Hyperdensity on non-contrast CT immediately after intra-arterial revascularization

Abstract

Non-contrast enhanced computed tomography (NCCT) is usually performed to estimate bleeding complications immediately after procedures. However, hyperdense areas on NCCT have not yet been understood; different interpretations have been reported in the literature. It remains unclear whether NCCT performed immediately after intra-arterial revascularization (IAR) could be useful for predicting hemorrhagic transformation (HT) or clinical outcomes. Therefore, we investigated the diagnostic values of hyperdense areas on NCCT images obtained immediately after IAR. This was a retrospective study of acute ischemic stroke patients who underwent IAR between October 2007 and December 2010. NCCT scans were routinely obtained immediately after IAR and additional follow-up imaging protocols included diffusion weighted imaging (DWI)/gradient echo imaging (GRE) 24 h after IAR. HT was assessed by means of GRE obtained 24 h after IAR. Hounsfield Unit (HU) of the hyperdensity was measured in the manually drawn regions of interest. A total of 68 patients were analyzed in this study. Twenty-nine patients (42.6%) developed HT on follow-up images. Thirty-eight patients had hyperdense areas on NCCT immediately after IAR. Hyperdensity on NCCT performed immediately after IAR revealed 23 (60.5%) of the 38 patients with six false negative areas. NCCT performed immediately after IAR showed a sensitivity of 79.3%, a specificity of 61.5%, a positive predictive value of 60.5% and a negative predictive value of 80% for HT. The HU value was a predictor of HT without statistical significance (area under curve of 0.629; 95% CI: 0.49-0.76; p = 0.068). In addition, an HU of >90 poorly predicted HT with a low sensitivity (23%) and a high specificity (94%). In conclusion, our results showed that although hyperdensity on NCCT images obtained immediately after IAR had a moderate predictive value for HT, there were limitations to the prediction of subsequent parenchymal hematoma and symptomatic intracranial hemorrhage, with a low specificity and a low positive predictive value.

Predictive value of flat-panel CT for haemorrhagic transformations in patients with acute stroke treated with thrombectomy

“…All patients were followed up with a conventional CT or MRI with a T2* sequence, performed within 24 h of mechanical thrombectomy to detect any haemorrhagic transformation, which was defined as any parenchymal hyperdensity on the 24 h follow-up CT or any hyposignal on the MRI T2* images3 5 13. Haemorrhagic transformations were evaluated in accordance with the ECASS criteria9.…”

“…Immediately after completion of mechanical thrombectomy, in most institutions, a non-enhanced CT scan is performed to assess potential haemorrhagic complications4 5. In our institution, we perform a CT-like control at the end of the treatment with a C-arm-mounted flat-panel detector immediately after completion of the procedure, on the angiography table.…”

Relevance of Blood–Brain Barrier Disruption After Endovascular Treatment of Ischemic Stroke

“…9 However, in the early post-ET period, this distinction is not feasible using conventional post-treatment CT. [2][3][4][5]10 Dual-energy CT (DE-CT) is a relatively new technique that allows for a reliable differentiation between tissue high attenuation areas related to iodine contrast material extravasation and parenchymal hemorrhage.11-13 The technique is based on the different attenuation effects of normal brain tissue, iodine, and blood at different irradiation energy levels. In patients receiving ET, DE-CT has shown a good accuracy for early differentiation between hemorrhage and contrast extravasation, but these studies did not address specifically the prognostic implications of this segregation.…”

“…9 However, in the early post-ET period, this distinction is not feasible using conventional post-treatment CT. [2][3][4][5]10 Dual-energy CT (DE-CT) is a relatively new technique that allows for a reliable differentiation between tissue high attenuation areas related to iodine contrast material extravasation and parenchymal hemorrhage.…”

Evaluation of the CT High-density Area after Endovascular Treatment for Acute Ischemic Stroke

“…After excluding one article not providing details of the recanalization procedure, a total of 705 patients consisting of those reported in the remaining 13 articles and our patients were analyzed. [10][11][12][16][17][18][19][20][21][22][23][24][25] Concerning the recanalization procedure, the method for endovascular treatment differed after the report in 2012, and the treatments described in the 13 reports that we reviewed were IAT or clot disruption alone before 2012 and mechanical thrombectomy alone after 2012. IV-tPA was performed concomitantly in both groups.…”