The length difference between the two kidneys should not exceed how many centimeters?

The length difference between the two kidneys should not exceed how many centimeters?

• A. 1 cm
• B. 3 cm
• C. 4 cm
• D. 2 cm

Answer: (D)

Kidneys should be similar in size. In a normal adult, the right and left kidneys are expected to be within about two centimeters of each other in length. A difference exceeding roughly two centimeters suggests unilateral renal pathology, such as atrophy from chronic obstruction, reduced function, scarring, or congenital/anatomic variations. When assessing, measure along the kidney’s long axis from the upper to the lower pole in a consistent plane for both kidneys, and interpret any asymmetry with this two-centimeter threshold in mind. Small differences can be normal due to technique or patient factors, but a difference over two centimeters is considered abnormal and should prompt further evaluation.

Kidneys should be similar in size. In a normal adult, the right and left kidneys are expected to be within about two centimeters of each other in length. A difference exceeding roughly two centimeters suggests unilateral renal pathology, such as atrophy from chronic obstruction, reduced function, scarring, or congenital/anatomic variations. When assessing, measure along the kidney’s long axis from the upper to the lower pole in a consistent plane for both kidneys, and interpret any asymmetry with this two-centimeter threshold in mind. Small differences can be normal due to technique or patient factors, but a difference over two centimeters is considered abnormal and should prompt further evaluation.