Diagnosing Appendicitis. with Imaging

Transcription

1 CT, US, MRI all Plain film from Diagnosing Appendicitis in the Emergency Department with Imaging Heather Burns Gunn, HMS III Gillian Lieberman, MD Radiology Core BIDMC November 2007

2 Let s meet our patient in the emergency room

3 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

4 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 during palpation of LLQ) Labs of note: WBC: 16.6 with 83% Neutrophils Creatinine: 0.9

5 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 lower quadrant pain. AJR 2005.

6 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 lower quadrant pain. AJR 2005.

7 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% Davies G et al. The burden of appendicitis related hospitalizations in the United States in Surg Infect Otero H et al. Imaging utilization in the management of appendicitis and its impacton hospital charges. Emerg Radiol Weyant MJ et al. Is imaging necessary for the diagnosis of acute appendicitis? Adv Surg 2003.

8 Before 1997, because of appendicitis high mortality rate, surgeons agreed that a 20% negative appendectomy rate was acceptable. That is no longer the case...

9 ... because of advances in imaging in emergency departments. Colson M et al. High negative appendectomy rates are no longer acceptable. Am J Surg 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.

10 Plain film from because of advances in imaging in emergency departments. Colson M et al. High negative appendectomy rates are no longer acceptable. Am J Surg 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.

11 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.

12 ACR appropriateness criteria for RLQ Pain fever, 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 High US 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 None X-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 None X-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

13 ACR appropriateness criteria for RLQ Pain fever, leukocytosis, pregnant woman Radiologic Procedure Rating (1 = least appropriate, 9 = most appropriate) Relative Radiation Level US abdomen RLQ graded compression 8 None MRI 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 High X-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 Med X-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

14 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

15 Pregnant Woman and Appendicitis COMMON: Acute appendicitis is most common surgical emergency during pregnancy. 1 TRICKY: Clinical diagnosis can be difficult 2 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: 1 Cobben L et al. MRI for clinically suspected appendicitis during pregnancy. AJR ,3 Birchard K et al. MRI of acute abdominal and pelvic pain in pregnant patients. AJR 2005.

16 Consideration in imaging the appendix (besides whether or not patient is pregnant or a child): Where is the appendix?

17 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.

18 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.

19 Exploring the Menu of Tests Plain films Ultrasound MRI CT

21 Abdominal Plain Films 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 Companion Patient 1: Abdominal Plain Film of Appendicitis Abdominal plain film of appendicoliths from 1 Rao P et al. Plain abdominal radiography in clinically suspected appendicitis: diagnostic yield, resource use, and comparison with CT. American Journal of Emergency Medicine Greene C. Indications for plain abdominal radiography in the emergency department. Annals of Emergency Medicine Olutola PS. Plain film radiographic diagnosis of acute appendicitis: an evaluation of the signs. Can Assoc Radiol J

22 Abdominal Plain Films of Appendicitis Altering position of this pediatric patient revealed two different radiographic signs of appendicitis. Upright abdominal plain film Companion patient 2 Supine abdominal plain film Both images from

23 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 Supine abdominal plain film Both images from

24 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 Supine abdominal plain film Both images from

26 Ultrasound No radiation exposure good for pregnant women and children Patient need not be cooperative good for children Sensitivity for diagnosing appendicitis = Specificity for diagnosing appendicitis = Findings on ultrasound: 3 Appendiceal Findings Diameter of appendix 6 mm MOST SENSITIVE AND SPECIFIC FINDING Lack of compressibility of appendix 2 ND 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 and adolescents. Ann Inten Med Kessler N et al. Appendicitis: evaluation of sensitivity, specificity, and predictive values of US, Doppler US, and laboratory findings. Radiology 2004.

27 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

28 Ultrasounds of Appendicitis Companion Patient 4 Companion Patient 5 Intraluminal fluid Doppler flow in wall

29 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 uterus 1 Negative predictive value of nonvisualized appendix is Pedrosa I et al. MR imaging evaluation of acute appendicitis in pregnancy. Radiology Kessler N et al. Appendicitis: evaluation of sensitivity, specificity, and predictive values of US, Doppler US, and laboratory findings. Radiology 2004.

31 MRI No radiation exposure good for pregnant women Sensitivity for diagnosing appendicitis = Specificity for diagnosing appendicitis = 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 I et al. MR Imaging Evaluation of Acute Appendicitis in Pregnancy. Radiology Nitta N et al. MR imaging of the normal appendix and acute appendicitis. Journal of Magnetic Resonance Imaging 2005.

32 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

33 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

34 Exploring the Menu of Tests Plain films Ultrasound MRI } for children and pregnant women } for pregnant women CT test of choice for non-pregnant adults

35 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 = Specificity for diagnosing appendicitis = 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 1,2,3 Rhea J et al. The status of appendiceal CT in an urban medical center 5 years after its introduction: experience with 753 patients. AJR Moteki T et al. New CT criterion for acute appendicitis: maximum depth of intraluminal appendiceal fluid. AJR 2007.

36 CT Coronal Reconstruction of Appendicitis: Companion Patient 8 Focal cecal wall thickening. Extensive fat stranding. Dilated appendix.

37 Axial CT of appendicitis: Companion Patient 9 Where s the appendix?

38 Axial CT of appendicitis: Companion Patient 9 Dilated appendix, not filling with contrast

39 Axial CT of Appendicitis: Companion Patient 10 Dilated appendix, not filling with contrast.

40 Axial CT of Appendicitis: Companion Patient 11 Appendix not filling with contrast

41 Axial CT of Appendicitis: Companion Patient 12 Fat stranding Dilated appendix

42 Axial CT of Appendicitis: Companion Patient 13 Where is this man s inflamed appendix? Look for the fat stranding.

43 Axial CT of Appendicitis: Companion Patient 13 An aside: do you notice any other abnormality in this man s pelvis?

44 CT Coronal Reconstruction of Appendicitis: Companion Patient 13 A kidney transplanted into the pelvis.

45 Coronal Reconstruction CT: Companion Patient 14 That s the appendix, but is this appendicitis? Where s the appendix in this coronal reconstruction?

46 Appendix is filled with contrast. Appendix diameter = 5.0 mm (less than 6.0 mm) No periappendiceal inflammatory changes to be seen! Normal appendix Coronal Reconstruction CT: Companion Patient 14

47 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.

48 Patient CH: Axial CT

56 Patient CH: Axial CT Let s find the appendix.

57 Patient CH: Axial CTs An elongated and dilated appendix. Considerable fat stranding (as well as air in appendiceal lumen)

58 Diagnosis: Patient CH: Axial CTs An elongated and dilated appendix. acute appendicitis! Considerable fat stranding (as well as air in appendiceal lumen)

59 We have our diagnosis but let s look at the coronal reconstructions as well.

60 Patient CH s CT: Coronal Reconstruction

66 Patient CH s CT: Coronal Reconstruction Some individual coronal slices.

67 Patient CH s CT: Coronal Reconstruction The appendix pops in and out of plane in this slice. Dilated appendix Air bubble Plenty of fat stranding

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

69 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?

70 Take another look at the CT coronal reconstruction....

71 CH s CT: Coronal Reconstruction Retrocecal appendix Right ovarian dermoid cyst

72 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.

73 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

74 Bibliography American College of Radiology (2007) ACR appropriateness criteria. Acute right lower quadrant pain. Available at Last accessed November 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: Colson M, Skinner KA, Dunnington G. High negative appendectomy rates are no longer acceptable. American Journal of Surgery 1997; 174: Cobben LP, Groot I, Haans L, Blickman JG, Puylaert J. MRI for clinically suspected appendicitis during pregnancy. American Journal of Roentgenology 2004; 183: Davies GM, Dasback EJ, Teutsch S. The burden of appendicitis related hospitalizations in the United States in Surgical Infections 2004; 5: Greene C. Indications for plain abdominal radiography in the emergency department. Annals of Emergency Medicine 1986; 15: 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: Moteki T, Horikoshi H. New CT criterion for acute appendicitis: maximum depth of intraluminal appendiceal fluid. American Journal of Roentgenology 2007; 188: 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: Olutola PS. Plain Film radiographic diagnosis of acute appendicitis: an evaluation of the signs. Canadian Association of Radioliogists Journal 1988; 39: 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 Pedrosa I, Levine D, Eyvazzadeh AD, Siewert B, Ngo L, Rofsky NM. MR Imaging Evaluation of Acute Appendicitis in Pregnancy. Radiology 2006; 238: Rao PM, Rhea JT, Novellline RA. Appendiceal and peri-appendiceal air at CT: prevalence, appearance, and clinical significance. Clinical Radiology 1997; 52: 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: 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: Tamburrini S, Brunetti A, Brown M, Sirlin CB, Casola G. CT appearance of the normal appendix in adults. European Radiology 2005; 15: 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: Weyant MF, Eachempati Sr, Maluccio MA, Barie PS. Is imaging necessary for the diagnosis of acute appendicitis? Advances in Surgery 2003; 37: 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: 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: Additional images from the following websites:

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