Clinical significance of post-interventional cerebral hyperdensities after endovascular mechanical thrombectomy in acute ischaemic stroke

Abstract

PCHD was not a risk factor for parenchymal haemorrhage in our series. The occurrence of PCHD was strongly related to the prior presence of infarction. PCHD was also a strong predictor for final infarction size.

MRI Appearance of Intracerebral Iodinated Contrast Agents: Is It Possible to Distinguish Extravasated Contrast Agent from Hemorrhage?

“…Discriminating between hemorrhage and contrast agent with the help of conventional CT is usually based on thresholds and cutoffs, assuming that hemorrhage persists after 24 hours and does not exceed 90 HU. 2 However, systematic studies, which aimed to validate the value of attenuation cutoffs or the 24-hour cutoff, are lacking to date. 2 Thus such cutoffs and thresholds may only serve as a rule of thumb, on which clinically relevant decisions should not be based.…”

“…2 However, systematic studies, which aimed to validate the value of attenuation cutoffs or the 24-hour cutoff, are lacking to date. 2 Thus such cutoffs and thresholds may only serve as a rule of thumb, on which clinically relevant decisions should not be based. 2 Recent studies dealing with dual-energy CT imply that it is possible to distinguish contrast extravasation from hemorrhage by using this method.…”

“…2 Thus such cutoffs and thresholds may only serve as a rule of thumb, on which clinically relevant decisions should not be based. 2 Recent studies dealing with dual-energy CT imply that it is possible to distinguish contrast extravasation from hemorrhage by using this method. 1,3 However, the limited availability of these scanners remains a relevant hurdle in daily clinical practice.…”

“…There is uncertainty about the true nature of postinterventional cerebral hyperattenuation, specifically the extent to which postinterventional cerebral hyperattenuations correspond to hemorrhage or extravasation of iodinated contrast agent into infarcted parenchyma. [1][2][3][4] In theory, hemorrhage can be distinguished from iodinated contrast agents via MR imaging, given that blood degradation products are paramagnetic and cause specific changes on T2WI and T2 * WI, whereas iodine is diamagnetic. However, it has been shown in phantom models that at a field strength of 1.5T, side chains of iodinated contrast agents cause T1 and T2 shortening, which theoretically may mimic the imaging characteristics of intracellular methemoglobin present in early subacute intracerebral hemorrhage.…”

Arteriovenous shunts and capillary blush as an early sign of basal ganglia infarction after successful mechanical intra-arterial thrombectomy in ischaemic stroke

“…The second sign, u s u a l l y a c c o m p a n i e d w i t h t h e f i r s t o n e , i s a (pseudo-)arteriovenous shunt, resulting in the early visibility of the terminal vein -the so-called early venous drainagewhich drains into the vein of Galen [14]. In some cases, staining of the basal ganglia on post-therapeutic CT images was observed and described as post-interventional cerebral hyperdensity (PCHD) [15].…”