diff --git a/Packages/lesiontracker/lib/calculateTotalLesionBurden.js b/Packages/lesiontracker/lib/calculateTotalLesionBurden.js
index f2e1ab566..691544f8f 100644
--- a/Packages/lesiontracker/lib/calculateTotalLesionBurden.js
+++ b/Packages/lesiontracker/lib/calculateTotalLesionBurden.js
@@ -22,7 +22,7 @@ calculateTotalLesionBurden = function(criteriaType) {
 
             measurements.forEach(function(measurement) {
                 var LD = parseFloat(measurement.longestDiameter);
-                var SD = parseFloat(measurement.longestDiameter);
+                var SD = parseFloat(measurement.shortestDiameter);
 
                 if (measurement.nodal === true) {
                     sumShortAxisNodal += SD;