Dr. Morgan Penzler is an Emergency Medicine Resident and Drs. Raza Ahmad and Ansley Ricker 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 cases include: - Gastric Perforation - Pneumoperitoneum - Lower GI Bleed - Parastomal Hernia

1. Adult Abdominal Imaging Case Studies
Raza Ahmad, MD, Morgan Penzler, MD, Ansley Ricker, MD
Departments of Surgery & Emergency Medicine
Carolinas Medical Center & Levine Children’s Hospital
Brent Matthews, MD – Guest Editor
Kyle Cunningham, MD & Michael Gibbs MD – Faculty Editors
Abdominal Imaging Mastery Project
December 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. It’s All About The Anatomy!

4. Systematic Approach to Abdominal CT Interpretation
● 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

5. CASE #1:
A 64-year-old male
presenting after being
found down in a
parking lot. He is a
diabetic with a 40 pack-
year smoking history.
The exam reveals
tachycardia and
peritonitis on exam. CT
imaging was obtained.
Diagnosis?

6. CASE #1:
The patient was
suffering from a gastric
ulcer perforation. On
CT imaging there was
significant
pneumoperitoneum, a
large perforation along
the lesser curvature of
the stomach, and
extravasation of gastric
contents into the
peritoneal cavity.
Pneumoperitoneum
Lesser Curvature Perforation With
Extravasation Of Gastric Content

7. Gastric Ulcer Perforation
• Pathophysiology: there is a full-thickness injury to the stomach wall. Partial-
thickness injuries from trauma or electrocautery can progress to a full-
thickness injury over time causing perforation.
• History: peptic ulcer disease1, a previous diagnosis of H. pylori, NSAID
or aspirin use, recent instrumentation or surgery, and ingested foreign
body.
• Incidence: 3 to 6.5 per 100,000 individuals
• Presentation: the sudden onset severe abdominal pain, tachycardia,
and abdominal rigidity represent the “classic triad” of peptic ulcer
perforation.
1Peptic ulcer disease is the most common cause of stomach and duodenal perforation.

8. Back To Our Case!
• Our patient adamantly denied NSAID usage, so peptic ulcer as the cause
of gastric ulcer perforation was assumed.
• The patient was taken emergently to the operating room by General
Surgery for an exploratory laparotomy with subtotal gastrectomy left in
discontinuity, abdominal washout, and ABThera™ placement.
• He was taken back to surgery the following days for completion
antrectomy, vagotomy, Billroth 2 gastrojejunostomy, gastrojejunostomy
feeding tube placement, further washout, and abdominal closure.

9. Pneumoperitoneum – Imaging Findings

10. There Are Several
Radiographic Findings And
“Signs” Associated With
Pneumoperitoneum.

11. 4-Year-Old With Abdominal Pain
Bowel Perforation Due To Enteritis
 Subphrenic air (solid white arrow)
 Falciform ligament sign (dashed white
arrows)
 Rigler sign (dashed black arrows)
 Ligamentum teres sign (solid black arrows)

12. 87-Year-Old With Peptic Ulcer Disease
Presents With Three Days Of Abdominal Pain
Duodenal Perforation
A. Falciform ligament sign on plain radiograph
B. Seen as a vertical band on abdominal CT

13. 56-Year-Old With Three Days Of Diarrhea And
Epigastric Abdominal Pain
Perforated Gastric Ulcer
• Small triangular pocket of air outlined by
three adjacent bowel loops
• The telltale triangle sign

14. 69-Year-Old On Dexamethasone For Cerebral
Edema Presents With Abdominal Pain
Bedside Venting Procedure Performed And Then
The Patient Was Made Comfort Care
• Massive pneumoperitoneum
• Centralization of abdominal organs
• Air outlining the liver and gallbladder
(arrow)

15. 65-Year-Old Becomes Unstable During An
Elective Colonoscope
Perforation Of The Ascending Colon. The Patient
Recovered After Decompressive Laparotomy
• Massive pneumoperitoneum
• Centralization of abdominal contents,
consistent with tension pneumoperitoneum

16. Two-Year-Old Receives CPR Briefly Following A
Witnessed Seizure
Posterior Gastric Perforation. The Child
Recovered After Surgical Repair
• Massive pneumoperitoneum
• Centralization of abdominal contents
• Football sign representing air outlining the
entire abdominal wall
IMAGES IN CLINICAL MEDICINE
Pneumoperitoneum from aGastricPerforation
Alexandra Masson, M.D., and Gerard Cheron, M.D., Ph.D.
JANUARY 2, 2022
PHYSICIAN J
OBS
J
uly 4, 2019
N Engl JMed 2019; 381:75
DOI: 10.1056/NEJ
Micm1814352
Metrics
Cambridge, Massachusetts
EmergencyMedicine
post-marketing period, non-serious and serious cases
of DILI were reported. Cases of severe liver injury with
fatal outcome have been reported in the post-
marketing period. The majority of hepatic events occur
within the first three months of treatment. OFEV was
associated with elevations of liver enzymes (ALT, AST,
ALKP, and GGT) and bilirubin. Liver enzyme and
bilirubin increases were reversible with dose
modification or interruption in the majority of cases.
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OBS
A two-and-a-half-year-old boywasbrought to theemergencydepartment a! er hehad aseizureduring a
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DOI: 10.1056/NEJ
M
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17. Subdiaphragmatic Free Air

18. Free Air On Lateral Decubitus Film

19. Subdiaphragmatic Free Air, Lucent Liver Sign (LLS), And Cupola Sign (➤)
LLS
➤
➤

20. Subdiaphragmatic Free Air

21. Subdiaphragmatic Free Air And Rigler Sign (➤)

22. Free Air On Lateral Decubitus Film

23. Rigler Sign, Also Known As The Double Wall Sign

24. Subdiaphragmatic Free Air And Cupula Sign (➤)

25. Free Air On Lateral Decubitus Film

26. Falciform Ligament Sign

27. Reappraisal of radiographic signs of pneumoperitoneum
at emergency department
Yu-Hui C
hiu MDa,b
, Jen-Dar C
hen MDb,c,
, C
hui-Mei Tiu MDb,c
, Yi-Hong C
hou MDb,c
,
David Hung-Tsang Yen MD, PhDa,b
, C
hun-I Huang MDa,b
, C
heng-Yen C
hang MDb,c
a
Department of Emergency Medicine, Taipei Veterans General Hospital, Taiwan, ROC
b
National Yang-Ming University School of Medicine, Taiwan
c
Department of Radiology, Taipei Veterans General Hospital, Taipei, Taiwan, ROC
Received 4 January 2008; revised 14 February 2008; accepted 1 March 2008
Abstract
Purpose: Thisstudy aimed to evaluate the sensitivities of thereported free air signs on supine chest and
abdominal radiographs of hollow organ perforation. We also verified the value of supine radiographic
images as compared with erect chest and decubitus abdominal radiographs in detection of
pneumoperitoneum.
Methods: Two hundred fifty cases with surgically proven hollow organ perforation were included. Five
hundred twenty-seven radiographs were retrospectively reviewed on the picture archiving and
communication system. Medical charts were reviewed for operative findings of upper gastrointestinal
tract, small bowel, or colon perforations. The variable free air signs on both supine abdominal
radiographs (KUB) and supine chest radiographs (CXR) were evaluated and determined by consensus
without knowledge of initial radiographic reports or final diagnosis. Erect CXR and left decubitus
abdominal radiographs were evaluated for subphrenic free air or air over nondependent part of the right
abdomen.
Result: Upper gastrointestinal tract perforation was proven in 91.2%; small bowel perforation, in 6.8%;
and colon perforation, in 2.0%. Thepositiverateof freeair was80.4% on supineKUB, 78.7% on supine
CXR, 85.1% on erect CXR, and 98.0% on left decubitus abdominal radiograph. Anterior superior oval
sign was the most common radiographic sign on supine KUB (44.0%) and supine CXR (34.0%). Other
free air signs ranged from 0% to 30.4%.
C
onclusions: Most free air signs on supine radiographs are located over the right upper abdomen.
Familiarity with free air signs on supine radiographs is very important to emergency physicians and
American Journal of Emergency Medicine (2009) 27, 320–327
a
Department of Emergency Medicine, Taipei Veterans General Hospital, Taiwan, ROC
b
National Yang-Ming University School of Medicine, Taiwan
c
Department of Radiology, Taipei Veterans General Hospital, Taipei, Taiwan, ROC
Received 4 January 2008; revised 14 February 2008; accepted 1 March 2008
Abstract
Purpose: This study aimed to evaluate the sensitivities of the reported free air signs on supine chest and
abdominal radiographs of hollow organ perforation. We also verified the value of supine radiographic
images as compared with erect chest and decubitus abdominal radiographs in detection of
pneumoperitoneum.
Methods: Two hundred fifty cases with surgically proven hollow organ perforation were included. Five
hundred twenty-seven radiographs were retrospectively reviewed on the picture archiving and
communication system. Medical charts were reviewed for operative findings of upper gastrointestinal
tract, small bowel, or colon perforations. The variable free air signs on both supine abdominal
radiographs (KUB) and supine chest radiographs (CXR) were evaluated and determined by consensus
without knowledge of initial radiographic reports or final diagnosis. Erect CXR and left decubitus
abdominal radiographs were evaluated for subphrenic free air or air over nondependent part of the right
abdomen.
Result: Upper gastrointestinal tract perforation was proven in 91.2%; small bowel perforation, in 6.8%;
and colon perforation, in 2.0%. Thepositiverateof freeair was80.4% on supineKUB, 78.7% on supine
CXR, 85.1% on erect CXR, and 98.0% on left decubitus abdominal radiograph. Anterior superior oval
at emergency department
Yu-Hui C
hiu MDa,b
, Jen-Dar C
hen MDb,c,
, C
hui-Mei Tiu MDb,c
, Yi-Hong C
hou M
David Hung-Tsang Yen MD, PhDa,b
, C
hun-I Huang MDa,b
, C
heng-Yen C
hang MD
a
Department of Emergency Medicine, Taipei Veterans General Hospital, Taiwan, ROC
b
National Y
ang-Ming University School of Medicine, Taiwan
c
Department of Radiology, Taipei Veterans General Hospital, Taipei, Taiwan, ROC
Received 4 January 2008; revised 14 February 2008; accepted 1 March 2008
Abstract
Purpose: Thisstudy aimed to evaluatethesensitivitiesof thereported freeair signson supinechest and
abdominal radiographs of hollow organ perforation. We also verified the value of supine radiographic
images as compared with erect chest and decubitus abdominal radiographs in detection of
pneumoperitoneum.
Methods: Two hundred fifty caseswith surgically proven hollow organ perforation wereincluded. Five
hundred twenty-seven radiographs were retrospectively reviewed on the picture archiving and
communication system. Medical charts were reviewed for operative findings of upper gastrointestinal
tract, small bowel, or colon perforations. The variable free air signs on both supine abdominal
radiographs (KUB) and supine chest radiographs (CXR) were evaluated and determined by consensus
without knowledge of initial radiographic reports or final diagnosis. Erect CXR and left decubitus
abdominal radiographs wereevaluated for subphrenic freeair or air over nondependent part of theright
abdomen.

28. KUB Findings

29. CXR Findings

30. hundred twenty-seven radiographs were retrospectively reviewed on the picture archiving and
communication system. Medical charts were reviewed for operative findings of upper gastrointestinal
tract, small bowel, or colon perforations. The variable free air signs on both supine abdominal
radiographs (KUB) and supine chest radiographs (CXR) were evaluated and determined by consensus
without knowledge of initial radiographic reports or final diagnosis. Erect CXR and left decubitus
abdominal radiographs were evaluated for subphrenic free air or air over nondependent part of the right
abdomen.
Result: Upper gastrointestinal tract perforation was proven in 91.2%; small bowel perforation, in 6.8%;
and colon perforation, in 2.0%. Thepositiverateof freeair was80.4% on supineKUB, 78.7% on supine
CXR, 85.1% on erect CXR, and 98.0% on left decubitus abdominal radiograph. Anterior superior oval
sign was the most common radiographic sign on supine KUB (44.0%) and supine CXR (34.0%). Other
free air signs ranged from 0% to 30.4%.
C
onclusions: Most free air signs on supine radiographs are located over the right upper abdomen.
Familiarity with free air signs on supine radiographs is very important to emergency physicians and
radiologists for detection of hollow organ perforation.
© 2009 Elsevier Inc. All rights reserved.
1. Introduction
American Journal of Emergency Medicine (2009) 27, 320–327

31. CASE #2:
A 79-year-old female
with a history of
diverticulosis and atrial
fibrillation (on
apixaban) presents to
the ED with maroon-
colored stools. The
patient’s vital signs and
hemoglobin are
normal.
Diagnosis?

32. CASE #2:
CT angiography of the
abdomen and pelvis
revealed an acute
diverticular bleed in the
mid descending colon.
Active Diverticular
Bleeding With A
Contrast Blush

33. Lower GI Bleed
• Occurs in 20-35 per 100,000 adults per year, mortality rate 2-5%
• More common in patients who are female and elderly
• Caused by diverticular disease, colitis, polyps, AVM, angiodysplasia,
malignancy, brisk upper gastrointestinal bleeding, hemorrhoids
• Diverticulosis represents 30% of lower GI bleeding:
• Usually painless, typically results from penetrating artery erosion
• Some require embolization by interventional radiology for control
• Clinician can consider using the Oakland Score to identify patients
who may be able to be discharged home safely

34. Back To Our Case!
• The patient was transferred to interventional radiology for
embolization.
• She had intermittent bleeding of the distal left colic branch, which
was embolized.
• Hemoglobin on admission was 11.2, it trended down to 9.3 where it
remained stable. She did not require transfusion.
• She was instructed to restart her apixaban (Eliquis®) once her stools
had returned to normal.

40. CASE #3:
45-year-old male with
1 day of no ostomy
output, nausea,
abdominal pain, and
feculent vomiting. The
patient is tachycardic
and hypotensive. He
has abdominal
tenderness and a
parastomal hernia.
Diagnosis?

41. Small Bowel Obstruction Transition Point -
Proximally Dilated & Distally Decompressed
Questionable Transition Point, But Notice
That The Bowel Is Not Dilated
Parastomal Hernia

42. Parastomal Hernia
• Parastomal hernias occur up to 50% of patients after construction of
a colostomy or ileostomy.
• A parastomal hernia is a type of incisional hernia that allows
protrusion of abdominal contents through the abdominal wall defect
created during ostomy formation.
• Surgical repair is generally avoided due to the propensity for
parastomal hernia to recur.
• Patients with incarcerated or strangulated bowel within the hernia
sac can have symptoms of bowel obstruction, and these patients
require an operation.

43. Back To Our Case!
• The patient was taken to the operating room after failing
conservative management with nasogastric decompression and a
Gastrograffin challenge.
• A lysis of adhesions was performed followed by revision of
parastomal hernia. The adhesive band was found deep in the pelvis,
and not in the parastomal hernia sac.
• Postoperatively the patient recovered bowel function, however
developed an entero-cutaneous (EC) fistula.
• He was discharged to long-term-care with TPN to optimize nutrition
and aid with wound healing and EC fistula closure.

54. See You Next Month!