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Original research
Falsely normal CT perfusion ischemic core readings are common and often associated with deep infarcts
  1. Mehdi Bouslama1,
  2. Krishnan Ravindran2,
  3. Gabriel Martins Rodrigues3,4,
  4. Leonardo Pisani5,
  5. Diogo C Haussen3,4,
  6. Michael R Frankel3,4,
  7. Raul G Nogueira3,4
  1. 1 Neurology, Weill Cornell Medicine, New York, NY, USA
  2. 2 Neurosurgery, Mayo Clinic, Jacksonville, FL, USA
  3. 3 Marcus Stroke and Neuroscience Center, Grady Memorial Hospital, Atlanta, Georgia, USA
  4. 4 Department of Neurology, Emory University School of Medicine, Atlanta, Georgia, USA
  5. 5 Radiology, St Vincent Hospital, Worcester, MA, USA
  1. Correspondence to Dr Raul G Nogueira, Neurology and Interventional Neuroradiology, Emory University School of Medicine, Atlanta, Georgia, USA; nogueirarg{at}


Background Proper identification of infarct extent is crucial for thrombectomy and prognostication. We sought to study the frequency and topographic aspects of those cases in which CT perfusion (CTP) misses a core lesion that is present on initial non-contrast CT (NCCT).

Methods A review was carried out of a prospectively collected database of endovascular patients with anterior circulation large vessel occlusion strokes from January 2014 to November 2018. Patients with an e-ASPECTS <10 and adequate CTP maps were included. Total missed ischemic core (TMC) was defined as a CTP core lesion (relative cerebral blood flow <30%) <1 mL with a visualized hypodensity on NCCT.

Results In total, 629 patients were analyzed of which 161 (25.6%) had a TMC. On univariate analysis, TMC was associated with isolated deep middle cerebral artery (MCA) strokes (77.6% vs 56.6%, p<0.001), lower National Institutes of Health Stroke Scale (NIHSS) score (9 (15–20) vs 17 (13–21), p=0.007) and longer times to treatment (452 (288–652) min vs 355 (236–655) min, p=0.03). After adjusting for identifiable confounders, isolated deep MCA stroke was an independent predictor of TMC (OR 2.49 (95% CI 1.63 to 3.8), p<0.001). There were no differences between patients presenting with a TMC and those not with good outcomes (modified Rankin Scale 0–2) (50.8% vs 47.6%, p=0.53) or 90-day mortality (23% vs 17.6%, p=0.17). However, TMC was associated with lower rates of any parenchymal hematomas (5.2% vs 14.6%, p=0.02; aOR 0.11 (95% CI 0.01 to 0.91), p=0.04) and smaller final infarct volumes (20.5 (11.3–42.9) mL vs 47.5 (20.3–85) mL, p<0.001).

Conclusions CTP may completely fail to detect ischemic core in as many as 25% of cases, especially in isolated deep MCA strokes. Technical refinements of the post-processing algorithms are therefore warranted. TMC infarcts may have a lower risk of reperfusion hemorrhage, potentially due to greater preservation of the neurovascular unit structure in face of delayed recovery of cerebral blood flow.

  • thrombectomy
  • CT perfusion
  • CT
  • stroke

Data availability statement

Data are available upon reasonable request. The unpublished data from this dataset is held by Grady Memorial Hospital/Emory University and MB/RGN. Requests for data sharing would have to be discussed with them directly.

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Data availability statement

Data are available upon reasonable request. The unpublished data from this dataset is held by Grady Memorial Hospital/Emory University and MB/RGN. Requests for data sharing would have to be discussed with them directly.

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  • Contributors Study design: MB, RGN. Data collection, analysis, and interpretation: MB, KR, GMR, LP, DCH, MRF, RGN. Drafting the original manuscript: MB. Revising the work critically for important intellectual content: MB, KR, GMR, LP, DCH, MRF, RGN. Final approval: MB, KR, GMR, LP, DCH, MRF, RGN. Agreement to be accountable for all aspects of the work: MB, KR, GMR, LP, DCH, MRF, RGN. Guarantor of the work is RGN.

  • Funding The authors have not declared a specific grant for this research from any funding agency in the public, commercial or not-for-profit sectors.

  • Competing interests MB, KR, GMR, LP, MRF: no disclosures. DCH reports being a consultant for Stryker, Vesalio, Cerenovus, and Jacobs Institute and holding stock options with VizAi during the conduct of the study. RGN reports consulting fees for advisory roles with Anaconda, Biogen, Cerenovus, Genentech, Hybernia, Imperative Care, Medtronic, Phenox, Philips, Prolong Pharmaceuticals, Stryker Neurovascular, Shanghai Wallaby, Synchron, and stock options for advisory roles with Astrocyte, Brainomix, Cerebrotech, Ceretrieve, Corindus Vascular Robotics, Vesalio, Viz-AI, RapidPulse and Perfuze. RGN is one of the Principal Investigators of the “Endovascular Therapy for Low NIHSS Ischemic Strokes (ENDOLOW)” trial. Funding for this project is provided by Cerenovus. RGN is an investor in Viz-AI, Perfuze, Cerebrotech, Reist/Q’Apel Medical, Truvic, and Viseon.

  • Provenance and peer review Not commissioned; externally peer reviewed.

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