Serial MR Analysis of Early Permanent and Transient Ischemia in Rats: Diffusion Tensor Imaging and High b Value Diffusion Weighted Imaging.
10.3348/kjr.2013.14.2.307
- Author:
Ji Hoon KIM
1
;
Dong Gyu NA
;
Kee Hyun CHANG
;
In Chan SONG
;
Seung Hong CHOI
;
Kyu Ri SON
;
Kyung Won KIM
;
Chul Ho SOHN
Author Information
1. Department of Radiology, Seoul National University Hospital, Seoul 110-744, Korea. neurorad63@gmail.com
- Publication Type:Original Article ; Research Support, Non-U.S. Gov't
- Keywords:
Ischemia;
Diffusion weighted imaging;
Diffusion tensor imaging;
Apparent diffusion coefficient;
Fractional anisotropy
- MeSH:
Animals;
Contrast Media/diagnostic use;
Diffusion Magnetic Resonance Imaging/*methods;
Gadolinium DTPA/diagnostic use;
Ischemic Attack, Transient/*diagnosis;
Male;
Rats;
Rats, Sprague-Dawley
- From:Korean Journal of Radiology
2013;14(2):307-315
- CountryRepublic of Korea
- Language:English
-
Abstract:
OBJECTIVE: To evaluate the temporal evolution and diagnostic values of the diffusion tensor imaging (DTI) and the high b value diffusion weighted imaging (DWI) in the early permanent and transient cerebral ischemia. MATERIALS AND METHODS: For permanent or 30-minute transient-ischemia induced 30 rats, DTI and DWIs at both high b (b = 3000 s/mm2) and standard b value (b = 1000 s/mm2) were obtained at the following conditions: at 15, 30, 45, 60 minutes after the occlusion of what for hyperacute permanent ischemia; at 1, 3, 5, 7, 9 hours after the occlusion for acute permanent ischemia; and at 15 minutes before reperfusion, 0.5, 2.5, and 24 hours after reperfusion for transient ischemia. The diffusion parameters and their ratios were obtained and compared between different b values, and among different time points and groups, respectively. RESULTS: For both b values, the apparent diffusion coefficient (ADC) ratio decreased for first three hours, and then slightly increased until 9 hours after the occlusion during a gradual continuous increase of DWI signal intensity (SI) ratio, with excellent correlation between ADC ratios and DWI SI ratios. The DWI showed a higher contrast ratio, but the ADC map showed a lower contrast ratio for permanent ischemia at high b value than at standard b value. Fractional anisotropy (FA) increased for 1 hour, then gradually decreased until 9 hours after the occlusion in permanent ischemia and showed transient normalization and secondary decay along with change in ADC in transient ischemia. CONCLUSION: This study presents characteristic initial elevation and secondary decay of FA, higher contrast ratio of DWI, and lower contrast ratio of ADC map at high b value, in addition to the time evolutions of diffusion parameters in early permanent and transient ischemia.
