// Init cornerstone tools cornerstoneTools.init(); // Enable any elements, and display images // ... // Add our tool, and set it's mode const RectangleScissorsTool = cornerstoneTools.RectangleScissorsTool; cornerstoneTools.addTool(RectangleScissorsTool) cornerstoneTools.setToolActive('RectangleScissors', { mouseButtonMask: 1 })