The　extraction　of　intima　and　adventitia　from　intravascular　ultrasound　(IVUS)　images　is　of　great　significance　for　the　diagnosis　and　treatment　of　coronary　artery　disease.　However,　traditional　IVUS　image　segmentation　methods　have　complex　modeling,　poor　robustness,　and　need　to　design　different　algorithms　for　internal　and　external　boundaries.　This　article　proposes　a　method　of　simultaneous　intima　and　adventitia.　We　firstly　detect　extreme　regions　of　the　pre-processed　image,　and　then　design　a　screening　vector　to　extract　two　extreme　regions　representing　the　lumen　and　media.　After　that,　the　convex-concave　boundaries　of　the　two　regions　are　adjusted　by　the　opening　operation　with　a　variable　radius　of　the　structural　element　and　the　superposition　of　a　circle.　Finally,　the　contours　are　fitted　with　ellipse　to　complete　the　segmentation.　In　order　to　evaluate　the　performance　of　the　method,　we　first　qualitatively　display　the　extreme　region　contours　and　the　final　contours,　and　compare　the　results　with　those　drawn　manually　by　clinical　experts.　Then,　we　use　Jaccard　measure,　Dice　coefficient,　percentage　of　area　difference　and　Hausdorff　distance　to　test　the　robust　performance　and　generalization　performance,　and　the　index　values　of　inner　and　outer　borders　are　0.92　+/-　0.03,　0.96　+/-　0.02,　0.06　+/-　0.04,　0.26　+/-　0.07　mm,　and　0.92　+/-　0.04,　0.95　+/-　0.02,　0.06　+/-　0.05,　0.29　+/-　0.08　mm,　respectively.　Besides,　we　make　a　quantitative　comparison　with　the　relevant　studies.　Experiment　results　show　that　the　proposed　automatic　methods　not　only　have　high　accuracy,　but　also　have　good　robustness.