Pelvic Girdle and Hindlimbs

Question 1

what are pelvic views used for?

Answer 1

to evaluate dysplastic or degenerative changes of the coxofemoral joints, fractures, arthritis, joint associated neoplasia

Question 2

lateral pelvic view

Answer 2

positioning: Rt or Le, affected side closest to cassette, foam wedges between limbs to superimpose pelvic bones, limbs in scissor position (bottom leg extended cranially and top leg extended caudally) or parallel
measurement: measure at level of trochanter/hip joint
beam center: greater trochanter or femur
collimation: cranial: slightly cranial to cranial edge of ilium, caudal: caudal border of ischium, dorsal: include 1/3 of femurs, ventral: spinous processes of vertebrae

Question 3

VD- extended leg pelvic view

Answer 3

positioning: dorsal recumbency in V-trough, forelimbs extended cranially, stifles rotated medially so they are parallel, patellas centered over trochlear groove, tail aligned with spine
measurement: thickest part of pelvis
beam center: midline at the level of the ischial tuberosities
collimation: cranial: cranial to crest of ilium, caudal: distal to patellas, lateral: lateral to greater trochanters

Question 4

VD- frogleg pelvic view

Answer 4

positioning: dorsal recumbency in V-trough, forelimbs extended cranially, hindlimbs in a natural flexed position
measurement: at thickest part of pelvis
beam center: midline between ischial tuberosities
collimation: cranial: cranial to wing of ilium, caudal: caudal border of ischium (include proximal 1/3 of femur)

Question 5

special evaluations of hip rads: OFA

Answer 5

Orthopedic Foundation for Animals (OFA): provides evaluation services for dogs to certify that they don’t have genetic hip dysplasia, they maintain a database of certified dogs for breeders, sedation recommended for VD extended hip

Question 6

special evaluations of hip rads: PennHIP

Answer 6

evaluates quality of hip joints and the degree of hip joint laxity, must be performed by PennHIP certified vet staff, reviewed by certified vet radiologists, requires 3 views that are used to make precise measurements of hip laxity (VD extended leg, distraction, compression)

Question 7

size and shape distortions

Answer 7

foreshortening, elongation, magnification

Question 8

foreshortening

Answer 8

image on radiograph appears shorter than actual size
caused by area of interest not being parallel to film/IP

Question 9

elongation

Answer 9

image on radiograph is longer than actual size
caused by film/IP not being perpendicular to tube head

Question 10

magnification

Answer 10

image will appear larger than actual size
caused by decreased film focal distance and increased object film distance

Question 11

what are hindlimb views used for?

Answer 11

to evaluate dysplastic/degenerative changes of the joints, fractures, arthritis, joint associated neoplasia

Question 12

what should be included in long bone imaging?

Answer 12

the joint above and below the bone

Question 13

what should be included in joint imaging?

Answer 13

1/3-1/2 of the length of the bone above and below the joint

Question 14

lateral (mediolateral) femur view

Answer 14

positioning: patient in lateral recumbency with affected limb on table, forelimbs pulled cranially, unaffected limb abducted laterally to be out of the way, femoral head toward cathode end of x-ray tube
measurement: mid-shaft of femur
beam center: mid-shaft of femur
collimation: coxofemoral joint to stifle, include proximal 1/3 of tibia, no more than 1 inch on either side of limb

Question 15

craniocaudal femur view

Answer 15

positioning: dorsal recumbency in V-trough, pull femurs inward so patellas lie straight with distal femurs, place band of tape around femurs just proximal to stifles, place sponge under tarsus to avoid stifle rotation, place sandbag over distal portion of limbs
measurement: mid-shaft of femur
beam center: mid-shaft of femur
collimation: greater trochanter to proximal 1/3 of tibia, no more than 1 inch on either side of limb

Question 16

mediolateral stifle view

Answer 16

positioning: lateral recumbency with affected limb down, flex unaffected limb: abduct and pull laterally out of way, extend affected limb keeping stifle in a natural position and secure to table
measurement: distal portion of femur
beam center: stifle joint indentation
collimation: proximal 1/3 of tibia and distal 1/3 of femur, no more than 1 inch on either side of limb

Question 17

caudocranial stifle view

Answer 17

positioning: patient in V-trough in ventral recumbency, pull forelimbs cranially, extend affected limb, foam pad under tarsus to prevent tarsus rotation, allow unaffected limb to remain in natural position
measurement: distal portion of femur
beam center: stifle joint indentation
collimation: proximal 1/3 of tibia/fibula and distal 1/3 of femur, no more than 1 inch on either side of limb

Question 18

mediolateral tibia view

Answer 18

positioning: lateral recumbency with affected limb down, flex unaffected limb: abduct and pull laterally out of the way, foam pad under tarsus to prevent rotation and maintain limb parallel to table
measurement: mid-shaft of tibia
beam center: mid-shaft of tibia
collimation: include distal 3rd of femur and proximal 3rd of tarsus, no more than 1 inch on either side of limb

Question 19

caudocranial tibia/fibula view

Answer 19

positioning: patient in ventral recumbency in V-trough, extend forelimbs cranially, extend affected limb, foam pad under tarsus to prevent rotation, allow unaffected limb to remain in. natural position
measurement: mid-shaft of tibia
beam center: mid-shaft of tibia
collimation: include tarsus and stifle, no more than 1 inch on either side of limb

Question 20

mediolateral foot view (tarsus, metatarsals, phalanges)

Answer 20

positioning: lateral recumbency with affected limb down, flex unaffected limb: abduct and pull laterally out of the way
measurement: tarsus: at tarsus joint, metatarsals/phalanges: on central bone
beam center: tarsus: at tarsus joint, metatarsals/phalanges: on central bone
no more than 1 inch on either side of limb

Question 21

dorsoplantar foot view

Answer 21

positioning: dorsal recumbency in V-trough, tape foot strap to patient to keep control
measurement: center of joint or bone
beam center: center of joint/bone
collimation: distal 3rd of tibia to phalanges, no more than 1 inch on either side of limb