Radiography of STN and Abdomen

7/29/2019 Radiography of STN and Abdomen

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Procedure folder

Prepared by:

Sudil Paudyal

B.Sc.MIT 1st year

Roll no.51

Tribhuvan University, Institute Of Medicine

Maharajgunj Medical Campus

Topic: Radiography of

Soft tissue of neck (STN) and

Abdomen



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Soft Tissue of Neck (STN)

GENERAL ANATOMY:

The neck occupies the region between skull and thorax, its upper limit being

defined by an imaginary line extending from inferior border of symphysis menti to

the external occipital protuberance and its lower limit being defined by a line

extending from the suprasternal notch to superior border of the first thoracic

vertebra. For radiographic purposes the neck is divided into posterior and anterior

portions in accordance with the tissue composition and function of the contained

structures.

The portion of neck lying in front of the vertebrae is composed largely of soft

tissues, the upper part of respiratory and digestive systems being the principal

structures. The thyroid and parathyroid glands and large part of sub maxillary

glands, are also located in the anterior portion of neck.

The thyroid gland consists of two central lobes connected together by a narrow

median portion called the isthmus. The gland lies at the front and sides of the upper

part of trachea, its lobes reaching from lower third of the thyroid cartilage to thelevel of first thoracic vertebrae.

The parathyroid glands are small ovoid bodies and are normally four in number-

two on each side. They are situated, one above the other on the posterior part of

adjacent lobe of thyroid gland.

The pharynx serving as a passage for both food and air is common to the respiratory

and digestive systems. It is a musculomembranous, tubular structure situated in

front of vertebrae and behind the nose, mouth and larynx. It is approximately 5

inches in length, extending from the undersurface of body of sphenoid bone and the

basilar part of the occipital bone inferiorly to the level of disk between the sixth and

seventh cervical vertebrae, where it becomes continuous with oesophagus. The

pharyngeal cavity is further subdivided into nasal, oral and laryngeal portions. The



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nasopharynx lies above soft palate. The

oropharynx is the portion extending from

soft palate to the level of hyoid bone. The

base of tongue forms anterior wall of oropharynx. The laryngopharynx lies

behind larynx, its anterior wall being

formed by the back of larynx and

communicates with it by means of the

upper laryngeal aperture.

The larynx is organ of voice, and serving

as the air passage between pharynx and thetrachea, it is also one of the divisions of

the respiratory system. It is a movable,

tubular structure, broader above than below. It is situated below the root of tongue

and in front of the laryngopharynx, where it extends from the level of the superior

margin of fourth cervical vertebrae to its junction with the trachea at the level of the

inferior margin of the sixth cervical vertebrae. The framework of larynx is

composed of nine cartilages- three single (epiglottis, thyroid, and cricoid) and three paired (arytenoids, corniculate, cuneiform). The thin leaf shaped epiglottis is

situated behind the root of tongue and the hyoid bone. The thyroid cartilage forms

the laryngeal prominence, or “Adam’s apple”.

The laryngeal cavity is subdivided into three compartments by two pairs of mucosal

folds. The upper pair of folds, called the rima vestibule are known as the false vocal

cords. The space above them is called laryngeal vestibule. The lower pair of folds is

called the rima glottidis and they are known as true vocal cords. The vocal cordsand the rima glottidis make up the vocal apparatus of the larynx and are collectively

called the glottis.



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RADIOGRAPHY:

Plain radiography is requested to investigate the presence of soft tissue swellings

and their effects on the air passages, as well as to locate the presence of foreign

bodies or assess laryngeal trauma. The main routinely done projections aredescribed below.

STN- Antero posterior

Indications:

Trauma

Foreign body localization

Patient position:

Patient lies supine, with the median sagittal plane

adjusted to coincide with the central long axis of the

table.

Chin is raised to show the soft tissues below the

mandible and to bring the radiographic baseline to an

angle of 20 degrees from the vertical. Cassette is centered at the level of the fourth

cervical vertebra.

Centring of beam:

Central ray is directed 10 degrees cephalic and in the midline at

level of fourth cervical vertebra.

Exposure is made on forced expiration.

Radiation protection:

Collimation should be done to include only the area of interest.

Lead apron should be used to cover the lower part of the body.



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All the other radiation protection measures that are applied in the

department and universally should be applied.

Equipment setting:

Kv mAs FFD mA Film size mS Grid Focus

70 15 100 cm 100 25 X 30 cm 150 No Small

Picture criteria:

The image should demonstrate an area

from the occipital bone to the seventh

cervical vertebra.

Mandible should not overlap the laryngeal

area.

Neck should be free of rotation.



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STN-lateral

Indications:

Trauma

Foreign body localization

Patient position:

Patient stands or sits with either shoulder

against a vertical cassette.

The median sagittal plane of the trunk

and head are parallel to the cassette.

The jaw is raised so that the angles of the

mandible are separated from the bodies of

the upper cervical vertebra.

Immediately before exposure the patient

is asked to depress the shoulders forcibly

so that their structures are projected

below the level of the seventh cervical vertebra.

Centring of the beam:

The horizontal central ray is directed to a point vertically below

the mastoid process at the level of the prominence of the thyroid

cartilage through the fourth cervical vertebra.


Collimation should be done to include only the area of interest. Lead apron should be used to cover the lower part of the body.

All the other radiation protection measures that are applied in the

department and universally should be applied.



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Equipment setting:


70 15 100 cm 100 25 X 30 cm 150 No Small

Picture criteria:

The soft tissues should be demonstrated from the skull base to the

root of the neck (C7).

Radiograph should allow clear visualization of the laryngeal

cartilage and any possible foreign body. Shoulders should not superimpose the trachea.



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ABDOMEN

GENERAL ANATOMY:

The abdomen is the portion of trunk lying below the diaphragm and bounded

by pelvic bones inferiorly. In order to describe the location of organs or an

area, the abdomen is divided either into four quadrants or nine regions.

The abdomen is divided into four

quadrants by a transverse and a mid

sagittal plane that intersect at the

umbilicus. The quadrants are named

Right Upper Quadrant (RUQ), Right

Lower Quadrant (RLQ), Left Upper

Quadrant (LUQ), and Left Lower

Quadrant (LLQ). Dividing the

abdomen into four quadrants is useful

in describing the locations of various

abdominal organs.

The abdomen can be divided into nine regions by using four planes; two

transverse and two vertical planes.

The upper transverse plane, called the transpyloric plane, is midway between

suprasternal notch and symphysis pubis, approximately midway between the

upper border of xiphisternum and umbilicus. Posteriorly, it passes through the

body of the first lumbar vertebra; anteriorly, it passes through the tips of the

right and left ninth costal cartilages. The lower transverse plane, called thetranstubercular plane, is at the level of tubercles of the iliac crest anteriorly

and near the upper border of the fifth lumbar vertebra posteriorly.



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The two parasagittal (vertical)

planes are at right-angles to the

two transverse planes. They run

vertically, passing through a point midway between the

anterior superior iliac spine and

the symphysis pubis on each

side.

These planes divide the

abdomen into nine regions centrally from above to below epigastric, umbilical

and hypogastric regions and laterally from above to below right and lefthypochondriac, lumbar and iliac regions.

The principal structures of abdominal cavity are peritoneum, liver, gall

bladder, pancreas, spleen, stomach, intestines, kidneys, ureters and major

blood vessels.

The peritoneum is a double walled, membranous sac which lines theabdominal cavity. The outer layer of peritoneum closely adheres to the

abdominal walls and to the undersurface of the diaphragm. The inner layer

forms folds called the mesentery or omenta which serve to support the visceral

organs in position. The narrow space between the two layers is called the

peritoneal cavity.

RADIOGRAPHY:

Preparation:

Careful preliminary preparation of the intestinal tract is important in

radiologic investigation of the abdominal viscera. In the presence of non acute

conditions, the preparation can consist of any combination of controlled diet,



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laxative or enemas. The preparation ordered is generally determined by the

medical facility in which the examination is to be performed. The emergency

patients need not perform the preparation.

Exposure technique:

In examinations of the abdomen without a contrast medium, it is necessary to

obtain maximum soft tissue differentiation throughout its different regions.

Because of the wide range in thickness of the abdomen and the delicate

differences in physical density between the contained viscera, it is necessary

to use a more critical exposure technique than is required to demonstrate the

difference in density between an opacified organ and the structures adjacent toit. The exposure factors should thus be adjusted to produce a radiograph with

moderate gray tones and less black and white contrast. A sharply

demonstrated outline of the psoas muscles, lower borer of liver, kidneys ribs

and spinous processes of the lumbar vertebra are the best criteria for judging

the quality of an abdominal radiograph.

Immobilization:

One of the prime requisite in abdominal examinations is the prevention of

movement, both voluntary and involuntary. To prevent muscle contraction the

patient must be adjusted in a comfortable position so that he can relax. A

compression band may be applied across the abdomen for immobilization but

not compression. The exposure should be made 1-2 sec after suspension of

respiration to allow involuntary movement of viscera to subside.

Radiographic projections:

Radiography of the abdomen may include one or more radiographic

projections. The most commonly performed is the Antero-posterior supine

abdomen projection, often called a KUB (so named because it includes the

kidneys, ureters and bladder). Projections used to complement the AP supine



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may include AP erect and/or a lateral decubitus (the left lateral is generally

preferred). Both projections are useful in assessing the abdomen in cases of

falling down of abdominal viscera and in determining air fluid levels. Other

projections may include a lateral abdominal image using a horizontal beamtaken with the patient lying in the dorsal decubitus body position. These

projections are described below.

Abdomen-supine (KUB):

Indications:

Bowel gas patterns in obstruction

Perforation

Renal pathology

Control or preliminary films for contrast studies

Aortic Aneurysm

To detect calcification or abnormal gas collection

Patient position:

The patient lies supine on the table

with the median sagittal plane at rightangles.

The pelvis is adjusted so that the

anterior superior iliac spines are

equidistant from the table.

The cassette is placed longitudinally

and positioned so that the symphysis pubis is included on the

film.

The arms placed alongside the trunk or above the head.

Centring of beam:

The vertical central ray is directed approximately at the level of

a point 1 cm below the line joining the iliac crests.



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Strict application of the “pregnancy rule” or the “ten day rule”

is important in females of the child bearing age.

For males, the correct size of gonad protection should be

selected and applied carefully so that the gonads are shielded

and pelvic region not obscured with lead.

Equipment setting:


65 36 100 cm 300 35 X 43 cm 0.12 Yes Large

Picture criteria:

The image should cover whole of

abdomen to include diaphragm to

symphysis pubis.

Soft tissue gray tones should demonstrate

Lateral abdominal wall and the

properitoneal fat layer.

Psoas muscle, lower border of liver

and the kidneys.

Ribs and spinous processes of the

lumbar vertebra. The whole of the urinary tract should be visualized.

The bowel pattern should be demonstrated with minimal

unsharpness.



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Abdomen – Erect

Indications:

Trauma over abdomen

Suspected GI perforation

Abdominal malignancy

Intestinal obstruction

Patient position:

The patient stand with their back against the

vertical bucky.

The median sagittal plane is adjusted at rightangles and coincident with the midline of the

table.

The pelvis is adjusted so that the anterior

superior iliac spines are equidistant from the

table.

Centring of beam:

The horizontal central ray is directed perpendicular to midpointat the level of iliac crests.


The pregnancy rule or the rule of ten should be followed.

Gonad shielding should be used.

Equipment setting:


70 36 100 cm 300 35 X 43 cm 0.12 Yes Large



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Picture criteria:

The area from dome of diaphragm to

symphysis pubis should be included without

rotation. Lateral abdominal wall and properitoneal fat

should be visualized.

Psoas muscle, lower border of liver and

kidney shadows should be visualized.

Vertebra should be in center of film.

Side identification marker should be placed

properly.

Abdomen Lat. Decubitus

Lateral decubitus is done instead of abdomen erect if patient is

unable to stand or sit.Indications:

Abdominal perforation



Patient position:

The patient lies in left side with elbowsand arms flexed so that hands can rest

near the patients head.

The cassette is positioned transversely

in vertical bucky or a grid cassette is

kept behind the patient vertically against the posterior aspect of



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the trunk, with its upper border high enough to project above

the right lateral abdominal and thoracic walls.

Exposure is made on arrested respiration.

Centring of beam:

The central ray is directed perpendicular to midpoint at the

level of iliac crest with x-ray tube horizontally.



is important in females of the child bearing age. For males, the correct size of gonad protection should be



Equipment setting:


70 36 100 cm 300 35 X 43 cm 0.12 Yes Large

Picture criteria:

Lung area above dome of diaphragm

should be included.

Lateral abdominal wall and

properitoneal fat should bevisualized.

Psoas muscle, lower border of liver

and kidney shadows should be

visualized. Patient should not be rotated.



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Lateral dorsal decubitus (supine):

Occasionally, the patient cannot sit or even be rolled on to the side,

in which case the patient remains supine and a lateral projection is

taken using a horizontal central ray.

Indications:

Abdominal perforation



Patient position:

The patient lies supine, with

the arms raised away from the

abdomen and thorax.

A grid cassette is supported

vertically against the patient’s

side, to include the thorax to

the level of mid-sternum and

as much of the abdomen as possible.

Alternatively, when using a

trolley, the patient may be

positioned against a vertical

Bucky.

Centring of the beam:

The horizontal central ray is directed to the lateral aspect of the

trunk so that it is at right-angles to the cassette and centred to it.



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is important in females of the child bearing age. For males, the correct size of gonad protection should be



Equipment setting:


70 36 100 cm 300 35 X 43 cm 0.12 Yes Large

Picture criteria:

Lung area above dome of diaphragm

should be included without motion.

Abdominal contents should be seen with

soft tissue gray tones.

Patient should be elevated so entire

abdomen is demonstrated.



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References:

1. Clark’s positioning in radiography, 12th

edition

2. Merrill’s atlas of radiographic positions and radiologic procedures,12

thedition

3. Encyclopedia of radiography

Documents

Radiography of STN and Abdomen