Correlation between the clinical pretest probability score and the lung ventilation and perfusion scan probability

Area of Science:

• Radiology
• Diagnostic Imaging
• Pulmonary Medicine

Background:

• Clinical pretest probability (PTP) scores are used to estimate the likelihood of pulmonary embolism (PE).
• Lung ventilation/perfusion (VQ) scans are a common diagnostic tool for PE.
• Evaluating the accuracy of PTP scores in conjunction with VQ scans is crucial for effective PE diagnosis.

Purpose of the Study:

• To determine the diagnostic accuracy of the clinical PTP score.
• To assess the association between the clinical PTP score and lung VQ scan results.
• To compare the accuracy of the clinical PTP score and lung VQ scan in diagnosing PE.

Main Methods:

• Retrospective analysis of 510 patients undergoing lung VQ scans between 2008 and 2010.
• Categorization of VQ scans into normal (30%), low-probability (57%), and high-probability (11%) groups.
• Comparison of VQ scan results with computed tomography pulmonary angiography (CTPA) in 103 patients.

Main Results:

• The clinical PTP score demonstrated a low correlation (r = 0.20) with lung VQ scan findings.
• The area under the curve (AUC) for the clinical PTP score was 52% compared to CTPA.
• Lung VQ scan accuracy (AUC = 74%) was significantly better than the clinical PTP score for PE assessment.

Conclusions:

• The clinical PTP score alone is unreliable for diagnosing PE.
• Lung VQ scans offer superior accuracy in assessing pulmonary embolism compared to the clinical PTP score.
• The clinical PTP score may provide adjunctive information when interpreting lung VQ scans.