Emergency Ultrasound Course For Radiologists.

1. Emergency Ultrasound Course
Urgent Sonographic signs – Part-1 Echogenic Fat
By:
Dr/ Ismail Sayed Ismail
Radiologist
is
Great doctor

2. Sonographic signs of inflammation / edema, …
1. Fat edema (ECHOGENIC FAT is the most
Significant Single Sonographic Sign of Inflammation).
2. Free air.
3. Interstitial edema.
4. Free fluid.
5. Reactive lymph nodes.
6. Reactive ileus (in abdominal inflammation).
7. Specific features (differs according to
organ or area of inflammation).
Echogenic Fat is
your best friend
in U/S emergencies

3. 1. Fat edema = ECHOGENIC FAT
1. Appearance.
– Normal fat is isoechoic to slightly hypoechoic to nearby muscles.
– Inflamed / edematous fat is hyperechoic to echogenic.
Normal
visceral fat
Edematous /
Inflamed /
Echogenic
visceral fat

4. – Inflamed fat is significantly hyperechoic = Echogenic, as compared to
normal slightly hypoechoic visceral (mesenteric) fat.
Normal
visceral fat
Edematous /
Inflamed /
Echogenic
visceral fat

5. – Inflamed fat is significantly hyperechoic = Echogenic, as compared to
normal slightly hypoechoic visceral (mesenteric) fat.
Normal
visceral fat
Edematous /
Inflamed /
Echogenic
visceral fat

6. – Inflamed fat is significantly hyperechoic = Echogenic, as compared to
normal slightly hypoechoic subcutaneous fat.
– An associated indistinct skin–subcutaneous interface at the abnormal side
(Yellow arrow) as compared to normal side (Blue arrow).
Normal
subcutaneous
fat
Edematous /
Inflamed /
Echogenic
subcutaneous
fat

7. 2. Degree of brightness.
– The degree of brightness is directly proportional to the degree of
inflammation = the more the echogenic (brightness), the more the
inflammation. Mild degree in green and marked degree in red.

8. – The degree of fat brightness = the degree of inflammation in certain
cases as in appendicitis, so it will help to decide the next step in
management.
Mild increased in
the visceral fat
echogenicity,
suggests mild
inflammation
Appendix with mild
echogenic fat &
preserved gut
signature = early =
Catarrhal phase

9. – The degree of fat brightness = the degree of inflammation in certain
cases as in appendicitis, so it will help to decide the next step in
management.
Markedly
increased visceral
fat echogenicity,
suggests severe
inflammation
Appendix with
highly echogenic
fat & lost gut
signature = late =
Gangrenous phase

10. 3. Distribution / site of maximum tenderness / site of maximum brightness.
– The site of maximum fat brightness is the center of inflammation.
Terminal ileum
Appendix

11. – The organ in the center of echogenic fat is the primary source of
inflammation.
– Any nearby organ (away from center of echogenic fat) may show
reactive/ milder inflammatory changes.
Terminal ileum
Appendix
LN

12. Example:
– If both terminal ileum and appendix are located near the echogenic fat,
How to decide weather appendicitis or terminal ileitis >>
See which one located in the center of maximum fat echogenicity.

13. 4. Distribution / In diffuse abdominal pain, what to do ?
– Trace the echogenic fat > if you can not reach a specific diagnosis,
then >>> enlist 2 / 3 DD based on distribution of echogenic fat.
Stomach
DD
Peptic ulcer/gastritis
Pancreatitis
Cholecystitis
This case diagnosed as peptic ulcer

14. – Look for the site of maximum brightness ?
Trace the echogenic fat, it will lead you to the source.
RT Psoas
DD
Appendicitis(retrocecal
or subhepatic)
Pancreatitis
RT Pyelonephritis
This case diagnosed as Subhepatic appendicitis

15. – Look for the site of maximum brightness ?
Trace the echogenic fat, it will lead you to the source.
Colon
DD
Colitis or
Diverticulitis or
Focal Omental infarct
This case diagnosed as Sigmoid diverticulitis

16. 5. Finally >> reaching a specific diagnosis ?
– Echogenic fat surrounds both appendix and terminal ileum.
– Appendix located within the center of echogenic fat >> appendicitis.
– Decreased clarity of gut signature >> Gangrenous phase.
Acute appendicitis
Right iliac fossa
acute pain and
tenderness with
leukocytosis, ….

17. 5. Finally >> reaching a specific diagnosis ?
– Echogenic fat surrounds the renal pelvis and proximal ureter.
– Pelvicalyceal system and its draining ureter showing significant urothelial
thickening with possible debris inside. Young patient.
Right loin pain,
leukocytosis,
urinary bladder
irritative
symptoms….
Acute Pyelitis / Pyelonephritis

18. 5. Finally >> reaching a specific diagnosis ?
– Echogenic fat surrounds rounded avascular structure in left iliac fossa,
adjacent to left ovary and left internal iliac vessels.
– Pregnant lady.
Left ovarian vein thrombophlebitis
Left iliac fossa
pain and
tenderness with
leukocytosis, ….

19. 5. Finally >> reaching a specific diagnosis ?
– Echogenic fat surrounds the right ovary and uterus.
– The affected ovary is enlarged, with heterogenous stroma with scattered
echogenic foci (air), …. . This case also had subinvoluted uterus, pelvic
abscesses, …
Oophoritis as a part of PID
Post-partum (few
days),
pelvic pain and
tenderness,
leukocytosis,
discharge, …

20. 5. Finally >> reaching a specific diagnosis ?
– Echogenic fat surrounds RLQ peristaltic bowel loop (ileum).
– The affected bowel loop shows mural thickening (Mainly echogenic
submucosal layer), suggesting enteritis / colitis. Preserved gut signature.
Right iliac
fossa pain and
tenderness
with
leukocytosis,
….
Terminal ileitis, Infectious DD Crohn’s

21. 5. Finally >> reaching a specific diagnosis ?
– Echogenic fat surrounds LLQ bowel loop (sigmoid colon ‫.)غالبا‬
– The affected bowel loops shows mural thickening (Mainly hypoechoic
musculosa layer), suggesting muscular hypertrophy / diverticulosis.
Acute sigmoid diverticulitis
Left iliac fossa /
pelvic pain and
tenderness with
leukocytosis, ….
Extra-luminal
echogenic focus
with posterior
shadowing
=fecalith in
inflamed
diverticulum

22. LT O.V. thrombophlebitisAcute gang. appendicitis
RLQ LLQ
Do NOT forget,
We are Clinical Radiologists
These two cases have similar
sonographic appearance, so if you relied
on US only, we will NEVER reach the
diagnosis confidently.
Please add clinical and laboratory
data.

23. 6. Is it inflamed organ or inflamed fat ?
– Any organ located in the center of echogenic fat ?
Appendix > appendicitis, colonic diverticulum > diverticulitis, ...
– What if No organ in the center of echogenic fat ? Inflamed visceral fat.
Around IMA – No organ
Mesenteric panniculitis
Mesenteric
Panniculitis

24. – Echogenic visceral fat ? Beneath abdominal wall ? Clear borders ?
– No organ in the center ? Normal wall or nearby bowel/colon ?
Epiploic appendagitis Mesenteric panniculitis Omental infarction
Usually on the
LT side, may mimic
diverticulitis, milder pain
Usually paramidline upper
or mid abdomen, may
mimic pancreatitis
Usually on the
RT side, may mimic
appendicitis, milder pain

25. Another example:
• Inflamed fat in inguinal canal along the spermatic cord (around the
vessels only) is known as spermatic cord panniculitis, clinically funniculitis
• Commonly associated with epididymo-orchitis.
Spermatic cord
Testis
Spermatic cord panniculitis

26. Another example:
• Inflamed fat in the subcutaneous fat in abdominal wall (as in post-
operative status) or in the thigh or …… >> subcutaneous panniculitis.
• Usually diffuse in appearance, if focal >> fat necrosis.
RT thigh LT thigh
Subcutaneous panniculitis

27. – Echogenic subcutaneous fat ?
– Focal ? Or Diffuse ? Or Surround veins / fluid ,… ?
Focal echogenic fat
within SC layer with
pain.
If no Pain, Lipoma
Diffuse echogenic
fat / compare with
normal side.
Echogenic fat
surrounds
non-compressible
superficial veins
Echogenic fat
intermingled with
hypoechoic lines of
interstitial edema.
Fat necrosis SC panniculitis
Superficial
thrombophlebitis Cellulitis
Hotness/ redness >
Do not forget
Clinical, …

28. Echogenic fat ? Degree of echogenicity / brightness
Center of echogenicity / Max. brightnessSpecific features
Password
ECHOGENIC FAT

29. Part 2