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/mm2±137). The epidermoid cyst proved to be markedly hyperintense on DWI, with reduced ADC values (855 s/mm2±109). The neurofibroma was isointense on DWI, with ADC values not compatible with CSF (1,467 s/mm2±130). Conclusions. DWI and ADC values seem to be able to clearly differentiate Tarlov cysts from slow-growth lesions, allowing for adequate treatment.
|Translated title of the contribution||Chronic cystic lesion of the sacrum: Characterisation with diffusion-weighted MR imaging|
|Number of pages||8|
|Publication status||Published - Aug 2008|
ASJC Scopus subject areas
- Radiology Nuclear Medicine and imaging