What Does This Spinal CT Scan On Thecal Compression Mean?

Hi, had a CT scan of lumbar area findings are: L4/5 broad based diffused disc bulge producing moderate thecal compression and bilateral inferior neural foraminal narrowing. Bilateral facetal hypertrophy is seen. L5/S1: small central disc bulge indenting on the epidural fat. No foraminal compromise. Mild bilateral facetal hypertrophy is noted. I have loss of bladder and bowel tone the Dr. may want to image the thoracolumbar spine with MRI to rule our any cord contusion. I suffered an injury to L4/L5 prolapsed disc in 2002. could you please explain what this means. thank you