Peripheral arterial disease (PAD) is characterized by arterial obstruction in the lower extremities due to atherosclerosis, and manifests itself as intermittent claudicating, limb ischemia, or gangrene. Diagnosis of PAD using magnetic resonance imaging (MRI) equipment without contrast medium is available as a useful visual screening in clinical practice. In this article, we propose a new method for the segmentation of arterial images which are obtained from non-contrast-enhanced magnetic resonance angiography (MRA) based on a dot enhancement filter and 3-D region-growing methods, and satisfactory experimental results are obtained.