Comparisons among MRI signs, apparent diffusion coefficient, and fractional anisotropy in dogs with a solitary intracranial meningioma or histiocytic sarcoma.
Although MRI has become widely used in small animal practice, little is known about the validity of advanced MRI techniques such as diffusion-weighted imaging and diffusion tensor imaging. The aim of this retrospective analytical observational study was to investigate the characteristics of diffusion parameters, that is the apparent diffusion coefficient and fractional anisotropy, in dogs with a solitary intracranial meningioma or histiocytic sarcoma. Dogs were included based on the performance of diffusion MRI and histological confirmation. Statistical analyses were performed to compare apparent diffusion coefficient and fractional anisotropy for the two types of tumor in the intra- and peritumoral regions. Eleven cases with meningioma and six with histiocytic sarcoma satisfied the inclusion criteria. Significant differences in apparent diffusion coefficient value (× 10-3mm2/s) between meningioma vs. histiocytic sarcoma were recognized in intratumoral small (1.07 vs. 0.76) and large (1.04 vs. 0.77) regions of interest, in the peritumoral margin (0.93 vs. 1.08), and in the T2 high region (1.21 vs. 1.41). Significant differences in fractional anisotropy values were found in the peritumoral margin (0.29 vs. 0.24) and the T2 high region (0.24 vs. 0.17). The current study identified differences in measurements of apparent diffusion coefficient and fractional anisotropy for meningioma and histiocytic sarcoma in a small sample of dogs. In addition, we observed that all cases of intracranial histiocytic sarcoma showed leptomeningeal enhancement and/or mass formation invading into the sulci in the contrast study. Future studies are needed to determine the sensitivity of these imaging characteristics for differentiating between these tumor types.
Department of Clinical Veterinary Medicine, Nippon Veterinary and Life Science University, 180-8601, Tokyo, Japan.|ORM Co. Ltd., 330-0803, Saitama, Japan.
Masae
M
Wada
Department of Clinical Veterinary Medicine, Nippon Veterinary and Life Science University, 180-8601, Tokyo, Japan.
Daisuke
D
Hasegawa
Department of Clinical Veterinary Medicine, Nippon Veterinary and Life Science University, 180-8601, Tokyo, Japan.
Yuji
Y
Hamamoto
Department of Clinical Veterinary Medicine, Nippon Veterinary and Life Science University, 180-8601, Tokyo, Japan.
Yoshihiko
Y
Yu
Department of Clinical Veterinary Medicine, Nippon Veterinary and Life Science University, 180-8601, Tokyo, Japan.
Aki
A
Fujiwara-Igarashi
Department of Clinical Veterinary Medicine, Nippon Veterinary and Life Science University, 180-8601, Tokyo, Japan.
Michio
M
Fujita
D000818:Animals; D016880:Anisotropy; D004058:Diffusion; D038524:Diffusion Magnetic Resonance Imaging / Q000379:methods / Q000662:veterinary*; D056324:Diffusion Tensor Imaging / Q000379:methods / Q000662:veterinary*; D004283:Dog Diseases / Q000000981:diagnostic imaging*; D004285:Dogs; D005260:Female; D054747:Histiocytic Sarcoma / Q000000981:diagnostic imaging / Q000662:veterinary*; D008297:Male; D008579:Meningioma / Q000000981:diagnostic imaging / Q000662:veterinary*; D012189:Retrospective Studies
diffusion tensor imaging; diffusion-weighted imaging; dog