Utility of MRI Enhancement Pattern in Myelopathies With Longitudinally Extensive T2 Lesions

Abstract

ObjectiveTo determine if MRI gadolinium enhancement patterns in myelopathies with longitudinally-extensive T2-lesions can be reliably distinguished and assist in diagnosis.MethodsWe retrospectively identified 74 Mayo Clinic patients (1/1/1996–12/31/2019) fulfilling the following criteria: 1) Clinical myelopathy; 2) MRI spine available; 3) Longitudinally-extensive T2-hyperintensity (≥3 vertebral segments); and 4) Characteristic gadolinium enhancement pattern associated with a specific myelopathy etiology. Thirty-nine cases with alternative myelopathy etiologies, without previously described enhancement patterns, were included as controls. Two independent readers, educated on enhancement patterns, reviewed T2-weighted and post-gadolinium T1-weighted images and selected the diagnosis based on this knowledge. These were compared to the true diagnoses and agreement was measured with Kappa coefficient.ResultsAmong all cases and controls (n=113), there was excellent agreement for diagnosis using post-gadolinium images (Kappa, 0.76) but poor agreement with T2-weighted characteristics alone (Kappa, 0.25). A correct diagnosis was more likely when assessing post-gadolinium image characteristics than with T2-weighted images alone (Rater 1: 100/113 [88%] vs 61/113 [54%] correct, p<0.0001; Rater 2: 95/113 [84%] vs 68/113 [60%] correct, p<0.0001). Of the 74 with characteristic enhancement patterns, 55 (74%) were assigned an alternative incorrect or non-specific diagnosis when originally evaluated in clinical practice, 12 (16%) received immunotherapy for non-inflammatory myelopathies, and 2 (3%) underwent unnecessary spinal cord biopsy.ConclusionsMisdiagnosis of myelopathies is common. The gadolinium enhancement patterns characteristic of specific diagnoses can be identified with excellent agreement between raters educated on this topic. This study highlights the potential diagnostic utility of enhancement patterns in myelopathies with longitudinally-extensive T2-lesions.

Myelin Oligodendrocyte Glycoprotein Antibody-Associated Disease (MOGAD): A Review of Clinical and MRI Features, Diagnosis, and Management

“…Although highly suggestive of MOGAD, these signs are not 100% specific and can be seen in other myelopathies (e.g., acute flaccid myelitis, viral myelitis, idiopathic myelitis) (60,78). Similar to brain lesions, acute gadolinium enhancement is often nonspecific, differing from other myelitis for which characteristic enhancement patterns have been described (e.g., "elongated ring" in AQP4-IgG+NMOSD, dorsal subpial enhancement and "trident sign" in spinal cord sarcoidosis) (78)(79)(80)(81). Leptomeningeal enhancement accompanying the myelitis can occur, and may be more common in children (60).…”

Neuroimaging features in inflammatory myelopathies: A review

“…On the axial plane, it usually extends inward, outlining a trident shape, in the so-called “trident sign” ( 99 ). This pattern of enhancement can be reliably identified amongst a group of myelopathies ( 98 ). A ventral subpial enhancement with a “braid-like” aspect has also been described in patients with sarcoidosis ( 100 ).…”

“…Specific patterns of gadolinium enhancement have proven helpful in the correct identification of the diagnosis associated with longitudinally extensive lesions, as demonstrated by a recent study where, in a blinded setting, a trained neurologist and a trained neuroradiologist were required to identify the diagnosis of 113 cases of longitudinally extensive lesions based on features of T2-weighted and post-gadolinium T1-weighted images. The correct etiology was identified more often using post-gadolinium T1-weighted images (84–88%) when compared to T2 weighted images (54–60%), further highlighting the utility of post-gadolinium images in the evaluation of myelopathy ( 98 ).…”

“…Spinal cord infarction is one of the main mimics of inflammatory myelopathies, and the recognition of this entity is crucial for a prompt and appropriate treatment. The presence of a linear “pencil-like” strip of T2-hyperintensity with corresponding enhancement in the anterior horns of the spinal cord (“owl or snake-eye sign”) may indicate spinal cord infarct ( 98 ). However, this signal abnormality has also been reported in a similar proportion of patients with AQP4+NMOSD, therefore clinical findings must be accurately assessed ( 97 ).…”

Case report: Dueling etiologies: Longitudinally extensive spinal cord lesion mimicking spinal cord infarct with simultaneous positive Lyme serology and amphiphysin antibody

“…The differential diagnosis is broad and includes metabolic, vascular, inflammatory, autoimmune, neoplastic, infective, traumatic, compressive, and idiopathic causes ( 4 ). Identifying the cause of myelopathy is critical, as delay in diagnosis and treatment could lead potentially to severe neurologic deficits ( 5 ).…”