Sensitivity of New-generation Computed Tomography in Subarachnoid Hemorrhage
Article first published online: 29 SEP 2008
© 1996 Society for Academic Emergency Medicine
Academic Emergency Medicine
Volume 3, Issue 1, pages 16–20, January 1996
How to Cite
Sames, T. A., Storrow, A. B., Finkelstein, J. A. and Magoon, M. R. (1996), Sensitivity of New-generation Computed Tomography in Subarachnoid Hemorrhage. Academic Emergency Medicine, 3: 16–20. doi: 10.1111/j.1553-2712.1996.tb03296.x
- Issue published online: 29 SEP 2008
- Article first published online: 29 SEP 2008
- Received: May 21, 1995; revision received: August 1, 1995; accepted: August 4, 1995; updated: August 31, 1995.
- subarachnoid hemorrhage;
- computed tomography;
- intracranial hemorrhage;
- cerebrovascular accident;
- lumbar Duncture
Objective: To determine the sensitivity of the initial new-generation CT (NGCT) scan interpretation for detection of acute nontraumatic subarachnoid hemorrhage (SAH) and to decide whether lumbar puncture (LP) should follow a “normal” NGCT scan.
Methods: A retrospective chart review was performed of patients admitted between March 1988 and July 1994 with proven SAH. Exclusion criteria were age <2 years, diagnosis other than acute SAH, history of head trauma within 24 hours before symptom onset, NGCT scan not done before diagnosis, and records not available. Patients were placed into two groups: symptom duration <24 hours (group 1) and >24 hours (group 2) prior to CT scan. The resolution of each NGCT scanner was recorded. An NGCT sceinner was defined as a third-generation scanner or more recent.
Results: Of 349 SAH patients, 181 met inclusion criteria. The sensitivity of NGCT scans for SAH was 93.1% for the group 1 patients (n = 144) and 83.8% for the group 2 patients (n = 37). The overall sensitivity was 91.2%. All the patients who had SAH not detected by NGCT scans were diagnosed by LP. There was no significant relationship between NGCT scanner resolution and sensitivity for SAH.
Conclusion: Initial interpretation of NGCT scans to detect SAH does not approach 100% sensitivity. A “normal” NGCT scan does not reliably exclude the need for LP in patients who have symptoms suggestive of SAH.