Adjunctive Flat Panel CT-Based Reperfusion Grading after Endovascular Therapy: Enhanced Detection of Residual Distal
Sung Hyun Baik1, Cheolkyu Jung2, Jun Yup Kim3
1From the Department of Radiology (S.H.B., C.J.), Seoul National University Bundang Hospital, Seongnam, Republic of Korea.
Background And Purpose:
The detection of residual distal vessel occlusion is crucial for the evolution of endovascular therapy (EVT) outcomes. This study evaluated whether distal occlusion tracker signs on immediate postprocedural flat panel CT (FPCT) could assist in the detection of residual distal vessel occlusion in patients with acute ischemic stroke due to large-vessel occlusion after thrombectomy.
Materials And Methods:
A single-center retrospective analysis was conducted on patients with anterior circulation large-vessel occlusion who achieved successful reperfusion, defined as a modified TICI score of ≥2b, following EVT and underwent immediate postprocedural FPCT and perfusion MRI. Two reviewers, blinded to the clinical data and perfusion findings, independently assessed the presence, number, and location of distal occlusion tracker signs on FPCT and the final reperfusion state on cerebral DSA. Distal occlusion tracker signs were defined as dotlike, round, or tubular hyperdensities along the course of the distal intracranial arteries on immediate postprocedural FPCT. Two data sets were compared using DSA alone and DSA combined with FPCT. A core laboratory determined the TICI grading and residual distal occlusion using both DSA and postprocedural perfusion MRI as reference standards.
Results:
The distal occlusion tracker sign was present in 65/156 patients (41.7%), with excellent interrater agreement (weighted κ = 0.91; 95% CI, 0.85-0.96). Distal occlusion tracker signs demonstrated a sensitivity and specificity of 81.5% and 96.2%, respectively. The diagnostic accuracy in detecting residual distal occlusion was greater with the addition of FPCT findings to DSA than with DSA alone (the area under the curve increased from 0.884 to 0.955, P = .009). Reperfusion grading overestimation decreased from 17.9% with DSA alone to 3.8% with the addition of FPCT to DSA.
Conclusions:
Distal occlusion tracker signs are common findings on immediate postprocedural FPCT, indicating residual distal vessel occlusion. The addition of FPCT findings to DSA may enhance the detection of residual distal vessel occlusion after EVT.
