<Li> The thoracic plane separates the superior and inferior mediastinum . It is a plane at the level of the sternal angle, and the intervertebral disc of T4--T5 . </Li> <Li> The inferior mediastinum from this level to the diaphragm . This lower part is subdivided into three regions, all relative to the pericardium--the anterior mediastinum being in front of the pericardium, the middle mediastinum contains the pericardium and its contents, and the posterior mediastinum being behind the pericardium . </Li> <P> Anatomists, surgeons, and clinical radiologists compartmentalize the mediastinum differently . For instance, in the radiological scheme of Felson, there are only three compartments (anterior, middle, and posterior), and the heart is part of the anterior mediastinum . </P> <P> The superior mediastinum is bounded: </P>

Where is the heart located in the mediastinum
find me the text answering this question