ULTRASOUND - CH.1

solid mass

Abnormal mass within the body composed of one thing, tissue. EX: a solid mass is classified as an abnormal tissue collection within the body that disrupts the otherwise normal echo pattern of body structures on an US image.

Color Flow Doppler

Doppler shift information in a two-dimensional presentation superimposed on a real-time gray scale anatomic cross-sectional image. EX: flow directions are presented as different colors on the US display screen.

Anechoic

Echo-free appearing as a dark region on the image EX: a true cyst appears anechoic.

Endocavitary scanning planes

Endovaginal imaging and endorectal imaging are obtained from an inferior transcavitary approach. *see image*

crura of diaphragm

Right and left crus or fibromuscular bands arising from the lumbar vertebrae that insert into the central tendon of the diaphragm. EX: the crura of the diaphragm are often visualized on US images as curvilinear structures immediately adjacent to the spine. their sonographic appearance varies from bright to hypoechoic relative to adjacent structures.

depth of penetration

Maximum distance the sound beam travels from the transducer through a medium. EX: the greater intensity of the US beam, the greater the distance the beam will travel through a medium. the greater attenuation of a medium, the less the distance of travel.

Longitudinal (view or section)

Pertains to length; running lengthwise. EX: longitudinal waves of the aorta may be seen in coronal or sagittal scanning plane images. a longitudinal section of the splenic vein can be visualized in transverse scanning plane images of the midhypogastrium.

Reverberation

US image artifact caused when sound waves pass through and beyond a structure whose acoustic impedance is noticeably different from an adjacent structure, causing a huge amount of reflection back to the transducer. EX: reverberation occurs commonly when scanning intercostally. In general, an image of a structure (in this case a rib) is repeated, with the repeated images taken at an equal distance from the others.

low number MHz transducers are best for imaging ______________ structures.

deep

homogeneous

describes a uniform or similar echo patterns on a sonographic image. EX: most normal organ parenchyma appears homogenous on US images.

heterogeneous

describes an irregular or mixed echo pattern on a sonographic image. EX: an organ can appear heterogenous when pathology disrupts its otherwise normal, uniform sonographic appearance.

Echogenic

describes an organ or tissue that is capable of producing echoes by reflecting the acoustic beam EX: body structures are echogenic or capable of producing echoes.

cystic

describes the sonographic appearance of a fluid collection within the body that does not meet the criteria to be considered a true cyst EX: ascites is said to be cystic in nature.

infiltrative disease

diffuse disease process that spreads throughout an entire organ EX: the echo pattern of an organ is altered throughout due to infiltrative disease.

Transducer (ultrasound)

a device capable of converting electrical energy to mechanical energy and vice versa EX: US transducers include: - linear sequential array - curved linear array - annular array - sector-phased array - single element - transesophageal - intraoperative - endocavitary

mesentery

a fold of the peritoneum that attaches the stomach, small intestine, pancreas, spleen, and other organs to the posterior wall of the abdomen. EX: gallbladder position is variable due to its long mesentery.

Focal/multifocal change

disease process confined to isolated area(s) of an organ EX: a focal area of altered echo pattern may be visualized in only a part of an organ.

Midsagittal and parasagittal scanning planes

a sagittal scanning plane image demonstrates the anatomy visualized in an anterior-to-posterior (or posterior-to-anterior) dimension and superior-to-inferior dimension.

through transmission (acoustic enhancement)

a sonographic artifact in which is defined as the amount of the sound beam passing through a structure. (same as acoustic enhancement) Ex: Seen posterior to fluid filled objects, cysts, urinary bladder, & blood vessels.

a. how many planes must images be scanned in? b. what is required when taking your images?

a) documented areas of interest, required images, and abnormal findings must be represented in at least 2 scanning planes that are perpendicular to each other to give a more dimensional and accurate representation. b) - required to calculate volume measurements. - images must be documented in a logical sequence (follow a scanning protocol) - abnormal US findings are documented after a scanning protocol's normal sequence of images for an exam. otherwise, the documentation may become confusing for the interpreting physician.

sonogram

an image formed using reflected ultrasound waves

Transverse scanning plane

any plane perpendicular to the long axis of the body; divides the body into unequal superior and inferior sections EX: a transverse scanning plane image demonstrates the anatomy visualized in an anterior-to-posterior (or posterior-to-anterior) dimension and right-to-left dimension or a lateral-to-medial dimension and anterior-to-posterior dimension.

Axial (short axis) (view or section)

at right angles to longitudinal sections. term used to describe the section of a structure portrayed within a scanning plane image. EX: - axial views of the aorta may be seen in transverse scanning plane images. - axial sections of the pancreas can be visualized in sagittal scanning plane images of the midhypogastrium.

Inferior (caudal)

away from the head end or toward the lower part of a structure or the body; below - a structure below another structure EX: the uterus is situated inferiorly in the body. the superior mesenteric artery is inferior to the celiac axis. The body of the pancreas is inferior to the esophageal gastric junction. the bifurcation of the aorta is inferior to the level of the renal arteries.

Posterior (dorsal)

Situated at or directed toward the back. A structure behind another structure. EX: the kidneys are situated posteriorly in the body. The inferior vena cava is directly posterior to the head of the pancreas. The splenic vein is directly posterior to the pancreas tail and body. The right renal artery runs posterior to the inferior vena cava along its course to the right kidney.

Interface

The boundary between 2 materials or structures. EX: use the bright sonographic appearance of fat interfaces to differentiate body structures from each other.

calculi/"stones"

concentration of mineral salts that may accompany some disease processes EX: calculi are often visualized within the gallbladder as BRIGHT, moveable structures that vary in size and cast posterior shadows

Distal

farther from the origin of a body part or the point of attachment of a limb to the body trunk EX: the abdominal aorta is distal to the thoracic aorta.

Echopenic or Hypoechoic

few echoes. EX: the bile-filled gallbladder may appear echopenic.

Anterior (ventral)

front of the body or toward the body. A structure in front of a structure. EX: - the liver is situated anteriorly in the body. - the body of the pancreas is anterior to portions of the: splenic vein, superior mesenteric artery, left renal vein, abdominal aorta, spine. - the head of pancreas is anterior to the inferior vena cava

TGC (time gain compensation)

increase in receiver gain with time to compensate for loss in echo amplitude, usually due to attenuation, with depth (basically, its controls that compensate for the loss (attenuation) of the sound beam as it passes through tissue.) EX: most US techs include a group of sliding potentiometers to control the amplification of received echoes. most US displays include a TGC curve, which is a graphic display of the settings of the receiver's gain controls.

Medial

situated at, on, or toward the middle/midline of the body. EX: the spine is situated medially within the body. the pancreas neck is medial to the head of the pancreas; the pancreas body is medial to the head, beck and tail of the pancreas.

Contralaterlal

situated on or affecting the opposite side. EX: the ovaries are contralateral organs.

Superficial (external)

situated on or toward the surface EX: the testicles are superficial structures. The thyroid is a superficial gland.

retroperitoneum

space behind the peritoneal lining of the abdominal cavity EX: structures posterior to the peritoneum are: - pancreas - inferior vena cava - abdominal aorta - urinary system - adrenal glands - colon - uterus (only their anterior surfaces are in contact with the parietal peritoneal lining)

parenchyma

tissue composing an organ Ex: normal organ parenchyma appears homogeneous on an US image.

Hypoechoic

tissue that reflects less sound back to the transducer than the surrounding tissues; appears dark EX: the kidney typically appears hypoechoic relative to the liver.

Hyperechoic

tissue that reflects more sound back to the transducer than the surrounding tissues; appears bright EX: the pancreas usually appears hyperechoic relative to the liver.

Superior (cranial or cephalad)

toward the head; situated above or directed upward; a structure higher than another structure. EX: the lungs are situated superiorly in the body. the diaphragm is the superior margin of the abdominopelvic cavity.

ipsilateral

on the same side of the body. EX: the spleen and left kidney are ipsilateral.

focal zone

the point at which the sound beam is the narrowest and the resolution is the best EX: different transducers have different depths where their focus or focal zone is optimal. Therefore, the depth of a structure (of interest) within the body determines which transducer should be used.

Echotexture

the sonographic appearance of a structure EX: Normal organ parenchyma (soft tissue) is characterized sonographically as homogenous or uniform in echo texture, If disrupted or changed by disease..(like cancer), the parenchyma typically assumes an irregular or heterogenous echotexture or pattern. The nature of this change may be diffuse disease (infiltrative focal) or localized disease (a mass or multiple masses circumscribed to a specific area).

systemic

pertaining to the body as a whole EX: systemic circulation transports blood from the heart to all parts of the body (except the lungs) and back again.

localized disease

represents a circumscribed mass or multiple masses EX: masses may be classified as solid, cystic, or complex.

gray scale

scale of achromatic colors having multiple graduations from white to black. EX: sonographic display format where echo amplitude (intensity) is recorded and presented as various in brightness of shades of gray.

ultrasound scanning planes

scanning planes in US are the same as anatomic body planes, but their interpretations depend on the location of the transducer and the sound wave approach (where the sound waves enter the body). EX: sagittal scanning plane orientation is usually indicated by a notch or raised portion on the top surface of the transducer. once the transducer orientation is established, the scanning plane can be changed by turning the transducer counterclockwise.

Attenuation of ultrasound in media

water--extremely low blood, urine, biologic fluids--low fat--low soft tissue--intermediate muscle--higher bone and lung--even higher air--extremely high

Isogenic/isoechoic

Same echogenicity or Echo patterns are equal in echogenicity. Example: the spleen may appear isogenic relative to the liver.

Ultrasound

Sound waves with frequencies above 20,000 Hz, or above the range of human hearing.

Peritonium

Thin sheet of tissue that lines the paratonia cavity and secrete series food, which serves as a lubricant and facilitates free movement between organs. - Classified as parietal (portion of the lining that forms a closed sac) and visceral (portion of lining that directly covers organs and various body structures) - Characterized as intraperitoneal (inside the sac) and retroperitoneal (posterior or behind the sac)

respiration moves internal body structures. T/F?

True.

Diffuse disease

infiltrative disease throughout an organ that disrupts the otherwise normal sonographic appearance of organ parenchyma EX: infiltrative disease alters the normal echo pattern throughout an organ

deep inspiration forces the diaphragm and everything below it in the abdomen to ___________________.

move down.

deep exhalation forces the diaphragm and everything below it in the abdomen to ___________________.

move upward.

coupling agent

substance used to reduce air between the ultrasound transducer and surface of the skin EX: gel is a typical coupling agent used in sonography.

high number MHz transducers are best for imaging _______________ structures.

superficial

Transmission

term implying passage of energy through a material. EX: a sonographic image is a result of configured transmissions.

ascites

the accumulation of fluid in the peritoneal cavity, causing abdominal swelling. EX: ascites may be visualized in the posterior cul-de-sac of the abdominopelvic cavity.

Sonologist

the physician who interprets a sonogram

acoustic impedance

the resistance a material provides to the passage of sound waves (basically, the density of a substance and the speed of sound in that substance.) EX: bone portrays more acoustic impedance than tissue.

beam divergence

- widening of the sound beam as it travels - Ex: the pyramid appearance of an ultrasound image typifies beam divergence

medium

Material through which sound waves travel. EX: most fluid collections are non-attenuating mediums, whereas bone is an attenuating medium.

diffuse infiltrative disease of the head of pancreas may displace adjacent (neighboring) structures, which can dilate the common bile duct (CBD) and compress the anterior surface of the inferior vena cava (IVC). a description might be?

"Pancreas appears heterogenous and markedly hyperechoic relative to the liver. Small shadowing calcifications throughout, and irregular outline is noted. Head appears focally enlarged: 6cm anteroposteriorly. There is a posterior displacement (or anterior compression) of the IVC. CBD appears dilated: 12mm. The duodenum is not seen.

diffuse infiltrative disease of the spleen may displace adjacent (neighboring) structures, particularly the left kidney. a description might be?

"Spleen appears enlarged and hyperechoic relative to the left kidney, which is displaced inferomedially. Superior pole of kidney appears flattened by the lumpy contour of the spleen."

Mirror image artifact (non-Doppler)

the sonographic image of a structure is duplicated in an atypical position and appears as a mirror image of the original EX: mirror images usually occur when scanning structures that share a distinctly curved interface, such as the interface between the diaphragm and liver, and diaphragm and spleen.

Calipers (electronic)

two or more measurement cursors that can be manipulated to calibrate the distance between echoes of interest on the imaging screen EX: measurement calipers are used to obtain length, width, and anteroposterior measurements to provide the dimensions or total volume of a structure of interest.

common US terms for reports

(terms referring to texture) homogenous: uniform or similar echo patterns heterogenous: irregular or mixed echo patterns (referring to sonographic appearance or echogenicity) - anechoic: echo free; black - hyperechoic: increased echogenicity compared with an adjacent structure(s) - hypoechoic: decreased echogenicity compared with an adjacent structure(s) - isoechoic/isogenic: same echogenicity

Quadrant Divisions of the Abdomen

*see image*

Surface Landmarks of the Abdomen

*see image*

body planes

*see image*

coronal scanning plane - left lateral approach - right lateral approach

*see image*

patient positions for an ultrasound

*see image*

regional divisions of the abdomen

*see image*

sagittal scanning plane - anterior approach

*see image*

sagittal scanning plane - posterior approach

*see image*

transverse scanning plane - left lateral approach - right lateral approach - anterior approach - posterior approach

*see image*

Ultrasound Artifacts

- Can be falsely interpreted as real pathology (such as a blood clot, foreign body, etc..) - May obscure pathology - Important to understand and acknowledge EX: there are 8 main artifacts: 1. Mirror Image Artifact 2. Acoustic Shadowing Artifact 3. Posterior Acoustic Enhancement 4. Edge Shadowing Artifact 5. Reverberation Artifact 6. Comet Tail Artifact 7. Ring Down Artifact 8. Side Lobe Artifact

describing localized disease

- a localized change in the normal appearance of parenchyma represents a mass or multiple masses, which are circumscribed to a specific area. - mass descriptions should include origin (or location), size, composition, number, and any associated complication with adjacent structures. ORIGIN:

describe the normal sonographic appearance of the BONES, FAT, AIR, FISSURES, LIGAMENTS, TENDONS, DIAPHRAGM

- appear echogenic and vary in brightness depending on the density of the structure, its distance from the second beam, and the angle at which the beam strikes the structure - because these structures either reflect or attenuate the sound beam, they appear hyperechoic or brighter compared with adjacent structures; they may cast a posterior shadow.

describe the normal sonographic appearance of NERVES

- appearance is generally described in comparison with adjacent structures: hyperechoic or brighter when compared with the appearance of muscle; hypoechoic or less echogenic when compared with the appearance of tendons. - peripheral nerve fibers present as very low gray or echo-poor with a distinctive internal echo pattern that appears stippled in axial sections and honeycombed in longitudinal sections.

describe the normal sonographic appearance of PLACENTA

- echo texture changes throughout a pregnancy, from homogenous or uniform with moderate to high echogenicity to heterogenous or mixed echo pattern, when interrupted by multiple vascular components. - normally hyperechoic or brighter appearance relative to uterine myometrium.

describe the normal sonographic appearance of TISSUE

- echo texture is homogenous or uniform and moderately echogenic. -margins appear very bright or hyperechoic compared with adjacent structures.

describe the normal sonographic appearance of MUSCLE

- homogenous or uniform echo texture with low echogenicity - typically appear hypoechoic or less echogenic relative to the organ(s) or body structures they are adjacent to. - skeletal bundles are distinctly separated by bright symmetric bands of fibroadipose septate that appear hyperechoic or more echogenic compared with the low gray appearance of the muscle. *see image* abbreviations: SCM: sternocleidomastoid OH: omohyoid muscle ST: sternothyroid muscle SH: sternohyoid muscle LCM: longus colli muscle THY: thyroid CCA: common carotid artery JV: jugular vein E: esophagus TR: trachea RLN: recurrent laryngeal nerve VN: vagus nerve

describe the normal sonographic appearance of ORGAN PARENCHYMA

- homogenous or uniform echo texture with range in echogenicity - liver parenchyma, for example, could be described as homogenous and moderately echogenic.

Image Documentation Criteria - labeling?

- labeling should be confined to the margins surrounding the image - labels should not cover any part of the image being submitted for diagnostic interpretation bc it could cover some important info pertinent to the dx - if labeling or measurement calipers are used on an image, it is standard practice to document that same image with labels or calipers REMOVED!

describe the normal sonographic appearance of fluid-filled structures such as: - blood vessels - ducts - umbilical cord - amniotic sac - brain ventricles - ovarian follicles - renal calyces - urine-filled urinary bladder - bile-filled gallbladder - bursa

- lumens appear anechoic (black; echo-free) - walls appear bright; highly echogenic or hyperechoic compared with adjacent structures - may exhibit bright posterior through transmission, making them easy to distinguish sonographically.

Directional Terms

*see image*

Extraorgan pathology

Abnormal disease process that originates out side of an organ. EX: an extraorgan mass may be visualized originating outside of an organ, causing abnormalities such as displacement of other organs and structures, obstruction of other organs or structures from view, internal invagination of organ capsules, and discontinuity of organ capsules.

Intraorgan pathology

Abnormal disease process that originates within an organ. EX: an intraogran mass may be visualized originating within an organ and causing abnormalities such as disruption of the normal internal architecture, external bulging of the organ's capsule, and displacement or shifting of adjacent body structures.

complex mass

Abnormal mass within the body composed of both tissue and fluid.

True cyst (simple cyst)

Abnormal mass within the body composed of fluid. - Must meet 3 specific sonographic appearance criteria: (1) anechoic, (2) well-defined and thin, smooth walls, and (3) exhibits posteriorly through transmission. If not, the mass is characterized as cystic in nature. Either way, a true cyst or a cystic mass disrupts the otherwise normal echo pattern of organ parenchyma.

Coronal scanning planes

Any plane parallel to the long axis of the body and perpendicular to sagittal scanning planes. EX: a coronal scanning plane image demonstrates the anatomy visualized in a lateral to medial dimension and superior to inferior dimension.

ALARA (as low as reasonably achievable)

As low as reasonably achievable. Adopted as a culture and attitude by professionals who work with ionizing radiation to minimize radiation exposure and risks. (basically means that output level and exposure time to ultrasound is minimized while obtaining diagnostic data) EX: always consider this while scanning . The thermal index (TI) and mechanical index (MI) are components of US bioeffects that should be monitored while scanning. the TI and MI values are displayed usually in the upper right hand of screen.

orthogonal

At right angles, perpendicular Ex: coronal planes are orthogonal to Sagittarius planes.

deep

Away from the body surface; more internal. EX: the kidneys are deep structures within the body.

Proximal

Closer to the origin of the body part or the point of attachment of a limb to the body trunk Ex: The common hepatic duct is proximal to the common bile duct.

contrast

a comparison to show differences. EX: an US image produces dark and light comparative gray-scale tones.

mass

circumscribed disease process. EX: a mass is defined according to its composition: solid, cystic, or complex.

necrotic

dead tissue EX: many complex masses are described as necrotic tissue

neoplasm

new growth (tumor- can be benign or malignant) EX: a neoplasm is characterized as either a tumor or a mass.

describe the normal sonographic appearance of the GI TRACT:

- walls are thin and generally appear hypoechoic or less echogenic compared with adjacent structures; however they can appear very bright if they are surrounded by an extensive amount of fat. - the appearance of the lumen in GI tract varies depending on its contents - a fluid-filled lumen appears anechoic - a gas or air-filled lumen will appear bright, highly echogenic, and generally hyperechoic relative to adjacent structures - the lumen can also have complex or mixed appearance, displaying anechoic portions from fluid, along with echogenic portions that vary in brightness depending on their composition (partially digested food, indigestible material, gas, air) - all or individual sections of GI tract may cast a posterior shadow where air or gas is present in the lumen - empty, collapsed bowel has a distinctive "bull's eye" appearance due to the contrast between the very bright, collapsed lumen and hypoechoic walls. *see image* abbreviations: - STO: stomach - AO: aorta - IVC: inferior vena cava

the abdominal aorta is one of the deepest structures of the abdomen. which transducer is best to use?

3.0 - 3.5 MHz transducer.

your patient is thin. which transducer would you use?

5.0 MHz transducer.

patient should fast for ___________ hours before a US study. why?

8 hrs - to reduce gas which can obscure visualizations of the structure of interest (in the abdomen)

Doppler (effect)

A change in sound frequency caused by motion of the sound source, motion of the listener, or both.

pleural effusion

A collection of fluid inside the lung. Ex: A plural effusion appears anechoic and hypoechoic relative to the bright appearance of adjacent ribs.

list the responsibilities of a sonographer

- Provide quality patient care - excellent communication skills - strong computer skills - obtain and record pt data pertinent to the US study into pt's EMAR - proper use of US systems and equipment - acquire, modify, select images for physician to formulate a dx - use US terminology to document the technical summary of the Us findings - assist with US guided invasive procedures - knowledge of standard precautions - measure internal organ size - explain procedure to pt/ comfort them

describing diffuse disease

- normal organ parenchyma (soft tissue) is described sonographically as HOMOGENOUS, or uniform in texture. Parenchyma typically assumes an irregular, or HETEROGENOUS, echo pattern if disrupted or changed by disease. The nature of this disease change may be diffuse (infiltrative) or localized (a mass or multiple masses circumscribed to a specific area) EX: "The liver appears enlarged and hyperechoic compared with the pancreas." ____________________________________________________________________________ - As disease advances, organ parenchyma can become more coarse or patchy looking with necrotic (degenerating), blood-filled spaces. sonographic appearance of progressive diffuse disease could be characterized by a sonographer as: EX: "Liver shape appears altered with coarse, scattered increases in echogenicity and multiple fluid-filled, anechoic spaces 1-5mm in diameter throughout." _____________________________________________________________________________ - when diffuse disease causes enlargement of an organ, sonographer must determine the extent of increase and describe whether any adjacent structures have been compromised. all or just a portion of an organ may extend far beyond its normal boundaries, displacing other organs and structures from their normal positions or blocking them entirely from view. *see image* EX: "Right lateral lobe of the liver appears markedly enlarged and moderately hyperechoic compared with the right kidney. Few internal vascular structures noted. Right kidney appears compressed posteroinferiorly. ______________________________________________________________________________

Acoustic shadowing artifact

- occurs when ultrasound waves encounter a structure that has a high attenuation coefficient. - EX: black posterior shadowing can be visualized posterior to the fetal femur. - commonly occurs in bones, ribs, gallstones

Acoustic Enhancement Artifact

- opposite of the acoustic shadowing artifact - occurs when ultrasound waves pass through a structure with significantly low attenuation such as blood or fluid-filled structures. EX: bright posterior through transmission can be visualized posterior to the urinary bladder.

Image Documentation Criteria - the following must be included on an image...

- patients name and DOB - date and time - scanning site (name of hospital, private office, etc..) - sonographers name - transducer MHz - patient position - scanning plane - area of interest: general (ex: aorta) and specific (ex: proximal, mid, or distal).

describe/list the legal scope of the sonographer

- sonographers acquire, assess, modify, analyze, document, and describe the US findings using US terminology in an oral or written technical observation. - sonographer is not expected to know all pathologies detectable with US to be able to accurately describe their sonographic appearance. however, they should know the echo patterns of normal anatomy. any change in normal appearance would suggest abnormality. if sonographer does not know what is causing the change or deviation in the normal echo pattern, recognizing it as a deviation is what is most important. (keep in mind that all pathologies visualized with US disrupts the normal sonographic appearance of the structure involved - by changing one, some or all of the characteristics of the structures typical normal appearance.) - sonographer must: a. differentiate abnormal echo patterns from normal echo patterns b. document any differences in echo pattern appearance c. describe any difference in echo pattern appearance using sonographic terminology.

septations

- thin, membranous inclusion(s) within a mass - Ex: single or multiple septations may be visualized in cystic or complex masses

How to Document Abnormal Findings

1. determine the number - how many? 2. determine the origin of the abnormality - which organ or structure is/are involved? - which adjacent structures (if any) are involved? 3. determine the composition of the abnormality. is it solid, cystic, complex? 4. pathology images are documented AFTER the standard protocol images and include the size of the abnormality with volume measurements (measure the greatest dimensions in length, height, and width in 2 perpendicular scanning planes) and high and low gain images (gain range helps to resolve composition) in at least 2 scanning planes.

what should be included in a US request form?

1. pt identification (name, DOB, address, MRN, phone #) 2. clinical S&Sx 3. type of examination requested 4. reason for examination

what are the proper steps to take before a US exam?

1. review US request form 2. review pt's chart (EMAR) - (determine where in the EMAR the US orders are located so that you can ensure the orders are properly vetted - that the order matched the indication for the exam)

how to accurately measure structures?

1. scan as perpendicular to the structure as possible for size to be minimally distortion free. 2. the degree of distortion will be proportional to the angle of the sound beam - the greater the angle, the greater the distortion.

list the 4 motions of a transducer

1. tilting 2. rocking 3. sliding (left-right, up-down) 4. rotating

Lateral

Away from the midline of the body - structure that is on, at, or toward the side. EX: the spleen is situated laterally in the body. the carotid arteries are lateral to the thyroid gland. the pancreas head, neck, and tail are lateral to the pancreas body. the kidneys are lateral to the spine.

sonographer

Highly skilled allied-health professional qualified by technologic education to perform ultrasound examinations of patients and document the results under the supervision of a physician.

Long axis (view or section)

Represents the longest length of a structure. Ex. It is standard practice in sonography to measure the long axis section of most structures.

attenuation in ultrasound

continuous loss of energy as pulse travels through tissue; caused by absorption, scatter, or beam divergence EX: the density, composition, and angle of the sound beam when it strikes an object determine how much of the sound beam is attenuated.

intraperitoneal

within the peritoneal cavity EX: the liver (except for the bare area posterior to the dome. gallbladder, spleen (except for the hilum), stomach, the majority of the intestines, and the ovaries' are considered intraperitoneal.