Objective <p>Lumbar disc herniation (LDH) is common, often leading to lumbosacral nerve damage in affected patients. This study aims to assess the correlation between nerve root compression and clinical symptoms of LDH using magnetic resonance neurography (MRN) combined with T2 mapping.</p> Methods <p>This prospective study included patients with unilateral LDH-related nerve root compression. All participants underwent 3.0T MRI with 3D SHINKEI and T2 mapping sequences. Clinical symptoms were evaluated using ODI and VAS scores. Measure T2 values of the lumbosacral plexus (LSP) using T2 mapping and calculate the difference in T2 values between the compressed and uncompressed sides. MRN image results and symptoms were analyzed with Fisher’s exact test. Paired samples t-test compared T2 values of compressed and uncompressed groups. Correlation between T2 differences and ODI/VAS scores was examined. A two-sample t-test assessed T2 differences in postganglionic segments of MRN high and non-high signal groups. The significance level was set at <i>P</i> &lt; 0.05.</p> Results <p>There was a significant correlation between MRN image results and clinical symptoms, with MRN visual observation showing 91.7% sensitivity and 50.0% specificity. T2 values of the postganglionic segment on the compressed side and the uncompressed side were 76.04 ± 12.82 ms and 68.91 ± 12.24 ms. The difference in T2 values between compressed nerves and uncompressed segments correlated positively with leg numbness VAS scores (<i>r</i> = 0.35, <i>P</i> = 0.045). T2 values differed significantly between high and non-high signal groups (t = -2.57, <i>P</i> = 0.015).</p> Conclusion <p>MRN and quantitative data from T2 mapping can help in assessing nerve edema and provide a basis for clinical management.</p>