FDCT-augmented reperfusion assessment may provide additional tissue-relevant information after EVT by identifying residual vessel occlusions associated with larger final infarct volume.
DOT signs on flat-panel detector CT were identified in 43% of EVT-treated patients with TICI ≥ 2b reperfusion.
FDCT-augmented TICI grading reclassified more patients as having incomplete reperfusion compared to operator-graded TICI.
Incomplete reperfusion defined by FDCT-augmented TICI was significantly associated with larger final infarct volume, whereas operator-defined incomplete reperfusion was not.
The model incorporating FDCT-augmented TICI explained slightly more variance in final infarct volume than the model using operator-graded TICI.
Flat-panel detector CT with DOT sign assessment identifies residual vessel occlusions that are underestimated by conventional angiography after endovascular thrombectomy.
This research suggests that using a specialized imaging technique called flat-panel detector CT (FDCT) immediately after a stroke procedure can provide a more accurate picture of how well blood flow has been restored than the standard visual assessment doctors typically make during the procedure. In a study of 200 stroke patients who underwent endovascular thrombectomy (a procedure to remove blood clots from brain arteries), FDCT identified small residual clots — called 'DOT signs' — in 43% of patients, even though standard angiography suggested these patients had adequate reperfusion. When these FDCT findings were incorporated into reperfusion grading, 17 additional patients were reclassified as having incomplete reperfusion compared to standard operator assessment. The practical significance is that incomplete reperfusion defined using FDCT-augmented grading was meaningfully linked to a larger area of permanent brain damage (final infarct volume), with an estimated difference of 24 mL compared to patients with better reperfusion. In contrast, incomplete reperfusion defined by the standard operator assessment alone was not significantly associated with larger brain damage. The FDCT-based model also explained slightly more of the variation in brain damage volume (adjusted R² of 0.256 vs. 0.239). This research suggests that adding FDCT imaging at the end of a stroke intervention could help clinicians more precisely identify patients who still have residual blockages and who may go on to have worse outcomes, even when the procedure initially appears successful. This could potentially guide decisions about further treatment steps. The study was retrospective, so future prospective research is needed to confirm whether acting on these FDCT findings improves patient outcomes.
Koge J, Hashimoto T, Suyama K, Tanaka K, Kuwahara K, Fujiwara E, et al.. (2026). Refining reperfusion assessment with flat-panel detector CT: association with final infarct volume after endovascular thrombectomy.. European stroke journal. https://doi.org/10.1093/esj/aakag104