Povezovanje računalniško-tomografskih in magnetno-resonančnih lastnosti umetnih krvnih strdkov na modelu možganske cirkulacije

Viltužnik, Rebeka (author), Serša, Igor (mentor), Vidmar, Jernej (comentor)

Uvod in pregled literature: Neravnovesje v delovanju hemostaze lahko povzroči možgansko kap, ki spada med najpogostejše vzroke smrti in invalidnosti. Ishemično možgansko kap povzročajo trombi, katerih lastnosti vplivajo na izid zdravljenja. Optimiziranje protokola obravnave kapi je nujno za boljši izid zdravljenja, kjer za slikovno diagnostiko večinoma uporabljamo CT, čeprav se je MR izkazal za boljšo metodo. Ne glede na slikovno diagnostiko doslej ta ni dajala poudarka ugotavljanju lastnosti trombov. Cilj in namen raziskave: Z namenom nadaljnjega optimiziranja protokola obravnave kapi, smo raziskali možnost CT in MR meritev za definicijo strukture umetnih trombov, hkrati smo želeli ugotovitve umestiti tudi v klinično okolje, kjer smo opazovali povezave med CT in MR lastnostmi zapore ter kliničnimi parametri in parametri zdravljenja dejanskih pacientov. Metode in materiali: Najprej, smo preiskovali učinkovitost MR in CT analize pri definiranju strukture umetnih trombov. V kliničnem delu so bili obravnavani pacienti s potrjeno ishemično možgansko kapjo, kjer so uspešno odstranili trombe in jih analizirali z MR ter histološko. Od pacientov smo pridobili še klinične podatke in podatke zdravljenja ter obdelali CT slike, kjer smo pridobili in vivo meritve CT števil trombov. Vse smo ustrezno statistično obdelali. Rezultati in Razprava: MR difuzijske in CT meritve pri umetnih trombih so uspešno razlikovale med eritrocitnimi in trombocitnimi trombi, hkrati so bile vse meritve občutljive na spremembe v deležu eritrocitov. V klinični študiji smo ugotovili pomembne korelacije med variabilnostjo difuzije in trajanjem mehanske rekanalizacije, odstopanjem v povprečnem CT številu in številom prehodov pri trombektomiji, dolžino tromba, deležu eritrocitov in drugimi dejavniki. V primeru, da bi MR diagnostika dosegala ustrezno prostorsko ločljivost pri sprejemljivem času slikanja, bi bila bolj uporabna pri definiranju lastnosti trombov, saj je občutljiva na molekularne spremembe, med tem ko CT zgolj zazna spremembe v absorpciji. Sklepi: Nadaljnjo optimiziranje obravnave kapi je lahko mogoče in naša raziskava je lahko podlaga za nadaljnjo raziskovalno delo na tem področju, kjer napredek v CT (spektralni CT) in MR diagnostiki nakazuje, da se lahko bolj osredotočimo tudi na lastnosti trombov.

• Language: Slovenian
• Keywords: Umetni trombi, lastnosti trombov, CT, MRI, MRM, možganska kap, trombektomija
• Work type: Doctoral dissertation
• Organization: MF - Faculty of Medicine
• Year: 2023
• PID: 20.500.12556/RUL-152643
• Publication date in RUL: 02.12.2023

Secondary language

• Language: English
• Title: Correlations between computer-tomographic and magnetic-resonance characteristics of artificial blood clots in a brain circulation model

Abstract

Introduction: Haemostatic imbalance can cause stroke, which is one of the leading causes of death and disability. Ischemic stroke is caused by thrombi, whose properties can affect treatment outcome. Optimising stroke diagnosis and treatment protocol is essential for better outcome, where in imaging diagnostics CT is most commonly used, although MR has been proven to be more efficient. Regardless of the diagnostic imaging modality used, presently no emphasis is put on definition of thrombi properties. Objectives: With the aim of further optimising the stroke protocol, we investigated the possibility of CT and MR measurements in defining the structure of artificial thrombi. We also wanted to apply these findings clinically, where we observed correlations between CT and MR properties of thrombi with treatment and clinical parameters of actual patients. Methods and materials: Firstly, we investigated effectiveness of NMR and CT analysis in defining the structure of artificial thrombi. In the clinical part, patients with confirmed ischemic stroke had successfully removed thrombi, which were later analysed by MR and histology. Clinical and treatment data were also obtained, as well as CT numbers from the corresponding CT images of thrombi. All data were appropriately statistically analysed. Results and discussion: MR diffusion and CT measurements of artificial thrombi successfully differentiated between RBC and platelet thrombi and all measurements were sensitive to changes in RBC proportion. In the clinical study, we found significant correlations between the variability of diffusion and the duration of mechanical recanalization, deviation in mean CT number and the number of passes with the thrombectomy device, length of the thrombus, RBC proportion, and other factors. If MR diagnostics would achieve adequate spatial resolution with an acceptable imaging time, it would be more useful in defining thrombus properties, as it is sensitive to molecular changes, while CT only detects changes in absorption. Conclusions: Further optimization of stroke treatment is possible, and our study can serve as a basis for further research in this area, where advances in CT (spectral CT) and MR diagnostics suggest that we can focus more on thrombi properties.

• Keywords: Artificial trombi, trombi characteristics, CT, MRI, MRM, stroke, thrombectomy