SUVmax Values in Pulmonary Tuberculosis on PET-CT

Critical Diagnostic Pitfalls

• All SUVmax values >5.9 in one study were malignant rather than infectious, though this was in a non-endemic region 1
• In endemic TB regions, PET-CT specificity drops to as low as 25% due to high false-positive rates from granulomatous disease 1, 2

Clinical Application Algorithm

• In TB-endemic regions, expect decreased specificity with any elevated SUVmax; tissue diagnosis becomes more critical regardless of SUVmax value 1, 2

Important Caveats

• Visual assessment by experienced readers often outperforms strict SUVmax cutoffs alone, with sensitivity 96-100% and specificity 76-86% 2
• PET-CT cannot reliably differentiate TB from malignancy based solely on SUVmax; integration of clinical context, morphologic CT features, and quantitative values is essential 2