Editorial for “USPIO‐SWI Shows Fingolimod Enhanced Alteplase Action on Angiographic Reperfusion in eMCAO Rats”

Editorial for “USPIO-SWI Shows Fingolimod Enhanced Alteplase Action on Angiographic Reperfusion in eMCAO Rats” Angiography is a diagnostic imaging technique utilized to visualize blood vessels. It is typically executed by introducing a contrast agent into the blood vessel and imaging it via magnetic resonance angiography (MRA). Currently, an ischemic stroke is either treated with thrombectomy or intravenous alteplase capable. Compared to these two approaches, we see that thrombectomy is developing and spreading from highly specialized medical centers to primary stroke centers. On the other hand, reperfusion with the administration of intravenous recombinant tissue-type plasminogen activator is being used less and less. Therefore, experiment 2 in this study, treatment of fingolimod and tissue plasminogen activator (tPA), is seen as not so perspective as experiment. Nevertheless, after any procedure, it is necessary to evaluate the effectiveness of extraction and estimate infarct volume and infarct evolution compared with baseline. So, the information about the blood flow in small vessels can be significant after thrombolysis as well as thromboextraction. Even though the magnetic resonance imaging (MRI) technique is the most developed area presently, the issue of small arterioles detection is still open. A gadolinium contrast agent is widely used in clinical practice. We cannot evaluate small vessels without contrast or using gadolinium contrast. Of course, we use perfusion for this purpose, but MRI perfusion has many limitations. Additionally, we know that gadolinium contrast can cause nephrogenic sclerosis and gadolinium deposition in the brain. Therefore, physicians are questioning the use of gadolinium chelates and are actively seeking alternatives. Susceptibility weighted imaging (SWI) is known to be inefficient for detecting small arterioles either, but we can use an iron-based contrast agent enhanced to improve visualization of small vessels. According to contemporary studies, iron oxide does not extravasate in tissue. Therefore, it is potentially interesting for angiography and small vessels. It has a good perspective for angiography and diseases underlined with neovasculogenesis (eg, tumor or atherosclerosis), inflammation, and vascular malformations. Thus, one of the most exciting areas for scientists is ultrasmall superparamagnetic iron oxide enhanced susceptibility weighted imaging (USPIO-SWI). In the future, attention must probably be paid to the dose of iron oxide because a high dose can lead to artifacts mimicking thrombosis. Moreover, this study is an excellent example of moving in this direction. Furthermore, iron oxide is used in clinical practice in patients with anemia; therefore, patients’ medication must be considered. The impact of USPIO biodegradation on T2 and T2* signals is a field of future study further. In this study, the authors compared the visualization arterioles to Phase/SWI without USPIO administration and the visual cortical vessels with USPIO administration. The number of visual cortical vessels significantly increased on Phase/SWI with USPIO. The authors utilized different doses of USPIO and tried to find the dose that would show small arterioles best. This study showed that the dosage of 16.8 mg/kg USPIO provided better visualization of cortical penetrating arteries in an ischemic stroke. Additionally, the authors estimated that arterial visualization was barely visible after 12 h and completely disappeared after 24 h. Therefore, USPIO can be reused to evaluate arterial visualization after 24 h from vascular events. All the above analyses are important for future studies. One limitation of the study is the relatively low number of analyzed cases. Overall, the study provides valuable data and takes one step forward to impact USPIO in the clinical practice of cerebrovascular disease.