Review Question - QID 213660

A 55-year-old man presents to the emergency department after a motor vehicle accident. He was the restrained front seat driver in a head-on collision. The patient denies head impact or loss of consciousness but states that he is currently in pain. An initial exam in the trauma bay demonstrates 3/5 strength bilaterally in the patient’s lower extremities. The patient has a symmetric loss of sensation in the groin area and an absent Achilles reflex with 2+ patellar reflexes. A bedside ultrasound demonstrates a distended bladder with 900 mL of urine; however, the patient is unable to urinate on his own. The patient is sent for an emergent MRI. Which of the following is the most likely diagnosis?