The Usefulness and Limitations of Radiologic Findings for Diagnosis of Infectious Diseases: A Call for Antimicrobial Stewardship

Abstract

Radiological evaluation is pivotal in diagnosing infectious diseases, but its inherent limitations can lead to diagnostic uncertainty and inappropriate antibiotic use, exacerbating the global challenge of antimicrobial resistance (AMR). This review examines the utility and constraints of imaging studies—computed tomography (CT), magnetic resonance imaging (MRI), and ultrasonography (US)—in common infectious diseases, including pneumonia, acute pyelonephritis (APN), infectious colitis, and skin and soft tissue infections (SSTI). For pneumonia, CT and lung US offer higher sensitivity than chest X-rays, but distinguishing between bacterial and viral pathogens remains challenging. In APN, contrast-enhanced CT is the standard, but routine imaging is not recommended for uncomplicated cases. CT findings in infectious colitis are often nonspecific, necessitating a comprehensive clinical assessment. For SSTIs, particularly in differentiating necrotizing fasciitis, MRI and CT demonstrate high negative predictive value, but positive findings require careful clinical correlation. Furthermore, inter-reader variability exists in interpreting subtle imaging findings. This review highlights the gap between radiological findings and definitive diagnoses, underscoring that imaging is a powerful adjunct but cannot replace comprehensive clinical judgment. A multidisciplinary approach integrating clinical data with imaging findings is essential for accurate diagnosis, responsible antimicrobial stewardship, and effective patient management in the era of AMR.