What does the signal-to-noise ratio (SNR) represent in radiology?

The signal-to-noise ratio (SNR) is a crucial concept in radiology as it quantifies the level of a desired signal compared to the background noise. A higher SNR indicates a clearer distinction between the signal (which represents the actual data or information captured during imaging) and the noise (unwanted variations or anomalies that can obscure or distort the information of interest). This means that when the SNR is high, the radiographic image will be clearer and more diagnostically useful because the relevant anatomical or pathological features are more pronounced against the background noise. Understanding SNR helps radiologists assess the quality of the imaging and make informed decisions about the adequacy of the images for diagnostic purposes.