Cardiac Findings Should Be Noted on Chest CT When Observed

Increasing cardiac imaging training correlates with increased sensitivity and stable specificity to detect cardiac findings on routine chest CT without electrocardiographic gating, according to a study published in the Journal of the American College of Radiology.

Researchers from Harvard University in Boston, Mass., sought to evaluate the diagnostic ability of radiologists with different levels of cardiac training to identify cardiac findings on chest CT without electrocardiographic gating compared with a reference standard of electrocardiographically gated cardiac CTA.

The researchers retrospectively identified 140 electrocardiographically gated cardiac CT angiographic studies performed in patients with routine chest CT within six months. Fourteen radiologists at four stages of training performed blinded, anonymized cardiac readings of chest CT images. Four residents had no cardiac training (stage 1), three residents had completed at least one dedicated rotation of cardiac imaging (stage 2), three radiologists had no cardiac training (stage 3), and four radiologists had formal cardiac fellowship training (stage 4).

The findings were categorized (coronary arterial, noncoronary vessel, cardiac chamber, myocardial, pericardial, and valve findings) with cardiac CTA as a reference standard.

The results showed CT angiographic findings were reported in 63 of 77 patients.

Nongated CTA

• Sensitivity  43.6%
• specificity 96.8%
• Positive predictive value 83.0%
• Negative predictive value 81.6%
• Accuracy  81.8%

Increasing training was associated with higher sensitivity but similar specificity. Frequently missed findings categories were coronary arterial, myocardial, and cardiac chamber findings.

           Sensitivity Specificity
Stage 1    30.3% 96.4%
Stage 2    35.7% 96.7%
Stage 3    45.7% 96.3%
Stage 4    61.2% 97.6%

The researchers concluded that increasing cardiac imaging training correlates with increased sensitivity and stable specificity to detect cardiac findings on routine chest CT without electrocardiographic gating. Cardiac findings should be noted on chest CT when observed, and cardiac training should be encouraged.