This is solution which I have used in my app:
var image: UIImage = UIImage(named: "imageName")
imageView.layer.borderWidth = 1.0
imageView.layer.masksToBounds = false
imageView.layer.borderColor = UIColor.whiteColor().CGColor
imageView.layer.cornerRadius = image.frame.size.width/2
imageView.clipsToBounds = true
Swift 4.0
let image = UIImage(named: "imageName")
imageView.layer.borderWidth = 1.0
imageView.layer.masksToBounds = false
imageView.layer.borderColor = UIColor.white.cgColor
imageView.layer.cornerRadius = image.frame.size.width / 2
imageView.clipsToBounds = true