The authors investigated clinician transactions against the Digital Imaging and Communications in Medicine (DICOM) archive within a clinical image management system (CIMS) in support of patient care. A Neurosurgical Oncology practice was audited for image utilization. There were 400 requests for 233 image studies during 297 sessions. Fifty percent were for current studies, and 50% were for historical studies. Current studies alone were requested in 37% of the sessions, current plus historical in 31%, and historical alone in 32% of the sessions. Seventy percent of studies were within 8 weeks old and were rapidly available from the CIMS disk cache without an archive image transaction. Conversely, 30% were older than 8 weeks, requiring a clinician transaction against the archive for image retrieval. Approximately 25% of studies were older than 3 months and 10% older than 6 months. Clinician image needs are complex and any CIMS solution must include a DICOM archive that can support clinician-based transactions.