Assessment of regional lung functional impairment with co-registered respiratory-gated ventilation/perfusion SPET-CT images: initial experiences.

Abstract

In this study, respiratory-gated ventilation and perfusion single-photon emission tomography (SPET) were used to define regional functional impairment and to obtain reliable co-registration with computed tomography (CT) images in various lung diseases. Using a triple-headed SPET unit and a physiological synchroniser, gated perfusion SPET was performed in a total of 78 patients with different pulmonary diseases, including metastatic nodules (n = 15); in 34 of these patients, it was performed in combination with gated technetium-99m Technegas SPET. Projection data were acquired using 60 stops over 120 degrees for each detector. Gated end-inspiration and ungated images were reconstructed from 1/8 data centered at peak inspiration for each regular respiratory cycle and full respiratory cycle data, respectively. Gated images were registered with tidal inspiration CT images using automated three-dimensional (3D) registration software. Registration mismatch was assessed by measuring 3D distance of the centroid of the nine selected round perfusion-defective nodules. Gated SPET images were completed within 29 min, and increased the number of visible ventilation and perfusion defects by 9.7% and 17.2%, respectively, as compared with ungated images; furthermore, lesion-to-normal lung contrast was significantly higher on gated SPET images. In the nine round perfusion-defective nodules, gated images yielded a significantly better SPET-CT match compared with ungated images (4.9 +/- 3.1 mm vs 19.0 +/- 9.1 mm, P<0.001). The co-registered SPET-CT images allowed accurate perception of the location and extent of each ventilation/perfusion defect on the underlying CT anatomy, and characterised the pathophysiology of the various diseases. By reducing respiratory motion effects and enhancing perfusion/ventilation defect clarity, gated SPET can provide reliable co-registered images with CT images to accurately characterise regional functional impairment in various lung diseases.

• Authors: Kazuyoshi Suga, Kawakami Yasuhiko, Mohammed Zaki, Tomio Yamashita, Aska Seto, Tsuneo Matsumoto, Naofumi Matsunaga
• Journal: European journal of nuclear medicine and molecular imaging (Eur J Nucl Med Mol Imaging) Vol. 31 Issue 2 Pg. 240-9 (Feb 2004) ISSN: 1619-7070 [Print] Germany
• PMID: 15129707 (Publication Type: Clinical Trial, Comparative Study, Controlled Clinical Trial, Journal Article, Research Support, Non-U.S. Gov't)

Chemical References

• Radiopharmaceuticals
• Technegas
• Sodium Pertechnetate Tc 99m

Topics

• Adult
• Aged
• Aged, 80 and over
• Female
• Gated Blood-Pool Imaging (methods)
• Humans
• Imaging, Three-Dimensional (methods)
• Lung Diseases (diagnostic imaging)
• Male
• Middle Aged
• Radiopharmaceuticals
• Reproducibility of Results
• Sensitivity and Specificity
• Sodium Pertechnetate Tc 99m
• Subtraction Technique
• Tomography, Emission-Computed, Single-Photon (methods)
• Tomography, X-Ray Computed (methods)