IMAGING OF BLUNTABDOMINAL TRAUMA, PART II

Ruedi F. Thoeni, M. D.University of California, San Francisco

IMAGING OF BLUNTIMAGING OF BLUNTABDOMINAL TRAUMA, PART IIABDOMINAL TRAUMA, PART II

Ruedi F. Thoeni, M. DRuedi F. Thoeni, M. D..University of California, San FranciscoUniversity of California, San Francisco

SCBT-MR Summer Practicum, Williamsburg, 2009SCBTSCBT--MR Summer Practicum, Williamsburg, 2009MR Summer Practicum, Williamsburg, 2009

Learning Objectives for blunt abd. TraumaLearning Objectives for blunt abd. Trauma

• MDCT Trauma Protocol

• Incidence of bowel and mesenteric injuries

• Specific signs of bowel/mesenteric injuries

• Nonspecific findings of bowel/mesenteric injuries

• Plan in patients with nonspecific signs

•• MDCT Trauma Protocol MDCT Trauma Protocol

•• Incidence of bowel and mesenteric injuriesIncidence of bowel and mesenteric injuries

•• Specific signs of bowel/mesenteric injuriesSpecific signs of bowel/mesenteric injuries

•• Nonspecific findings of bowel/mesenteric injuries Nonspecific findings of bowel/mesenteric injuries

•• Plan in patients with nonspecific signsPlan in patients with nonspecific signs

ABD. TRAUMA (16 or 64) MDCTABD. TRAUMA (16 or 64) MDCT

• Contrast Materials:– Oral contrast (if possible): 3 cups of 450 ml of

2.2% Gastrografin (10 mL/450 of water)– Rectal contrast (if possible: shear force):

40 cc of Conray 60% in 1000 mL normal saline: use 500-1000 mL as tolerated

– IV contrast: 3 mL/sec for 150 ml• Important:

– Clamp bladder catheter to achieve full distention of bladder

•• Contrast Materials:Contrast Materials:–– Oral contrast (if possible):Oral contrast (if possible): 3 cups of 450 ml of 3 cups of 450 ml of

2.2% Gastrografin (10 mL/450 of water)2.2% Gastrografin (10 mL/450 of water)–– Rectal contrastRectal contrast (if possible: shear force):(if possible: shear force):

40 cc of Conray 60% in 1000 mL normal saline: 40 cc of Conray 60% in 1000 mL normal saline: use 500use 500--1000 mL as tolerated1000 mL as tolerated

–– IV contrast:IV contrast: 3 mL/sec for 150 ml3 mL/sec for 150 ml•• Important:Important:

–– Clamp bladder catheter to achieve full Clamp bladder catheter to achieve full distention of bladderdistention of bladder

ABD. TRAUMA (16 or 64) MDCT ABD. TRAUMA (16 or 64) MDCT

• MDCT Technique:- Detector config: 16 (64) x 1.25 mm, mode 1.375:1- Reconstruction thickness: axial: 1.25 mm & 5 mm- ALWAYS use coronal and sagittal MPRs (3mm)

• Scan delay:- 70-80 sec or smart prep- 3 minute delay- Diaphragm to ischial tuberosity

•• MDCT Technique:MDCT Technique:-- Detector config: 16 (64) x 1.25 mm, mode 1.375:1Detector config: 16 (64) x 1.25 mm, mode 1.375:1-- Reconstruction thickness: axial: 1.25 mm & 5 mmReconstruction thickness: axial: 1.25 mm & 5 mm-- ALWAYSALWAYS use coronal and sagittal MPRs (3mm)use coronal and sagittal MPRs (3mm)

•• Scan delay:Scan delay:-- 7070--80 sec or smart prep80 sec or smart prep-- 3 minute delay3 minute delay-- Diaphragm to ischial tuberosityDiaphragm to ischial tuberosity

ABD. TRAUMA (16 or 64) MDCT ABD. TRAUMA (16 or 64) MDCT

• Important:• Single acquisition: “total body” trauma CT scan:

head, cervical spine, chest, abdomen & pelvis• Delayed scans (3 min) optional: parenchymal organs,

excretory system incl. bladder, vasc. extravasation• CT cystogram for bladder injury: 300-400 cc of

20 cc of 60% contrast/500 cc of sterile saline

• • Important:Important:•• Single acquisitionSingle acquisition: : ““total bodytotal body”” trauma CT scan: trauma CT scan:

head, cervical spine, chest, abdomen & pelvishead, cervical spine, chest, abdomen & pelvis•• Delayed scans (3 min) optionalDelayed scans (3 min) optional: parenchymal organs, : parenchymal organs,

excretory system incl. bladder, vasc. extravasationexcretory system incl. bladder, vasc. extravasation•• CT cystogram for bladder injuryCT cystogram for bladder injury: 300: 300--400 cc of 400 cc of

20 cc of 60% contrast/500 cc of sterile saline20 cc of 60% contrast/500 cc of sterile saline

CT IN BLUNT TRAUMA: BOWEL + MESENTERYCT IN BLUNT TRAUMA: BOWEL + MESENTERY

• Bowel & mesenteric injuries are seen in 5% of blunt abdominal trauma at laparoscopy

• Third most common type of injury

• Mechanism: • Direct force crushes GI tract

• Rapid deceleration -> shearing force between fixed and mobile portions of GI tract

• Sudden increase in intraluminal pressure -> bursting

•• Bowel & mesenteric injuries are seen in 5% of Bowel & mesenteric injuries are seen in 5% of blunt abdominal trauma at laparoscopyblunt abdominal trauma at laparoscopy

•• Third most common type of injuryThird most common type of injury

•• Mechanism:Mechanism: • • Direct force crushes GI tractDirect force crushes GI tract

•• Rapid deceleration Rapid deceleration --> shearing force between > shearing force between fixed and mobile portions of GI tractfixed and mobile portions of GI tract

•• Sudden increase in intraluminal pressure Sudden increase in intraluminal pressure --> > burstingburstingHughes Tm, Elton C. The pathophysiology and management of bowel and mesenteric injuries due to blunt trauma. Injury 2002; 33: 295-302.

COMMON SITES OF INJURY TO SBCOMMON SITES OF INJURY TO SB

• Proximal jejunum near ligament of Treitz• Distal ileum near ileocecal valve• Mobile and fixed portions -> shear force

•• Proximal jejunum near ligament of TreitzProximal jejunum near ligament of Treitz•• Distal ileum near ileocecal valveDistal ileum near ileocecal valve•• Mobile and fixed portions Mobile and fixed portions --> shear force> shear force

Hawkins AE, Mirvis SE. Evaluation of bowel and mesenteric injury: role of multidetector CT. Abdominal Imaging 2003; 28: 505-514.

DX OF BOWEL & MESENTERIC INJURYDX OF BOWEL & MESENTERIC INJURY

• Increased morbidity and mortality if dx delayed• Caused by hemorrhage & peritonitis• Symptoms often nonspecific: pain• With head + cord injuries: symptoms unreliable• Clinical assessment alone: 40% negative lap.• Tests: peritoneal lavage, US and CT

•• Increased morbidity and mortality Increased morbidity and mortality if dx delayedif dx delayed•• Caused by hemorrhage & peritonitisCaused by hemorrhage & peritonitis•• Symptoms often nonspecific: painSymptoms often nonspecific: pain•• With head + cord injuries: symptoms unreliableWith head + cord injuries: symptoms unreliable•• Clinical assessment alone: 40% negative lap.Clinical assessment alone: 40% negative lap.•• Tests: peritoneal lavage, US and CTTests: peritoneal lavage, US and CT

Fryer JP, Graham TL, Fong HM, Burns CM. Diagnostic peritoneal lavage as an indicator for therapeutic surgery. Can J Surg 1991; 34: 471-46.7

TESTS FOR ABDOMINAL INJURIESTESTS FOR ABDOMINAL INJURIES

Talton DS, Craig MH, Hauser CJ, Poole GV. Major gastroenteric injuries from blunt trauma. Ann Surg 1995: 61: 69-73. Dohlich MOMcKenney MG, Varela JE, Compton RP, McKenney KL, Cohn SM. 2,576 ultrasounds for blunt abdominal trauma. J Trauma 2001;50: 108-112. Liu A, et al. A computer-based simulator for peritoneal lavage.Studies in Health Technology and Informatics. IOS Press, 2001;

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QuickTime™ and aTIFF (Uncompressed) decompressor

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Peritoneal lavage:- 90% sensitivity for hemoperitoneum- Insensitive for retroperitoneum- Perforation missed in up to 10% (early)- Can compromise results with CT

Peritoneal lavage:Peritoneal lavage:-- 90% sensitivity for hemoperitoneum90% sensitivity for hemoperitoneum-- Insensitive for retroperitoneumInsensitive for retroperitoneum-- Perforation missed in up to 10% (early)Perforation missed in up to 10% (early)-- Can compromise results with CTCan compromise results with CT

TESTS FOR ABDOMINAL INJURIESTESTS FOR ABDOMINAL INJURIES

Talton DS, Craig MH, Hauser CJ, Poole GV. Major gastroenteric injuries from blunt trauma. Ann Surg 1995: 61: 69-73.Dohlich MO, McKenney MG, Varela JE, Compton RP, McKenney KL, Cohn SM. 2,576 ultrasounds for blunt abdominal trauma. J Trauma 2001; 50: 108-112. Weekes AJ, Alteveer JG, Stahmer S. Emergency Us in trauma. PowerPoint Presentation.http://www.google.com/search?hl=en&q=ultrasound+in+emergency+room%2C+FAST%2C+images&btnG=Search&aq=f&oq=&aqi=

Ultrasound: FAST:- 86% sensitivity for free intra-abd. fluid- 98% specificity for free intra-abd. fluid- Nonspecific for organ injury

Ultrasound: FAST:Ultrasound: FAST:-- 86% sensitivity for free intra86% sensitivity for free intra--abd. fluidabd. fluid-- 98% specificity for free intra98% specificity for free intra--abd. fluidabd. fluid-- Nonspecific for organ injuryNonspecific for organ injury

TESTS FOR ABDOMINAL INJURIESTESTS FOR ABDOMINAL INJURIES

• MDCT:- 69-95% sensitivity for bowel & mesenteric inj.- 94-100% specificity for bowel & mesenteric inj.- Time to diagnosis significantly reduced- Less motion artifacts- Best assessment of organs and vessels

Most important CT function: distinction between injuries that require surgery from those treated conservatively

•• MDCT:MDCT:-- 6969--95% sensitivity for bowel & mesenteric inj.95% sensitivity for bowel & mesenteric inj.-- 9494--100% specificity for bowel & mesenteric inj.100% specificity for bowel & mesenteric inj.-- Time to diagnosis significantly reducedTime to diagnosis significantly reduced-- Less motion artifactsLess motion artifacts-- Best assessment of organs and vesselsBest assessment of organs and vessels

Most important CT function: Most important CT function: distinctiondistinction between injuries between injuries that require surgerythat require surgery from those from those treated conservativelytreated conservatively

Scaglione M, Castelguidone EL, Scialpi M, et al. Blunt trauma to the gastrointestinal tract and mesentery: is there a role for helical CT? Eur J Radiol 2004: 50: 67-73.

! !! !

MDCT OFMDCT OF ABDOMINAL TRAUMA:ABDOMINAL TRAUMA: MULTISYSTEMMULTISYSTEM

SIGNIFICANTSIGNIFICANT BOWEL/MESENTERIC INJURIESBOWEL/MESENTERIC INJURIES

• Bowel Injuries:- Complete tear of bowel wall- Incomplete tear that involves serosa and

muscularis but not mucosa

• Mesenteric Injuries:- Active mesenteric bleed- Disruption of the mesentery- Mesenteric injury with bowel injury (ischemia)

•• Bowel Injuries:Bowel Injuries:-- Complete tear of bowel wallComplete tear of bowel wall-- Incomplete tear that involves serosa and Incomplete tear that involves serosa and

muscularis but not mucosamuscularis but not mucosa

•• Mesenteric Injuries:Mesenteric Injuries:-- Active mesenteric bleedActive mesenteric bleed-- Disruption of the mesenteryDisruption of the mesentery-- Mesenteric injury with bowel injury (ischemia)Mesenteric injury with bowel injury (ischemia)

NONSIGNIFICANTNONSIGNIFICANT BOWEL/MESENTERIC INJURIESBOWEL/MESENTERIC INJURIES

• Bowel Injuries:- Hematoma- Tear that involves serosa only

• Mesenteric Injuries:- Isolated mesenteric hematoma

•• Bowel Injuries:Bowel Injuries:-- HematomaHematoma-- Tear that involves serosa onlyTear that involves serosa only

•• Mesenteric Injuries:Mesenteric Injuries:-- Isolated mesenteric hematomaIsolated mesenteric hematoma

LOCATION OF BOWEL INJURIESLOCATION OF BOWEL INJURIES

• Stomach injury 5%• Duodenal injuries 11%• Jejunal injuries 25%• Cecum/ascending colon 7%• Transverse colon 11%• Descending colon 2%• Sigmoid colon 5%• Multiple sites 34%

•• Stomach injuryStomach injury 5%5%•• Duodenal injuriesDuodenal injuries 11%11%•• Jejunal injuriesJejunal injuries 25%25%•• Cecum/ascending colonCecum/ascending colon 7%7%•• Transverse colonTransverse colon 11%11%•• Descending colonDescending colon 2%2%•• Sigmoid colonSigmoid colon 5%5%•• Multiple sitesMultiple sites 34%34%Brofman N, Atri M, Epid D, Hanson JM, Grinblat L, Chughtai T, Brenneman F. Evaluation of bowel and mesenteric blunt trauma with MDCT. RadioGraphics 2006; 26: 1119-1131.

FINDINGS SPECIFIC TO BOWEL INJURYFINDINGS SPECIFIC TO BOWEL INJURY

• Bowel discontinuity: 7% (4/54)• Extraluminal contrast material: 6% (3/54)• Extraluminal air: 20% (11/54), high spec.• Associated mesenteric features • Mesenteric foci of fluid or blood* (interloop, triangular) • Fat stranding due to bowel injury (streaky mesentery) • Retroperitoneal air (duodenum: air & fluid/contrast

in anterior pararenal space); asc. & desc. colon)

•• Bowel discontinuityBowel discontinuity: 7% (4/54): 7% (4/54)•• Extraluminal contrast material: 6% (3/54)Extraluminal contrast material: 6% (3/54)•• Extraluminal air: 20% (11/54), high spec.Extraluminal air: 20% (11/54), high spec.•• Associated mesenteric featuresAssociated mesenteric features •• Mesenteric foci of fluid or bloodMesenteric foci of fluid or blood** (interloop, triangular)(interloop, triangular) •• Fat stranding due to bowel injury (streaky mesentery)Fat stranding due to bowel injury (streaky mesentery) •• Retroperitoneal air (duodenum: air & fluid/contrast Retroperitoneal air (duodenum: air & fluid/contrast

in anterior pararenal space); asc. & desc. colon) in anterior pararenal space); asc. & desc. colon) Sentinel clot!Sentinel clot!

SENTINEL CLOT SIGN FOR VISCERAL INJURYSENTINEL CLOT SIGN FOR VISCERAL INJURY

SENSITIVITY 84%; 3 FP; sentinel clot the only sign in 14%SENSITIVITY 84%; 3 FP; sentinel clot the only sign in 14%SENSITIVITY 84%; 3 FP; sentinel clot the only sign in 14%Orwig D, Federle MP. Localized clotted blood as evidence off visceral trauma on CT: the sentinel clot sign. AJR 1989; 153-747-749.

• Mechanical ventilation• Pulmonary barotrauma• Peritoneal lavage• Pneumothorax• Chest injury• Entry of air through fallopian tubes• Intraperitoneal laceration of bladder (trauma or

due to cystography)• Pseudoperitoneum in abdominal wall

•• Mechanical ventilationMechanical ventilation•• Pulmonary barotraumaPulmonary barotrauma•• Peritoneal lavagePeritoneal lavage•• PneumothoraxPneumothorax•• Chest injuryChest injury•• Entry of air through fallopian tubesEntry of air through fallopian tubes•• Intraperitoneal laceration of bladder (trauma or Intraperitoneal laceration of bladder (trauma or

due to cystography)due to cystography)•• Pseudoperitoneum in abdominal wallPseudoperitoneum in abdominal wallKane NM, Francis IR, Burney RE, Wheatley MJ, Ellis JH, Korobkin Kane NM, Francis IR, Burney RE, Wheatley MJ, Ellis JH, Korobkin M. Traumatic pneumoperitoneum.M. Traumatic pneumoperitoneum.Implications of computed tomography diagnosis. Invest Radiol 199Implications of computed tomography diagnosis. Invest Radiol 1991; 26: 5741; 26: 574--578.578.

OTHER CAUSES: INTRAPERITONEAL AIR (78%)OTHER CAUSES: INTRAPERITONEAL AIR (78%)

DUODENAL TRAUMADUODENAL TRAUMA

• Uncommon: only 1% of abdominal trauma• Direct compression of duodenum against spine• Duodenal rupture (perf.) vs. intramural hematoma • Rupture requires emergency surgery • Hematoma usually treated conservatively

• Concomitant injuries may involve liver, pancreas, colon, stomach and small bowel

•• UncommonUncommon: only 1% of abdominal trauma: only 1% of abdominal trauma•• Direct compression of duodenum against spineDirect compression of duodenum against spine•• Duodenal rupture (perf.) vs. intramural hematomaDuodenal rupture (perf.) vs. intramural hematoma •• Rupture requires emergency surgeryRupture requires emergency surgery •• Hematoma usually treated conservativelyHematoma usually treated conservatively

•• Concomitant injuries may involve liver, pancreas, Concomitant injuries may involve liver, pancreas, colon, stomach and small bowelcolon, stomach and small bowel

CT OF DUODENAL TRAUMACT OF DUODENAL TRAUMA

• Duodenal rupture: • Gas, water-density fluid, blood or extravasated oral contrast in right anterior pararenal space• Duodenal hematoma • Mass in duodenal wall due to a hematoma • Obstructive symptoms within 48 hours of injury

• Both conditions • Duodenal wall thickening • Right anterior space fluid or hemorrhage• Important to distinguish as management differs!

•• Duodenal rupture:Duodenal rupture: •• Gas, waterGas, water--density fluid, blood or extravasated oraldensity fluid, blood or extravasated oral contrast in right anterior pararenal spacecontrast in right anterior pararenal space•• Duodenal hematomaDuodenal hematoma •• Mass in duodenal wall due to a hematomaMass in duodenal wall due to a hematoma •• Obstructive symptoms within 48 hours of injuryObstructive symptoms within 48 hours of injury

•• Both conditionsBoth conditions •• Duodenal wall thickeningDuodenal wall thickening •• Right anterior space fluid or hemorrhageRight anterior space fluid or hemorrhage•• Important to distinguish as management differs!Important to distinguish as management differs!

DUODENAL RUPTUREDUODENAL RUPTURE

Blood and water-density fluid in anterior pararenal space and thick-walled duodenum (contusion)

Blood and waterBlood and water--density fluid in anterior pararenal density fluid in anterior pararenal space space and thickand thick--walled duodenum (contusion)walled duodenum (contusion)

DUODENAL HEMATOMADUODENAL HEMATOMA

SENSITIVITY

FLUID IN INTRAFLUID IN INTRA-- OR EXTRAPERITONEAL SPACESOR EXTRAPERITONEAL SPACES

• Hemorrhage• Leakage of bowel contents• Leakage of urine• Pancreatic juice• Residual from peritoneal lavage

•• HemorrhageHemorrhage•• Leakage of bowel contentsLeakage of bowel contents•• Leakage of urineLeakage of urine•• Pancreatic juicePancreatic juice•• Residual from peritoneal lavageResidual from peritoneal lavage

FINDINGS SPECIFIC TO MESENTERIC INJURYFINDINGS SPECIFIC TO MESENTERIC INJURY

• Mesenteric extravasation• Specificity of 100%• Seen in 17% (9/54)• Indication for urgent laparotomy

• Mesenteric vascular beading• Indicative of vascular injury• Seen in 39% (21/54)

• Termination of mesenteric vessels• Abrupt termination of mesenteric art.or veins• Seen in 35% (19/54), highly specific (1 FP)

•• Mesenteric extravasationMesenteric extravasation•• Specificity of 100%Specificity of 100%•• Seen in Seen in 17%17% (9/54)(9/54)•• Indication for urgent laparotomyIndication for urgent laparotomy

•• Mesenteric vascular beadingMesenteric vascular beading•• Indicative of vascular injuryIndicative of vascular injury•• Seen in Seen in 39%39% (21/54)(21/54)

•• Termination of mesenteric vesselsTermination of mesenteric vessels•• Abrupt termination of mesenteric art.or veinsAbrupt termination of mesenteric art.or veins•• Seen in Seen in 35%35% (19/54), highly specific (1 FP)(19/54), highly specific (1 FP)

FINDINGS LESS SPECIFIC TO BOWEL FINDINGS LESS SPECIFIC TO BOWEL AND MESENTERIC INJURYAND MESENTERIC INJURY

• Bowel:• Bowel wall thickening:

- focal wall contusion- diffuse: overhydration or shock bowel

• Abnormal bowel wall enhancement: - patchy or irregular suggestive of full thickness injury

- absent or decreased -> ischemic bowel

•• Bowel:Bowel:•• Bowel wall thickeningBowel wall thickening: :

-- focal wall contusionfocal wall contusion-- diffuse: overhydration or shock boweldiffuse: overhydration or shock bowel

•• Abnormal bowel wall enhancementAbnormal bowel wall enhancement: : -- patchy or irregular suggestive of full patchy or irregular suggestive of full thickness injurythickness injury

-- absent or decreased absent or decreased --> ischemic bowel> ischemic bowel

OVERHYDRATION & SHOCK BOWELOVERHYDRATION & SHOCK BOWEL

OverhydrationOverhydrationOverhydration Shock bowel with liver lacShock bowel with liver lacShock bowel with liver lac

FINDINGS LESS SPECIFIC TO BOWEL FINDINGS LESS SPECIFIC TO BOWEL AND MESENTERIC INJURYAND MESENTERIC INJURY

• Mesentery• Mesenteric infiltration:

- Mesenteric injury with or without bowel injury; high sensitivity; seen in 69%

- DDx: mesenteritis• Mesenteric hematoma:

- Laceration of mesenteric vessel- May not need surgery, if not active bleed

• Bowel features (wall thickening & abnl. enh.) - Secondary to mesenteric injury indicative

of vascular compromise; may be delayed!

•• MesenteryMesentery•• Mesenteric infiltration: Mesenteric infiltration:

-- Mesenteric injury with or without bowel Mesenteric injury with or without bowel injury; high sensitivity; seen in 69% injury; high sensitivity; seen in 69%

-- DDx: mesenteritisDDx: mesenteritis•• Mesenteric hematoma: Mesenteric hematoma:

-- Laceration of mesenteric vesselLaceration of mesenteric vessel-- May not need surgery, if not active bleedMay not need surgery, if not active bleed

•• Bowel features (wall thickening & abnl. enh.) Bowel features (wall thickening & abnl. enh.) -- Secondary to mesenteric injury indicative Secondary to mesenteric injury indicative

of vascular compromise; may be delayed! of vascular compromise; may be delayed!

COMMON FEATURES: BOWEL/MESENT. INJURIESCOMMON FEATURES: BOWEL/MESENT. INJURIES

• Intraperitoneal & Extraperitoneal Fluid:- Intraperitoneal fluid associated with

bowel/mesenteric injuries common (93%, 50/54)- Specificity low because of other concomitant

injuries or pre-existing disease- Location:

- Retroperitoneal fluid -> retroperitoneal segmentof bowel

- Retroperitoneal blood -> close to site of injury- Hemoperitoneum + no parenchymal organ injury

= bowel or mesenteric injury

•• Intraperitoneal & Extraperitoneal Fluid:Intraperitoneal & Extraperitoneal Fluid:-- Intraperitoneal fluid associated with Intraperitoneal fluid associated with

bowel/mesenteric injuries common (93%, 50/54)bowel/mesenteric injuries common (93%, 50/54)-- Specificity low because of other concomitant Specificity low because of other concomitant

injuries or preinjuries or pre--existing diseaseexisting disease-- Location: Location:

-- Retroperitoneal fluid Retroperitoneal fluid --> retroperitoneal > retroperitoneal segmentsegmentof bowelof bowel

-- Retroperitoneal blood Retroperitoneal blood --> close to site of injury> close to site of injury

-- Hemoperitoneum + no parenchymal organ injury Hemoperitoneum + no parenchymal organ injury = bowel or mesenteric injury= bowel or mesenteric injury

COMMON FEATURES: BOWEL/MESENT. INJURIESCOMMON FEATURES: BOWEL/MESENT. INJURIES

• Abdominal Wall Injury:

- Abdominal wall injury (e. g., seat belt injury = soft tissue stranding, tear, hematoma) associated with

- Bowel or mesenteric injuries in 17% (9/54)

•• Abdominal Wall Injury:Abdominal Wall Injury:

-- Abdominal wall injury Abdominal wall injury (e. g., seat belt (e. g., seat belt injury = soft tissue stranding, tear, injury = soft tissue stranding, tear, hematoma) associated withhematoma) associated with

-- Bowel or mesenteric injuries in 17% Bowel or mesenteric injuries in 17% (9/54)(9/54)

DIAGNOSTIC PITFALLSDIAGNOSTIC PITFALLS

• Multiple injuries incl. liver/spleen• Large size of patients• Metallic monitoring devices• Arms in imaging field• Chaotic scene at imaging site

•• Multiple injuries incl. liver/spleenMultiple injuries incl. liver/spleen•• Large size of patientsLarge size of patients•• Metallic monitoring devicesMetallic monitoring devices•• Arms in imaging fieldArms in imaging field•• Chaotic scene at imaging siteChaotic scene at imaging site

SENSITIVITY & SPECIFICITY IN DIAGNOSING SENSITIVITY & SPECIFICITY IN DIAGNOSING SURGICALLY SURGICALLY IMPORTANT BOWEL/MESENTERIC INJURYIMPORTANT BOWEL/MESENTERIC INJURY

Bowel wall defect 11 100 *Extraluminal contrast 8 100 *Intraperitoneal air 24 95Thick large bowel wall 18 97 *Thick small bowel wall 45 76Retroperitoneal air 5 98Abnormal bowel enhanc. 8 90Positive (negative) Likelihood ratio useful * *

Bowel wall defectBowel wall defect 1111 100 100 **Extraluminal contrastExtraluminal contrast 88 100 100 **Intraperitoneal airIntraperitoneal air 2424 9595Thick large bowel wallThick large bowel wall 1818 97 97 **Thick small bowel wallThick small bowel wall 4545 7676Retroperitoneal airRetroperitoneal air 55 9898Abnormal bowel enhanc.Abnormal bowel enhanc. 88 9090Positive (Positive (negativenegative) Likelihood ratio useful * ) Likelihood ratio useful * **

Atri M, et al. Surgically important bowel and/or mesenteric injury in blunt trauma: accuracy of MDCT for evaluation.Radiology 2008; 249: 524-533.

SignSign Sensitivity (%) Specificity (%)Sensitivity (%) Specificity (%)

SENSITIVITY & SPECIFICITY IN DIAGNOSING SENSITIVITY & SPECIFICITY IN DIAGNOSING SURGICALLY SURGICALLY IMPORTANT BOWEL/MESENTERIC INJURYIMPORTANT BOWEL/MESENTERIC INJURY

Retroperitoneal fluid 37 52Mesenteric vessel beading 50 95 *Abrupt mes. vessel term. 45 93 *Mesenteric vessel extrav. 26 100 *Focal mesenteric hematoma 45 90Mesenteric air 21 95Intraperitoneal fluid 100 26 *Mesenteric fluid +/or strand. 84 66

Retroperitoneal fluidRetroperitoneal fluid 3737 5252Mesenteric vessel beadingMesenteric vessel beading 5050 95 95 **Abrupt mes. vessel term.Abrupt mes. vessel term. 4545 93 93 **Mesenteric vessel extrav.Mesenteric vessel extrav. 2626 100 100 **Focal mesenteric hematomaFocal mesenteric hematoma 4545 9090Mesenteric airMesenteric air 2121 9595Intraperitoneal fluidIntraperitoneal fluid 100100 26 26 **Mesenteric fluid +/or strand.Mesenteric fluid +/or strand. 8484 6666

Atri M, et al. Surgically important bowel and/or mesenteric injury in blunt trauma: accuracy of MDCT for evaluation.Radiology 2008; 249: 524-533.

SignSign Sensitivity (%) Specificity (%)Sensitivity (%) Specificity (%)

CONCLUSIONS: BOWEL/MESENTERIC INJURYCONCLUSIONS: BOWEL/MESENTERIC INJURY

• Recognize significant bowel/mesenteric injuries• CT signs of significant injuries: • Bowel wall defect • Free air (intraperitoneal, retroperitoneal or mesenteric) • Intraperitoneal bowel contrast material • Extravasation of contrast from mesenteric vessels • Evidence of bowel infarct

• CT signs: high specificity, low sensitivity!

•• Recognize significant bowel/mesenteric injuriesRecognize significant bowel/mesenteric injuries•• CT signs of CT signs of significant injuriessignificant injuries:: •• Bowel wall defectBowel wall defect •• Free air (intraperitoneal, retroperitoneal or mesenteric)Free air (intraperitoneal, retroperitoneal or mesenteric) •• Intraperitoneal bowel contrast material Intraperitoneal bowel contrast material •• Extravasation of contrast from mesenteric vesselsExtravasation of contrast from mesenteric vessels •• Evidence of bowel infarctEvidence of bowel infarct

•• CT signs: CT signs: high specificity, low sensitivity!high specificity, low sensitivity!

CONCLUSIONS: BOWEL/MESENTERIC INJURYCONCLUSIONS: BOWEL/MESENTERIC INJURY

Signs for injury needing surgery:

• Mesenteric hematoma combined with bowel thickening

• Significant amount of free fluid without solid organ injury

Signs for injury needing surgery:Signs for injury needing surgery:

•• Mesenteric hematoma combined with bowel Mesenteric hematoma combined with bowel thickeningthickening

•• Significant amount of free fluid without solid Significant amount of free fluid without solid organ injuryorgan injury

CONCLUSIONS: MESENTERIC INJURYCONCLUSIONS: MESENTERIC INJURY

• Two additional useful signs for mesenteric injury:• Mesenteric vascular beading• Abrupt termination of mesenteric vessels

• Both with high specificity and more frequently seen than mesenteric extravasation

•• Two additional useful signs for mesenteric injury:Two additional useful signs for mesenteric injury:•• Mesenteric vascular beadingMesenteric vascular beading•• Abrupt termination of mesenteric vesselsAbrupt termination of mesenteric vessels

•• Both with high specificity and more frequently Both with high specificity and more frequently seen than mesenteric extravasationseen than mesenteric extravasation

CONCLUSIONS: BOWEL/MESENTERIC INJURYCONCLUSIONS: BOWEL/MESENTERIC INJURY

• Nonspecific features of significant bowel or mesenteric injury:

• Decision for surgery depends on clinical judgment• Reevaluate with CT within 6-8 hours

• MDCT negative for bowel and/or mesenteric injury -> CT screening tool to discharge a patient

•• Nonspecific features of significant bowel or Nonspecific features of significant bowel or mesenteric injury:mesenteric injury:

•• Decision for surgery depends on clinical judgmentDecision for surgery depends on clinical judgment•• Reevaluate with CT within 6Reevaluate with CT within 6--8 hours8 hours

•• MDCT negative for bowel and/or mesenteric MDCT negative for bowel and/or mesenteric injury injury --> CT screening tool to discharge a patient> CT screening tool to discharge a patient