Quantification of left atrial fibrosis was obtained using delayed enhancement MRI imaging. Regions and severity of atrial wall fibrosis were determined from the relative intensity of contrast enhancement of the atrial wall. The 3D model of the left atrium was rendered from endocardial and wall segmentations in each MRI slice of the left atrium. The maximum enhancement intensities were projected on the surface of the model. The left atrium of this patient was categorized as stage 2 fibrosis (fibrosis involving ≥10% to <20% of the atrial wall).