Computation of ventilation-perfusion ratio with Kr-81m in pulmonary embolism
Diagnostic difficulties occur in pulmonary embolism (PE) during visual analysis of ventilation-perfusion images in matched defects or in chronic obstructive lung disease (COPD). In 44 patients with angiographically confirmed PE and in 40 patients with COPD, the regional ventilation-perfusion ratios (V/Q) were therefore computed using krypton-81m for each perfusion defect, and were displayed in a functional image. In patients with PE and mismatched defects, a high V/Q (1.96) was observed. A V/Q > 1.25 was also found in nine of 11 patients having PE and indeterminate studies (studies with perfusion abnormalities matched by radiographic abnormalities). COPD was characterized by matched defects and low V/Q. The percentage of patients correctly classified as having PE or COPD increased from 56% when considering the match or mismatched character to 88% when based on a V/Q of 1.25 in the region of the perfusion defect. This quantitative analysis, therefore, seems useful in classifying patients with scintigraphic suspicion of PE.
- Research Organization:
- Henri Mondor Hospital, Creteil, France
- OSTI ID:
- 5148413
- Journal Information:
- J. Nucl. Med.; (United States), Vol. 25:2
- Country of Publication:
- United States
- Language:
- English
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Related Subjects
EMBOLI
DIAGNOSIS
KRYPTON 81
SCINTISCANNING
LUNGS
ISOMERIC NUCLEI
PATIENTS
PERFUSED TISSUES
ANIMAL TISSUES
BETA DECAY RADIOISOTOPES
BODY
COUNTING TECHNIQUES
DIAGNOSTIC TECHNIQUES
ELECTRON CAPTURE RADIOISOTOPES
EVEN-ODD NUCLEI
INTERMEDIATE MASS NUCLEI
ISOMERIC TRANSITION ISOTOPES
ISOTOPES
KRYPTON ISOTOPES
NUCLEI
ORGANS
RADIOISOTOPE SCANNING
RADIOISOTOPES
RESPIRATORY SYSTEM
SECONDS LIVING RADIOISOTOPES
TISSUES
YEARS LIVING RADIOISOTOPES
550601* - Medicine- Unsealed Radionuclides in Diagnostics