Radiography - NOT Routine : Radiography - NOT Routine Connie Lyon, R.T.(R) (QM) 1A
Lower extremity - ankle : Lower extremity - ankle Mortise view
15-20 degree rotation
malleoli parallel with cassette
Oblique view
45 degree rotation of whole leg Courtesy of Kenneth Bontrager, “Pocket Atlas” 3rd edition
Lower extremity - ankle : Lower extremity - ankle Oblique
45 degree internal rotation
VIP - rotate entire leg, not just foot Flex ankle, not toes
Slide 4 : Flex ankle - not always possible
Slide 5 :
Lower extremity - lower leg : Lower extremity - lower leg may be able to use 48” SID to get more of leg on single image
place film tabletop and leg diagonally
adds about 0.6 inches of information
requires about a 50% increase in time or mAS
10 mAS becomes 15
can use an “in-between” setting Technique - www.controlthedose.com
Slide 7 : Lower extremity - lower leg
Lower extremity - AP knee : Lower extremity - AP knee entire leg in same plane
landmark for joint is 3/4 - 1 inch inferior to apex (bottom) of patella
may angle central ray as follows:
3-5 degrees caudal for patient less than 19 cm thick from ASIS to TT
no angle for patient 19-24 cm
3-5 degrees cephalic for patient more than 24 cm thick
Lower extremity - Lateral knee : Lower extremity - Lateral knee entire leg in same plane
many times hip is elevated higher than knee
supporting leg at ankle may correct the misalignment
Lower extremity - Lateral knee : Lower extremity - Lateral knee failure to have entire lower extremity in the same plane closes the joint between femur and tibia
the medial condyle will be magnified and obscure the joint even with “perfect” positioning
Lower extremity - Lateral knee : Lower extremity - Lateral knee addition of 5-7 degree cephalic tube tilt “throws” the medial condyle above the joint
Lateral knee : Lateral knee incorrect rotation closes joint between patella and femur
forward towards table - see more of fibula
backward towards ceiling - see less of fibula
Slide 13 : Congenital anomaly
Slide 14 : Congenital anomaly – bipartite patella
Lower extremity - lateral : Lower extremity - lateral Cross-table lateral Courtesy of Kenneth Bontrager, “Pocket Atlas” 3rd edition
Slide 16 :