title: Feasibility of respiratory triggering for MR-guided microwave ablation of liver tumors under general anesthesia.
abstract: We obtained clear and reproducible MR fluoroscopic images and temperature maps for MR image-guided microwave ablation of liver tumors under general anesthesia without suspending the artificial ventilation. Respiratory information was directly obtained from air-way pressure without a sensor on the chest wall. The trigger signal started scanning of one whole image with a spoiled gradient echo sequence. The delay time before the start of scanning was adjusted to acquire the data corresponding to the k-space center at the maximal expiratory phase. The triggered images were apparently clearer than the nontriggered ones and the location of the liver was consistent, which made targeting of the tumor easy. MR temperature images, which were highly susceptible to the movement of the liver, during microwave ablation using a proton resonance frequency method, could be obtained without suspending the artificial ventilation. Respiratory triggering technique was found to be useful for MR fluoroscopic images and MR temperature monitoring in MR-guided microwave ablation of liver tumors under general anesthesia.
authors.affiliation: Molecular Neuroscience Research Center, Shiga University of Medical Science, Seta Tsukinowa-cho, Ohtsu, Japan. morikawa@belle.shiga-med.ac.jp
authors.forename: Shigehiro
authors.initials: S
authors.lastname: Morikawa
authors.forename: Toshiro
authors.initials: T
authors.lastname: Inubushi
authors.forename: Yoshimasa
authors.initials: Y
authors.lastname: Kurumi
authors.forename: Shigeyuki
authors.initials: S
authors.lastname: Naka
authors.forename: Koichiro
authors.initials: K
authors.lastname: Sato
authors.forename: Koichi
authors.initials: K
authors.lastname: Demura
authors.forename: Tohru
authors.initials: T
authors.lastname: Tani
authors.forename: Hasnine A
authors.initials: HA
authors.lastname: Haque
mesh_terms: D000768:Anesthesia, General; D001831:Body Temperature; D017115:Catheter Ablation / Q000379:methods*; D005240:Feasibility Studies; D006801:Humans; D008113:Liver Neoplasms / Q000503:physiopathology* / Q000601:surgery*; D008279:Magnetic Resonance Imaging; D008872:Microwaves; D012119:Respiration; D012680:Sensitivity and Specificity