       path:
         get: ->
           @subject.path.concat([{session: @number }])
+
+      ###*
+       * The first modeling with a scan source.
+       *
+       * @property scanModeling
+      ###
+      scanModeling:
+        get: ->
+          _.find(@modelings, 'source.scan')
+
+      ###*
+       * The first modeling with a registration source.
+       *
+       * @property registrationModeling
+      ###
+      registrationModeling:
+        get: ->
+          _.find(@modelings, 'source.registration')
 
     ###*
      * @method hasDetailProperties

   * @return the extended session object
  ###
  extend: (session, subject, number) ->
    return session if not session?

    # Set the session subject property.
    ###*
     * The parent {{#crossLink "Subject"}}{{/crossLink}}.
     * 
     * @property subject {Object} 
    ###
    session.subject = subject

    # Set the session number property.
    ###*
     * The one-based subject session index in date order.
     * 
     * @property number {number} 
    ###
    session.number = number


    session

`export { Session as default }`
