A threshold of > 4 s delay for the maximum of the tissue residue function (Tmax) has historically defined tissues with likely benign oligemic delay, whereas ischemic territories with “tissue at risk” and “malignant hypoperfusion” have been assigned Tmax > 6 s and Tmax > 10 s thresholds, respectively. The total hypoperfused tissue volume was defined by the utilization of varying thresholds. Cine mode acquisition (kV 80, auto-mA 100) permitting high temporal resolution (60 s sampling window and continuous 1 s sampling interval) dynamic bolus passage imaging was obtained following the administration of iodinated contrast.
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Two contiguous CTP slabs were obtained for 8 cm of combined coverage of the supratentorial brain, obtained at 8 five-millimeter slices per slab.
ICAD NEUROLOGY SOFTWARE
ImagingĬTP was post-processed in a fully automated, commercially available software environment (RAPID version 4.5.0, iSchemaView, CA, USA). Tandem extracranial carotid occlusions and intracranial occlusions were excluded to minimize the delay and dispersion effects of extracranial steno-occlusive lesions upon dynamic bolus passage. Patients with a technically adequate CTP and an intracranial ICA, MCA-M1 or M2 occlusion were included.
![icad neurology icad neurology](https://img.yumpu.com/27118231/1/500x640/events-diary-touch-neurology.jpg)
This was a retrospective review of a prospectively collected database of acute LVOS undergoing endovascular therapy spanning September 2010 to March 2015. We aim to determine if signature profiles on baseline CTP can predict the presence of underlying ICAD in LVOS. We have anecdotally observed that patients with large vessel occlusion acute stroke (LVOS) due to ICAD have more benign automated CT perfusion (CTP) profiles, which we presume may potentially reflect greater, chronic collateralization recruitment in comparison to embolic LVOS. Unfortunately, there are no established biomarkers for ICAD and the lack of an adequate surrogate on noninvasive imaging makes procedural planning challenging. Conclusion: An automated CTP Tmax > 4 s/Tmax > 6 s ratio ≥2 profile was found independently associated with underlying ICAD LVOS.Ĭerebral thrombectomy is technically challenging in patients with underlying intracranial atherosclerotic disease (ICAD). Multivariate logistic regression revealed that Tmax > 4 s/Tmax > 6 s ratio ≥2 (OR 3.75, 95% CI 1.05–13.14, p = 0.04), higher LDL cholesterol (OR 1.1, 95% CI 1.01–1.03, p = 0.01), and higher systolic pressure (OR 1.03, 95% CI 1.01–1.04, p = 0.01) were independently associated with ICAD. Clinical outcomes were comparable amongst groups.
![icad neurology icad neurology](https://neurology.mect.cuhk.edu.hk/images/research/2021-ICAD.jpg)
A Tmax > 4 s/Tmax > 6 s ratio ≥2 showed specificity = 73%/sensitivity = 52% for ICAD and was observed in 47.6% of ICAD versus 26.1% of non-ICAD patients ( p = 0.07). Ischemic core (relative cerebral blood flow 4 s, Tmax > 6 s, and Tmax > 10 s absolute lesions, and a higher ratio of Tmax > 4 s/Tmax > 6 s volumes (median 2 vs. Patients with intracranial ICA/MCA-M1/M2 occlusions and CTP were dichotomized into ICAD versus non-ICAD etiologies. Methods: Retrospective review of a prospectively collected interventional stroke database from September 2010 to March 2015. We aim to determine if CTP profiles can predict ICAD in LVOS. Background and Purpose: We have observed that large vessel occlusion acute strokes (LVOS) due to intracranial atherosclerotic disease (ICAD) present with more benign CT perfusion (CTP) profiles, which we presume to potentially represent enhanced collateralization compared to embolic LVOS.