LRA 220 FINAL PAPER 2026 SOLVED
QUESTIONS AND FULL SOLUTION GRADED A+
◉ What are the clinical indications for AP knee?
Answer: Fractures, lesions, degenerative joint disease
◉ What is the minimum SID?
Answer: 40 inches (100 cm)
◉ What IR size is used?
Answer: 10 x 12 inches
◉ When is a grid required?
Answer: When part is greater than 10 cm
◉ When is nongrid used?
Answer: When part is less than 10 cm
◉ What is the kVp range?
Answer: 65-80 kVp
,◉ What is the patient position?
Answer: Supine, no pelvic rotation, leg extended
◉ How much internal rotation is required?
Answer: 3-5 degrees
◉ Why is internal rotation needed?
Answer: To align interepicondylar line parallel to IR
◉ What happens without internal rotation?
Answer: External rotation of knee
◉ Where is CR directed?
Answer: 1/2 inch distal to apex of patella
◉ What must CR be parallel to?
Answer: Tibial plateau
◉ What is CR angle for average patient?
Answer: 0 degrees
◉ What angle for thin patient?
, Answer: 5 degrees caudad
◉ What angle for thick patient?
Answer: 5 degrees cephalad
◉ Why adjust CR angle?
Answer: To open joint space
◉ What anatomy must be demonstrated?
Answer: Distal femur, proximal tibia and fibula
◉ What indicates open joint space?
Answer: Femorotibial joint open
◉ What does tibial plateau on end mean?
Answer: Minimal surface visible
◉ What indicates no rotation?
Answer: Symmetric condyles
◉ What is fibular head position on AP knee?
Answer: Medial half superimposed
QUESTIONS AND FULL SOLUTION GRADED A+
◉ What are the clinical indications for AP knee?
Answer: Fractures, lesions, degenerative joint disease
◉ What is the minimum SID?
Answer: 40 inches (100 cm)
◉ What IR size is used?
Answer: 10 x 12 inches
◉ When is a grid required?
Answer: When part is greater than 10 cm
◉ When is nongrid used?
Answer: When part is less than 10 cm
◉ What is the kVp range?
Answer: 65-80 kVp
,◉ What is the patient position?
Answer: Supine, no pelvic rotation, leg extended
◉ How much internal rotation is required?
Answer: 3-5 degrees
◉ Why is internal rotation needed?
Answer: To align interepicondylar line parallel to IR
◉ What happens without internal rotation?
Answer: External rotation of knee
◉ Where is CR directed?
Answer: 1/2 inch distal to apex of patella
◉ What must CR be parallel to?
Answer: Tibial plateau
◉ What is CR angle for average patient?
Answer: 0 degrees
◉ What angle for thin patient?
, Answer: 5 degrees caudad
◉ What angle for thick patient?
Answer: 5 degrees cephalad
◉ Why adjust CR angle?
Answer: To open joint space
◉ What anatomy must be demonstrated?
Answer: Distal femur, proximal tibia and fibula
◉ What indicates open joint space?
Answer: Femorotibial joint open
◉ What does tibial plateau on end mean?
Answer: Minimal surface visible
◉ What indicates no rotation?
Answer: Symmetric condyles
◉ What is fibular head position on AP knee?
Answer: Medial half superimposed
