RT Journal Article SR Electronic T1 Is the Subthalamic Nucleus Hypointense on T2-Weighted Images? A Correlation Study Using MR Imaging and Stereotactic Atlas Data JF American Journal of Neuroradiology JO Am. J. Neuroradiol. FD American Society of Neuroradiology SP 1516 OP 1523 VO 25 IS 9 A1 Didier Dormont A1 Kenneth G. Ricciardi A1 Dominique Tandé A1 Karine Parain A1 Carole Menuel A1 Damien Galanaud A1 Soledad Navarro A1 Philippe Cornu A1 Yves Agid A1 Jérôme Yelnik YR 2004 UL http://www.ajnr.org/content/25/9/1516.abstract AB BACKGROUND AND PURPOSE: Although the subthalamic nucleus is the most frequently used target for surgical treatment of Parkinson’s disease, the criteria on which it can be identified on T2-weighted images have never been clearly defined. This study was conducted to characterize the precise anatomic distribution of T2-weighted hyposignal in the subthalamic region and to correlate this hyposignal with iron content in the subthalamic nucleus.METHODS: The T2-weighted MR imaging acquisitions of 15 patients with Parkinson’s disease were fused with a digitized version of the Schaltenbrand and Wahren anatomic atlas. The MR signal intensity within the anatomic limits of the subthalamic nucleus was evaluated. An anatomic specimen obtained at autopsy was used to evaluate iron content.RESULTS: In all patients, the subthalamic nucleus was hypointense on both sides in the anterior half of the nucleus. At more posterior levels of the nucleus, hypointensity was less frequently observed (20–80%). Hypointensity was never observed at the most posterior pole. Iron was present in the anteromedial part of the nucleus but absent at the most posterior levels.CONCLUSION: The hypointense signal intensity located lateral to the red nucleus and dorsolateral to the substantia nigra correlates with the presence of iron and corresponds anatomically to the subthalamic nucleus. It can therefore be used as a landmark for electrode implantation in patients with Parkinson’s disease. It should, however, be emphasized that although hypointensity was always present in the anterior half of the subthalamic nucleus, the posterior part of the nucleus was not visible in most cases.