2. Ultrasound of acute appendicitis
① Techniques of ultrasound in acute appendicitis
② Ultrasound of normal appendix
③ Primary ultrasound features of acute appendicitis
④ Secondary ultrasound features of acute appendicitis
⑤ Recommendations of EFSUMB for acute appendicitis
⑥ Mimickers of acute appendicitis
EFSUMB: European Federation of Societies for Ultrasound in Medicine and Biology
4. Three steps positioning algorithm
1. Supine position
2. If appendix not identified: left posterior oblique in coronal plane
3. If appendix still not identified: second-look supine position
Chang ST et al. AJR 2014; 203:1006–1012.
Left posterior oblique position
5. Position of the appendix
Chang ST et al. AJR 2014;203:1006–1012.
https://teachmeanatomy.info/abdomen/gi-tract/appendix/
Retrocecal position: 25 – 65% of patients
Appendix arises from cecum 3 cm below ileocecal valve
6. Graded compression ultrasound
First described by Puylaert in 1986
• Step 1 Displacing small bowel loops by gentle compression
Visualization of iliac vessels & psoas muscle
• Step 2 Visualization of ascending colon, cecum & terminal ileum
• Step 3 Identification of appendix
Arising from cecum & separate from terminal ileum
Appendix followed along its whole length
• Step 4 Assess primary & secondary features of acute appendicitis
Puylaert JB et al. Radiology 1986;158: 355–360.
Quigley AJ et al. Insights Imaging 2013;4:741–751.
7. Visualization of ascending colon & cecum
Longitudinal US scan Transverse US scan
Ascending colon and cecum Cecum ( white arrows)
Quigley AJ et al. Insights Imaging 2013;4:741–751.
8. Normal cecum and ileocecal valve
Slit-like ileocecal valve (long arrow)
compressible appendix (5.8 mm)
(short arrow)
Transverse scan of ileocecal region
Base of appendix (arrow)
originating from cecum (C)
Normal terminal ileum (TI)
Jeffry RB et al. Ultrasound Quarterly 2018;34(3):133–140.
9. Normal appendix originated from cecum
Thin-walled appendix measuring 3 mm
Appendix seen in continuity with cecum
Quigley AJ et al. Insights Imaging 2013;4:741–751.
10. Left posterior oblique position
Supine position Left posterior oblique position
Extensive shadowing from gas
(G) in cecum obscures RLQ
Jeffrey RB et al. Ultrasound Quarterly 2018; 34(3):133–140.
Coronal scan of right flank
Normal appendix (arrow) parallel
to fibers of psoas muscle (P)
12. Ultrasound features of normal appendix
• Compressibility Compressible
• Diameter < 6 mm (from outside wall to outside wall)
• Wall thickness < 3 mm
• Lumen Empty or gas/fecal-filled
• Vascularity No evidence of hypervascularisation
Quigley AJ et al. Insights Imaging 2013;4:741–751.
13. Normal and compressible appendix
9-year-old girl with normal and compressible appendix
Transverse gray-scale US images
Without compression With compression
Gongidi P et al. Pediatr Radiol 2017;47:1091–1100.
Diameter 4 mm Diameter 3 mm
14. Normal appendix with air-filled lumen
Appendix with hyperechoic foci of air in its lumen (arrows)
Cecum (C)
Longitudinal US scan of appendix
Gongidi P et al. Pediatr Radiol 2017;47:1091–1100.
15. Normal appendix with stool-filled lumen
Longitudinal color US of appendix
Gongidi P et al. Pediatr Radiol 2017;47:1091–1100.
Echogenic stool filling lumen of mid and distal appendix
Absence of appendiceal hyperemia & periappendiceal inflammation
16. US examination of appendix requires
the visualization of its entire length
Dirks K et al. Ultraschall in Med 2019;40:163–175.
17. Normal appendix in cystic fibrosis
Gongidi P et al. Pediatr Radiol 2017;47:1091–1100.
Enlarged 10 mm & noncompressible appendix (calipers)
Heterogeneous echogenic mucoid material distending the lumen (L)
Absence of periappendiceal mesenteric fat
11-year-old girl with cystic fibrosis
Longitudinal linear US Transverse US
without compression
Transverse US
with compression
18. Patients with cystic fibrosis might have enlarged appendix
if inspissated mucoid material distends the lumen
Appendiceal average diameter 8.3 mm (up to 14.5 mm)
80% of patients have diameters ˃ 6 mm
Gongidi P et al. Pediatr Radiol 2017;47:1091–1100.
Diameter of appendix alone may not be a parameter for
diagnosing appendicitis in patients with cystic fibrosis
20. Primary US features of acute appendicitis
• Diameter > 6 mm (from outside wall to outside wall)
6 – 8 mm: equivocal zone of uncertainty
• Target sign Hypoechoic center, hyper- & hypoechoic rings
• Tenderness Maximal tenderness over thickened appendix
• Compressibility Non-compressible (compressible if perforated)
• Appendicolith Echogenic focus w posterior acoustic shadowing
• Vascularity Peripheral wall hyperemia in early stages
Quigley AJ et al. Insights Imaging 2013;4:741–751.
Dirks K et al. Ultraschall in Med 2019;40:163–175.
21. Enlarged and noncompressible acute appendicitis
Coronal US in left posterior oblique position
Chang ST et al. AJR 2014; 203:1006–1012.
Coronal scan of right flank
Non-compressible appendix (9 mm)
Psoas muscle (S)
Supine position Left posterior oblique position
Transverse RLQ scan
Acoustic shadow from gas in
cecum (C) but appendix not seen
22. Acute appendicitis
Hypoechoic center: fluid-filled lumen
Hyperechoic ring: mucosal/submucosal layer
Hypoechoic ring: muscular layer
Target sign
Birnbaum BA et al. Radiology 2000;215:337–348.
Transverse scan of appendix
23. Increased diameter without significant wall thickening
Lumen distended and filled with purulent content
Acute appendicitis
Hollerweger A et al. Trans abdominal Ultrasound of the gastrointestinal tract.
In: EFSUMB European course book.
24. Small appendicolith in acute appendicitis
Birnbaum BA et al. Radiology 2000;215:337–348.
Appendicitis (A) as blind-ended tubular structure with fluid-filled lumen
Appendicolith with posterior acoustic shadowing (arrow)
Longitudinal scan of right lower quadrant
25. Large appendicolith in acute appendicitis
Longitudinal US scan of appendix
Enlarged appendix with echogenic intraluminal appendicolith (calipers)
Thickened periappendicular hyperechogenic tissue (asterisks)
9-year-old boy with acute appendicitis
Gongidi P et al. Pediatr Radiol 2017;47:1091–1100.
26. Intraluminal appendicoliths do not implicate
complicated appendicitis, but are associated with
perforation and recurrence under antibiotic therapy
Dirks K et al. Ultraschall in Med 2019;40:163–175.
27. Wall hyperemia in acute appendicitis
Increased blood flow in appendicular wall
Reddan T et al. J Med Radiat Sci 2016;63:59–66.
Transverse color Doppler US
28. Do not do things by halves
• Entire appendix should be examined from cecal orifice to apex
• Segmental inflammation & mimicry w terminal ileum may occur
Lembcke B. Z Gastroenterol 2016;54:1151–1165.
Definite exclusion of acute appendicitis requires
visualization of normal appendix in its entire length
29. Tip appendicitis
Increased diameter & ill-defined wall of distal end of appendix
Localized collection near distal end favors possible perforation
Normal gut signature sign in rest of the appendix
31. Secondary US features of acute appendicitis
• Free fluid surrounding appendix
• Local abscess formation
• Increased echogenicity of local mesenteric fat
• Thickening & hyperechogenicity of overlying peritoneum
• Enlarged mesenteric lymph nodes
• Signs of secondary small bowel obstruction
• Thickening of cecal pole or adjacent small bowel
Quigley AJ et al. Insights Imaging 2013;4:741–751.
32. Free fluid surrounding appendix
Transverse ultrasound of RLQ
Target sign
Increased diameter (8 mm)
Free fluid surrounding the appendix (asterisk)
RLQ: right lower quadrant
Mostbeck G et al. Insights Imaging 2016;7(2):255–263.
33. Abscess with gas
6-year-old boy with right lower quadrant pain
Linear US of right lower quadrant
Enlarged appendix
Mucosal/submucosal discontinuity at tip (arrowheads)
Periappendiceal abscess (ab) with foci of extra-luminal gas (arrows)
Thickened periappendiceal hyperechogenic tissue (asterisk)
Gongidi P et al. Pediatr Radiol 2017;47:1091–1100.
34. Abscess with appendicolith
Gongidi P et al. Pediatr Radiol 2017;47:1091–1100.
Abscess (ab) containing appendicolith (arrow)
5-year-old boy with perforated appendicitis and abscess
Sagittal ultrasound of lower abdomen
35. Increased echogenicity of local mesenteric fat
Blind-ended tubular structure originates from base of cecum (C)
Wall layers no longer defined: suggestive of gangrenous change
Gas bubbles (arrows) outside tip of appendix: localized perforation
Halo of increased echogenicity around appendix: inflamed fat
Longitudinal US of appendix
Birnbaum BA et al. Radiology 2000;215:337–348.
36. Thickening of overlying peritoneum
Quigley AJ et al. Insights Imaging 2013;4:741–751.
Increased echogenic free fluid in right iliac fossa indicating pus
Adjacent thickening of peritoneum
2-year-old girl with acute appendicitis
37. Enlarged mesenteric lymph nodes
Multiple lymph nodes (arrows) in mesentery
of periappendiceal region
Quigley AJ et al. Insights Imaging 2013;4:741–751.
38. Secondary small bowel obstruction
Quigley AJ et al. Insights Imaging 2013;4:741–751.
Dilated fluid-filled small bowel
Echogenic free fluid seen adjacent to bowel indicating pus (white arrow)
2-year-old girl with acute appendicitis
39. Thickening of cecal pole
V-shaped or arrowhead appearance
Jeffrey RB et al. Ultrasound Quarterly 2018; 34(3):133–140.
Enlarged appendix & focal loss of submucosal layer (short arrow)
Thickening of echogenic submucosal layer of cecum (long arrow)
Gangrenous appendicitis found at surgery
Transverse US of right lower quadrant
40. 1. Maximum diameter of appendix > 6 mm
2. Maximum pain over the appendix
3. Hyperechoic periappendiceal mesenteric fat
Dirks K et al. Ultraschall in Med 2019;40:163–175.
Most important US features of acute appendicitis
41. Best indicator:
Loss of normal echogenic submucosal layer
Less investigated indicators:
Lack of vascularization on color Doppler
Signs of sealed perforation
Localized collections of periappendiceal fluid
Extraluminal gas
Extraluminal appendicolith
Abscess
Signs of gangrenous appendicitis
Dirks K et al. Ultraschall in Med 2019;40:163–175.
42. Performance of 3 steps positioning algorithm
in acute appendicitis
Diagnostic parameters All patients
486 patients
Adults
156 patients
Children
330 patients
Sensibility (95% CI) 76.5 (65.8–85.2) 81.8 (59.7–94.8) 74.6 (61.6–85.0)
Specificity (95% CI) 99.2 (97.8–99.8) 100.0 (97.3–100) 98.9 (96.7–99.8)
Positive predictive value (95% CI) 95.4 (87.1–99.0) 100.0 (81.5–100) 93.6 (82.5–98.7)
Negative predictive value (95%CI) 98.8 (97.1–99.6) 98.5 (94.8–99.8) 98.9 (96.7–99.8)
Accuracy (95% CI) 95.4 (93.1–97.1) 97.4 (93.6–99.3) 94.4 (91.3–96.7)
Chang ST et al. AJR 2014;203:1006–1012.
Validation cohort
44. Ultrasound in acute appendicitis
• 18 European experts in GI ultrasound from gastroenterology,
radiology and surgery created recommendations for use of
imaging, based on extensive literature review until May 2018
• 12 recommendations refined and voted on in an online survey
• Agreement/disagreement level scored on five-point Likert scale:
A+: agree, A–: rather agree
I: indecisive
D–: rather disagree, D+: disagree
EFSUMB: European Federation of Societies for Ultrasound in Medicine and Biology
Dirks K et al. Ultraschall in Med 2019;40:163–175.
Recommendation of EFSUMB 2019
45. Ultrasound imaging should be a routine procedure
in every patient with suspected appendicitis
Ultrasound in acute appendicitis
Recommendation of EFSUMB 2019
EFSUMB: European Federation of Societies for Ultrasound in Medicine and Biology
Dirks K et al. Ultraschall in Med 2019;40:163–175.
Consensus levels of agreement: A+ 16/18; A– 2/18
Consensus levels of agreement: A+ 14/18; A– 4/18
Routine sonography in all patients with suspected appendicitis
halves rate of unnecessary surgery (negative laparotomy)
46. Sensitivity & specificity of US in acute appendicitis similar to
CT & MRI for trained operators & adequate equipments
Ultrasound in acute appendicitis
Recommendation of EFSUMB 2019
EFSUMB: European Federation of Societies for Ultrasound in Medicine and Biology
Dirks K et al. Ultraschall in Med 2019;40:163–175.
Consensus levels of agreement: A+ 15/18; A– 2/18; I 1/18
Consensus levels of agreement: A+ 18/18
In any case of suspected appendicitis, an “ultrasound first”
strategy should be used in both children and adults
47. Graded compression technique should be used for
visualization of the appendix
Ultrasound in acute appendicitis
Recommendation of EFSUMB 2019
EFSUMB: European Federation of Societies for Ultrasound in Medicine and Biology
Dirks K et al. Ultraschall in Med 2019;40:163–175.
Consensus levels of agreement: A+ 18/18
Consensus levels of agreement: A+ 18/18
Systematic search for signs that suggest differential
diagnoses of appendicitis should be implemented
48. Complementary CT or MRI limited to inconclusive findings
& difficult conditions (very obese patients, pregnant women)
Ultrasound in acute appendicitis
Recommendation of EFSUMB 2019
EFSUMB: European Federation of Societies for Ultrasound in Medicine and Biology
Dirks K et al. Ultraschall in Med 2019;40:163–175.
Consensus levels of agreement: A+ 18/18
Consensus levels of agreement: A+ 12/18; A– 4/18; I 2/18
Atypical positions of appendix are the most frequent
cause of false-negative results
52. Cluster of enlarged mesenteric lymph nodes (arrowheads)
Normal appendix identified (not shown)
IVC: inferior vena cava
van Breda Vriesman AC et al. AJR 2006; 186:1103–1112.
Mesenteric adenitis
14-year-old boy with right lower quadrant pain
Ultrasound of right lower quadrant
53. Mesenteric adenitis
Benign lymph node:
Oval, preserved fatty hilum
and central vascular pedicle
7-year-old girl with right lower quadrant pain
Transverse US of RLQ
Enlarged lymph node
in right iliac fossa
Normal appendix was identified
Color Doppler US
Hwang JW. Ultrasonography 2017;36:204-221.
54. • This may occur in bacterial enterocolitis caused by:
Yersinia, Campylobacter, Salmonella or C. Difficile
• US findings: Mural thickening of ileum & cecum
Thickening of echogenic submucosal layer
Inflammation of surrounding fat
Moderate mesenteric adenopathy
Infectious enterocolitis
Can present with features indistinguishable from appendicitis
Puylaert JB et al. Eur Radiol 1997;7:3–9.
van Breda Vriesman AC et al. AJR 2006; 186:1103–1112.
Jeffrey RB et al. Ultrasound Quarterly 2018; 34(3):133–140.
55. Yersinia enterocolitis
Thickening of cecal wall (C)
Thickening of echogenic submucosal layer (arrow)
Adjacent hyperechoic mesenteric pericecal fat (F)
Stool cultures were positive for Yersinia enterocolitica
Transverse ultrasound of cecum
Jeffrey RB et al. Ultrasound Quarterly 2018; 34(3):133–140.
56. Infectious colitis
Longitudinal US of ascending colon
Wall thickening
Hyperechoic thickening of submucosa
Accordion sign: consequence of wall thickening and contraction
Hollerweger A et al. Trans abdominal ultrasound of the gastrointestinal tract.
In: EFSUMB European course book.
Accordion sign
57. Pseudomembranous colitis
Jeffrey RB et al. Ultrasound Quarterly 2018; 34(3):133–140.
Thickening of cecal wall
Hyperechoic thickening of submucosa (arrow)
Transverse ultrasound of cecum
58. Right-sided colonic diverticulitis
Fecalith (black arrow) below cecum (C)
Distal acoustic shadow (white arrow)
Thickening of diverticulum wall
69-year-old man with RLQ pain and fever
Fecalith (black arrow) along
periphery of the cecum (C)
Fat stranding (white arrow)
Axial CECT imageTransverse US scan of cecum
CECT: contrast enhanced computed tomography – US: ultrasound
Jeffrey RB et al. Ultrasound Quarterly 2018; 34(3):133–140.
59. Crohn’s disease
Transnural wall thickening of terminal ileum (arrows)
Hyperechoic inflammatory changes of surrounding fat (arrowheads)
Transverse US scanLongitudinal US scan
28-year-old man with ileocecal Crohn’s disease
van Breda Vriesman AC et al. AJR 2006; 186:1103–1112.
60. Ileocecal intussusception
van Breda Vriesman AC et al. AJR 2006; 186:1103–1112.
Target-like mass representing intussusception
of distal ileum (arrowhead) into cecum (arrow)
Transverse US scan of RLQ in a 2-year-old boy
61. Epiploic appendagitis
CT: computed tomography
van Breda Vriesman AC et al. AJR 2006; 186:1103–1112.
Hyperechoic inflamed fatty mass
(arrowheads) adjacent to colon (arrow)
at spot of maximum tenderness
Peritoneal outpouching of colon – More frequent on the left
US of right lower quadrant
Fatty lesion with hyperattenuating
ring (arrows) corresponding to
thickened visceral peritoneal lining
Abdominal CECT scan
62. Omental infarction
Cakelike area of slightly dense
inflamed omental fat (arrowheads)
larger than in epiploic appendagitis
and lacking hyperattenuating ring
van Breda Vriesman AC et al. AJR 2006; 186:1103–1112.
Abdominal CT scan
41-year-old man with omental infarction
US of right middle abdomen
Area of inflamed intraperitoneal
fat (arrowheads)
63. Meckel diverticulum
Named for Johann Friedrich Meckel, a German anatomist,
who described the anatomy and embryology in 1809
64. Rule of 2s’ in Meckel diverticulum
• Occurs in 2% of the population
• Male to female ratio 2:1
• Usually discovered by 2 years of age
• Located 2 feet (60 cm) from ileocecal valve
• Commonly 2 cm in diameter
• Commonly 2 inches long (5 cm)
• Can contain 2 types of heterotopic mucosa: gastric & pancreatic
Ultrasound is of limited diagnostic value
65. Meckel diverticulum & other remnants of yolk sac
Moore KL. The Developing Human. Philadelphia: WB Saunders; 1988
Viteline cyst Umbilical cyst Fibrous cord
Meckel diverticulum Umbilico-ileal fistulaDiverticulum w fibrous cord
66. Levy AD et al. RadioGraphics 2004;24:565–587.
Meckel diverticulitis
7-year-old boy with vague abdominal pain & vomiting
Longitudinal US of pelvis
Blind-ending tubular structure with internal echos from debris
The wall has the gut signature
67. Levy AD et al. RadioGraphics 2004;24:565–587.
Inverted Meckel diverticulum
61-year-old man with intermittent abdominal pain
Transverse ultrasound of RLQ
Targetlike mass with central hyperechogenicity from core of mesenteric
fat surrounded by wall of diverticulum and wall of intestine
68. Duplication cyst – Gut signature sign
Most common in distal ileum
Hyperechoic mucosa & hypoechoic muscle
Inflammation may obscure the layers
Ovarian/mesenteric cysts & Meckel diverticula may present layered wall
Di Serafino M et al. J Ultrasound 2016;19:131–133.
69. US features depends on degree of intestinal involvement:
• Group 0 Normal findings
• Group I Differentiated wall thickening
• Group II Pseudodifferentiated wall thickening
• Group III Dedifferentiated wall thickening
Henoch-Schönlein purpura
Association of skin, joint, GI & renal symptoms
Study of 43 children with Henoch-Schönlein purpura*
* Nchimi A et al. J Pediatr Gastroenterol Nutr 2008;46:48–53.
Thickness of bowel wall > 5 mm
70. Henoch-Schönlein purpura
Can involve any segment of bowel
Hwang JW. Ultrasonography 2017;36:204-221.
Bowel wall thickening with increased echogenicity
Loss of wall stratification
71. Cecal carcinoma
Mass (M) with
hypervascularity
Transverse US of cecum Axial CECT image
Enhancing cecal mass
Carcinoma at surgery
Color Doppler image
Hypoechoic mass (M)
at base of cecum (C)
CECT: contrast-enhanced computed tomography – US: ultrasound
Jeffrey RB et al. Ultrasound Quarterly 2018;34(3):133–140.
72. Mucocele of appendix
Jansen E et al. FVV Ob Gyn 2013;5 (3):209-212.
Whipped cream sign
Cystic mass of mixed echogenicity
Absence of septations
Characteristic whipped cream sign
Transvaginal ultrasound
73. Degani S et al. Ultrasound Obstet Gynecol 2002;19: 99–101.
Mucocele of appendix
Bottle-like appearance
Filled with viscose substance
Arranged in thin layers
Contents arranged in
‘onion-skin’ thin concentric layers
Longitudinal scan Transverse scan
75. Anatomy of the kidney
Ramakrishnan K et al. Am Fam Physician 2005;71:933-42.
76. Ureteral stone
Large ureter stone (white arrow)
Shadow at right UVJ (black arrows)
with edema (arrowheads)
RLQ: right lower quadrant – UVJ: uretero-vesical junction
Sung T et al. AJR 2006;186:67–74.
19-year-old woman with RLQ pain and vomiting
Sagittal scan of right kidney Transverse scan of pelvis
Moderate hydronephrosis (arrow)
77. Ultrasound of acute pyelonephritis
Ultrasound abnormalities (20%)
Renal enlargement (> 15 cm – affected kidney > 1.5 cm longer )
Hypoechoic renal parenchyma
Loss of corticomedullary differentiation
Loss of renal sinus fat
Dilatation of collecting system without obstructive cause
Abscess formation
Rumack CM et al. Diagnostic Ultrasound. Elsevier-Mosby, St. Louis, USA, 3rd edition, 2005.
Normal findings (80%)
Normal-appearing kidney – Routine Imaging not required
78. Diffuse acute pyelonephritis
Kao HW et al. J Med Ultrasound 2008;16(2):113–122.
Diffuse renal enlargement
Decreased echogenicity
Loss of corticomedullary differentiation
Longitudinal US of right kidney Longitudinal US of left kidney
Normal left kidney
79. Ultrasound of acute focal pyelonephritis
Hypoechoic mass Hypoechoic wedged-shaped area
Extending from medulla to capsule
Absence of distinct wall (abscess)
Representing interstitial edema
Hyperechoic mass Same features
May relate to hemorrhage
w
CT scan more sensitive than US to detect focal disease
Stunell H et al. Eur Radiol 2007;17:1820–1828.
80. Acute focal pyelonephritis
Wedge-shaped hyperechoic area
in upper pole of right kidney
US scan of right kidney Color flow US image
Diminished flow through
involved area
Craig WD et al. RadioGraphics 2008; 28:255–276.
81. CT (before, immediately after, and at delayed
intervals from contrast material injection)
is the preferred modality for evaluating
acute bacterial pyelonephritis
82. Types of urachal anomalies
Villavicencio CP et al. RadioGraphics 2016;36:2049–2063.
Vesicourachal
diverticulum
Patent urachus Urachal cyst Umbilical-urachal
sinus
83. Infected urachal cyst
Wassef SN et al. Ultrasound Quarterly 2015;31:210-211.
Midline cystic mass with thickened wall between bladder & umbilicus
Attempts to push urine from bladder into cyst not successful
Confirming isolated non-communicating urachal cyst
Longitudinal US scan of mid abdomen & upper pelvis
85. Bleeding ovarian cyst
Large ovarian cyst filled with blood (chocolate cyst)
Retrofexed uterus
Lembcke B. Z Gastroenterol 2016;54:1151–1165.
Longitudinal US scan of pelvis
D: 8.7 cm
86. Dermoid cyst (dot-dash pattern)
17-year-old girl presenting to ER with pelvic pain
Complex echogenic mass with posterior acoustic shadow (arrow)
Multiple thin echogenic bands (dot-dash pattern) in the mass
representing hair follicles
Findings compatible with dermoid cyst
Lee R et al. Ultrasonography 2018;37:78-87.
Longitudinal ultrasound scan of pelvis
87. Ultrasound in pelvic inflammatory disease
Hydrosalpinx (chronic)Pyosalpinx (acute)
Thick walls of fluid-filled tube
Thick incomplete septa
Romosan G et al. Arch Gynecol Obstet 2014;289:705–714.
Thin walls of fluid-filled tube
Thin incomplete septa
88. Ultrasound in pelvic inflammatory disease
‘‘beads on string’’Cogwheel sign
Mucosal folds of tube protruding
into intratubal cyst fluid (beads)
Typical of hydrosalpinx
Cogwheel-shaped structure
Swollen walls & swollen mucosal fold
Romosan G et al. Arch Gynecol Obstet 2014;289:705–714.
89. US features of ovarian torsion
• Unilateral enlarged ovary (> 4 cm)
• No arterial or venous flow on Doppler (non viable ovary)
• Peripheral follicles (string of pearls sign)
• Coexistent mass in twisted ovary (cyst or benign tumor)
• Twisted vascular pedicle
• Free pelvic fluid
Chang HC et al. RadioGraphics 2008;28:1355–1368.
Usually located in midline & superior to fundus of uterus
90. Ovarian torsion
Power Doppler US
No flow on power Doppler
Color in center of ovary due
to motion artifact
Chang HC et al. RadioGraphics 2008;28:1355–1368.
Enlarged right ovary (8 cm)
Multiple peripheral follicles
(string of pearls sign)
Longitudinal US of right ovary
91. Twisted pedicle in ovarian torsion
Vijayaraghavan SB. J Ultrasound Med 2004; 23:1643–1649.
Snail shell of twisted pedicle
Ovarian cyst (cyst)
Transverse US scan
Whirlpool sign
Twisted artery and
vein
Color Doppler US
92. Various locations of ectopic pregnancy
2% of all pregnancies - 10% of pregnancy-related deaths
Mausner Geffen G et al. Abdom Radiol 2017;42:1524–1542.
Tubal ectopic pregnancy is the most frequent (95%)
93. Ultrasound findings in ectopic pregnancy
Transvaginal US is the imaging modality of choice
• Extrauterine gestational sac: ± yolk sac, fetal pole, cardiac activity
• Tubal ring sign: 70 – 75% of patients
• Adnexal mass: Complex mass with variable echotexture
• Free fluid: Up to 25% of patients
• Echogenic fluid: Suggests hemoperitoneum
• Pseudo-gestational sac: 20 % of patients
Differentiates from normal gestational sac
Chandrasekhar C. Clinical Imaging 2008;32:468–473.
94. Extrauterine gestational sac
Chandrasekhar C. Clinical Imaging 2008;32:468–473.
Extrauterine gestational sac with fetal pole in posterior cul-de-sac
UT: uterus – GS: gestational sac
Longitudinal trans-abdominal US of pelvis
95. Adnexal ectopic pregnancy
Thick brightly echogenic ring surrounding central anechoic area
May contain a yolk sac, a fetal pole, or both
Created by trophoblast of ectopic pregnancy surrounding gestational sac
Chandrasekhar C. Clinical Imaging 2008;32:468–473.
Tubal ring within right adnexa
96. Adnexal ectopic pregnancy
Chandrasekhar C. Clinical Imaging 2008;32:468–473.
Tubal ring may be difficult to differentiate from corpus luteal cyst
Wall of tubal ring more echogenic than wall of corpus luteal cyst
Tubal ring with corpus luteal cyst
97. Tubal ring & ring of fire
Transvaginal color Doppler US
Lin EP et al. RadioGraphics 2008; 28:1661–1671.
Ectopic pregnancy with tubal ring
Peripheral hypervascularity surrounding extrauterine gestational sac
98. Corpus luteal cyst
Chandrasekhar C. Clinical Imaging 2008;32:468–473.
Wall of corpus luteal cyst less echogenic than endometrium
Wall of tubal ring more echogenic than endometrium
EM: endometrium – CL: corpus luteal cyst
99. Corpus luteal cyst & ring of fire
Lee R et al. Ultrasonography 2018;37:78-87.
Color Doppler US
Intraovarian cystic structure
Echogenic ring & internal debris
Most likely represents corpus luteum
Ring of fire
Significant peripheral vascularity
Often seen in corpus luteal cyst
Transvaginal US of right ovary
32-year-old woman presented to ER with lower abdominal pain
100. Adnexal mass
Chandrasekhar C. Clinical Imaging 2008;32:468–473.
Heterogenous mass next to right ovary
Composed of clotted blood within & around the tube
Does not necessarily signify ruptured ectopic pregnancy
Absence of IUP & positive B-hCG strongly suggests ectopic pregnancy
101. Echogenic fluid in ectopic pregnancy
Lee R et al. Ultrasonography 2018;37:78-87.
22-year-old woman with pelvic pain & positive pregnancy test
Large complex free fluid with internal echogenicity in pelvic cul-de-sac
Most likely representing hemoperitoneum
Ruptured tubal ectopic pregnancy confirmed at operation
102. Interstitial ectopic pregnancy
“interstitial line sign”
Endometrium extending into
interstitial ectopic pregnancy
Lin EP et al. RadioGraphics 2008; 28:1661–1671.
Chandrasekhar C. Clinical Imaging 2008;32:468–473.
Schematic drawing
Ectopic pregnancy located in interstitial portion of tube
Interstitial pregnancy
& interstitial line sign
Transvaginal ultrasound
104. Cesarean scar ectopic pregnancy
34-year-old female with a previous history of cesarean section
Gestational sac in direct contact with the bladder (arrow)
without overlying myometrium
Transvaginal ultrasound
Mausner Geffen E et al. Abdom Radiol 2017;42:1524–1542.
105. Normal US findings in early pregnancy
LMP: last menstrual period
Perriera L et al. Semin Reprod Med 2008;26:373–382.
Week after LMP Description
week 4 – 5 Small gestational sac visible within endometrium
Gestational age estimated by mean sac diameter (MSD)
Averaging 3 dimensions of gestational sac
Gestational age in days: adding 30 to MSD in mm
Week 5 Double decidual sac sign
2 echogenic rings surrounding intrauterine fluid collection
Week 5½ Yolk sac visible within gestational sac
Definitively confirm intrauterine pregnancy
Week 6 Embryonic pole visible
Gestational age estimated by crown-rump length (CRL)
Gestational age in days: adding 42 to CRL in mm
Week 6½ Cardiac activity should be apparent
Week 8 – 9 Amnion becomes apparent & embryo should fill the amnion
Maximal length of embryo within 2 mm of amnion diameter
106. Pseudo-gestational sac
versus normal early gestational sac
Double decidual sac sign
Lin EP et al. RadioGraphics 2008; 28:1661–1671.
Pseudo-gestational sac Normal early gestational sac
Fluid centrally in endometrial canal
107. Eccentrically located fluid collection
Separate from endometrial cavity
within decidua of endometrium
Mausner Geffen E et al. Abdom Radiol 2017;42:1524–1542.
Normal early gestational sac
Fluid centrally in endometrial canal
in contrast to normal gestational sac
Seen in 20% of ectopic pregnancy
Pseudo-gestational sac
Pseudo-gestational sac
versus normal early gestational sac
108. Differential diagnosis of ectopic pregnancy
• Adjacent bowel loops
• Pedunculated fibroid
• Tubo-ovarian abscess
• Tubal cyst
• Normal early intra-uterine pregnancy
• Corpus luteal cyst
Chandrasekhar C. Clinical Imaging 2008;32:468–473.
110. Psoas abscess
Enlarged & heterogenous psoas muscle
Internal hyperechoic foci (*) & posterior acoustic shadowing (arrow)
Iliac artery (A) and Iliac vein (V) medial to psoas muscle
Transverse US of right lower quadrant
Deanehan JK. Pediatric Emergency Care 2017;33:437-439.
111. Rectus sheath hematoma
Small lesion (arrow) in sheath of
rectus abdominis muscle with
fluid–fluid level
van Breda Vriesman AC et al. AJR 2006; 186:1103–1112.
68-year-old woman with right lower quadrant pain
Transverse US of mid lower abdomen
Partly hyperdense mass (arrow)
within rectus sheath
Abdominal CECT
112. Ultrasound of normal hip
Sagittal US image along femoral neck
Acetabulum (A), labrum (curved arrow), femoral head (H)
femoral neck (N), anterior capsule (arrowhead)
capsule over femoral neck (straight arrow)
Jacobson JA et al. AJR 2015;205:513–523.
113. Hip effusion
Sagittal US image along femoral neck
Anterior (A) and posterior (P) layers of joint capsule
separated by anechoic effusion
Pauroso S et al. J Ultrasound 2011;14:92–94.
114. Pigmented villo-nodular synovitis
Heterogeneous hypoechoic synovial hypertrophy (arrows)
Predominantly distends anterior recess
Bone erosion (arrowheads) – H = femoral head – N = femoral neck
Jacobson JA et al. AJR 2015;205:513–523.
Sagittal US image along femoral neck
115. Conclusion
“Yes we can rely on US”
“CT by reflex”
For acute appendicitis, turn from
to
CT: computed tomography – US: ultrasound
Lembcke B. Z Gastroenterol 2016;54:1151–1165.
ultrasound has been found to be less sensitive and specific in the diagnosis of acute pyelonephritis than other modalities: scintigraphy, spiral CT, & MRI.
The proposed mechanism of this dilatation is that bacterial endotoxins may inhibit normal ureteric peristaltic motion, resulting in hydroureter and hydronephrosis.