Knowledge - U/S finding

posted on 22 Sep 2015 22:04 by pf3nz

U/S finding

 

Acute Cholecystitis

Major Criteria

Gallstones

Sonographic Murphy's sign

 Minor Criteria

Wall thickening > 3 mm

Pericholecystic fluid

 

Gallstones

1) Echogenic foci in GB lumen

2) Acoustic shadowing

3) Rolling stone sign - movement of gallstones with GB with position change

 

Biliary Dilatation

 the common bile duct (red arrowheads) is anterior to the portal vein (PV) and the gallbladder (red arrow) is also visualized

1) Shotgun sign ö intrahepatic biliary ducts (IHBD) : diameter > 2 mm or >40% of the PV

a double-barrel shotgun.

2) Confluence of enlarged intrahepatic biliary ducts (IHBD) create a stellate appearance of merging tubes.

3) CBD > 7 mm

 

AAA

1) Abdominal aorta > 3 cm,(inner wall to inner wall)

2) Hypoechoic mural thrombus within AAA.

3) Rupture of AAA is suggested by fluid or hematoma around the aorta.

 

Pancreatitis

 inferior vena cava (V), abdominal aorta (A), and the superior mesenteric artery (a).  The junction of the splenic vein (sv) with the superior mesenteric vein marks the commencement of the portal vein (PV) and is recognized by its teardrop shape.  The head (H), body (B), and tail (T) of the pancreas course anterior and parallel to the splenic vein (sv).

1) Diffuse enlargement of pancreas with ill-defined margins and hypoechoic parenchyma

2) Peripancreatic fat decreased in echogenicity with hypoechoic stranding densities

3) Hemorrhage may cause hyperechoic masses of clot of blood

 

A  B 

Acute Pancreatitis.  A.  Transverse scan.  B.  Longitudinal scan.  The head of the pancreas (H) is enlarged as revealed by the red arrowheads and decreased in echogenicity because of edema.  The surrounding structures are superior mesenteric vein (v), superior mesenteric artery (a), abdominal aorta (A), and inferior vena cava (IVC).

4) Peripancreatic fluid collections in lesser sac, perirenal areas, and small bowel mesentery

 

Transverse image shows huge fluid collection (F) surrounding the pancreas (P).

 

Appendicitis

-aperistaltic tubular structure > 6 mm in diameter, non-compressible

-appendix with a fecolith

 

Nephrolithiasis

1) Both radiopaque and radiolucent calculi produce highly echogenic foci with acoustic shadowing.

2) Obstructing stones in the ureter are dectected by following the dilated ureter to the point of obstruction. Color Doppler can produce twinkling sign within or just distal to urinary tract calculi.

 

Hydronephrosis

1) Dilation of calyces, pelvis, and ureter. Calyces appear rounded and cystic and communicate with the renal pelvis.

2) Absence of ureteral jet on the affected side during several minutes of observation confirms complete obstruction.

3) Intrarenal artery resistive index (RI) > 0.70 is highly suggestive of obstruction.

 

Adenexal Mass

Measure ovarian cysts that are larger than 2.5 cm

1) Functional cyst ö smooth, round, anechoic, thin-walled ovarian cyst larger than 2.5 cm.

2) Hemorrhagic cyst - homogeneous internal echoes, fishnet appearance, retracting clots and fibrous strands, and fluid-fluid levels.

A B

Hemorrhagic Cyst - Fishnet Appearance.  A.  The cyst (red arrowheads) on the ovary shows fine internal echoes with a fishnet appearance of thin, linear, fibrous strands (red arrows) characteristic of hemorrhage.  B.  Color Doppler of cyst (red arrowheads) demonstrates lack of internal blood flow characteristic of hemorrhagic cyst.

3) Cystic teratoma ö tip of iceberg sign, hyperechoic mass with dark acoustic shadow, and heterogeneous tissues.

4) Endometrioma ö adnexal cystic mass with diffuse, low-level internal echoes and hyperechoic foci in the wall.

5) Ovarian Torsion - absence of blood flow demonstrating ovarian torsion.

6) Ovarian malignancy ö a solid component to an ovarian lesion, irregular thick wall and septa > 3mm

 

Ultrasound Landmarks in Normal Pregnancy

 

Finding

Expected Visualization

Approximate Weeks

Gestational sac

BHCG > 1000 by EV; BHCG > 1800 by TA

4.5 - 5

Yolk sac

Mean sac diameter > 8 EV, > 18 TA

5.5 - 6

Embryo

Mean sac diameter > 16 EV, > 25 TA

6 - 6.5

Fetal heartbeat

Embryo > 5mm EV, any size TA

6 - 6.5

 

 

 

cr https://www.med-ed.virginia.edu/courses/rad/edus/index.html