXR
Aortic laceration
MVAunresponsive
Patient demise at start of scan
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Conclusions
Hemodynamically stable patient
CT angiographic technique for aorta
Dynamic enhancement technique for h l i jparenchymal injury
Delayed scans for urinary tract injury
Conclusions
Elevated serum creatinine level should not Elevated serum creatinine level should not preclude the use of intravenous contrast in a trauma patient
l d d id if i Delayed scan mandatory to identify urine leak
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Conclusions cont.
If the delayed scan is negative but the If the delayed scan is negative but the clinical concern for bladder injury is high, consider a CT cystogram Antegrade filling may not raise bladder
pressure sufficientlyp y The need for a post void sequence is
questionable
With rapid scan acquisition during the Conclusions cont.
vascular phase of enhancement a multislice scanner can go past an active bleeder before it has time accumulate a significant amount of extraluminal contrast.
Maintain a low threshold for delayed scan
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Heres a crazy thought
I NG t b tiIs NG tube suction
really helping the patient
with the big bleed?
Heres a crazy thought
Is the NG tube to suction reallyIs the NG tube to suction really helping the patient with the big bleed?
Its all about the potential space
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Thank you
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Lumbar artery pseudoaneurysm
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internal iliac bleed
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subtle mural aortic hematoma
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Can chest CT be used to exclude aortic injury?
1009 patients 1009 patients 10 true positives, no false negatives 100% sensitivity 100% negative predictive value
Dyer DS et al.Radiology 1999;213(1):195-202
Post traumatic dissection
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Not all metal is necessarily Artifact
Gunshot wound
Natural history of arterial injuries diagnosed with arteriography.Hoffer EK, Sclafani SJ, et al.Hoffer EK, Sclafani SJ, et al.
105 arterial injuries were identified average duration of observation was 23.5 days 42 healed spontaneously p y no significant M&M due to delay
J Vasc Interv Radiol. 1997 Jan-Feb;8(1 Pt 1):43-53
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Delayed scan (bolus drip technique) has little role in solid organ injury
Redistribution of contrast hides lacerationsRedistribution of contrast hides lacerations