Magnetic resonance imaging of the head and spine: effective for the clinician or the patient? OBJECTIVES--To test how the results of magnetic resonance imaging influence clinicians' diagnoses and management plans for patients with cranial and spinal problems and to assess changes in the quality of life of these patients. DESIGN--Survey of patients undergoing cranial and spinal magnetic resonance imaging with questionnaires about diagnoses and intended management plans before and after imaging and quality of life questionnaires at the time of imaging and again four months later. SETTING--Regional magnetic resonance imaging and spectroscopy unit. SUBJECTS--100 consecutive patients referred for cranial imaging in early 1989; 100 similar patients referred for spinal imaging. MAIN OUTCOME MEASURES--Changes in clinicians' leading diagnoses after magnetic resonance imaging and their confidence in these diagnoses; changes in intended management plans; assessment of the contribution to the future management of the patient; changes in patients' quality of life. RESULTS--Magnetic resonance imaging altered the clinicians' leading diagnoses in 35 of 169 (21%) cases. The clinicians became more confident about their leading diagnoses in 90 of 167 (54%). There was a change in management plan in 113 of 182 (62%). The clinicians considered that magnetic resonance imaging made an important contribution to management in 119 of 162 (73%) patients. Overall, the patients' quality of life was unchanged at the four month assessment. CONCLUSIONS--Magnetic resonance imaging of patients with cranial and spinal problems influences clinicians' diagnoses and management plans, but the quality of life of these patients remains unchanged. 