DIGITAL ASSESSMENT OF MRI FOR LUMBAR DISC DESICCATION - A COMPARISON OF DIGITAL VERSUS SUBJECTIVE ASSESSMENTS AND DIGITAL INTENSITY PROFILES VERSUS DISCOGRAM AND MACROANATOMIC FINDINGS

During magnetic resonance imaging, a vast amount of digital data on an atomic structures is translated into images, which are then assessed s ubjectively. The development of an objective, sensitive method to dire ctly assess the digital data would have clear benefits, particularly f or clinical research on disc degeneration. The study goals were to dev elop a method of digital assessment of disc desiccation and to compare digital signal intensity profiles with discographic patterns and macr oanatomic findings. Proton density-weighted MRIs were obtained from 45 males (9-77 years) and digital analysis was done with a freely select able region of interest facility. The adjacent cerebrospinal fluid (CS F) was used as a reference for disc signal-intensity scores, and the d isc to CSF-intensity ratio provided ''adjusted digital scores.'' The C SF-adjusted digital method yielded reproducible scores that correlated with the subjective assessments. However, the CSF-adjusted digital sc ores were more sensitive than the subjective assessments, identifying findings that otherwise were undetected in younger subjects. Additiona lly, 10 cadaveric spines were evaluated using MRI with T2 and proton d ensity-weighted sequences, discography, and macroanatomic dissection. MRI disc-intensity profiles were determined along a midsagittal line d rawn through the disc. The profile of the digital scores along this li ne was then compared with discograms and macroanatomic sections. In al l cases of disc degeneration on discograms, changes were present in th e intensity profile. Based on both the living subjects and the cadaver ic specimens, the digital assessments and disc intensity profiles appe ar to demonstrate disc degeneration, particularly in early stages.