Imaging Appendicitis

8/18/2019 Imaging Appendicitis

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Plain film from www.learningradiology.com

Diagnosing Appendicitis

Heather Burns Gunn, HMS IIIGillian Lieberman, MD

Radiology Core

BIDMCNovember 2007

CT, US, MRI all PACS BIDMC

with Imaging

in the Emergency Department


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Let’s meet our patient in the emergency room


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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 becamesharper several episodes of N/V in last 12 hours

denies diarrhea, constipation, melena, BRBPR endorses reduced appetite


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Patient CH: Physical Exam & Labs

Physical exam normal except abdominal

exam Soft, non-distended, tender RLQ

No rebound tenderness

+ Rovsing’s sign (pain in RLQ duringpalpation of LLQ)

Labs of note: WBC: 16.6 with 83% Neutrophils Creatinine: 0.9


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DDx

of RLQ pain

•

GI–

Appendicitis–

Crohn’s

–

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 lowerquadrant pain. AJR 2005.


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DDx

of RLQ pain

•

GI–

Appendicitis–

Crohn’s

–

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 lowerquadrant pain. AJR 2005.


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•

COMMON Appendicitis is the most

common cause of acuteabdomen.1

•

EXPENSIVE:In 2004, 300,000 cases

in US alone, totalhealthcare cost of 5.8 billion.2

•

DANGEROUS:Before universal

acceptance ofappendectomy asstandard of care,mortality for appendicitis was more than 50%.3

http://history1900s.about.com/library/photos/blywwiip251.htm

1Davies G et al. The burden of appendicitis relatedhospitalizations in the United States in 1997. Surg

Infect2004.

2 Otero H et al. Imaging utilization in the management of

appendicitis and its impacton

hospital charges. Emerg

Radiol

2007.

3 Weyant MJ et al. Is imaging necessary for the diagnosisof acute appendicitis? Adv Surg 2003.


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Before 1997, because of appendicitis’high mortality rate, surgeons agreed

that a 20% negative appendectomyrate was acceptable.

That is no longer the case . . .


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. . . 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.


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. . . 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

Plain film from www.learningradiology.com


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Before we consider our menu of imaging tests

to narrow our diagnosis . . . . What additional lab test should we order forour patient CH?

A pregnancy test!

+ A positive pregnancy test will change our imagingoptions.

-

A negative pregnancy test will remove ectopic pregnancyfrom our differential.


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ACR appropriateness criteria for RLQ Painfever, leukocytosis, and classic presentation for appendicitis in adults

Radiologic Procedure

Rating(1 = least appropriate,

9 = most appropriate)Relative Radiation Level

CT abdomen and pelvis with contrast 8 HighUS abdomen RLQ graded compression 6 None

CT abdomen and pelvis without contrast 6 High

X-ray chest 5 Min

US pelvis transabdominal

and transvaginal 5 NoneX-ray abdomen supine and upright 5 Low

X-ray colon barium enema double-contrast 4 Med

X-ray colon barium enema single-contrast 4 Med

MRI abdomen and pelvis 4 NoneX-ray small bowel series with barium 3 Low

NUC gallium scan abdomen 3 High

NUC WBC scan abdomen pelvis 3 Med

X-ray small bowel enteroclysis 2 Med

www.acr.org


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ACR appropriateness criteria for RLQ Painfever, leukocytosis, pregnant woman

Radiologic Procedure

Rating(1 = least appropriate,

9 = most appropriate)Relative Radiation Level

US abdomen RLQ graded compression 8 NoneMRI abdomen and pelvis 7 None

US pelvis transabdominal

and transvaginal 6 None

CT abdomen and pelvis with contrast X-ray chest 6 High

CT abdomen and pelvis without contrast 5 HighX-ray chest 4 Min

X-ray abdomen supine and upright 2 Low

X-ray colon barium enema double-contrast 2 Med

X-ray small bowel enteroclysis 2 MedX-ray colon barium enema single-contrast 2 Med

NUC WBC scan abdomen pelvis 2 Med

X-ray small bowel series with barium 2 Low

NUC gallium scan abdomen 2 High

www.acr.org


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Not pregnant

1.

CT C+ abd/pelv 2.

US abd

RLQ gradedcompression

3.

CT C-

abd/pelv

4.

X-ray chest

5.

US pelvis transabd

&transvag

Pregnant

1.

US abd

RLQ gradedcompression

2.

MRI abd

and pelvis

3.

US pelvis transabd

&transvag

4.

CT C+ abd/pelv 5.

CT C-

abd/pelv

Comparison of Appropriate Tests


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Pregnant Woman and Appendicitis

•

COMMON: Acute appendicitis is mostcommon surgical emergency

during pregnancy.

1

•

TRICKY:Clinical diagnosis can be difficult2

–

Appendix may have moved due togravid uterus –

pain may notlocalize to RLQ

–

Leukocytosis

can be physiologicalduring pregnancy

–

Nausea and vomiting common in both pregnancy and appendicitis

•

DANGEROUS:

In appendicitis, fetal loss is morethan 30% with ruptured appendixand 2% with unruptured

appendix.3

1 Cobben L et al. MRI for clinically suspected appendicitis during pregnancy. AJR 2004.2,3 Birchard K et al. MRI of acute abdominal and pelvic pain in pregnant patients. AJR 2005.

MR Abdomen –

Sagittal: PACS BIDMC


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Consideration in imaging the appendix

(besides whether or not patient ispregnant or a child):

Where is the appendix?


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Anterior view Posterior view

Tamburrini S et al. CT appearance of the normal appendixin adults. Eur Radiol 2005.

Variability in the location of the appendix


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Anterior view Posterior view

Tamburrini S et al. CT appearance of the normal appendixin adults. Eur Radiol 2005.

Variability in the location of the appendix

18%

26%

MostMost

commoncommon

locationslocations


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Exploring the Menu of Tests

•

Plain films

•

Ultrasound•

MRI

•

CT


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••

Plain filmsPlain films

•

Ultrasound•

MRI

•

CT


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AbdominalPlain Films

•

Abdominal plain films areneither sensitive nor specificfor acute appendicitis.1

•

X-ray of chest often ordered

in acute abdomen–

to check for free air underdiaphragm

–

because chest disease cansimulate abdominal

conditions.2•

Some radiographic signs ofacute appendicitis:3

–

Appendicolith

–

Scoliosis–

RLQ fluid levels–

Ileus–

Bowel wall edema

1Rao P et al. Plain abdominal radiography in clinically suspected appendicitis: diagnostic yield, resource use, and comparison with CT. American Journalof 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 film of appendicoliths

from www.learningradiology.com

Companion Patient 1: Abdominal Plain Film of Appendicitis


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Supine abdominal plain filmUpright abdominal plain film

Altering position of this pediatricpatient revealed two different

radiographic signs of appendicitis.

Both images from http://www.hawaii.edu/medicine/pediatrics/pemxray/v4c10.html


of Appendicitis

Companion

patient 2


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Scoliosis dueto RLQsplinting

Appendicolith


of Appendicitis

Companion

patient 2


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of Appendicitis

Scoliosis dueto RLQsplinting

Appendicolith

Companion

patient 2


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•

Plain films √

••

UltrasoundUltrasound•

MRI

•

CT


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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•

Inflammatory fat changes•

Cecal

wall thickening

•

Periileal

lymph nodes•

Peritoneal fluid

1,2 Terasawa

T et al. Systematic review: computed tomography and ultrasonography

to detect acute appendicitis in adults andadolescents. Ann Inten Med 2004.3 Kessler N et al. Appendicitis: evaluation of sensitivity, specificity, and predictive values of US, Doppler US, and laboratoryfindings. Radiology 2004.


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Ultrasound of Appendicitis

Appendix diameteris larger than 6 mm

PACS BIDMC

Note how roundappendix is despite

compression withultrasoundtransducernon-compressibleappendix

Companion Patient 3


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PACS BIDMC

Intraluminal

fluid Doppler flow in wall

Ultrasounds of Appendicitis

Companion Patient 4 Companion Patient 5


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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 2006.2Kessler N et al. Appendicitis: evaluation of sensitivity, specificity, and predictive values of US, Doppler US, and laboratory findings. Radiology 2004.


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•

Plain films √

•

Ultrasound √ ••

MRIMRI

•

CT


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MRI

•

No radiation exposure –

good for pregnant women

•


•


•

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 weightedimages

1,2 Pedrosa

I et al. MR Imaging Evaluation of Acute Appendicitis in Pregnancy. Radiology 2006.3

Nitta N et al. MR imaging of the normal appendix and acute appendicitis. Journal of Magnetic Resonance Imaging 2005.


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MRI of appendicitis

in a pregnant woman

PACS BIDMC

•

Appendixdiameter ≥ 6 mm

• Dilated lumenfilled with high

intensity material

Companion Patient 6: MR T2

SSFSE ( S ingle S hot F ast S pin E cho)

Coronal


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PACS BIDMC

Appendix is dilated

Appendiceal

walls are

thickened and highintensity

Increased intensity ofperiappendiceal

tissue

indicatinginflammatory changes

Companion Patient 7: MR T2

SSFSE ( S ingle S hot F ast S pin E cho)

Coronal

MRI of appendicitis

in a pregnant woman


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•

Plain films √

•

Ultrasound √ •

MRI √

••

CTCT –

test of choice for non-pregnant adults

} for children and pregnant women

} for pregnant women


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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),

otherdiagnoses may be made.

•


•


•

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 C l R t ti f A di iti


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CT Coronal Reconstruction of Appendicitis:Companion Patient 8

Focal cecal

wall

thickening.

Extensive fatstranding.

Dilated appendix.

PACS BIDMC


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Where’s the appendix?

PACS BIDMC

Axial CT of appendicitis: Companion Patient 9


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PACS BIDMC

Axial CT of appendicitis: Companion Patient 9

Dilated appendix, not filling with contrast

Axial CT of Appendicitis:


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PACS BIDMC

Dilated appendix, not filling with contrast.

Axial CT of Appendicitis:Companion Patient 10

A i l CT f A di iti


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PACS BIDMC

Appendixnot filling

with contrast


Axial CT of Appendicitis:


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Fatstranding

Dilated appendix

PACS BIDMC



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PACS BIDMC

Where is thisman’s inflamedappendix?

Look for the fat

stranding.



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An aside: do younotice any otherabnormality in thisman’s pelvis?


PACS BIDMC


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A kidneytransplanted

into thepelvis.

PACS BIDMC

CT Coronal

Reconstruction of Appendicitis:Companion Patient 13


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PACS BIDMC

Appendix is filled with contrast.

Appendix diameter= 5.0 mm (less than

6.0 mm)No periappendicealinflammatorychanges to be seen!

Normal appendix

Coronal Reconstruction CT: Companion Patient 14


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Back to our patient CH . . .

• she wasn’t pregnant

• her renal function was fine (creatinine

was 0.9)

. . . so she was given a CT scan

with contrast.

P i CH A i l CT


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PACS BIDMC

Patient CH: Axial CT

P ti t CH A i l CT


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PACS BIDMC

P ti t CH A i l CT


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PACS BIDMC

P ti t CH A i l CT


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PACS BIDMC

P ti t CH A i l CT


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PACS BIDMC

P ti t CH A i l CT


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PACS BIDMC

P ti t CH A i l CT


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PACS BIDMC



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PACS BIDMC



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Let’s find the appendix.


PACS BIDMC


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PACS BIDMC

An elongated anddilated appendix.

Considerable fatstranding (as well as air inappendiceal

lumen)

Patient CH:

Axial CTs


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PACS BIDMC

An elongated anddilated appendix.

Considerable fatstranding (as well as air inappendiceal

lumen)

Diagnosis:Diagnosis:acuteacute

appendicitis!appendicitis!

Patient CH:

Axial CTs


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We have our diagnosis butlet’s look at the coronal

reconstructions as well.

Patient CH’s CT: Coronal Reconstruction


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PACS BIDMC

Patient CH s CT: Coronal Reconstruction



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PACS BIDMC



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PACS BIDMC



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PACS BIDMC



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PACS BIDMC



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PACS BIDMC



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Some individual

coronal slices.

PACS BIDMC


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PACS BIDMC

Air inappendixlumen doesnot rule outappendicitis. Air is presentin lumen of

appendix inover 15% ofcases ofappendicitis

imaged onCT.1

1Rao P et al. Appendiceal and peri-appendiceal air at CT: prevalence,appearance, and clinical significance. Clin Radiol 1997.



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•

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. Dilatedlumen of up to 0.8 cm containing some

fecal material.•

After removing the appendix and

irrigating the abdomen, the surgeonsturned the case over to a different team –

can you guess which kind?


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Take another look at the CT

coronal reconstruction . . . .

CH’s CT: Coronal Reconstruction


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PACS BIDMC

Retrocecal

appendix

Right ovarianRight ovarian dermoiddermoid

cystcyst


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•

Ob/Gyn

service felt it was not prudent to

remove dermoid

at this time.•

Patient was discharged from hospital twodays later with plans for Ob/Gyn

followup.


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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


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Imaging Appendicitis

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