Hirofumi Yamada1, Akira Yamamoto2, Tomohisa Okada1, Mitsunori Kanagaki1, Yasutaka Fushimi1, David A Porter3, Masahiro Tanji4, Masato Hojo4, Susumu Miyamoto4, Kaori Togashi1. 1. Department of Diagnostic Imaging and Nuclear Medicine, Kyoto University Graduate School of Medicine, 54 Shogoin-Kawaharacho, Sakyo-ku, Kyoto 606-8507, Japan. 2. Department of Diagnostic Imaging and Nuclear Medicine, Kyoto University Graduate School of Medicine, 54 Shogoin-Kawaharacho, Sakyo-ku, Kyoto 606-8507, Japan. Electronic address: yakira@kuhp.kyoto-u.ac.jp. 3. Fraunhofer MEVIS, Universitätsallee 29, 28359, Bremen, Germany. 4. Department of Neurosurgery, Kyoto University Graduate School of Medicine, 54 Shogoin-Kawaharacho, Sakyo-ku, Kyoto 606-8507, Japan.
Abstract
PURPOSE: To evaluate the impact of surgery on the optic pathway of patients with intra- or parasellar mass lesions, as evidenced by readout-segmented DTI. MATERIALS AND METHODS: Twenty-four patients with intra- or parasellar mass lesions were included in the study. Readout-segmented DTI and T2WI were obtained before and after surgery. The ROIs were set on the optic chiasm as well as the anterior and posterior optic tracts. For each ROI, axial diffusivity (AD), radial diffusivity (RD), fractional anisotropy (FA), and ADC values were calculated. DTI parameters in preoperative studies of all patients were compared and related to the presence of tumor compression. In patients who underwent surgery, pre- and postoperative DTI parameters were compared. The correlation between DTI parameters and visual function was determined. RESULTS: In the preoperative studies, the optic chiasm of patients with tumor compression showed significant lower AD and RD values. The optic chiasm of patients with visual field disorder showed significantly lower AD and RD values compared to patients without the disorder. There was a negative correlation with a trend toward significance between FA values and visual field disorder scores. The comparative analysis of patients in pre- and postoperative studies showed that the optic chiasm of patients with tumor compression presented a significant lower FA (0.41 versus 0.30, p=0.0068) and higher RD values after surgery. CONCLUSIONS: DTI is a useful tool to assess the impact of surgery on the optic chiasm and nerve.
PURPOSE: To evaluate the impact of surgery on the optic pathway of patients with intra- or parasellar mass lesions, as evidenced by readout-segmented DTI. MATERIALS AND METHODS: Twenty-four patients with intra- or parasellar mass lesions were included in the study. Readout-segmented DTI and T2WI were obtained before and after surgery. The ROIs were set on the optic chiasm as well as the anterior and posterior optic tracts. For each ROI, axial diffusivity (AD), radial diffusivity (RD), fractional anisotropy (FA), and ADC values were calculated. DTI parameters in preoperative studies of all patients were compared and related to the presence of tumor compression. In patients who underwent surgery, pre- and postoperative DTI parameters were compared. The correlation between DTI parameters and visual function was determined. RESULTS: In the preoperative studies, the optic chiasm of patients with tumor compression showed significant lower AD and RD values. The optic chiasm of patients with visual field disorder showed significantly lower AD and RD values compared to patients without the disorder. There was a negative correlation with a trend toward significance between FA values and visual field disorder scores. The comparative analysis of patients in pre- and postoperative studies showed that the optic chiasm of patients with tumor compression presented a significant lower FA (0.41 versus 0.30, p=0.0068) and higher RD values after surgery. CONCLUSIONS: DTI is a useful tool to assess the impact of surgery on the optic chiasm and nerve.