House mentions that Dominika made a trip to Bosnia. Her character is from the Ukraine, and not yet being a legal permanent resident alien, if she had gone outside of the country, she would not have been allowed back in, and her application would have had to be started again from the very beginning. Being outside of the U.S. it would take about one to two years for her to have been able to return to the country.
The patient (character Joe Reese played by Jake Weber) wears his wedding ring during the MRI. It is unlikely that House's staff would have allowed this as it could interfere with the results and be magnetically sensitive.