Motion modeling from 4D MR images of liver simulating phantom.

Background And Purpose: A novel method of retrospective liver modeling was developed based on four-dimensional magnetic resonance (4D-MR) images. The 4D-MR images will be utilized in generation of the subject-specific deformable liver model to be used in radiotherapy planning (RTP). The purpose of this study was to test and validate the developed 4D-magnetic resonance imaging (MRI) method with extensive phantom tests.

Determination of acceptance criteria for geometric accuracy of magnetic resonance imaging scanners used in radiotherapy planning.

Background And Purpose: Magnetic resonance imaging is increasingly used in radiotherapy planning; yet, the performance of the utilized scanners is rarely regulated by any authority. The aim of this study was to determine the geometric accuracy of several magnetic resonance imaging scanners used for radiotherapy planning, and to establish acceptance criteria for such scanners.

Materials And Methods: The geometric accuracy of five different scanners was measured with three sequences using a commercial large-field-of-view phantom.

Retrospective four-dimensional magnetic resonance imaging of liver: Method development.

Purpose of our research was to develop a four-dimensional (4D) magnetic resonance imaging (MRI) method of liver. Requirements of the method were to create a clinical procedure with acceptable imaging time and sufficient temporal and spatial accuracy. The method should produce useful planning image sets for stereotactic body radiation therapy delivery both during breath-hold and in free breathing.