Image Gated Cardiac CT

LSU Medical PhysicsSeminar

February 4, 2005Given by Will Hill

With advice from Dr. Kip Mathews

A presentation of“Automatic Phase Determination for Retrospectively Gated

Cardiac CT” fromthe December 2004 issue of Medical Physics

Introduction and Objectives

What is Gated Cardiac Computed Tomography (CT) ?

Why bother? What This Lecture will cover:

Basics of CT Basics of cardiac timing How this is done now How the author did it The author's results

Literature Review

“Automatic Phase Determination for Retrospectively Gated Cardiac CT,” by R. Manzke, Th. Kohler, T. Neilsen, D. Hawkes and M. Grass, Medical Physics 31-12.

The Essential Physics of Medical Imaging, Lippncott Williams and Wilkins, Second Edition.

The Basics of Computed Tomography

Who Likes Guessing Games?

The Basics of Computed Tomography

How about this one?

The Basics of Computed Tomography

Pretend you can't see through it.

The Basics of Computed Tomography

and that you have x-rays and a counter.

The Basics of Computed Tomography

Ta-dah!

The Basics of Computed Tomography

So, that's how it works.

Timing: Your Heart

Timing: Your Heart

Timing: EKG Methods Triggered Continuous

Materials and Method

This Method: Low Pitch Helical Cardiac Scan and ECG Reconstruction of Low-Resolution 4D Volume Automatic Motion Calculations Reconstruction of High Resolution Volumes

Philips MX 8000 IDT 16-line CT system at University Hospital in Ulm, Germany and at the Carmel Hospital in Haifa, Israel.

Similar Low Resolution Volumes

Motion Determination

Motion Map

Results

Simulation Study Three Patient's Data

Conclusions

Computational Efficiency similarity is easy low resolution scans are used first

Automatically Reduces Motion Artifacts patient and cycle variation are accounted for different phases can be used for different heart

segments by use of new motion maps

The Future

Authors promise larger clinical trials.