Step 1: Understanding kidney disorders.
Acute kidney injury occurs suddenly and is often reversible, while chronic kidney disease develops slowly over time.
Step 2: Structural changes.
In chronic kidney disease, prolonged damage leads to shrinkage of kidneys.
Step 3: Diagnostic feature.
Small kidney size on imaging is a key indicator of chronic kidney disease.
Step 4: Conclusion.
Hence, small kidney size helps differentiate chronic kidney disease from acute kidney injury.