instruction: what is the number of hours passed since patient 010-21105 had a last mri - head in this hospital visit?
response: SELECT 24 * (STRFTIME('%j', CURRENT_TIME()) - STRFTIME('%j', treatment.treatmenttime)) FROM treatment WHERE treatment.patientunitstayid IN (SELECT patient.patientunitstayid FROM patient WHERE patient.patienthealthsystemstayid IN (SELECT patient.patienthealthsystemstayid FROM patient WHERE patient.uniquepid = '010-21105' AND patient.hospitaldischargetime IS NULL)) AND treatment.treatmentname = 'mri - head' ORDER BY treatment.treatmenttime DESC LIMIT 1