Focal leasions in the liver

Hemangioma in the live:

In the 7th segment of the liver, a 13 mm rounded echogenic area is seen, elsewhere the liver is homogeneous.
- Dont`t confuse with focal fatty infiltration of the liver usually seen arround the GB, or the echogenic ligamentum teres.

- A hemangioma can be echogenic or isoechoic.

- Smooth margins, round or oval in shape.

- Often multiple, may contain calcifications, rarely has a peripheral rim.

- Unlike FNH hemangiomas are vascularised in a peripheral-to-central pattern => aka iris diaphragm sign.

CEUS:

Arterial phase (20-30 sec): outer portions enhance, center remains hypoechoic.

Portal phase (40-100 sec): central portions become increasingly echogenic.

Venous phase (110-180 sec): the entire leasion is hypoechoic.

LINKS:

http://www.radiologyassistant.nl/en/448eef3083354

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Hepatic cyst

Differential diagnosis for cystic leasions:

inflammatory, infectious (echinococciasis, abscess), traumatic (hematoma), neoplastic (cyst-like mets, regressive necrotic liquified mets).

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Echinoccocal cyst: anechoic, round, echogenic wall, calcifications in cystic echinococcosis.

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Hematoma: irregular in shape, no wall, has low level internal echos

Traumatic liver rupture with hematoma

Subcapsular hematoma - US

Subcapsular hematoma - CT

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Abscess: irregular in shape, no wall, internal echos

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Cyst-like mets:

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Hepatic tumors

A: Illustration of morphologic patterns of hepatic tumors in the B-mode ultrasonography; B: Illustration of enhancement patterns of hepatic tumors in the arterial phase

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HYPOECHOIC CHANGES:

Focal sparing in fatty infiltration:

- Mostly seen in periportal region next to GB or lig. Trias

- Elliptical or triangular

- May occasionally show a patchy or flame like distribution in the liver

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Focal Nodular Hyperplasia

- The 2nd most common bening liver tumor after hemangioma

- It is usually asymptomatic, rarely grows or bleeds, and has no malignant potential. This tumour is often resected because it is difficult to distinguish from hepatic adenoma.

- Hypoechoic round or elliptical

- Smooth margins

- Heterogeneous echo-pattern due to central scarring

- Echogenic extensions radiating to periphery (stellate scar)

- CDS: vessels passing through the radial connective tissue (spoked wheel pattern)

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Adenoma:

- Resembles FNH in B mode US

- Made up from hepatocytes, and vessels

- Isoechoic or hypoechoic

- Smooth margins

- Pseudocapsule or hypoechoic rim

- Small internal echos if has hemorrhage

- CDS: well vascularised, characteristic vascular pattern, feeding artery can be seen

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Hepatocellular carcinoma (HCC):

-Variable appearance

- Hypoechoic, isoechoic, hyperechoic, nonhomogeneous

- Solitary or isolated

- In cirrhotic liver

- Frequent regressive changes (hemorrhage, calcifications)

- CDS: increased vascularisation, no typical pattern of arrangement

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Cholangiocellular carcinoma:

- Diffuse growth

- Isoechoic or sometomes hypoechoic (due to scarring)

- Regional mets with ascites

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Hematologic malignant systemic diseases:

- Micronodular malignant systemic diseases (CML), or macronodular lesions ( high grade lymphomas, lymphogranulomatosis)

- Intensly hypoechoic without a peripheral halo

- Accompanied by othe intra-abdominal sites of LN infiltration

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Other images:

Two hyperechoic leasions in the liver.

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LINKS:

-http://giyabradiology.blogspot.com/2011/05/fatty-liver.html

-http://radiology.rsna.org/content/201/2/327.short

-http://www.learningradiology.com/archives2007/COW%20235Liver%20mets/livermetscorrect.html

-http://rfs.acr.org/gamuts/data/GI-11.htm

-http://www.diagnostico.med.br/conteudo_trabalhos/abdomem_digestivo/Focal_liver_lesion_CT.pdf

(Text main source: Teaching Manual of CDS-Thieme, Thieme Clinical Companion Ultrasound)

(Images: Pecs University Department of Radiology, google images, ultrasoundcases.info)

Cholelithiasis

A gall stone pulling an acoustic shadow.
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(Images: Pécs University Department of Raddiology)

False aneurysm

-Most commonly results from puncture of femoral artery. So mostly iatrogenic in etiology. Can also develope at suture sites following vascular surgery.

-The arterial wall defect results in a pulsatile jet into adjacent tissue.

-The aneurysmal mass seen on the patient consists of a perivascular hematoma that comunicates with the vessel.

-We can induce therapeutic thrombosis in some cases by compressing the region under CDS monitoring. The rate of spontaneous pseudoaneurysm thrombosis is only about 30-58%.

-CDS will show a to and fro pulsed doppler wave form (uniform bidirectional flow at the neck) as seen in the US image above above.

-Main complication is nerve compression.

Other related images:

Blood leaking into surrounding tissue, where an area of decreased echogenicity (hematoma) is seen.

Different types of aneurysms

False aneurysm of the popliteal artery

False aneurysm of the femoral artery, arrow showing point of puncture site.

Cardiac rupture, blood leaking out of LV.

LINKS:

http://radiopaedia.org/articles/false_aneurysm

http://www.ajronline.org/cgi/content/full/180/3/659

(Text main source: Teaching Manual of CDS-Thieme, Thieme Clinical Companion Ultrasound)

(Images: Pecs University Department of Radiology, google images)

Pancreas anatomy

The ultrasonographic anatomy of the pancreas, look for the splenic vein to find the pancreas.

The splenic vein joins the superior mesenteric vein to form the portal vein.

The pancreas normally has an echogenic fatty ultrasonographic texture.

Vascular anatomy arround the pancreas:

Parts and anatomic relations

1. Head
   • lies within the curve of the duodenum
   • uncinate process is a prolongation of the head. The superior mesenteric artery and vein crosses this process.
2. uncinate process
   • the part of the head that wraps behind the superior mesenteric artery and vein and comes to lie adjacent to the ascending part of the duodenum.
3. Neck
   • a constricted portion to the left of the head. It abuts the pylorus above and the beginning of the portal vein behind.
4. Body
   • anterior surface separated from the stomach by the omental bursa
   • posteriorly related to the aorta, splenic vein, left kidney and renal vessels, left suprarenal, origin of superior mesenteric artery and crura of diaphragm.
5. Tail
• extends into the lienorenal ligament and abuts the spleen

Pancreatic duct (Wirsung)

Whats the clinical significance?

Compression, obstruction or inflammation of the pancreatic duct may lead to acute pancreatitis. The most common cause for obstruction is choledocholithiasis, or gallstones in the common bile duct. Obstruction can also be due to Duodenal Inflammation in Crohn's Disease. A gallstone may get lodged in the constricted distal end of the ampulla of Vater, where it blocks the flow of both bile and pancreatic juice into the duodenum. Bile backing up into the pancreatic duct may initiate pancreatitis.

The mean diameter of the duct in the area of the head-neck 3 mm, in the body proximal and distal to the neck, duct diameters were 2.1 and 1.6 mm, respectively.

Common bile duct (ductus choledochus)

Formed by the union of the common hepatic duct and the cystic duct (from the gall bladder). It is later joined by the pancreatic duct to form the ampulla of Vater. There, the two ducts are surrounded by the muscular sphincter of Oddi.

Dilated in case of outflow obstruction.

The consensus is that most people have a common bile duct diameter of around 5mm, +/- 1 mm. However, there are reports were people with no hepatobilliary disease have a "normal" common bile duct size up to 10 mm. Also, there is a correlation between common bile duct diameter and age. Most physicians would like to check things further if the common bile duct diameter is greater than about 7 mm, particularly if there are symptoms indicating hepatobilliary disease (abdominal pain with or without jaundice, fever etc.). Finally, even "normal" common bile duct sizes do not exclude the possibility of disease (such as stones).

CBD is considered dilated in adults if its diameter > 7mm.

LINKS:

http://giyabradiology.blogspot.com/2011/04/liver-anatomy.html

Source: wikipedia.org