Dynamic-range compression in surface-coil MRI.

The large dynamic range in signal intensity present in MR surface-coil images makes proper windowing and photography difficult. By removing the low-spatial frequency information caused by variations in surface-coil field intensity from the high-spatial frequency information containing the image data, a considerable compression of this dynamic range of signal intensity is possible. To accomplish this, a technique was implemented on a digital computer for use with MR surface-coil image data. The compression was done as a postprocessing option after the patient scan had been completed and therefore did not alter actual scan times. Although the image signal-to-noise was not altered, the ease of photography for most images was improved. Thus, digital dynamic-range compression is a practical technique to aid in surface-coil MRI studies.