Abstract W P31: Does Portable CT Imaging in a Mobile Stroke Treatment Unit (MSTU) Provide Adequate Quality for Early Critical Decision Making?
BACKGROUND: Our hospital implemented a Mobile Stroke Treatment Unit (MSTU) on July 18, 2014 involving a pre-hospital delivery of stroke thrombolysis. The MSTU team evaluates potential IV tPA candidates using a portable CT head (pCTH) scan in the field. OBJECTIVE: To determine adequacy of MSTU CT quality for early ischemic changes and IV tPA administration. METHODS: A retrospective analysis was performed of patients approached by MSTU who received a pCTH (CereTom, Neurologica, Danvers, MA). Assessment of quality, artifacts, physician confidence and findings (intracranial hemorrhage (ICH), early ischemic changes using Alberta Stroke Program Early CT score (ASPECTS)) was performed. Two neurologists with ASPECTS certification and blinded to patient history reviewed images independently. Inter-rater agreement and Spearman’s correlation of numeric variables between the two reviewers were compared. For comparison inter-rater reliability, control CT scans performed in emergency department (ED) for early stroke evaluation in different sets of 20 patients were assessed by two reviewers. RESULTS: A total of 23 patients underwent pCTH in the MSTU since initiation. Two patients were found to have ICH, later confirmed by a standard hospital CT scan. The remaining 21 patients did not have any evidence of ICH, 10 (48%) of whom had a subsequent hospital CT or MRI confirming absence of ICH. pCTH quality was assessed to be adequate in 18 (85%) subjects by both reviewers to make decisions on thrombolysis treatment. CT artifacts were noted in 15 (71%) scans by reviewer 1 and 16 (76%) scans by reviewer 2 (k 0.4, p=0.2). ASPECTS on pCTH did not have high correlation between two raters (spearman’s rho=0.3, p=0.1). Confidence of ASPECTS was low in both reviewers (52% reviewer 1 vs 66% reviewer 2). In comparison, correlation between ED controls was better between the two reviewers (spearman’s rho= 0.6, p=0.01). Confidence of ASPECT score was high for both reviewers in the control group (95% reviewer 1; 100% reviewer 2). Artifacts were noted in few scans of controls (n=5, 25% reviewer 1; n=3, 15%, reviewer 2). CONCLUSION: The quality of pCTH on the MSTU is adequate for thrombolysis contraindications, but artifacts are common and subtle early ischemic changes are difficult to assess.
Author Disclosures: L. Sheikhi: None. A. Itrat: None. R. Cerejo: None. A. Taqui: None. M. Buttrick: None. M. Stecker: None. S. Winners: None. P. Ruggieri: None. M. Donohue: None. P. Rasmussen: Ownership Interest; Significant; Blockade Medical. M. Hussain: None. K. Uchino: None.
- © 2015 by American Heart Association, Inc.