Bhanu Mahajan MBBS, Presenter: Nothing to Disclose

Jayender Jagadeesan PHD, , Abstract Co-Author: Nothing to Disclose

Rivka Rachel Colen MD, Abstract Co-Author: Nothing to Disclose

Paul Richard Morrison MSC, Abstract Co-Author: Nothing to Disclose

Stuart G. Silverman MD, Abstract Co-Author: Author, Lippincott Williams & Wilkins

Christopher Thompson MD, Abstract Co-Author: Nothing to Disclose

Kirby Gannett Vosburgh MS, PhD, Abstract Co-Author: Investigator, Ascension Technology Corporation

To evaluate the anticipated change in position of the abdominal organs, explore the possible linkage in the displacement of the Pancreas and Kidneys when the position of the patient is changed from supine to left lateral decubitus(LLD).

Supine CT/MRI scans and LLD CT scans from a dataset of 10 patients who underwent CT-guided Kidney tumor cryoablation procedure performed in the LLD position were included in this retrospective study. The supine and LLD scans were registered such that the vertebrae in both the scans are rigidly aligned. The centroids and eigen vectors of the corresponding organs were then computed to evaluate the organ displacement. All the registration and segmentation was done using Slicer 3.6(slicer.org).

Our initial results support the hypothesis that the motion of the left kidney and the pancreas tail are well correlated (p = 0.045), while the motion of the right kidney and pancreas head are correlated (p = 0.0617) when the position of the patient is changed from supine to left lateral decubitus position. In all the patients studied thus far, the right kidney and pancreas head droop under gravity, while the contact force with the table deforms the left kidney and the pancreas tail.

This initial study suggests that the motion of the retroperitoneal structures is predictable, implying that a population based statistical deformation map is feasible and can accurately correct the shifts and displacement that occur on the left lateral decubitus scan relative to the supine scan.

It lays the ground for advanced image registration for procedures done in LLD position, which will increase the accuracy of procedures.

Mahajan, B, Jagadeesan, J, Colen, R, Morrison, P, Silverman, S, Thompson, C, Vosburgh, K, Retroperitoneal Organ Deformation Due to Position Change from Supine to Left Lateral Decubitus: Quantitative Results in 10 Patients.  Radiological Society of North America 2011 Scientific Assembly and Annual Meeting, November 26 - December 2, 2011 ,Chicago IL. http://archive.rsna.org/2011/11034625.html