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To demonstrate the glenoid fossa in profile, the patient is positioned

45° oblique, affected side down

When viewing the glenoid fossa from the anterior,

it is seen to angle posteriorly and laterally approximately 45°. To view it in profile, then, it must be placed so that its surface is perpendicular to the image recorder. The patient is positioned in a 45° oblique, affected side down, which places the glenoid fossa approximately perpendicular to the image recorder. The arm is abducted slightly, the elbow flexed, and the hand and forearm placed over the abdomen. The CR is directed perpendicular to the glenohumeral joint.

LPO of the lumbar spine

The patient is positioned so that the lumbar spine forms a 45° angle with the IR. The apophyseal joints (those closest to the IR) are well demonstrated in this position. The typical "scotty dog" image is depicted. The "ear" of the scotty is the superior articular process and the front foot is the inferior articular process. The scotty's eye is the pedicle; its "body" is the lamina, and its nose is the transverse process.

Routine excretory urography usually includes a postmicturition radiograph of the bladder. This is done to demonstrate

1. tumor masses.
2. residual urine.
3. prostatic enlargement.

Variance from the normal bladder contour will be noted while

the bladder is full of contrast medium. However, a postmicturition (postvoiding) radiograph is also an essential part of an IVU/IVP. The presence of residual urine may be an indication of small tumor masses or, in male patients, enlargement of the prostate gland.

To demonstrate the intercondyloid fossa, the central ray must be directed

perpendicular to the long axis of the tibia. Because the knee is flexed so that the tibia forms a 40° angle with the IR, the central ray must be directed 40° caudad to place the central ray perpendicular to the long axis of the tibia. Directing the central ray to the popliteal depression aligns the central ray parallel with the knee joint space.

Esophageal varices are best demonstrated in which of the following positions?

Recumbent

Esophageal varices are best demonstrated when

there is increased venous pressure and when blood is flowing against gravity. Therefore, to demonstrate the twisted, dilated condition of venous varicosities, esophagograms must be performed in the recumbent position. In the erect position, the veins appear more smooth and normal.

The midcoronal plane

divides the body into anterior and posterior halves

A coronal plane

is any plane parallel to the midcoronal plane

The midsagittal plane

divides the body into left and right halves.

A sagittal plane

is any plane parallel to the midsagittal plane.

A transverse or horizontal plane

is perpendicular to the midsagittal plane and midcoronal plane, dividing the body into superior and inferior portions.

radial flexion deviation maneuver

To position, the hand and wrist are placed PA, and the elbow is moved toward the body without moving the hand and wrist. Or, the hand can be turned medialward in extreme radial flexion (deviation). This position is used to better demonstrate the medial carpals (pisiform, triangular, hamate, and medial aspect of capitate and lunate) and their interspaces. In the proximal carpal row, the lunate is seen particularly well. Just medial to the lunate, the superimposed triquetrum and pisiform are seen. In the distal carpal row, the most lateral carpal, the hamate, is well seen. Just medial to it is the capitate. The self-superimposed and foreshortened scaphoid is seen distal to the radius and lateral to the lunate.

The carpal scaphoid may be demonstrated in the following projections of the wrist:

1. PA oblique
2. PA with ulnar flexion/deviation
3. PA with forearm elevated 20°

Lateral carpals, especially the scaphoid, are demonstrated

in the PA oblique projection and the ulnar flexion/deviation maneuver. The scaphoid may also be demonstrated with the wrist PA and elevated 20°. The central ray is directed perpendicular to the carpal scaphoid. The medial carpals, especially the pisiform, are well demonstrated in the AP oblique projection and with the radial flexion/deviation maneuver.

During endoscopic retrograde cholangiopancreatography (ERCP) examination, contrast medium is injected into the

common bile duct

Endoscopic retrograde cholangiopancreatography is performed to diagnose

disease of the biliary and/or pancreatic organs. Fluoroscopic control is used to introduce the fiberoptic endoscope through the mouth and into the duodenum. The hepatopancreatic ampulla (of Vater) is then located and cannulated, and contrast medium is injected into the common bile duct.

The patient is usually required to drink barium sulfate suspension in order to demonstrate which of the following structure

Stomach

Oral administration of barium sulfate is used to demonstrate

the upper digestive system, esophagus, fundus, and body and pylorus of the stomach, and barium progression through the small bowel. The ilium refers to the bony pelvis, whereas the ileum refers to the small bowel—which would be demonstrated by oral administration of barium.

The large bowel, including the cecum, is usually demonstrated via

rectal administration of barium.

The secondary center of ossification in long bones is the

epiphysis

Bones are classified as

long, short, flat, and irregular. Many of the bones making up the extremities are long bones. Long bones have a shaft and two extremities (ends). The shaft (or diaphysis) of long bones is the primary ossification center during bone development. It is composed of compact tissue and covered with a membrane called periosteum. Within the shaft is the medullary cavity, which contains bone marrow and is lined by the membrane called endosteum. In the adult, yellow marrow occupies the shaft, and red marrow is found within the proximal and distal extremities of long bones. The secondary ossification center, the epiphysis, is separated from the diaphysis in early life by a layer of cartilage, the epiphyseal plate. As bone growth takes place, the epiphysis becomes part of the larger portion of bone and the epiphyseal plate disappears, but a characteristic line remains and is thereafter recognizable as the epiphyseal line.

Which of the following is (are) demonstrated in the AP projection of the thoracic spine?

Intervertebral spaces

The thoracic intervertebral (disk) spaces are demonstrated

in the AP and lateral projections, although they are probably best demonstrated in the lateral. The thoracic apophyseal joints are 70° to the MSP and are demonstrated in a steep (70°) oblique position. The thoracic intervertebral foramina, formed by the vertebral notches of the pedicles, are 90° to the MSP. They are therefore well demonstrated in the lateral position.

The AP projection of the sacrum requires the central ray to be directed

15° cephalad to a point approximately 2 inches superior to the pubis

For the AP projection of the sacrum,

the patient is AP supine with the MSP perpendicular to the x-ray tabletop. The central ray is directed 15° cephalad to a point 2 inches superior to the pubis (approximately midway between the ASIS and the pubic symphysis). In this projection, the central ray angulation parallels the sacral curve and provides less distorted visualization of the sacrum and its foramina.

A "blowout fracture" usually occurs in which aspect of the orbital wall?

Inferior

The bony walls of the orbit are

thin, fragile, and subject to fracture. A direct blow to the eye results in a pressure that can cause fracture. That fracture is usually to the orbital floor (the inferior aspect of the bony orbit). Because the fracture results from increased pressure within the eye, it is referred to as a "blowout" fracture.

The AP axial projection of the pulmonary apices requires the central ray to be directed

15° cephalad

It is occasionally necessary to view the lung apices free of superimposition with the clavicles.

This objective can be achieved in the AP axial projection. The patient is positioned AP erect with the central ray directed 15° cephalad, entering the manubrium. An AP axial projection can also be obtained with the patient in the lordotic position. If sufficient lordosis can be assumed, the central ray is directed perpendicular to the IR.

Which cholangiographic procedure uses an indwelling drainage tube for contrast medium administration?

T-tube cholangiography

Contrast media may be administered in a variety of manners in cholangiography, including

1. an endoscope with a cannula placed in the hepatopancreatic ampulla (of Vater) for an ERCP.
2. a needle or small catheter placed directly in the common bile duct for an operative cholangiogram.
3. a very fine needle through the patient's side and into the liver for a percutaneous transhepatic cholangiogram.
4. via an indwelling T-tube for a postoperative or T-tube cholangiogram.

Free air in the abdominal cavity is best demonstrated in which of the following?

1. Erect AP abdomen
2. Left lateral decubitus abdomen

When air-fluid levels are to be demonstrated,

it is important to direct the central ray horizontally. If the central ray is angled or directed vertically, the air or fluid level will be distorted or entirely obliterated. Free air in the abdominal cavity is best visualized when the patient is left lateral decubitus or erect AP. The decubitus allows the air to accumulate around the homogeneous liver.

Which of the following statements is (are) true with respect to the differences between the male and female bony pelvis?

1. The female pelvic outlet is wider.
2. The pubic angle is 90° or less in the male.

The female pelvis differs from the male pelvis

in that it is more shallow and its bones are generally lighter and more delicate (see figure). The pelvic outlet is wider and more circular in the female, and the ischial tuberosities and acetabula are farther apart; the angle formed by the pubic arch is also greater (more than 100°) in the female. All these bony characteristics facilitate childbearing and birth.

A patient is being positioned for a particular radiographic examination. The x-ray tube, image recorder, and grid are properly aligned, but the body part is angled. Which of the following will result?

Image distortion

Proper alignment

of the x-ray tube, body part, and image recorder is required to avoid image distortion in the form of foreshortening or elongation. Foreshortening will usually result when the part is out of alignment. Elongation is often a result of angulation of the x-ray tube. Grid lines or grid cutoff will occur when the grid itself is off-center or not in alignment with the x-ray tube.

The right anterior oblique of the cervical spine requires which of the following combinations of tube angle and direction?

15° to 20° caudad

the cervical intervertebral foramina lie

45° to the midsagittal plane (MSP) and 15° to 20° to a transverse plane. When the posterior oblique position (LPO, RPO) is used, the central ray is directed 15° to 20° cephalad and the cervical intervertebral foramina demonstrated are those farther from the image recorder. There is therefore some magnification of the foramina (because of the OID). In the anterior oblique position (LAO, RAO), the central ray is directed 15° to 20° caudad, and the foramina disclosed are those closer to the image recorder.

The sternum has three parts:

The uppermost portion is the manubrium (and is quadrilateral in shape), the midportion is the body or gladiolus, and the distal portion is the ensiform or xiphoid process. The sternum supports the clavicles superiorly and provides attachment for the ribs laterally. The first seven pairs of ribs are true or vertebrosternal ribs, as they attach directly to the sternum. The ribs angle obliquely anteriorly and inferiorly so that their anterior portions are 3 to 5 inches inferior to their posterior attachment. The sternoclavicular joints afford the only bony attachment between the thorax and the upper extremity.

Which of the following is (are) accurate positioning or evaluation criteria for an anteroposterior projection of the normal knee?

Femorotibial interspaces equal bilaterally

In the AP projection of the normal knee,

the space between the tibial plateau and the femoral condyles is equal bilaterally. It is therefore important that there be no pelvic rotation that could change the appearance of an otherwise-normal relationship. The AP projection of the knee superimposes the patella and femur. The central ray should enter at the knee joint, located 1/2 inch distal to the patellar apex.

Which of the following radiographic examinations require the patient to be npo 8 to 10 hours prior to examination for proper patient preparation?

1. Upper GI series
2. BE

There is no preparation required for

an abdominal survey. For an upper gastrointestinal (upper GI) series and a lower GI series (BE), the patient should be npo, or have nothing by mouth, for 8 to 10 hours prior to the examination. In addition, a low-residue diet may be imposed, fluid intake may be increased, and cleansing enemas and laxatives may be prescribed to rid the colon of fecal matter.

Which surface of the forearm must be adjacent to the IR to obtain a lateral projection of the fourth finger with optimal recorded detail?

Medial

A lateral projection of the fourth finger is best obtained

if the finger is positioned so that there is as little OID as possible. Therefore, with only the fourth finger extended in the lateral position, the arm is positioned on the ulnar (medial) surface. This places the finger closer to the IR than if it were positioned radial side down. Excessive magnification distortion is avoided, and better recorded detail is obtained.

Which of the following should be used to evaluate glenohumeral joint dislocation?

1. Transthoracic lateral
2. Scapular Y projection

Although the inferosuperior axial projection can be used to evaluate the glenohumeral joint,

he required abduction of the arm would be contraindicated when evaluating a shoulder for possible dislocation. The transthoracic lateral projection is used to evaluate the glenohumeral joint and upper humerus when the patient is unable to abduct the arm (as in dislocation). The scapular Y projection is an oblique projection of the shoulder and is used in demonstrating anterior or posterior dislocation.

Which of the following is (are) demonstrated in the lateral projection of the cervical spine?

1. Intervertebral joints
2. Apophyseal joints

Intervertebral joints are well visualized in the

lateral projection of all the vertebral groups. Cervical articular facets (forming apophyseal joints) are 90° to the MSP and therefore are well demonstrated in the lateral projection. The cervical intervertebral foramina lie 45° to the MSP (and 15° to 20° to a transverse plane), and are therefore demonstrated in the oblique position.

All of the following statements regarding the RAO position of the sternum are true

A. the sternum is generally projected to the left of the vertebral column.
B. shallow breathing during the exposure can obliterate prominent pulmonary markings.
C. it is helpful to project the sternum over the heart.

A thin chest would require

a greater degree of obliquity to separate the vertebrae and sternum from superimposition than would a thick chest. With the patient in the RAO position, the sternum is projected to the left of the vertebral column and superimposed on the heart. This superimposition promotes more uniform tissue density and therefore more uniform radiographic density. Prominent pulmonary vascular markings may be obliterated by allowing the patient to breathe (shallow breaths only) during a long exposure (with a very low mA).

Improper support of a patient's fractured lower leg (tibia/fibula) while performing radiography could result in

1. movement of fracture fragments.
2. tearing of soft tissue, nerves, and blood vessels.
3. initiation of muscle spasm.

Improper support of a patient's fractured lower leg (tibia/fibula) while performing radiography could result in

movement of the fracture fragments, which can cause tearing of the soft tissue, nerves, and blood vessels. In addition, lack of support may cause muscle spasm, which can make closed reduction of some fractures difficult.

Which of the following statements is (are) correct with respect to postoperative cholangiography?

1. A T-tube is in place in the common bile duct.
2. Water-soluble contrast material is injected.
3. The patency of biliary ducts is evaluated.

Postoperative, or T-tube, cholangiography

is frequently performed to evaluate the patency of the biliary ducts and to identify any previously undetected stones. Following surgery, a T-tube is left in place within the common bile duct, with the vertical portion of the T extending outside the body. Water-soluble iodinated medium is injected, and fluoroscopic examination is carried out.

In myelography, the contrast medium is generally injected into the

subarachnoid space between the third and fourth lumbar vertebrae.

Generally, contrast medium is injected into the

subarachnoid space between the third and fourth lumbar vertebrae. Because the spinal cord ends at the level of the first or second lumbar vertebra, this is considered to be a relatively safe injection site. The cisterna magna can be used, but the risk of contrast entering the ventricles and causing side effects increases. Diskography requires injection of contrast medium into the individual intervertebral disks.

The RAO position

The barium-filled esophagus can be projected between the vertebrae and heart in this position. This RAO position is also used to superimpose the sternum onto the heart shadow, to provide uniform density throughout the sternum. The degree of obliquity depends on the patient's body habitus—greater obliquity required for thinner chests. The RAO position is also used to see axillary portions of left anterior ribs; in the anterior oblique positions, the affected side is away from the IR.

The thoracic cavity is lined by

parietal pleura

The thoracic and abdominal cavities are associated with

serous membranes: the thoracic cavity with the pleura and the abdominal cavity with the peritoneum. The pleura and peritoneum each have two walls, a parietal (outer) wall and a visceral (inner) wall. The parietal pleura lines the thoracic cavity, while the visceral pleura is reflected over the surface of the lungs and projects between the fissures. The parietal peritoneum lines the abdominal cavity, and the visceral peritoneum invests the abdominal viscera.

Rotation of the chest is evidenced in the following ways:

The distance between the medial aspect of the clavicles and the lateral portion of the vertebral column is asymmetrical, the air-filled trachea is off midline, and the scapulae and air-filled lungs are asymmetric

Even minimal rotation of the chest introduces significant distortion of

the heart

Which of the following groups of organs/structures are located in the left upper quadrant?

Left kidney, left suprarenal gland, and gastric fundus

The abdomen is divided anatomically into

nine regions and four quadrants. The region designation is usually used for anatomic studies, while the quadrant designation is most often used to describe the location of a lesion, pain, tumor, or other abnormality. Some of the structures found in the left upper quadrant (LUQ) are the fundus of the stomach, the left kidney and suprarenal gland, and the splenic flexure.

autotomography

that is, the part moves itself rather than actual tomographic apparatus being employed.

lateral thoracic spine

Motion from "breathing technique" employed to blur out the superimposed pulmonary vascular markings and bony rib details in order to better demonstrate the bony structure of the thoracic spine. Since the shoulder area of the upper thoracic spine is so much thicker and more dense than the lower thoracic area, employment of the anode heel effect is also a valuable tool here. The thicker shoulder area is placed under the more intense cathode end of the x-ray beam, and the thinner anatomic part is placed under the anode end of the x-ray beam.

Which of the following barium-filled anatomic structures is best demonstrated in the left anterior oblique (LAO) position?

Splenic flexure

In the prone oblique positions (RAO, LAO)

the flexure disclosed is the one closer to the image receptor. Therefore, the LAO position will "open up" the splenic flexure; the RAO position will demonstrate the hepatic flexure. The AP oblique positions (RPO, LPO) demonstrate the side farther from the image receptor.

In which of the following procedures is quiet, shallow breathing recommended during the exposure to obliterate prominent pulmonary vascular markings?

1. RAO sternum
2. Lateral thoracic spine
3. AP scapula

Pulmonary vascular markings are often prominent in

the elderly and in smokers. Quiet, shallow breathing may be used during a long exposure (with a compensating low mA) to blur them out. Oblique sternum, AP scapula, and the lateral thoracic spine are examinations in which this technique is useful.

air-contrast barium enema examination

The intent of this examination is to coat the intestinal mucosa with barium, then fill the lumen with air. Typically, some structures will be imaged filled with barium, and others will be imaged as double-contrast (barium and air); how structures are filled depends to a large extent on the position employed. Radiographic examinations of the large bowel generally include the AP or PA axial position to "open" the S-shaped sigmoid colon, the lateral position especially for the rectum, and the LAO and RAO (or LPO and RPO) to "open" the colic flexures. Left and right decubitus positions are usually employed only in double-contrast barium enemas to better demonstrate double contrast of the medial and lateral walls of the ascending and descending colon.

The LPO and RAO positions demonstrate

the hepatic flexure and adjacent ascending colon. The LAO and RPO positions demonstrate the splenic flexure and descending colon.

Double-contrast examinations of the stomach or large bowel are performed to better visualize

the gastric or bowel mucosa

Double-contrast studies of the stomach or large intestine involve

coating the organ with a thin layer of barium sulfate and then introducing air. This permits seeing through the organ to the structures behind it, and most especially allows visualization of the mucosal lining of the organ. A barium-filled stomach or large bowel demonstrates the position, size, and shape of the organ and any lesion that projects out from its walls, such as diverticula. Polypoid lesions, which project inward from the wall of an organ, may go unnoticed unless a double-contrast examination is performed.

Which of the following positions may be used to effectively demonstrate the hepatic flexure during radiographic examination of the large bowel?

1. RAO
2. LPO

The hepatic and splenic flexures are not generally well demonstrated in the

AP and PA projections. To "open" the flexures, oblique projections are required. The hepatic flexure is usually well demonstrated in the RAO (right PA oblique) and LPO (left AP oblique) positions. The LAO and RPO positions are used to demonstrate the splenic flexure.

viscera assume a lower position in the

erect position). The gallbladder may be moved away from the spine by using the LAO position. The right lateral decubitus will also move the gallbladder away from the spine.

If your patient is unable to stay erect for a paranasal sinus examination, which of the following alternatives should be chosen?

Lateral cross-table recumbent

Radiography of the paranasal sinuses should be performed in the

erect position whenever possible to demonstrate the presence of an air-fluid level. The only way air-fluid levels can be demonstrated is to have the central ray parallel the floor, as in erect, decubitus, and cross-table projections. Therefore, of the choices provided, the cross-table lateral is the only one that will demonstrate air-fluid levels.

In the parietoorbital projection (Rhese method) of the optic canal, the median sagittal plane and central ray form what angle?

37°

n the parietoorbital projection (Rhese method)

the patient is prone with the acanthomeatal line perpendicular to the IR. The head rests on the forehead, nose, and chin, and the MSP should form 53° with the IR (37° with the central ray). Radiographically, the optic canal should appear in the lower outer quadrant of the orbit. Incorrect rotation of the MSP results in lateral displacement, and incorrect positioning of the baseline results in longitudinal displacement of the optic canal.

An axial projection of the clavicle is often helpful in demonstrating a fracture that is not visualized using a perpendicular central ray. When examining the clavicle in the AP position, how is the central ray directed for the axial projection?

Cephalad

With the patient in the AP position,

the central ray is directed cephalad 25° to 30°. This serves to project the clavicle away from the pulmonary apices and ribs, projecting most of the clavicle above the thorax. The reverse is true when the patient is examined in the PA position.

Which of the following positions would best demonstrate the left apophyseal articulations of the lumbar vertebrae?

LPO

The posterior oblique positions (LPO, RPO)

of the lumbar vertebrae demonstrate the apophyseal articulations closer to the image receptor. The left apophyseal articulations are demonstrated in the LPO position, while the right apophyseal articulations are demonstrated in the RPO position. The lateral position is useful to demonstrate the intervertebral disk spaces, intervertebral foramina, and spinous processes.

The AP oblique projection (medial rotation) of the elbow demonstrates which of the following?

1. Olecranon process within the olecranon fossa
2. Coronoid process free of superimposition

The AP oblique projection (medial rotation) of the elbow

superimposes the radial head and neck on the proximal ulna. It demonstrates the olecranon process within the olecranon fossa, and it projects the coronoid process free of superimposition. The radial head is projected free of superimposition in the AP oblique projection (lateral rotation) of the elbow.

With the patient supine, the left side of the pelvis elevated 25°, and the central ray entering 1 inch medial to the left anterior superior iliac spine (ASIS), which of the following is demonstrated?

Left sacroiliac joint

The sacroiliac joints angle

posteriorly and medially 25° to the MSP. Therefore, to demonstrate them with an AP oblique projection, the affected side must be elevated 25°. This places the joint space perpendicular to the IR and parallel to the central ray. When the PA oblique projection is used, the unaffected side will be elevated 25°

parietoacanthial projection (Waters' position) of the skull, mouth open may be taken to demonstrate

the sphenoidal sinuses.

The best projection to demonstrate the articular surfaces of the femoropatellar articulation is the

tangential ("sunrise") projection

The tangential ("sunrise") projection is used to demonstrate

the articular surfaces of the femur and patella. It is also used to demonstrate vertical fractures of the patella. The AP, PA, and oblique projections of the knee are used primarily to evaluate the joint space and articulating structures. The "tunnel" view is used to demonstrate the intercondyloid fossa.

The sternoclavicular joints will be best demonstrated in which of the following positions?

Anterior oblique

The (diarthrotic) sternoclavicular joints are formed by

the medial (sternal) extremities of the clavicles and the clavicular notches of the manubrium (of the sternum). They can be demonstrated in the LAO and RAO positions. The LAO demonstrates the left sternoclavicular joint, while the RAO demonstrates the joint on the right. The patient is obliqued about 15° with the side of interest adjacent to the image recorder

The submentovertical (SMV) oblique axial projection of the zygomatic arches requires that the skull be rotated

15° toward the affected side

The oblique axial projection is valuable when

the zygomatic arches cannot be demonstrated bilaterally with the submentovertical projection, because they are not prominent enough or because of a depressed fracture. The patient may still be positioned as for an SMV, but the head is obliqued 15° toward the side being examined. This serves to move the zygomatic arch away from superimposed structures and provides a slightly oblique axial projection of the arch.

Which of the following is (are) located on the distal aspect of the humerus?

1. Capitulum
2. Coronoid fossa

The distal humerus articulates with

the radius and ulna to form the elbow joint. The lateral aspect of the distal humerus presents a raised, smooth, rounded surface, the capitulum, that articulates with the superior surface of the radial head. The trochlea is on the medial aspect of the distal humerus and articulates with the semilunar notch of the ulna. Just proximal to the capitulum and the trochlea are the lateral and medial epicondyles; the medial is more prominent and palpable. The coronoid fossa is found on the anterior distal humerus and functions to accommodate the coronoid process with the elbow in flexion. The intertubercular (bicipital) groove is located on the proximal humerus.

How can object-image distance (OID) be reduced for a posteroanterior (PA) projection of the wrist?

Flex the metacarpophalangeal joints

When the hand is pronated and the fingers are extended for a PA projection of the wrist, the wrist

arches and an OID is introduced between the wrist and the cassette. To reduce this OID, the metacarpophalangeal joints should be flexed slightly. This maneuver will bring the anterior surface of the wrist into contact with the cassette.

A dorsal decubitus projection of the chest may be used to evaluate small amounts of

fluid in the posterior chest

The dorsal decubitus position is obtained

with the patient supine and the x-ray beam directed horizontally. The finished radiograph looks similar to a routine lateral projection of the chest. However, small amounts of fluid will gravitate posteriorly, and small amounts of air will rise anteriorly.

Which of the following statements is (are) true regarding the lateral projection of the lumbar spine?

1. The MSP is parallel to the tabletop.
2. The pedicles are well visualized.

With the patient in the lateral position,

the MSP is parallel to the x-ray tabletop. Because the intervertebral foramina, which are formed by the pedicles, are 90° to the MSP, they are well demonstrated in the lateral projection. The intervertebral joints (disk spaces) are also well demonstrated. The spinal cord passes through the vertebral foramina, which would not be visualized in conventional radiography of the lumbar spine.

Which of the following statements are true regarding radiographic examination of the acromioclavicular joints?

1. The procedure is performed in the erect position.
2. The use of weights helps demonstrate small joint changes.

Evaluation of the acromioclavicular joints requires

bilateral AP or PA erect projections with and without the use of weights. Weights are used to emphasize the minute changes within a joint caused by separation or dislocation. The use of weights should be avoided if a fracture of the affected area is suspected.

During an intravenous urogram, the RPO position is used to demonstrate the

1. left kidney parallel to the IR.
2. right kidney perpendicular to the IR.

Since the kidneys do not lie parallel to the IR in the AP

the oblique positions are used during IV urography to visualize them better. With the AP oblique projections (RPO and LPO positions), the kidney that is farther away is placed parallel to the IR, and the kidney that is closer is placed perpendicular to the IR. Therefore, in the RPO position, the right kidney, being closer, is perpendicular to the IR. The left kidney, the one farther away, is placed parallel to the IR.

Which of the following is a functional study used to demonstrate the degree of AP motion present in the cervical spine?

Flexion and extension laterals

The degree of anterior and posterior motion is occasionally diminished with

a "whiplash"-type injury. Anterior (forward, flexion) and posterior (backward, extension) motion is evaluated in the lateral position with the patient assuming flexion and extension as best as he or she can. Left and right bending images of the thoracic and lumbar vertebrae are frequently obtained when evaluating scoliosis. The AP open-mouth projection is used to evaluate the first two cervical vertebrae. The moving mandible AP is used to demonstrate the entire cervical spine while blurring out the superimposed mandible.

Differences between body habitus types are likely to affect all of the following

A. size and shape of an organ.
B. position of an organ.
C. position of the diaphragm

The four types of body habitus are

(from upper extreme to lower extreme) hypersthenic, sthenic, hyposthenic, and asthenic. The gallbladder and stomach are higher and more lateral and the large bowel more peripheral in the hypersthenic. The diaphragm is in a higher position in the hypersthenic individual. Recognition of a patient's body habitus and its characteristics is an important part of accurate radiography. Bone porosity is generally unrelated to body habitus type.

In the 15° medial oblique projection of the ankle, the

1. talotibial joint is visualized.
2. plantar surface should be vertical.

The medial oblique projection of the ankle can be performed

either as a 15° to 20° oblique or as a 45° oblique. The 15° to 20° oblique demonstrates the ankle mortise, that is, the articulations between the talus, tibia, and fibula. The 45° oblique opens the distal tibiofibular joint. In all three cases, the plantar surface must be vertical.

A parietoacanthial projection (Waters' position) of the skull with the mouth open may be taken to demonstrate

the sphenoidal sinuses

A parietoacanthial projection (Waters' position) of the skull

the single best projection to demonstrate the facial bones.

Which baseline should be used for a lateral projection of facial bones?

The infraorbitomeatal line (IOML)

The infraorbitomeatal line (IOML)

is an imaginary line extending from the infraorbital margin to the external auditory meatus

The IOML is used for

most lateral skull projections, including lateral projections of facial bones. The skull is positioned so that the MSP is parallel to the cassette, the interpupillary line is perpendicular to the cassette, and the IOML is parallel to the long (transverse) axis of the cassette.

Which of the following positions may be used to effectively demonstrate the right posterior axillary ribs?

RPO

To place the right posterior axillary ribs parallel to the IR,

an RPO position is required. The LAO will also demonstrate the right axillary ribs, but primarily the anterior portion. The RAO position will demonstrate the left anterior axillary ribs, and the LPO will demonstrate the left posterior axillary ribs.

Which of the following is most useful for bone age evaluation?

PA hand

A PA projection of the left hand and wrist is most often obtained to evaluate

skeletal maturation. These images are compared to standard normal images for the age and sex of the child. Additional supplemental images may be requested

The AP projection of the sacrum requires the central ray to be directed

15° cephalad to a point approximately 2 inches superior to the pubis

For the AP projection of the sacrum

the patient is AP supine with the MSP perpendicular to the x-ray tabletop. The central ray is directed 15° cephalad to a point 2 inches superior to the pubis (approximately midway between the ASIS and the pubic symphysis). In this projection, the central ray angulation parallels the sacral curve and provides less distorted visualization of the sacrum and its foramina

Impingement on the wrist's median nerve causing pain and disability of the affected hand and wrist is known as

carpal tunnel syndrome

Carpal tunnel syndrome

palmar surface of thumb, index finger, and radial half of fourth finger and palm). Carpal tunnel syndrome frequently occurs in those who continually use vibrating tools or machinery. Carpopedal spasm is spasm of the hands and feet, commonly encountered during hyperventilation. Carpal boss is a bony growth on the dorsal surface of the third metacarpophalangeal joint.

Which of the following radiologic examinations requires preparation consisting of a low-residue diet, cathartics, and enemas?

Barium enema

To have high diagnostic quality, a barium enema examination requires

rigorous and complete patient preparation. This usually consists of a modified low-residue diet for a few days before the examination, cathartics the day before, and cleansing enemas the morning of the examination. Instructions for a UGI, small bowel series, and IV cystogram are usually to be npo after midnight

PA axial Caldwell position

demonstrates the frontal and ethmoidal sinuses. The Caldwell position requires an angle of 15° caudad, exiting the nasion. The petrous ridges should be projected in the lower third of the orbits. The maxillary sinuses are demonstrated in the parietoacanthial projection (Waters' position), and the sphenoidal sinuses are demonstrated through the open mouth in a modified Waters' position. The mastoid sinuses/air cells are part of the temporal bone and are radiographically unrelated to the paranasal sinuses.

What is the most superior structure of the scapula?

Acromion process

It is easy to determine the highest point of the scapula when it is viewed

laterally. The coracoid process projects anteriorly and is quite superior. However, the acromion process, which is an anterior extension of the scapular spine, projects considerably more superior than the coracoid.

The greater tubercle should be visualized in profile in which of the following?

AP shoulder, external rotation

The greater and lesser tubercles

are prominences on the proximal humerus, separated by the bicipital groove. The AP projection of the humerus in external rotation demonstrates the greater tubercle in profile. With the arm placed in internal rotation, the humerus is placed in a true lateral position and the lesser tubercle is demonstrated.

Which of the following positions would demonstrate the right lumbar apophyseal articulations closest to the IR?

RPO

The posterior oblique positions (LPO and RPO) of the lumbar vertebrae demonstrate

the apophyseal joints closer to the IR. The left apophyseal joints are demonstrated in the LPO position, while the right apophyseal joints are demonstrated in the RPO position. The lateral position is useful to demonstrate the intervertebral disk spaces, intervertebral foramina, and spinous processes.

Which of the following may be used as landmark(s) for an AP projection of the hip?

1. Two-inch medial to the anterior superior iliac spine (ASIS)
2. Prominence of the greater trochanter

For an AP projection of the hip

two bony landmarks are used. The central ray is directed perpendicular to a point located 2 inches medial to the ASIS at the level of the greater trochanter. A point midway between the iliac crest and the pubic symphysis is too superior and medial to coincide with the hip articulation.

The AP axial projection of the chest for pulmonary apices

1. requires 15° to 20° cephalad angulation.
2. should demonstrate the medial ends of the clavicles equidistant from the vertebral column.

The AP axial projection is used to project the clavicles from superimposition on the

pulmonary apices. A 15° to 20° cephalad angle projects the clavicles above the apices. The radiograph is evaluated for rotation by checking the distance between the medial ends of the clavicles and the lateral border of the vertebral column.

Which of the following is used to obtain a lateral projection of the upper humerus on patients who are unable to abduct their arm?

Transthoracic lateral

A transthoracic projection is used to obtain

a lateral projection of the upper half to two thirds of the humerus when the arm cannot be abducted. The affected arm is placed next to the upright Bucky, the unaffected arm rests on the head, and the central ray is directed horizontally through the thorax, exiting the upper humerus. The superoinferior and inferosuperior projections of the shoulder both require abduction of the arm.

An LPO of the lumbar spine

The patient is positioned so that the lumbar spine forms a 45° angle with the IR. The apophyseal joints (those closest to the IR) are well demonstrated in this position. The typical "scotty dog" image is depicted. The "ear" of the scotty is the superior articular process and the front foot is the inferior articular process. The scotty's eye is the pedicle; its "body" is the lamina, and its nose is the transverse process

Inspiration and expiration images are frequently requested when examining patients for

pneumothorax, or to demonstrate degree of diaphragm excursion or the presence of a foreign body, Because a smaller volume of air is contained within the lungs, the expiration radiograph requires an increase in exposure of approximately 6 to 8 kVp.

Which of the following procedures requires that contrast medium be injected into the ureters?

Retrograde pyelogram

Contrast injection into the ureters can be achieved only by

first catheterizing the bladder, locating the ureteral orifices, then injecting the contrast agent into the ureters. This procedure is called a retrograde (because contrast is being introduced against the normal direction of flow) pyelogram. A cystogram is an examination of the bladder. A cystourethrogram is an examination of the bladder and urethra.

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