Magnetic resonance imaging of the liver by oblique sections

The authors have applied magnetic resonance imaging (MRI) to the anatomic study of the liver by comparing cadaveric sections with those obtained with MRI. This study deals with sections oblique in relation to a sagittal or frontal plane, whose orientation is determined from landmarks visible on transverse sections. Oblique sections were made in 10 cadavers using an original method. First, adjacent transverse sections were made of the frozen trunk and two landmarks were located in these sections: the course of the middle hepatic v. and the direction of the division of the portal venous trunk. The transverse sections were then stacked and the block so reconstituted was refrozen and then cut in adjacent oblique sections oriented either along the plane of the middle hepatic v. (sagittal oblique sections) or along the plane of division of the portal venous trunk (frontal oblique sections). Oblique MRI sections were made in 15 healthy volunteers, mainly based on the same venous landmarks but sometimes on other landmarks visible on the transverse sections. Oblique MRI sections can be made in the plane of any anatomic structure located in the transverse sections in order to define its position. Sections based on identical landmarks differently oriented in different subjects allow for definition of the individual anatomy of the liver investigated. The frontal oblique sections clearly show the course of the trunk of the portal v. and the junctions of the hepatic vv. with the inferior vena cava. The sagittal oblique sections are particularly useful for investigating the thinnest part of the left side of the liver and also the caudate lobe.