Factorial analysis in diagnosis of left-to-right shunts

Conference · Wed May 01 04:00:00 EDT 1985 · J. Nucl. Med.; (United States)

OSTI ID:5936057

Villanueva-Meyer, J; Philippe, L; Mena, I

Factor analysis (FA) extracts curves and images from a dynamic study with minimal operator intervention. This study applies FA to the left-to-right (L-R) shunt diagnosis, using it with deconvolution and gamma fitting techniques and comparing it to current procedures. 14 patients with a L-R shunt confirmed by catheterization and 10 normal subjects were studied. A first-pass ventriculogram was gathered in list mode for 25 sec after bolus injection of 15-20 mCi Tc99m. .5 sec frames were created. For FA 3 factors were requested, the dixel size was 4 by 4 pixels and 30 dixels were analyzed. The heart was masked out for the analysis. Three images and curves were obtained: venous input, lungs and background. The lung curve was deconvolved by the venous input curve using the lagged normal algorithm. The unit impulse response was used to obtain a calculated output lung curve. Gamma functions were fitted on this curve and area ratios yielded the Qp/Qs. Only FA with deconvolution separates the shunt patients from the control group with a p <0.001. Qp/Qs for the shunt group was 2.30, SD .54 and the control group was 1.12, SD .07. The best correlation with oximetry was obtained with this technique, r=.87 and SEE .28. The FA lung curve has excellent counting statistics derived from 48% of the total counts, thus the improvement of results.

• Research Organization: UCLA School of Medicine, Harbor-UCLA Medical Center, Torrance, CA
• OSTI ID: 5936057
• Report Number(s): CONF-850611-
• Conference Information: Journal Name: J. Nucl. Med.; (United States) Journal Volume: 26:5
• Country of Publication: United States
• Language: English

Related Subjects

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551001 -- Physiological Systems-- Tracer Techniques
59 BASIC BIOLOGICAL SCIENCES
62 RADIOLOGY AND NUCLEAR MEDICINE
ALGORITHMS
BETA DECAY RADIOISOTOPES
BETA-MINUS DECAY RADIOISOTOPES
BLOOD FLOW
BLOOD VESSELS
BODY
CARDIOVASCULAR SYSTEM
COMPARATIVE EVALUATIONS
CORRELATIONS
COUNTING TECHNIQUES
DIAGNOSTIC TECHNIQUES
HEART
HOURS LIVING RADIOISOTOPES
IMAGE PROCESSING
INTERMEDIATE MASS NUCLEI
ISOMERIC TRANSITION ISOTOPES
ISOTOPES
LUNGS
MATHEMATICAL LOGIC
MEDICAL SUPPLIES
NUCLEI
ODD-EVEN NUCLEI
ORGANS
PROCESSING
PROSTHESES
RADIOISOTOPE SCANNING
RADIOISOTOPES
RESPIRATORY SYSTEM
SCINTISCANNING
TECHNETIUM 99
TECHNETIUM ISOTOPES
YEARS LIVING RADIOISOTOPES