PT  - JOURNAL ARTICLE
AU  - Machado-Rivas, F.
AU  - Afacan, O.
AU  - Khan, S.
AU  - Marami, B.
AU  - Rollins, C.K.
AU  - Ortinau, C.
AU  - Velasco-Annis, C.
AU  - Warfield, S.K.
AU  - Gholipour, A.
AU  - Jaimes, C.
TI  - Tractography of the Cerebellar Peduncles in Second- and Third-Trimester Fetuses
AID  - 10.3174/ajnr.A6869
DP  - 2021 Jan 01
TA  - American Journal of Neuroradiology
PG  - 194--200
VI  - 42
IP  - 1
4099  - http://www.ajnr.org/content/42/1/194.short
4100  - http://www.ajnr.org/content/42/1/194.full
SO  - Am. J. Neuroradiol.2021 Jan 01; 42
AB  - BACKGROUND AND PURPOSE: Little is known about microstructural development of cerebellar white matter in vivo. This study aimed to investigate developmental changes of the cerebellar peduncles in second- and third-trimester healthy fetuses using motion-corrected DTI and tractography.MATERIALS AND METHODS: 3T data of 81 healthy fetuses were reviewed. Structural imaging consisted of multiplanar T2-single-shot sequences; DTI consisted of a series of 12-direction diffusion. A robust motion-tracked section-to-volume registration algorithm reconstructed images. ROI-based deterministic tractography was performed using anatomic landmarks described in postnatal tractography. Asymmetry was evaluated qualitatively with a perceived difference of >25% between sides. Linear regression evaluated gestational age as a predictor of tract volume, ADC, and fractional anisotropy.RESULTS: Twenty-four cases were excluded due to low-quality reconstructions. Fifty-eight fetuses with a median gestational age of 30.6 weeks (interquartile range, 7 weeks) were analyzed. The superior cerebellar peduncle was identified in 39 subjects (69%), and it was symmetric in 15 (38%). The middle cerebellar peduncle was identified in all subjects and appeared symmetric; in 13 subjects (22%), two distinct subcomponents were identified. The inferior cerebellar peduncle was not found in any subject. There was a significant increase in volume for the superior cerebellar peduncle and middle cerebellar peduncle (both, P < .05), an increase in fractional anisotropy (both, P < .001), and a decrease in ADC (both, P < .001) with gestational age. The middle cerebellar peduncle had higher volume (P < .001) and fractional anisotropy (P = .002) and lower ADC (P < .001) than the superior cerebellar peduncle after controlling for gestational age.CONCLUSIONS: A robust motion-tracked section-to-volume registration algorithm enabled deterministic tractography of the superior cerebellar peduncle and middle cerebellar peduncle in vivo and allowed characterization of developmental changes.FAfractional anisotropyGAgestational ageICPinferior cerebellar peduncleMCPmiddle cerebellar peduncleMCPcogcognitive pathway of middle cerebellar peduncleMCPmotmotor pathway of middle cerebellar peduncleMT-SVRmotion-tracked slice-to-volume registrationSCPsuperior cerebellar peduncle