ABSTRACT
I. Introduction 182
II. Paramagnetic Properties of Oxygen 182
III. Prerequisites for Oxygen-Enhanced Imaging 184
IV. Implementation 186
A. Image Acquisition 186
B. Image Post-processing 189
V. Healthy Volunteer Studies and Experimental Optimizations 190
VI. Potential Clinical Applications 192
A. Oxygen-Enhanced Ventilation Imaging of Pulmonary
Diseases 193
B. V/Q Imaging 195 V/Q Imaging in Animal Models 198 V/Q Imaging in Patients 199 V/Q Ratio of Signal Intensity 201
C. Dynamic Oxygen-Enhanced Imaging 201
D. Mapping Partial Pressure of Oxygen in the Lung 205
VII. Oxygen-Enhanced Imaging at 3.0 T 205
Acknowlegdment 206
References 206
I. Introduction
Assessment of ventilation is crucial in the evaluation of a host of pulmonary
disorders because sufficient ventilation of the lung tissue is a major determinant
of efficient gas exchange in the lung. There are several imaging methods avail-
able to evaluate lung ventilation such as radionuclide scintigraphy and the
recently developed hyperpolarized gas magnetic resonance imaging (MRI).
Radionuclide scintigraphy encounters limitations such as poor spatial resolution
and the need for a radioactive tracer (1). Hyperpolarized 3He and 129Xe MR
imaging have provided detailed images of the lung, but the high cost of the
laser polarizer, the expenses for the 3He and 129Xe gases, and the need for
nonproton imaging apparatus currently limit its wide spread application (2-4).
