Dr. Kelsey Lena is an Emergency Medicine Resident and Drs. Michael Avery and Joshua Davis are Surgery Residents at Carolinas Medical Center in Charlotte, NC. They are interested in medical education. With the guidance of Drs. Kyle Cunningham and Michael Gibbs, they aim to help augment our understanding of emergent abdominal imaging. Follow along with the EMGuideWire.com team as they post these monthly educational, self-guided radiology slides. This month’s topics include: - Large Bowel Obstruction - Blunt Aortic Injury - Abdominal Aortic Aneurysm with Rupture

1. Adult Abdominal Imaging Case Studies
Michael Avery, DO, Joshua Davis, MD, Kelsey Lena, MD
Department of Surgery & Emergency Medicine
Carolinas Medical Center & Levine Children’s Hospital
Kyle Cunningham, MD & Michael Gibbs MD - Faculty Editors
Abdominal Imaging Mastery Project
April 2021

2. Disclosures
▪ This ongoing abdominal imaging interpretation series is proudly co-
sponsored by the Emergency Medicine & Surgery Residency Programs
at Carolinas Medical Center.
▪ The goal is to promote widespread interpretation mastery.
▪ There is no personal health information [PHI] within, and ages have been
changed to protect patient confidentiality.

3. Process
▪ Many are providing cases and these slides are shared with all contributors.
▪ Contributors from many Carolinas Medical Center departments, and now…
Brazil, Chile and Tanzania.
▪ Cases submitted this month will be distributed next month.
▪ When reviewing the presentation, the 1st slide will show an image without
identifiers and the 2nd slide will reveal the diagnosis.

4. It’s All About The Anatomy!

5. Systematic Approach to Abdominal CTs
● Aorta Down - follow the flow of blood!
○ Thoracic Aorta → Abdominal Aorta → Bifurcation → Iliac a.
● Veins Up - again, follow the flow!
○ Femoral v. → IVC → Right Atrium
● Solid Organs Down
○ Heart → Spleen → Pancreas → Liver → Gallbladder → Adrenal
→ Kidney/Ureters → Bladder
● Rectum Up
○ Rectum → Sigmoid → Transverse → Cecum → Appendix
● Esophagus down
○ Esophagus → Stomach → Small bowel

6. Systematic Approach to Abdominal CTs
● Abdominal Wall/Soft tissue Up
○ Free air, abscesses, hernias
● Retroperitoneum Down
○ Hematoma, masses
● GU Up
○ Masses
● Tissue specific windows
○ Lung
○ Bone
● Don’t forget to look at multiple planes
○ Axial, sagittal, coronal

7. CBD
SMV
SMA
duodenum
Portal vein
CBD and PD
CASE #1:
52-year-old male with 6-12
months of constipation,
bloating, and a 15-pound
weight loss is transferred to
the ED from the
Endoscopic Suite after
ongoing abdominal
distention and incomplete
bowel prep. CT scan
revealed the following .
Diagnosis?

8. CBD
SMV
SMA
duodenum
Portal vein
CBD and PD
Massively dilated loops of
bowel
Possibly obstructing rectal
mass
CASE #1:
52-year-old male with 6-12
months of constipation,
bloating, and a 15-pound
weight loss is transferred to
the ED from the
Endoscopic Suite after
ongoing abdominal
distention and incomplete
bowel prep. CT scan
revealed the following .
Diagnosis?
Large Bowel Obstruction

9. Common Causes of Large Bowel Obstruction
• Malignancy
• Colorectal carcinoma most common
• Volvulus:
• Cecal volvulus
• Sigmoid volvulus (more common)
• Fecal impaction
• Colonic Diverticulitis
• Ischemic Stricture

12. Radiographic Essentials
of Large Bowel
Obstruction
• Computed tomography is the imaging
method of choice as it can establish the
diagnosis and cause of large-bowel
obstruction (LBO)
• Certain findings are dependent on cause of
LBO

13. Treatment of
Large Bowel
Obstruction
• Depends on cause
• All cases require adequate resuscitation and electrolyte
correction
• If peritonitis is involved or perforation is suspected need an emergent
surgery
• Decompressive colostomy proximal to obstruction

14. Colorectal Carcinoma: Quick Hits
• Most common cancer of the GI tract in adults
• Risk factors:
• Obesity
• IBD
• Ulcerative Colitis
• Crohn Disease
• Colonic adenoma
• Dysplasia of the colon
• Family history of benign and malignant colorectal tumors

15. Presentation:
• Constipation and/or diarrhea
• Bowel obstruction
• Rectal bleeding
• Weight loss
• Change in eating habits
Colorectal Carcinoma: Quick Hits

16. Colorectal Cancer
screening (USPSTF)
• For persons >50 years of age: an annual fecal
occult blood test (often a fecal immunochemical
test and sigmoidoscopy/barium enema every 3 to 5
years
• For first-degree relatives of patients with colon
cancer: screening should start at age 40

17. CASE #2:
A 30-year-old otherwise
healthy male presents after
sustaining a crush injury of
his torso at work. His blood
pressure is 119/71 and his
heart rate is in the 120’s.
The FAST examination is
positive on all abdominal
views.
The patient was then taken
to the CT scanner with the
resulting images.
Identify the CT findings

18. CASE #2:
A 30-year-old otherwise
healthy male presents after
sustaining a crush injury of
his torso at work. His blood
pressure is 119/71 and his
heart rate is in the 120’s.
The FAST examination is
positive on all abdominal
views.
The patient was then taken
to the CT scanner with the
resulting images.
Identify the CT findings
Hemoperitoneum
(HU=60)
Grade III Blunt Aortic
Transection With
Retroperitoneal Hematoma
SMA Dissection With
Proximal Occlusion And
Distal Reconstitution
Grade II Spleen Laceration
Grade IV Liver Laceration

19. Aortic Contrast
Extravasation

20. CASE #2:
The patient was identified
to have multiple solid
organ and vascular injuries
as listed.
Shortly after the CT is
completed, the patient
became hypotensive with a
systolic pressure in the 80’s
and tachycardic with a
heart rate in the 150’s.
Next steps?
Hemoperitoneum
(HU=60)
Grade III Blunt Aortic
Transection With
Retroperitoneal Hematoma
SMA Dissection With
Proximal Occlusion And
Distal Reconstitution
Grade II Spleen Laceration
Grade IV Liver Laceration

21. CASE #2:
The patient was resuscitated
and taken emergently to the
operating room.
He underwent a trauma
laparotomy with
splenectomy followed by
endovascular graft repair of
the aortic and SMA injuries.
Also note CT finding of
pancreatic injury.
Ultimately, after additional
take-back operations the
patient also required a distal
pancreatomy.
Finding Concerning For A Distal Pancreatic
Contusion vs Laceration
Additional Image Of The Blunt
Abdominal Aortic Injury

22. Thoracoabdominal Endovascular Aortic Stent.

23. Management of blunt
hepatic and splenic
injuries
EAST guidelines provide an evidenced based review for the management of these
injuries. Briefly summarized:
• Hemodynamically unstable patients should undergo immediate exploratory
laparotomy
• Stable patients should undergo CT imaging for injury staging
• When possible, hemodynamically stable patient should be treated angiographically
• When local resources are limited, patients should be transferred to a regional
Trauma Center

24. Objective: To examine the presentation, management, and outcomes of blunt abdominal aortic injury (BAAI).
Methods: 12-center Western Trauma Association registry review 1996 to 2011.
Results:  Of 392,315 blunt trauma patients, 113 (0.3%) had BAAI
 Motor vehicle crashes the leading cause (60%)
 The most common associated injuries were spine fractures (44%)
 Solid organ, small bowel, and large bowel injuries each occurred in ≈30% of patients
 BAAI: intimal flaps (34%), free rupture (32%), pseudoaneurysm (16%)
 89% of intimal tears managed non-operatively; 96% of free ruptures managed surgically
 Overall mortality 39%, the majority (68%) occurring in the first 24 hours because of hemorrhage
 Highest mortality in Zone II aortic ruptures

28. 12-year-old male passenger restrained by a lap belt is involved in a motor vehicle crash. Injuries include an L4
vertebral Chance fracture, retroperitoneal hematoma, and injury of the abdominal aorta at the L4 level.
Arrows demonstrate an intimal flap on the Axial and Coronal views (arrows).
The injury was managed non-operatively.

29. Aortic Injury + Chance Fracture Of L2: Black Arrowheads Demonstrate Intimal Flaps And
White Arrowheads Indicate Periaortic Hematoma.

33. Classification Of Blunt Aortic Injuries
Aortic injuries are graded based on CT findings:
• Grade I: intimal tear or localized hematoma
• Grade II: intramural hematoma
• Grade III: pseudoaneurysm
• Grade IV: rupture with active extravasation
For more information: Blunt thoracic aortic injury – concepts and management | Journal of Cardiothoracic Surgery | Full Text
(biomedcentral.com)
Grade I Often resolve with conservative management & monitoring
Grade II-III Frequently amenable to endovascular repair
Grade IV Patients usually in extremis, and require emergent open repair

34. CASE #3:
A 72-year-old-female
presented to the ED
obtunded and
hemodynamically unstable
with a BP of 72/53, HR
140, SAO2 88%. The
family notes that she was
walking in the house when
she experienced a
witnessed syncope event
with no return to baseline.
Physical examination
revealed a protuberant
abdomen, and a CT
angiography of the
abdomen & pelvis was
quickly obtained.
Diagnosis?

35. Note the acute hemorrhage in the
aneurysm wall and right retroperitoneal
hematoma, consistent with early rupture
Abdominal aortic aneurysm
measuring up to 8.8 cm in size
CASE #3:
A 72-year-old-female
presented to the ED
obtunded and
hemodynamically unstable
with a BP of 72/53, HR
140, SAO2 88%. The
family notes that she was
walking in the house when
she experienced a
witnessed syncope event
with no return to baseline.
Physical examination
revealed a protuberant
abdomen, and a CT
angiography of the
abdomen & pelvis was
quickly obtained.
Diagnosis?
Abdominal aortic
aneurysm

36. CASE #3:
Current images
(4/2021)
compared with
those obtained
in 12/2019.
Arrows point
to periaortic
hematoma.
2019: 4.4 x 5.6 2021: 6.6 x 6.6

37. CASE #3:
Current images
(4/2021)
compared with
those obtained
in 12/2019.
Arrows point
to periaortic
hematoma.
2019: 5.1 x 9.6 2021: 6.8 x 11.7

38. CASE #3:
Current images
(4/2021)
compared with
those obtained
in 12/2019.
Arrows point
to periaortic
hematoma.
2019: 5.2 x 8.3 2021: 7.1 x 14.1

39. Abdominal Aortic Aneurysm (AAA)
• Focal dilation of the aorta with respect to the adjacent artery.
• A AAA is defined as an aortic diameter at least 1 ½ the normal
diameter, which is typically > 3.0 cm.
• Approximately 200,000 people are diagnosed with AAA each year in
the U.S.

40. Non-Modifiable
• Age1
• Family history of aneurysm2
• Gender3
1Starting at 50 years for men and at 60 years for women, the
incidence of AAA increases.
2The risk is four times higher in patients with a family
history of aneurysm.
3The risk of aneurysm is four times higher in men that in
women.
Modifiable
• Smoking (#1)
• Hypertension
• Elevated cholesterol
• Obesity
Risk Factors

41. • The mortality from aortic rupture is 85% to 90%.
• 150,000 deaths in the U.S. each year.
• Most patients are asymptomatic until rupture occurs… a strong incentive
for periodic aortic screening with ultrasound!
Aortic Rupture

42. • Intraperitoneal rupture is lethal.
• Patients with retroperitoneal rupture
and a contained hematoma may present
with stable vital signs.
• Rupture into the inferior vena cava
manifests with pain and high-output
heart failure.
• Rupture into the bowel (aorto-enteric
fistula) present with pain and a massive
GI bleed.
Aortic Rupture

43. Aortic Rupture

44. Treatment Options
The ACC/AHA recommendations for AAA repair:
• 5.5 cm in diameter or greater in asymptomatic patients
• Symptomatic aneurysms or aneurysms that increase in diameter by 0.5 cm or
greater in 6 months
Surgical repair vs. endovascular repair:
• Endovascular repair is less invasive, less expensive, and is associated with
reduced hospital stay, and reduction in 30-day all cause mortality rate
• Growth body of outcome literature

49. Results:
• 444 patients were assigned to endovascular repair and 437 to open repair.
• During the first 4 years of follow-up, overall survival appeared to be higher with
endovascular repair than with open repair; from 4 through 8, overall survival was higher
in the open group; and after years, overall survival was once again higher in the
endovascular-repair group (hazard ratio for death, 0.94; 95% CI, 0.74 to 1.18). None of
these trends were statistically significant.

56. Summary Of Diagnoses This Month
● Large bowel obstruction secondary to malignancy
● Blunt aortic injury
● Abdominal aortic aneurysm with rupture

57. See You Next Month!