Advanced

AJNR - American Journal of Neuroradiology

This Article Figures Only Full Text Full Text (PDF) Alert me when this article is cited Alert me if a correction is posted Citation Map Services Similar articles in this journal Similar articles in PubMed Alert me to new issues of the journal Download to citation manager Citing Articles Citing Articles via CrossRef Citing Articles via Google Scholar Google Scholar Articles by Caulo, M. Articles by Colosimo, C. Search for Related Content PubMed PubMed Citation Articles by Caulo, M. Articles by Colosimo, C.

American Journal of Neuroradiology 28:1480-1485, September 2007
DOI 10.3174/ajnr.A0597
© 2007 American Society of Neuroradiology

BRAIN

New Morphologic Variants of the Hand Motor Cortex as Seen with MR Imaging in a Large Study Population

M. Caulo^a, C. Briganti^a, P.A. Mattei^a, B. Perfetti^a, A. Ferretti^a, G.L. Romani^a, A. Tartaro^a and C. Colosimo^b

^a From the Institute Advanced Biomedical Technologies of the Department of Clinical Sciences and Bioimaging, University "G. d’Annunzio," Chieti, Italy
^b Department of Radiology, Catholic University of Rome, Italy

Please address correspondence to Massimo Caulo, MD, PhD, ITAB–Institute for Advanced Biomedical Technologies, University "G. d’Annunzio" of Chieti-Pescara, Via dei Vestini, n. 33, 66100 Chieti, Italy; e-mail: massimo.caulo{at}itab.unich.it

BACKGROUND AND PURPOSE: The hand motor cortex (HMC) has been classically described as having an omega or epsilon shape in axial-plane images obtained with CT and MR imaging. The aim of this study was to use MR imaging and Talairach normalization in a large sample population that was homogeneous for age and handedness to evaluate in a sex model a new classification with 5 morphologic variants of the HMC in the axial plane (omega, medially asymmetric epsilon, epsilon, laterally asymmetric epsilon, and null).

MATERIALS AND METHODS: Structural brain MR images were obtained from 257 right-handed healthy subjects (143 men and 114 women; mean age, 23.1 ± 1.1 years) via a Talairach space transformed 3D magnetization-prepared rapid acquisition of gradient echo sequence. The frequencies of the different HMC variants were reported for hemisphere and sex.

RESULTS: The new variants of the HMC (medially asymmetric epsilon, laterally asymmetric epsilon, and null) were observed in 2.9%, 7.0%, and 1.8% of the hemispheres, respectively. Statistically significant sex differences were observed: The epsilon variant was twice as frequent in men, and an interhemispheric concordance for morphologic variants was observed only for women.

CONCLUSION: The large study population permitted the description of a new morphologic classification that included 3 new variants of the HMC. This new morphologic classification should facilitate the identification of the precentral gyrus in subsequent studies and in everyday practice.