PMC4712210_01
Magnetic resonance imaging of the thoraco-lumbar spine at diagnosis: unenhanced T2-weighted (a), short tau inversion recovery (STIR) (b), diffusion-weighted (DW) (c), apparent diffusion coefficient (ADC) map (d), and T1-weighted (e) sagittal and T2-weighted axial (g) images, and gadolinium-enhanced T1-weighted sagittal (f) and axial (h) images. At the thoracolumbar junction, a posterior median-left paramedian epidural collection compressing the caudal spinal cord, conus medullaris, and upper cauda equina is clearly evident. The lesion shows irregular signal intensity on unenhanced conventional sequences (a, b, and e, black arrows), restricted diffusion on DW images and ADC map (c, d, white arrows), and peripheral gadolinium-enhancement (f, h). Note also that the lesion shows extent toward the left intervertebral foramen (g, h, arrow head). STIR image does not show associated abnormal signal intensity of the bone marrow.
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Urgent gadolinium-enhanced cerebral and spinal magnetic resonance imaging (MRI) disclosed a large epidural purulent collection in the posterior and median-paramedian left spinal canal, extending from T11 to L2, with mass effect on spinal nerve roots (Fig. 1).
Magnetic resonance imaging follow-up by STIR (upper line) and gadolinium-enhanced fat-suppressed T1-weighted (lower line) sagittal images obtained 24 days after surgery (a) and one month (b), three months (c), and seven months (d) later. Besides complete removal and absence of relapse of the epidural abscess, a clearcut reduction of gadolinium-enhancing reactive changes is evident. Note also the progressive development of kyphosis with fulcrum at L1-L2 level, together with increase of lumbar lordosis.
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On the 21st day, the patient was discharged from hospital with the final diagnosis of SEA by MSSA and with the advice to continue antimicrobial therapy with iv ceftriaxone 2 g daily and oral clindamycin 600 mg tid Lumbar spinal MRI, performed approximately one month after surgery (Fig. 2a, b), showed complete resolution of the abscess and gadolinium-enhancing postoperative reactive changes in the fascial muscular planes. After total 8 months of antimicrobial treatment, lumbar spinal MRI showed further reduction of reactive changes (Fig. 2d), despite development of thoracolumbar kyphosis and lumbar lordosis.