Sonographic Terminology

CUHAS

SONOGRAPHIC

TERMINOLOGY

Ultrasound image

Composed of a variety of bright dots on a film that vary in intensity according to the strength of returning echoes from tissues or structures in the body Provides anatomic and non-anatomic information

Echogenicity

• Brightness of the dots generated by returning echoes from the body
• Intensity of echoes reflected by tissues or structures from inside the body

Echogenicity of a structure is described relative to surrounding or adjacent tissue

Echogenicity

Echogenicity

Echogenicity of a structure is described relative to surrounding or adjacent tissue

• Hyperechoic

High intensity echoes

The hyperechoic solid mass within this spleen represents a focal deposit of lymphoma.

Due to sickle cell nephropathy,

• the cortex of this kidney is
• hyperechoic relative
• to the adjacent liver parenchyma,
• which, due to its size,
• becomes the standard of
• comparison for most adjacent

parenchymal organs.

Right kidney

The round mass in this kidney is relatively hyperechoic when compared to the adjacent renal cortex. The echogenicity of a mass is compared to its organ of origin. Although the tumor itself is not very bright in echogenicity, it contains tiny hyperechoic foci due to microcalcifications scattered throughout the mass, which is a renal cell carcinoma (hypernephroma).

Hypoechoic:spleen

This is an image the spleen, which is of moderate echogenicity, and contains several hypoechoic masses (arrows) representing deposits of lymphoma.The masses are hypoechoic relative to surrounding normal splenic parenchyma.

The relative echogenicity of a mass is compared to the echogenicity of the organ to which it relates.

Liver

A large lobulated hypoechoic masses of low echogenicity represent metastatic deposits within the liver . The masses are hypoechoic relative to adjacent normal liver parenchyma.

M

Sonographic Terminology

In this transverse scan of the scrotum, the normal right (R) testis is moderately echogenic, while the left (L) is enlarged and hypoechoic due to testicular cancer. The standard for comparison in this case is the contralateral normal-sized (right) testis.

L

Anechoic

• Anechoic means without echoes or having no internal echoes.

Simple fluid generally has no internal reflections and is anechoic.

Isoechoic-The same intensity

The dominant mass in this picture is an enlarged spleen.

Adjacent to the spleen are two small round isoechoic masses representing splenules or accessory spleens.

They are of the same echogenicity as the spleen itself.

Another example of an oval-shaped solid isoechoic mass adjacent to the lower pole of the spleen.

The mass is of the same echogenicity as the spleen.

ECHOTEXTURE

• Homogeneous
• -uniform echoes
• Heterogeneous
• -non-uniform echoes

Echotexture refers to the uniformity of echoes within a mass.

Echotexture can be homogeneous, in which case the echoes are uniform, or inhomogeneous, in which case the echoes are non-uniform.

Homogeneous

• Uniform echoes
• Fine, smooth texture
• Includes slightly coarse texture
• The liver in this patient with chronic
• hepatitis has a very homogeneous

echotexture.

Sonographic Terminology

This mass is almost entirely filled with low-level homogeneous internal echoes, which are very uniform in their appearance and distribution.

The straight line in the mass is due to an interface of fluid and blood in an ovarian endometrioma, which is shown on this sagittal transvaginal scan.

Heterogeneous

• Non-uniform echoes

Irregular texture

Sonographic Terminology

This liver is very heterogeneous in its echotexture due to multiple small hyperechoic rounded masses scattered throughout the parenchyma due to a myriad of small hemangiomas in this case of diffuse hemangiomatosis.

Sonographic Terminology

This heterogeneous mass with echoes of variable intensities: high, medium and none, represents the internal contents of a hemorrhagic ovarian cyst.

IMAGE ARTIFACTS

Improper representation of structures on an image due to certain characteristics of the imaging technique Non-anatomic information derived from sonography Sometimes useful for proper image interpretation and diagnosis Other times a hindrance

Useful image artifacts

• Posterior enhancement
• Attenuation
• Acoustical shadowing

Reverberation

Posterior acoustic enhancement

Increased intensity in echoes from reflectors behind a structure that weakly attenuates sound Classical feature of fluid -usually signifies fluid Other terms,

• Increased sound transmission

“Flashlight” effect

Sonographic Terminology

This round anechoic liver cyst causes posterior enhancement of sound, manifested by increased echogenicity emanating from the entire posterior border of the cyst. The “veil” of increased echogenicity makes the underlying liver parenchyma look brighter than normal.

False posterior acoustic enhancement

The increased echogenicity (arrow) behind this myoma (M) is not due to posterior enhancement, but rather to reverberations from bowel or bone posterior to the mass.

The increased echogenicity does not come from the entire back border of the mass and may extend beyond its border. The echogenicity is not uniform and fades with depth.

M

ATTENUATION

• Decrease in amplitude and intensity of sound waves passing through a medium
• Weakening of echoes (both penetrating and returning)
• Due to absorption, scattering, and beam divergence

Caused by a solid mass

This pelvic mass causing sound attenuation and shadowing is due to a large dense posterior myoma in the uterus.

Echoes returning from the mid and posterior parts of the myoma are weakened and barely visible on the image.

Anatomic information is lost, but the attenuation signifies a dense solid mass affecting the sound beam.

POSTERIOR ACOUSTIC SHADOWING

Marked decrease in intensity of echoes from reflectors that lie behind a structure that is strongly reflecting or attenuating Sound waves do not reach the area

Sonographic Terminology

Shadowing produced by a gallstone. There is total loss of information in the area of the shadow, therefore a mass behind the gallstone would be missed.

However, the shadow is useful, because it tells us that it comes from a markedly reflecting or attenuating structure, such as a stone.

Complete lack of acoustical & anatomical information in the area of shadowing

Caused by reflection, refraction, marked attenuation, total absorption or any combination of these or other effects

Types of shadows

The classical shadow is a “clean”, sharp, black shadow with no echoes or reverberations deep to a mass or area.

Shadows which have numerous internal echoes or reverberations look ”dirty” or gray due to the artifactual echoes.

A “white” shadow, it is not a conventional shadow.

This is the shadowing usually seen distal to air or gas, which create very strong reverberations that make the shadow hyperechoic or white.

This type of shadowing is due to numerous reverberations and is not to be confused with the posterior enhancement distal to fluid.

Summary;types of echoes

• Black” Clean”, sharp
• No echoes
• Gray” “Dirty”, some echoes,
• reverberations

“White” Full of strong reverberations

sharp/clean/black shadow

Classical clean, sharp, “black” shadow posterior to a gallstone.

No echoes visible in the shadow. Complete lack of information about structures behind the stone.

Classical clean, sharp, “black” shadow posterior to the falciform ligament.

Classical “black” shadows posterior to granulomata in a spleen.

Sonographic Terminology

The arrow on this sagittal scan of the inferior vena cava points to a hyperechoic linear reflector, which causes a “dirty” shadow, due to a pocket of air, which escaped into the lumen of the inferior vena cava during catheter placement into an iliac vein. The “dirtiness” or grayness of the shadow is caused by reverberations from the air.

The arrows point to a gray

• shadow, which is due to
• reverberations and artifactual
• echoes caused by reflections
• from air-filled lung posterior to

the right hemidiaphragm.

The arrow points to a gray

• shadow, which is due to
• reverberations caused by a
• pocket of gas and debris in a

liver abscess.

REVERBERATION

• Reverberations are multiple, repetitive artifactual echoes
• caused by multiple reflections between the transducer and a strongly reflecting surface.

These false reflections are written on the image at very regular intervals behind the original reflector and usually appear weaker as they repeat themselves.

Reverberation artifacts within a shadow caused by air in a gallbladder.

Sonographic Terminology

White” shadow (w) due to very strong reverberations caused by a pocket of gas in the stomach. Notice that the reverberations are repetitive, giving the appearance of striated, parallel, bright echoes, unlike the homogeneous enhancement distal to fluid (F) seen behind a small liver cyst.

F W

TYPES OF MASSES

• Cystic
• Solid
• Complex or mixed
• Predominantly cystic

Predominantly solid

SONOGRAPHIC FEATURES:CYSTIC MASSES

• Anechoic
• Smooth thin walls
• Well-defined, sharp back wall

Posterior enhancement

Sonographic Terminology

This gallbladder in transverse cross-section meets the sonographic criteria for a cyst: anechoic round mass with a thin, well-defined back wall and excellent sound transmission or posterior enhancement.

SONOGRAPHIC FEATURES:SOLID MASSES

• Echogenic
• No well-defined back wall
• Posterior attenuation of sound
• from no visible effect to shadowing

Exception lymphoma (may have enhancement)

Sonographic Terminology

The rounded heterogeneous hypoechoic mass, a myoma in the uterus, has a poorly defined back wall and attenuates sound behind it. All of these are features of a solid mass. The attenuation of the sound beam by the myoma (X) is more than by the uterus itself (Y).

• X

Y

Sonographic Terminology

There are multiple round echogenic solid masses with hypoechoic borders filling the liver. They do not cause posterior enhancement or shadowing. The brightness (X) behind the rounded part of the liver is due to bowel gas, not posterior enhancement.

X

COMPLEX MASSES

• Predominantly cystic
• Mostly cystic
• Posterior enhancement
• Internal echoes

Thick walls

An example of a complex, predominantly cystic mass.

It is mostly cystic with a few thin linear strands, therefore it does not meet the strict criteria of a simple cyst, which would have no internal echoes.

This is a hemorrhagic splenic cyst.

Predominantly cystic

An example of a complex, predominantly cystic mass.

It is mostly cystic, shows excellent sound transmission, but contains internal echoes This is a hemorrhagic ovarian cyst.

Sonographic Terminology

An example of a complex, predominantly cystic mass. It is mostly cystic, has excellent posterior enhancement, but has a thick layer of echogenic material anteriorly and a few internal echoes, therefore it is complex. This is an abdominal aortic aneurysm with thrombus anteriorly and echoes from slowly moving blood in the lumen.

Predominantly solid

• Mostly echogenic
• Internal cystic changes

Posterior attenuation

Sonographic Terminology

An example of a complex, predominantly solid mass (arrows), which has a central cystic component, which in turn contains a solid nodule. The mass is mostly solid and the borders are somewhat difficult to define, because this is a malignant ovarian neoplasm.

Unusual sonographic features:Echogenic cyst

• Well-defined back wall
• Posterior enhancement
• Homogeneous, echogenic contents (looks solid)

Blood, pus, crystals, debris

Sonographic Terminology

This mass is filled with homogenous internal echoes, but also has a well-defined back wall and increased sound transmission or posterior enhancement.

This is an echogenic cyst, meaning that it is a cyst completely filled with internal echoes, which may be due to hemorrhage, pus, debris or crystals.

SONOGRAPHIC FEATURES OF A MASS

• Location
• Size
• Shape
• Borders, walls
• Internal echoes
• echogenicity, echotexture

Posterior enhancement or attenuation

This is a lobulated, anechoic liver mass with suggestion of a few internal echoes.

The mass has posterior enhancement and therefore is a complicated cyst.

The hyperechoic focus along its anterior wall (arrow) causes shadowing and is therefore a calcification.

Sonographic Terminology

This is a large, round, complex, predominantly cystic mass with a thick, irregular wall, a solid nodular component and posterior enhancement. This is due to a tumor with central cystic necrosis.

Sonographic Terminology

In the right pelvis there is a round, well-marginated thin-walled mass with a sharply defined back wall, thin internal septations and low intensity echoes, and excellent posterior enhancement.

The features are those of a complex, predominantly cystic mass, in this case a hemorrhagic ovarian cyst.

Sonographic Terminology

This is a lobulated, nodular, slightly inhomogeneous solid mass with a few tiny bright reflectors expanding the entire testicle, in this case a malignant tumor, seminoma.

Sonographic Terminology

Posterior to the uterus there is a round well-defined mass with a thin wall and layering of echogenic material and posterior enhancement, therefore a complex, predominantly fluid mass, in this case the end of a pus-filled infected fallopian tube.

Sonographic Terminology

This is an oval shaped anechoic mass with two irregular nodular solid components along its posterior wall and posterior enhancement (faint, but present) due to tumefactive sludge in a gallbladder.

Sonographic Terminology

The center of this kidney is expanded by an anechoic structure, which has dilated, blunted, branches coming together into one larger area, delineating a dilated intrarenal collecting system and hydronephrosis.