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Updated: Jul 4, 2026
Diffusion Tensor Magnetic Resonance Imaging in Chronic Spinal Cord Compression
Published on: May 7, 2019
Chronic cystic lesion of the sacrum: characterisation with diffusion-weighted MR imaging
R Manara1, M Severino, R Mandari
1Neuroradiologic Unit, University of Padua, Via Giustiniani 2, 35128 Padova, Italy. renzo.manara@sanita.padova.it
Purpose:
Sacral bone remodelling with abnormal dilatation of intervertebral foramina is usually associated with Tarlov cysts but can be caused by slow-growth lesions, which also may present cerebrospinal-fluid (CSF)-like signal or density. We describe three patients with a similar history of lower back pain presenting CSF-like density/signal lesions with extensive sacral bone remodelling who were affected by a Tarlov cyst, an epidermoid cyst and a giant neurofibroma, respectively.
Materials And Methods:
Magnetic resonance imaging (MRI) studies were performed with 1.0-T magnet; axial and sagittal pre- and postcontrast T1-and T2-weighted images were obtained. Moreover, axial and sagittal diffusion-weighted (DWI) echoplanar images were produced, and corresponding apparent diffusion coefficient (ADC) values were calculated. ADC values were measured within the lesions on axial images.
Results:
All lesions presented a CSF-like signal on conventional MRI. The Tarlov cyst was hypointense on DWI with high ADC values (2,793 s/mm(2)+/-137). The epidermoid cyst proved to be markedly hyperintense on DWI, with reduced ADC values (855 s/mm(2)+/-109). The neurofibroma was isointense on DWI, with ADC values not compatible with CSF (1,467 s/mm(2)+/-130).
Conclusions:
DWI and ADC values seem to be able to clearly differentiate Tarlov cysts from slow-growth lesions, allowing for adequate treatment.
