Here is an example of SPECT imaging offered by Howard Corbus and Wes Wooton as indicative of the power of the imaging modality itself to extract meaningful data from otherwise "fuzzy" planar images even in the presence of extensive parenchymal disease.

Howard F. Corbus, MD
Wesley W. Wooten, PhD
September 1998
Fresno, California
(email for Dr Wooten)

Examples of Lung SPECT images.

These sample images demonstrate that SPECT can distinguish embolic disease from extensive associated pulmonary disease. (Arrows are labeled "MM" to indicate mismatching defects, and "RMM" to indicate reverse mismatching defects.) Ventilation images are acquired 1.5 hours after perfusion images using Tc-99m DTPA aerosol. Prominent large airway deposition does not impair SPECT interpretation.

PERFUSION FINDINGS:

1. Distribution of MAA is grossly irregular throughout lungs.
2. Prominent defects are seen in right posterior and lateral basal segments, and in left posterior basal segment

VENTILATION FINDINGS:

1. Ventilation 1.5 hours after perfusion.
2. Areas of absent perfusion in both lower lobes are well ventilated; constituting mismatching defects.
3. Extensive matching defects are seen throughout.
4. Moderate deposition of radioaerosol in the right and left lobar bronchi.
5. Areas of reverse ventilation/perfusion indicative of venous admixture.

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CONCLUSIONS:

1. Multiple perfusion/ventilation mismatching defects: high probability for pulmonary embolism.
2. Signs of advanced chronic obstructive pulmonary disease.