1. Department of Anesthesia, Japanese Red Cross Society of Suwa Hospital, Suwa, Japan.
2. Department of Anesthesiology and Resuscitology, Shinshu University School of Medicine, Matsumoto, Japan.
3. Department of Cardiovascular Surgery, Japanese Red Cross Society of Suwa Hospital, Suwa, Japan.
4. Department of Radiology, Japanese Red Cross Society of Suwa Hospital, Suwa, Japan.