Abstract： Objective To compare the diagnostic value between spinal MR myelography (MRM) and intrathecal Gadolinium MR myelography (GdM) in detecting spinal cerebrospinal fluid (CSF) leaks of spontaneous intracranial hypotension (SIH). Methods Retrospective analysis of imaging findings in 158 cases with SIH was performed. Both MRM and GdM were available in 24 cases, and MRM was performed first, followed by GdM within one week. Morphological abnormalities of nerve root, CSF leaks along the nerve roots, and abnormal CSF collections were observed and compared between the two methods by using McNemar statistics and Kappa test statistics. Results Morphological abnormalities of nerve root were detected in 176 lesions on GdM and 163 lesions on MRM, respectively, and GdM was more sensitive in the detection of morphological abnormalities of nerve root (χ2=6.26,P=0.011). CSF leaks along nerve roots were identified in 15 patients on both GdM and MRM while in 5 cases on neither GdM nor MRM, and identified in 4 patients on GdM but not on MRM. CSF leaks along the nerve roots were detected in 67 lesions on GdM and 55 lesions on MRM, respectively, and GdM was more sensitive in the detection of CSF leaks along nerve (χ2=6.05,P=0.012). MRM and GdM showed good consistency(Kappa =0.837,P=0.001)in detecting CSF leaks for patients with SIH. Six and 14 lesions of abnormal CSF collections in bony rims of spines were respectively detected by GdM and MRM, 12 and 28 lesions of abnormal CSF collections in bony rims of the ribs were respectively detected by GdM and MRM. MRM was more sensitive in the detection of abnormal CSF collections in bony rims of the spines and the ribs(χ2=6.13 ,14.06 ,P=0.008 ,0.001). Eleven and 10 lesions of CSF collections in epidural space were respectively detected by GdM and MRM, 1 and 3 lesions of CSF collections of C1—2 retrospinal space were respectively detected by GdM and MRM. No statistically significant differences existed between MRM and GdM in detecting CSF collections of epidural space and C1—2 retrospinal space (χ2=0.01,0.50,P=1.000,0.500). Conclusions MRM and GdM have their respective advantages in detecting spinal CSF leaks along the nerve roots, morphological abnormalities of nerve root and abnormal CSF collections. MRM combined with GdM can provide more information in localizing spinal CSF leaks for patients with SIH.