Positioning and Small Animal Radiographs

Question 1

Use of relatively high Peak Kilovoltage (kVp) provides ___ among abdominal and thoracic structures because the higher kVp results in ___.

Answer 1

-Greater contrast
Greater shades of gray

Question 2

If difference between the target areas is small, the patient is positioned with the ___ part towards the ___ end of the X-ray tube to take advantage of the heel effect

Answer 2

-Thickest
-Cathode

Question 3

When taking a lateral abdominal view, place foam pads ___ to avoid rotation of the abdomen

Answer 3

-Under the sternum and between limbs

Question 4

Describe collimation for a lateral abdominal view.

Answer 4

-Cranial: Halfway between the caudal border of the scapula and the xiphoid (includes diaphragm and apex of heart)

-Caudal: Coxofemoral joints

-Dorsal: Spinous processes of vertebral column

Ventral: Sternum

Question 5

Describe collimation for a ventrodorsal abdominal view.

Answer 5

-Lateral: Abdominal wall within V-trough

-Cranial: Halfway between the caudal border of the scapula and the xiphoid (includes diaphragm and apex of heart)

-Caudal: Coxofemoral joints

Question 6

What should you ensure are superimposed when taking a ventrodorsal abdominal projection with the horizontal beam (Lateral Decubitus)?

Answer 6

Ensure the sternum and spine are superimposed

Question 7

___ is used when the heart is the primary organ of interest, whereas the ___ provides better visualization of the lungs.

Answer 7

-Dorsoventral
-Ventrodorsal

Question 8

When lesions are suspected in one lung, the patient should be positioned with the ___ lung down on the table.

Answer 8

Unaffected

Question 9

Maximum contrast is obtained when the lungs are ___.

Answer 9

-Filled with air

Question 10

When are thoracic images exposed on a patient with suspected pneumothorax?

Answer 10

The image would be exposed during the expiratory pause

Question 11

How should foam pads be positioned when taking a lateral thoracic view?

Answer 11

Place foam pads under the sternum to avoid rotation and maintain alignment of the sternum and spine

Question 12

Describe collimation for a lateral thoracic view.

Answer 12

-Cranial: Thoracic inlet

-Caudal: 1st lumbar vertebrae

-Dorsal: Spinous processes of the vertebrae

-Ventral: Xiphoid process of sternum

-Entire rib cage within collimated area

Question 13

Describe collimation for a ventrodorsal thoracic view.

Answer 13

-Cranial: Thoracic inlet

-Caudal:1st lumbar vertebrae

-Lateral: Body wall
V-trough entirely within collimated area

Question 14

When should the lateral decubitus thoracic view be used?

Answer 14

-When the presence of air or fluid within the thorax is suspected
-When the animal would be compromised using the standard ventrodorsal position

Question 15

Describe collimation for a ventrodorsal thoracic horizontal beam/lateral decubitus view.

Answer 15

-Cranial: Thoracic inlet

-Cauda: 1st lumbar vertebrae

-Entire rib cage within collimated area

Question 16

A standing lateral position can be used when the presence of ___ within the thorax is suspected or when the animal would be compromised using the standard positioning

Answer 16

-Air or fluid

Question 17

The ___provides a number of services focused on reducing the incidence of inherited diseases

Answer 17

Orthopedic Foundation for Animals (OFA)

Question 18

OFA provides evaluation services for dogs to certify that they do not have ____.

Answer 18

Hip dysplasia

Question 19

The ___ technique is an additional procedure used for evaluation of dogs for hip dysplasia

Answer 19

PennHIP

Question 20

What does the PennHIP technique evaluate?

Answer 20

Evaluates both the quality of the hip joints and the degree of hip joint laxity

Question 21

What does PennHIP require?

Answer 21

-The procedure must be performed by a PennHIP certified veterinary staff and is reviewed by certified veterinary radiologists
-In addition to the traditional extended hip projection, the PennHIP method requires 2 radiographs (a distraction and compression view) that are used to make precise measurements of hip laxity

Question 22

Describe collimation for a lateral pelvic view.

Answer 22

-Cranial: Slightly cranial to the cranial edge of ilium

-Caudal: Caudal border of ischium

-Dorsal: Include 1⁄3 of femurs

-Ventral: Spinous processes of vertebrae

Question 23

Describe positioning for a lateral pelvic view.

Answer 23

-Affected side closest to the cassette

-Foam wedges between limbs to superimpose the pelvic bones and maintain femurs parallel to cassette

-Limbs in scissor position (bottom leg extended cranially and upper leg extended caudally) OR parallel with foam wedge to maintain position

Question 24

Describe positioning for a ventrodorsal pelvic view.

Answer 24

-Hindlimbs extended evenly into full extension and parallel to each other (digits even and parallel to the table)

-Stifles rotated medially so that they are parallel to each other and the table

-Patellas must be centered over the trochlear groove

-Tail must be aligned with spine

Question 25

Describe collimation for a ventrodorsal pelvic view.

Answer 25

-Cranial: Cranial to the crest of the ilium -Caudal: Distal to the patellas -Lateral: Lateral to the greater trochanters

Question 26

Describe positioning for a ventrodorsal frogleg pelvic view.

Answer 26

-Hindlimbs in natural flexed position -For most patients, the femurs will assume an angle of 45 degrees to the spine -In larger dogs, the angle is often 90 degrees

Question 27

Describe collimation for a ventrodorsal frogleg pelvic view.

Answer 27

-Cranial: Cranial to the wing of the ilium -Caudal: Caudal border of ischium -Include proximal 1⁄3 of femurs

Question 28

Care must be taken to keep the limb as close to the cassette as possible and parallel to the cassette to avoid ___.

Answer 28

Magnification and distortion of the image

Question 29

When the area of interest is a long bone, the ___ to the bone are included.

Answer 29

Joints proximal and distal

Question 30

Images of the joints include about __ of the bone proximal and distal to the joint.

Answer 30

1/3

Question 31

Describe positioning for a mediolateral femoral view.

Answer 31

-Patient in lateral recumbency with affected limb toward cassette -Forelimbs pulled cranially -Unaffected limb abducted laterally to be out of the way of the affected femoral head -Femoral head toward cathode end of X-ray tube

Question 32

Describe positioning for a craniocaudal femoral view.

Answer 32

-Dorsal recumbency in V-trough -Tape legs down individually to table -Place band of tape around femurs just proximal to the stifles and pull femurs together so as to bring the patellas straight over the distal femurs -Place sponge under tarsus to avoid rotation of stifle

Question 33

Describe positioning for oblique tarsal views.

Answer 33

-For the dorsolateral/planteromedial oblique projection, tilt the patient or the X-ray tube head 15 to 20 degrees so that the medial side of the limb is facing the X-ray tube head -For the dorsomedial/plantarolateral oblique projection, tilt the patient or the X-ray tube head 15 to 20 degrees so that the lateral side of the limb is facing the X-ray tube head

Question 34

Describe positioning for a flexed lateral tarsal view.

Answer 34

-Patient in lateral recumbency with affected limb down -Use tape to hold affected limb in flexed position -Unaffected limb taped around stifle and tarsus and pulled laterally out of the way

Question 35

Describe positioning for a dorsopalmar projection of the digits.

Answer 35

-Patient in ventral recumbency -Hindlimbs extended caudally -Use tape or cotton balls to extend the lateral toe cranially and medial toe caudally

Question 36

Describe positioning for a caudocranial projection of the shoulder.

Answer 36

-Patient in dorsal recumbency in V-trough -Extend forelimbs cranially -Reflect head laterally toward unaffected limb

Question 37

Describe mediolateral positioning for a lateral projection of the scapula.

Answer 37

-Lateral recumbency with the affected limb against the cassette -Extend affected limb dorsally -Deflect head ventrally Extend unaffected limb cranially

Question 38

Describe mediolateral lateromedial positioning for a lateral projection of the scapula.

Answer 38

-Lateral recumbency with the unaffected limb against the cassette -Extend affected limb cranially -Deflect head ventrally Extend unaffected limb cranially

Question 39

Describe collimation for caudocranial projection of the scapula.

Answer 39

-Patient in dorsal recumbency with abdominal area in V-trough -Maintain head in alignment with spine (if spine appears superimposed over scapula, tilt the head slightly lateral from affected limb) -Extend hindlimbs caudally -Extend forelimbs cranially

Question 40

Forelimb images are usually taken with the X-ray cassette ___ because the measurement for dog and cat limbs tends to be fairly small

Answer 40

On the tabletop

Question 41

Describe positioning for a lateral view of the skull.

Answer 41

-Lateral recumbency with the affected side toward the cassette -Canine teeth are even and parallel with the cassette -Foam pads under the mandible to maintain the sagittal plane of the skull parallel to the cassette

Question 42

Describe positioning for a rostrocaudal sinuses closed mouth projection.

Answer 42

-Dorsal recumbency with forelimbs secured caudally -Foam pad or sandbag positioned under neck Tape the nose caudally to maintain hard palate perpendicular to the X-ray cassette and parallel to the X-ray beam

Question 43

Describe positioning for a rostrocaudal foramen magnum projection.

Answer 43

-Dorsal recumbency with forelimbs secured caudally -Foam pad or sandbag positioned under neck -Tape the nose caudally so that the patient’s nose is tilted approximately 30 degrees with the mandible close to the chest

Question 44

Describe positioning for a rostrocaudal sinuses open mouth projection.

Answer 44

-Dorsal recumbency with forelimbs secured caudally -Open the mouth, and tape the maxillary canines in a position that results in the hard palate parallel to the cassette -Tape the mandibular canines with the tongue (and endotracheal tube) and deflect caudally so that the mandible is about 10 degrees from the perpendicular plane of the X-ray beam

Question 45

Describe the positioning for a lateral oblique tympanic bulla view.

Answer 45

-Lateral recumbency with the unaffected side toward the cassette -Allow the head to lie naturally against the cassette to produce a 30 to 40 degree oblique projection

Question 46

Describe the positioning for a lateral oblique temporomandibular joint view.

Answer 46

-Lateral recumbency with the affected side toward the cassette -Allow the head to lie naturally against the cassette to produce an oblique projection -Use an oblique projection of approximately 10 degrees for dolichocephalic breeds, 15 degrees for mesocephalic breeds, and 25 to 30 degrees for brachycephalic breeds -Place a foam pad under the mandible to lift the rostral part of the skull (at the nose) up approximately 10 degrees

Question 47

Describe the positioning for a dorsoventral temporomandibular joint view.

Answer 47

-Ventral recumbency -Sandbag placed across the cervical region to maintain placement of the head parallel to the cassette -Tape across the maxilla to maintain vertical alignment of the head on the cassette

Question 48

Describe collimation for a ventrodorsal cervical spine view.

Answer 48

-Base of the skull to the shoulder joint -If there is a significant difference in measurement between the cranial and caudal areas of the cervical spine, two views are taken -Measure and center on the C2-C3 space and collimate from the base of the skull to C4 for the cranial view -The caudal view is measured and centered on the C5-C6 space and collimated to contain C4 through T1

Question 49

Describe positioning and collimation for a lateral cervical spine projection.

Answer 49

-Lateral recumbency -Forelimbs extended and secured caudally -Foam pad under mandible to maintain spinal column parallel to cassette -Foam pad along the sternum to avoid rotation of the spinal column -Base of the skull to the shoulder joint

Question 50

Describe positioning for an extended lateral cervical spine view.

Answer 50

-Lateral recumbency -Hindlimbs extended caudually; forelimbs extended cranially -Foam pad under mandible to maintain spinal column parallel to cassette -Foam pad along the sternum to avoid rotation of the spinal column -Use gauze or tape to hyperextend the neck dorsally

Question 51

Describe positioning for a flexed lateral cervical spine view.

Answer 51

-Lateral recumbency -Forelimbs extended and secured caudally -Foam pad under mandible to maintain spinal column parallel to cassette -Foam pad along the sternum to avoid rotation of the spinal column -Use gauze or tape to fully flex the neck caudally -Flexion must be even throughout all cervical vertebrae

Question 52

Describe collimation for a ventrodorsal thoracic spine view.

Answer 52

-Midpoint of xyphoid and last rib to spine of the scapula -Must include C7 to L1

Question 53

Describe collimation for a lateral thoracic spine view.

Answer 53

-Midpoint of xyphoid and last rib to spine of the scapula -Must include C7 to L1

Question 54

Describe collimation for ventrodorsal and lateral thoracolumbar spine views.

Answer 54

Xyphoid to last rib

Question 55

Describe collimation for ventrodorsal and lateral lumbar spine views.

Answer 55

Last rib to acetabulum

Question 56

Describe collimation for ventrodorsal and lateral lumbosacral spine views.

Answer 56

T13 to the lumbosacral joint

Question 57

Describe positioning and collimation for lateral and ventrodorsal coccygeal spine views.

Answer 57

-Dorsal recumbency in V-trough -Hindlimbs in natural position -Tail extended caudally -Cranial to lumbosacral joint to tip of tail