Magnetic Resonance Imaging (MRI) Practice Test

The height of a peak on an MR spectrum correlates to what aspect of a substance detected?

1. Purity

2. Amount

3. Concentration

4. Quality

The correct answer is: Amount

The correct answer relates to the height of a peak on an MR spectrum and its direct correlation to the amount of a substance present in the sample. In magnetic resonance spectroscopy, the amplitude or height of a peak is proportional to the number of nuclei contributing to that signal, which reflects the quantity of the analyte. More specifically, the greater the number of nuclei, the taller the peak will be on the spectrum. In this context, a higher peak indicates a larger amount of the substance, as it suggests that more atomic nuclei within the sample are resonating under the influence of the magnetic field and radiofrequency pulses applied during the MRI process. This measurement is critical in quantifying different components in complex mixtures and is often used in various applications, including medical diagnostics and research settings. While purity, concentration, and quality are important factors in the analysis of substances, they are not directly indicated by the height of the peak alone. Purity refers to the absence of contaminants, concentration involves the amount of a substance in a given volume, and quality encompasses various attributes of the substance that may not be reflected solely by peak height in the spectrum.