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J Digit Imaging (2012) 25:480485 DOI 10.1007/s10278-012-9454-x
Automatic Patient Table Removal in CT Images
Yang-Ming Zhu & Steven M. Cochoff & Ronald Sukalac
Published online: 19 January 2012# Society for Imaging Informatics in Medicine 2012
Abstract In many medical imaging applications, it is desirable and important to localize and remove the patient table from CT images. However, existing methods often require user interactions to define the table and sometimes make inaccurate assumptions about the table shape. Due to different patient table designs, shapes, and characteristics, these methods are not robust in identifying and removing the patient table. This paper proposes a new automatic approach which first identifies and locates the patient table in the sagittal planes and then removes it from the axial planes. The method has been tested successfully against different tables in different products from multiple vendors, showing it is both a versatile and robust technique for patient table removal.
Keywords Computed tomography. Patient table . Hough transform
Introduction
Computed tomography (CT) is a procedure that uses a scanner to acquire and reconstruct cross-sectional pictures of the body [1]. In many medical imaging applications, it is
desirable and sometimes important to localize and subsequently remove the patient table from CT images.
& For 3D visualization such as digitally reconstructed radio-graphs or maximum intensity projections (CT or CT fused with another dataset such as positron emission tomography (PET)), the table can obscure potentially vital data [2].
& In radiation treatment planning, the presence of the patient table in images can impact the dose modeling since the table used during imaging often has different attenuation properties than the table used during treatment [3]. In these cases, you want to modify the image and replace the imaging table with the treatment table to obtain more accurate planning.
& In PET/CT systems, the CT is used for attenuation and scatter correction in PET reconstruction [4]. The scatter correction is patient specific and the patient boundary has to be estimated accurately. Removal of the table facilitates accurate estimation of this boundary.
& In image registration, it is preferable that the two images to be registered have similar image content. Since the patient table is not visible in PET, MR (magnetic resonance), or SPECT (single photon emission computed tomography)...