What is the average length of the kidney?

What is the average length of the kidney?

• A. 9 to 12 cm
• B. 6 to 9 cm
• C. 12 to 15 cm
• D. 7 to 11 cm

Answer: (A)

Normal adult kidneys are about 9 to 12 cm in length when measured along the long axis from the upper to the lower pole. This range is the standard reference used in ultrasound to define a typical adult kidney size. The measurement is taken in the sagittal view with calipers placed along the kidney’s long axis to avoid foreshortening, and it reflects natural variation with body size and age. The left kidney is often a touch longer than the right due to the liver’s position pushing the right kidney slightly. Extremely short or extremely long measurements outside this range suggest variation from the typical size, while pediatric kidneys would naturally be smaller. Other ranges given fall outside the common adult reference, so the 9–12 cm interval best represents the average length.

Normal adult kidneys are about 9 to 12 cm in length when measured along the long axis from the upper to the lower pole. This range is the standard reference used in ultrasound to define a typical adult kidney size. The measurement is taken in the sagittal view with calipers placed along the kidney’s long axis to avoid foreshortening, and it reflects natural variation with body size and age. The left kidney is often a touch longer than the right due to the liver’s position pushing the right kidney slightly. Extremely short or extremely long measurements outside this range suggest variation from the typical size, while pediatric kidneys would naturally be smaller. Other ranges given fall outside the common adult reference, so the 9–12 cm interval best represents the average length.