Plain film from www.learningradiology.
com
CT, US, MRI all PACS BIDMC
Diagnosing Appendicitis
in the Emergency Department
with Imaging
Heather Burns Gunn, HMS III
Gillian Lieberman, MD
Radiology Core
BIDMC
November 2007
Lets meet our patient in the emergency room
Patient CH: History
24 yo woman
presents to ED with 2 days of abdominal pain
initially diffuse, crampy pain in epigastric area
pain migrated to RLQ 12 hours ago and became
sharper
several episodes of N/V in last 12 hours
denies diarrhea, constipation, melena, BRBPR
endorses reduced appetite
Patient CH: Physical Exam & Labs
Physical exam normal except abdominal
exam
Soft, non-distended, tender RLQ
No rebound tenderness
+ Rovsings sign (pain in RLQ during
palpation of LLQ)
Labs of note:
WBC: 16.6 with 83% Neutrophils
Creatinine: 0.9
DDx of RLQ pain
GI
Appendicitis
Crohns
Right sided diverticulitis
Mesenteric adenitis
Epiploic appendagitis
Bowel ischemia
Right colonic neoplasia
Infectious ileocolitis
Mucocele of the appendix
Typhilitis
Sigmoid diverticulitis
Intussusception
Pseudomembraneous or
cytomegalovirus colitis
Perforated peptic ulcer
Perforated cholecystitis
Pancreatitis
Renal
Acute pyelonephritis
Renal and urinary tract obstruction
Gynecological
Pelvic inflammatory disease
Hemorrhagic ovarian cyst
Ovarian vein thrombosis
Ovarian dermoid
Necrotic uterine leiomyoma
Ovarian torsion
Endometriosis
Ruptured ectopic pregnancy
Yu J et al. Helical CT evaluation of acute right lower
quadrant pain. AJR 2005.
DDx of RLQ pain
GI
Appendicitis
Crohns
Right sided diverticulitis
Mesenteric adenitis
Epiploic appendagitis
Bowel ischemia
Right colonic neoplasia
Infectious ileocolitis
Mucocele of the appendix
Typhilitis
Sigmoid diverticulitis
Intussusception
Pseudomembraneous or
cytomegalovirus colitis
Perforated peptic ulcer
Perforated cholecystitis
Pancreatitis
Renal
Acute pyelonephritis
Renal and urinary tract obstruction
Gynecological
Pelvic inflammatory disease
Hemorrhagic ovarian cyst
Ovarian vein thrombosis
Ovarian dermoid
Necrotic uterine leiomyoma
Ovarian torsion
Endometriosis
Ruptured ectopic pregnancy
Yu J et al. Helical CT evaluation of acute right lower
quadrant pain. AJR 2005.
COMMON
Appendicitis is the most
common cause of acute
abdomen.1
EXPENSIVE:
In 2004, 300,000 cases
in US alone, total
healthcare cost of 5.8
billion.2
DANGEROUS:
Before universal
acceptance of
appendectomy as
standard of care,
mortality for appendicitis
was more than 50%.3
1Davies G et al. The burden of appendicitis related
hospitalizations in the United States in 1997. Surg Infect
2004.
2 Otero
H et al. Imaging utilization in the management of
appendicitis and its impacton hospital charges. Emerg
Radiol 2007.
http://history1900s.about.com/library/photos/blywwiip251.htm
Weyant MJ et al. Is imaging necessary for the diagnosis
of acute appendicitis? Adv Surg 2003.
Before 1997, because of appendicitis
high mortality rate, surgeons agreed
that a 20% negative appendectomy
rate was acceptable.
That is no longer the case . . .
. . . because of advances in imaging in
emergency departments.
Colson M et al. High negative appendectomy rates are no longer acceptable. Am J Surg 1997.
Rhea J et al. The status of appendiceal CT in an urban medical center 5 years after its introduction: experience with 753 patients. AJR 2005.
Plain film from www.learningradiology.com
. . . because of advances in imaging in
emergency departments.
Colson M et al. High negative appendectomy rates are no longer acceptable. Am J Surg 1997.
Rhea J et al. The status of appendiceal CT in an urban medical center 5 years after its introduction: experience with 753 patients. AJR 2005.
PACS BIDMC
Before we consider our menu of imaging tests
to narrow our diagnosis . . . .
What additional lab test should we order for
our patient CH?
A pregnancy test!
+ A positive pregnancy test
will change our imaging
options.
- A negative pregnancy test
will remove ectopic pregnancy
from our differential.
ACR appropriateness criteria for RLQ Pain
fever, leukocytosis, and classic presentation for appendicitis in adults
Rating
Radiologic Procedure
(1 = least appropriate,
9 = most appropriate)
Relative Radiation Level
CT abdomen and pelvis with contrast
High
US abdomen RLQ graded compression
None
CT abdomen and pelvis without contrast
High
X-ray chest
Min
US pelvis transabdominal and transvaginal
None
X-ray abdomen supine and upright
Low
X-ray colon barium enema double-contrast
Med
X-ray colon barium enema single-contrast
Med
MRI abdomen and pelvis
None
X-ray small bowel series with barium
Low
NUC gallium scan abdomen
High
NUC WBC scan abdomen pelvis
Med
X-ray small bowel enteroclysis
Med
www.acr.org
ACR appropriateness criteria for RLQ Pain
fever, leukocytosis, pregnant woman
Rating
Radiologic Procedure
(1 = least appropriate,
9 = most appropriate)
Relative Radiation Level
US abdomen RLQ graded compression
None
MRI abdomen and pelvis
None
US pelvis transabdominal and transvaginal
None
CT abdomen and pelvis with contrast X-ray chest
High
CT abdomen and pelvis without contrast
High
X-ray chest
Min
X-ray abdomen supine and upright
Low
X-ray colon barium enema double-contrast
Med
X-ray small bowel enteroclysis
Med
X-ray colon barium enema single-contrast
Med
NUC WBC scan abdomen pelvis
Med
X-ray small bowel series with barium
Low
NUC gallium scan abdomen
High
www.acr.org
Comparison of Appropriate Tests
Not pregnant
1. CT C+ abd/pelv
2. US abd RLQ graded
compression
3. CT C- abd/pelv
4. X-ray chest
5. US pelvis transabd &
transvag
Pregnant
1. US abd RLQ graded
compression
2. MRI abd and pelvis
3. US pelvis transabd &
transvag
4. CT C+ abd/pelv
5. CT C- abd/pelv
Pregnant Woman and Appendicitis
COMMON:
Acute appendicitis is most
common surgical emergency
during pregnancy.1
TRICKY:
Clinical diagnosis can be difficult2
Appendix may have moved due to
gravid uterus pain may not
localize to RLQ
Leukocytosis can be physiological
during pregnancy
Nausea and vomiting common in
both pregnancy and appendicitis
DANGEROUS:
In appendicitis, fetal loss is more
than 30% with ruptured appendix
and 2% with unruptured
appendix.3
MR Abdomen Sagittal: PACS BIDMC
Cobben L et al. MRI for clinically suspected appendicitis during pregnancy. AJR 2004.
Birchard K et al. MRI of acute abdominal and pelvic pain in pregnant patients. AJR 2005.
2,3
Consideration in imaging the appendix
(besides whether or not patient is
pregnant or a child):
Where is the appendix?
Variability in the location of the appendix
Anterior view
Posterior view
Tamburrini S et al. CT appearance of the normal appendix
in adults. Eur Radiol 2005.
Variability in the location of the appendix
Most
common
locations
26%
18%
Anterior view
Posterior view
Tamburrini S et al. CT appearance of the normal appendix
in adults. Eur Radiol 2005.
Exploring the Menu of Tests
Plain films
Ultrasound
MRI
CT
Exploring the Menu of Tests
Plain films
Ultrasound
MRI
CT
Abdominal
Plain Films
Companion Patient 1: Abdominal Plain Film of Appendicitis
Abdominal plain films are
neither sensitive nor specific
for acute appendicitis.1
X-ray of chest often ordered
in acute abdomen
to check for free air under
diaphragm
because chest disease can
simulate abdominal
conditions.2
Some radiographic signs of
acute appendicitis:3
Appendicolith
Scoliosis
RLQ fluid levels
Ileus
Bowel wall edema
Abdominal plain film of appendicoliths from www.learningradiology.com
1Rao P et al. Plain abdominal radiography in clinically suspected appendicitis: diagnostic yield, resource use, and comparison with CT. American Journal
of Emergency Medicine 1999.
2Greene C. Indications for plain abdominal radiography in the emergency department. Annals of Emergency Medicine 1986.
3Olutola PS. Plain film radiographic diagnosis of acute appendicitis: an evaluation of the signs. Can Assoc Radiol J. 1988.
Abdominal
Plain Films
of Appendicitis
Upright abdominal plain film
Altering position of this pediatric
patient revealed two different
radiographic signs of appendicitis.
Companion
patient 2
Both images from http://www.hawaii.edu/medicine/pediatrics/pemxray/v4c10.html
Supine abdominal plain film
Abdominal
Plain Films
of Appendicitis
Altering position of this pediatric
patient revealed two different
radiographic signs of appendicitis.
Scoliosis due
to RLQ
splinting
Appendicolith
Upright abdominal plain film
Companion
patient 2
Both images from http://www.hawaii.edu/medicine/pediatrics/pemxray/v4c10.html
Supine abdominal plain film
Abdominal
Plain Films
of Appendicitis
Altering position of this pediatric
patient revealed two different
radiographic signs of appendicitis.
Scoliosis due
to RLQ
splinting
Appendicolith
Upright abdominal plain film
Companion
patient 2
Both images from http://www.hawaii.edu/medicine/pediatrics/pemxray/v4c10.html
Supine abdominal plain film
Exploring the Menu of Tests
Plain films
Ultrasound
MRI
CT
Ultrasound
No radiation exposure good for pregnant women and children
Patient need not be cooperative good for children
Sensitivity for diagnosing appendicitis = 0.861
Specificity for diagnosing appendicitis = 0.812
Findings on ultrasound:3
Appendiceal Findings
Diameter of appendix 6 mm MOST SENSITIVE AND SPECIFIC FINDING
Lack of compressibility of appendix 2ND MOST SENSITIVE AND SPECIFIC
Intraluminal fluid
Doppler flow in wall
Periappendiceal Findings
1,2 Terasawa
Inflammatory fat changes
Cecal wall thickening
Periileal lymph nodes
Peritoneal fluid
T et al. Systematic review: computed tomography and ultrasonography to detect acute appendicitis in adults and
adolescents. Ann Inten Med 2004.
3 Kessler N et al. Appendicitis: evaluation of sensitivity, specificity, and predictive values of US, Doppler US, and laboratory
findings. Radiology 2004.
Ultrasound of Appendicitis
Note how round
appendix is despite
compression with
ultrasound
transducer
non-compressible
appendix
Appendix diameter
is larger than 6 mm
Companion Patient 3
PACS BIDMC
Ultrasounds of Appendicitis
Companion Patient 4
Intraluminal fluid
Companion Patient 5
Doppler flow in wall
PACS BIDMC
Why would you ever use anything else
to diagnose appendicitis in pregnant women?
The Drawbacks to US:
Graded compression US is sometimes not
feasible because of enlarged uterus1
Negative predictive value of nonvisualized
appendix is .902
1Pedrosa
I et al. MR imaging evaluation of acute appendicitis in pregnancy. Radiology 2006.
N et al. Appendicitis: evaluation of sensitivity, specificity, and predictive values of US, Doppler US, and laboratory
findings. Radiology 2004.
2Kessler
Exploring the Menu of Tests
Plain films
Ultrasound
MRI
CT
MRI
No radiation exposure good for pregnant women
Sensitivity for diagnosing appendicitis = 1.001
Specificity for diagnosing appendicitis = 0.942
Findings on MRI:3
Diameter of appendix 6 mm
Thickening of appendiceal wall with high intensity on T2
weighted images
Dilated lumen filled with high intensity material on T2 weighted
images
Increased intensity of periappendiceal tissue on T2 weighted
images
1,2 Pedrosa
3
I et al. MR Imaging Evaluation of Acute Appendicitis in Pregnancy. Radiology 2006.
Nitta N et al. MR imaging of the normal appendix and acute appendicitis. Journal of Magnetic Resonance Imaging 2005.
MRI of appendicitis
in a pregnant woman
Appendix
diameter 6 mm
Dilated lumen
filled with high
intensity material
Companion Patient 6: MR T2
SSFSE (Single Shot Fast Spin Echo) Coronal
PACS BIDMC
MRI of appendicitis
in a pregnant woman
Appendix is dilated
Appendiceal walls are
thickened and high
intensity
Increased intensity of
periappendiceal tissue
indicating
inflammatory changes
Companion Patient 7: MR T2
SSFSE (Single Shot Fast Spin Echo) Coronal
PACS BIDMC
Exploring the Menu of Tests
Plain films
Ultrasound } for children and pregnant women
} for pregnant women
MRI
CT test of choice for non-pregnant adults
CT
Test of choice for non-pregnant adults and adolescents
CT is credited with drop in negative appendectomy rate from 20% to 3%1
Since CT provides view of entire abdomen and pelvis (unlike US), other
diagnoses may be made.
Sensitivity for diagnosing appendicitis = 0.992
Specificity for diagnosing appendicitis = 0.953
Findings on CT:4
Diameter of appendix 6 mm
Periappendiceal inflammatory changes
Fat stranding
Fluid collections
Phlegmon
Abscess formation
Wall thickness 3 mm
Extraluminal air
Adjacent adenopathy
Adjacent bowel wall thickening
Focal cecal wall thickening
1,2,3Rhea
J et al. The status of appendiceal CT in an urban medical center 5 years after its introduction: experience with 753 patients.
AJR 2005.
4Moteki T et al. New CT criterion for acute appendicitis: maximum depth of intraluminal appendiceal fluid. AJR 2007.
CT Coronal Reconstruction of Appendicitis:
Companion Patient 8
Focal cecal wall
thickening.
Extensive fat
stranding.
Dilated appendix.
PACS BIDMC
Axial CT of appendicitis: Companion Patient 9
PACS BIDMC
Wheres the appendix?
Axial CT of appendicitis: Companion Patient 9
PACS BIDMC
Dilated appendix, not filling with contrast
Axial CT of Appendicitis:
Companion Patient 10
Dilated appendix, not filling with contrast.
PACS BIDMC
Axial CT of Appendicitis:
Companion Patient 11
Appendix
not filling
with contrast
PACS BIDMC
Axial CT of Appendicitis:
Companion Patient 12
Fat
stranding
PACS BIDMC
Dilated appendix
Axial CT of Appendicitis:
Companion Patient 13
Where is this
mans inflamed
appendix?
Look for the fat
stranding.
PACS BIDMC
Axial CT of Appendicitis:
Companion Patient 13
An aside: do you
notice any other
abnormality in this
mans pelvis?
PACS BIDMC
CT Coronal
Reconstruction of
Appendicitis:
Companion Patient 13
A kidney
transplanted
into the
pelvis.
PACS BIDMC
Coronal
Reconstruction CT:
Companion Patient
14
Thats the appendix, but
is this appendicitis?
Wheres the
appendix in this
coronal
reconstruction?
PACS BIDMC
Appendix is filled
with contrast.
Appendix diameter
= 5.0 mm (less than
6.0 mm)
No periappendiceal
inflammatory
changes to be seen!
Normal appendix
PACS BIDMC
Coronal Reconstruction CT: Companion Patient 14
Back to our patient CH . . .
she wasnt pregnant
her renal function was fine (creatinine was 0.9)
. . . so she was given a CT scan
with contrast.
Patient CH: Axial CT
PACS BIDMC
Patient CH: Axial CT
PACS BIDMC
Patient CH: Axial CT
PACS BIDMC
Patient CH: Axial CT
PACS BIDMC
Patient CH: Axial CT
PACS BIDMC
Patient CH: Axial CT
PACS BIDMC
Patient CH: Axial CT
PACS BIDMC
Patient CH: Axial CT
PACS BIDMC
Patient CH: Axial CT
Lets find the appendix.
PACS BIDMC
Patient CH:
Axial CTs
An elongated and
dilated appendix.
Considerable fat
stranding (as
well as air in
appendiceal
lumen)
PACS BIDMC
Patient CH:
Axial CTs
Diagnosis:
acute
appendicitis!
An elongated and
dilated appendix.
Considerable fat
stranding (as
well as air in
appendiceal
lumen)
PACS BIDMC
We have our diagnosis but
lets look at the coronal
reconstructions as well.
Patient CHs CT: Coronal Reconstruction
PACS BIDMC
Patient CHs CT: Coronal Reconstruction
PACS BIDMC
Patient CHs CT: Coronal Reconstruction
PACS BIDMC
Patient CHs CT: Coronal Reconstruction
PACS BIDMC
Patient CHs CT: Coronal Reconstruction
PACS BIDMC
Patient CHs CT: Coronal Reconstruction
PACS BIDMC
Patient CHs CT: Coronal Reconstruction
Some individual
coronal slices.
PACS BIDMC
Patient CHs CT: Coronal Reconstruction
PACS BIDMC
PACS BIDMC
The appendix pops in
and out of plane in this
slice.
Dilated appendix
Air bubble
Plenty of fat stranding
Patient CHs CT: Coronal Reconstruction
Air in
appendix
lumen does
not rule out
appendicitis.
Air is present
in lumen of
appendix in
over 15% of
cases of
appendicitis
imaged on
CT.1
PACS BIDMC
1Rao
P et al. Appendiceal and peri-appendiceal air at CT: prevalence,
appearance, and clinical significance. Clin Radiol 1997.
The patient CH was taken to OR
Laparoscopic appendectomy
Pathological findings: erythematous
appendix, measuring 9.5 cm in length,
average of 1.2 cm in diameter. Dilated
lumen of up to 0.8 cm containing some
fecal material.
After removing the appendix and
irrigating the abdomen, the surgeons
turned the case over to a different team
can you guess which kind?
Take another look at the CT
coronal reconstruction . . . .
CHs CT: Coronal Reconstruction
Retrocecal appendix
Right ovarian dermoid cyst
PACS BIDMC
Ob/Gyn service felt it was not prudent to
remove dermoid at this time.
Patient was discharged from hospital two
days later with plans for Ob/Gyn follow
up.
Many thanks to . . .
Gillian Lieberman, MD
Melissa Gerlach, MD
Bettina Siewert, MD
Anne Catherine Kim, MD
Rich Rana, MD
Andrew Hines-Peralta, MD
Maria Levantakis
Bibliography
American College of Radiology (2007) ACR appropriateness criteria. Acute right lower quadrant pain. Available at www.acr.org. Last accessed November
2007.
Birchard KR, Brown MA, Hyslop WB, Firat Z, Semelka RC. MRI of acute abdominal and pelvic pain in pregnant patients. American Journal of Roentgenology
2005; 184: 452-458.
Colson M, Skinner KA, Dunnington G. High negative appendectomy rates are no longer acceptable. American Journal of Surgery 1997; 174: 723-726.
Cobben LP, Groot I, Haans L, Blickman JG, Puylaert J. MRI for clinically suspected appendicitis during pregnancy. American Journal of Roentgenology 2004;
183: 671-675.
Davies GM, Dasback EJ, Teutsch S. The burden of appendicitis related hospitalizations in the United States in 1997. Surgical Infections 2004; 5: 160-165.
Greene C. Indications for plain abdominal radiography in the emergency department. Annals of Emergency Medicine 1986; 15: 257-260.
Kessler N, Cyteval C, Gallix B, Lesnik A, Blayac PM, Pujol J, Bruel JM, Taourel P. Appendicitis: evaluation of sensitivity, specificity, and predictive values of
US, Doppler US, and laboratory findings. Radiology 2004; 230: 472-478.
Moteki T, Horikoshi H. New CT criterion for acute appendicitis: maximum depth of intraluminal appendiceal fluid. American Journal of Roentgenology 2007;
188: 1313-1319.
Nitta N, Takahashi M, Furukawa A, Murata K, Mori M, Fukushima M. MR imaging of the normal appendix and acute appendicitis. Journal of Magnetic
Resonance Imaging 2005; 21: 156-165.
Olutola PS. Plain Film radiographic diagnosis of acute appendicitis: an evaluation of the signs. Canadian Association of Radioliogists Journal 1988; 39: 254-6.
Otero HJ, Ondategui-Parra S, Erturk SM, Ochoa RE, Gonzalez-Beicos A, Ros PR. Imaging utilization in the management of appendicitis and its impact on
hospital charges. Emergency Radiology 2007.
Pedrosa I, Levine D, Eyvazzadeh AD, Siewert B, Ngo L, Rofsky NM. MR Imaging Evaluation of Acute Appendicitis in Pregnancy. Radiology 2006; 238: 891899.
Rao PM, Rhea JT, Novellline RA. Appendiceal and peri-appendiceal air at CT: prevalence, appearance, and clinical significance. Clinical Radiology 1997; 52:
750-754.
Rao PM, Rhea JT, Rao JA, Conn AKT. Plain abdominal radiography in clinically suspected appendicitis: diagnostic yield, resource use, and comparison with
CT. American Journal of Emergency Medicine 1999; 17: 325-328.
Rhea JT, Halpern EF, Ptak T, Lawrason JN, Sacknoff R, Novelline RA. The status of appendiceal CT in an urban medical center 5 years after its introduction:
experience with 753 patients. American Journal of Roentgenology 2005; 184: 1802-1808.
Tamburrini S, Brunetti A, Brown M, Sirlin CB, Casola G. CT appearance of the normal appendix in adults. European Radiology 2005; 15: 2096-2103.
Terasawa T, Blackmore CC, Bent S, Kohlwes RJ. Systematic review: computed tomography and ultrasonography to detect acute appenditicitis in adults and
adolescents. Annals of Internal Medicine 2004; 141: 537-546.
Weyant MF, Eachempati Sr, Maluccio MA, Barie PS. Is imaging necessary for the diagnosis of acute appendicitis? Advances in Surgery 2003; 37: 327-345.
Yu J, Fulcher AS, Turner MA, Halvorsen RA. Helical CT evaluation of acute right lower quadrant pain: part I, common mimics of appendicitis. American
Journal of Roentgenology 2005; 184: 1136-1142.
Yu J, Fulcher AS, Turner MA, Halvorsen RA. Helical CT evaluation of acute right lower quadrant pain: part II, uncommon mimics of appendicitis. American
Journal of Roentgenology 2005; 184: 1143-1149.
Additional images from the following websites:
http://history1900s.about.com/library/photos/blywwiip251.htm
www.learngingradiology.com
http://www.hawaii.edu/medicine/pediatrics/pemxray/v4c10.html
