Radiology Spotters Collection

Head Start Your Radiology Residency [Online] ↗️

RENAL Nephrometry Score Calculator

Other useful tools

What is Nephrometry score?

RENAL Nephrometry Score was developed to standardize the assessment of anatomical features of renal tumor. The scoring system is based on the five most reproducible features that characterize the anatomy of a solid renal mass on imaging, commonly contrast enhanced renal mass protocol CT scans:

R: Radius-scores tumor size as maximal diameter
E: Exophytic/endophytic properties of the tumor
N: Nearness of the deepest portion of the tumor to the collecting system or renal sinus
A: Anterior (a)/posterior (p) descriptor
L: Location relative to the polar line.

How do you calculate Nephrometry score?

Each component is scored, and the total gives the Nephrometry score. This helps to stratify renal lesions into low, intermediate and high risk of complications for surgical planning.

Component1 Point2 Points3 Points
R (radius, maximal diameter) (cm)≤ 44-7≥ 7
E (exophytic/endophytic)≥ 50 % exophytic< 50% exophyticCompletely endophytic
N (nearness to collecting system/renal sinus) (mm)≥ 74-7≤ 4
A (anterior/posterior locator)No points given. Descriptor of “a,” “p,” or “x” assigned to describe mass location
L (location relative to polar lines)Entirely below lower polar or above upper polar lineMass crosses polar line50% of mass is across polar line or mass is entirely between polar lines or mass crosses axial midline
R.E.N.A.L Nephrometry Score

How to determine location relative to polar lines for R.E.N.A.L. Nephrometry score:

Renal NEPHROMETRY Score Polar Lines
Renal NEPHROMETRY Score Polar Lines – Illustration by Dr. Disha Lokhandwala.


  1. Kutikov A, Uzzo RG. The R.E.N.A.L. nephrometry score: a comprehensive standardized system for quantitating renal tumor size, location and depth. J Urol. 2009;182(3):844-853. doi:10.1016/j.juro.2009.05.035
  2. Parsons RB, Canter D, Kutikov A, Uzzo RG. RENAL nephrometry scoring system: the radiologist’s perspective. AJR Am J Roentgenol. 2012;199(3):W355-W359. doi:10.2214/AJR.11.8355

Check out other radiology useful calculators:

Radiology Calculators

Disclaimer: The author makes no claims of the accuracy of the information contained herein; this information is for educational purposes only and is not a substitute for clinical judgment.

This page was last updated on Sep 27, 2023 @ 10:02 pm

Wish to be a BETTER Radiologist? Join 14000 Radiology Colleagues !

Enter your email address below to access HIGH YIELD radiology content, updates, and resources.

Email Newsletter Subscription Pop Up

No spam, only VALUE! Unsubscribe anytime with a single click.