Sehnervendurchmesser-Messung bei idiopathischer intrakranieller Hypertension mittels transorbitaler Sonographie und Magnetresonanztomographie

Abstract

Zusammenfassung: In dieser Arbeit behandele ich die Studie „Transorbital sonography and MRI reliability to assess optic nerve sheath diameter in idiopathic intracranial hypertension“ und die Grundlagen der Sehnervenscheidedurchmesser-Messung bei idiopathischer intrakranieller Hypertension. Die idiopathische intrakranielle Hypertension ist durch einen erhöhten intrakraniellen Druck gekennzeichnet, der sich in Form von typischen Symptomen wie Kopfschmerzen, Übelkeit, Erbrechen, Papillenödem und Sehverschlechterung äußert. Die Studie umfasste 23 Patienten mit idiopathischer intrakranieller Hypertension, im Durchschnitt 45,4 Jahre alt, wobei 70% weiblich waren. Alle eingeschlossenen Patienten erhielten sowohl eine kranielle Magnetresonanztomographie als auch eine transorbitale Sonographie und eine Lumbalpunktion. Es wurden mehrere Magnetresonanztomographie-Befunde mit einer idiopathischen intrakraniellen Hypertension in Verbindung gebracht, darunter das Auftreten einer leeren Sella turcica, das Hervortreten oder Verbiegung des Sehnervs, die Ausdehnung der Sehnervenscheide, die Abflachung des hinteren Augapfels und das Vorkommen einer Stenose der venösen Sinus. Das Hauptziel der Studie war es, die Sehnervenscheidedurchmesser-Messungen mittels transorbitaler Sonographie und Magnetresonanztomographie zu vergleichen und die Inter-Rater-Reliabilität der Magnetresonanztomographie-Messungen durch drei Neuroradiologen zu bewerten. Bei der Magnetresonanztomographie und bei der transorbitalen Sonographie wurde die Sehnervenscheidedurchmesser für jedes Auge 3 mm hinter der Lamina cribrosa gemessen. Die Messungen mittels Magnetresonanztomographie wurden von drei verschiedenen Neuroradiologen durchgeführt. Die transorbitale Sonographie wurde von der Promovierenden und einem geschulten Neurologen durchgeführt. Die Sehnervenscheidedurchmesser-Werte wurden als abhängige Variable betrachtet, und eine Regressionsanalyse wurde durchgeführt, um die Vergleichbarkeit der beiden Methoden zu untersuchen. Die Ergebnisse zeigten eine enge Korrelation zwischen den Sehnervenscheidedurchmesser-Werten, die mittels Magnetresonanztomographie und transorbitaler Sonographie gemessen wurden. Wir führten außerdem eine Korrelation zwischen dem Öffnungsdruck des Liquors und dem mittels transorbitaler Sonographie bzw. Magnetresonanztomographie gemessenen Sehnervenscheidedurchmesser durch. Hier konnte keine Korrelation gezeigt werden. Die Interrater-Reliabilität zwischen den Neuroradiologen für die Magnetresonanztomographie-Messungen war hoch, was darauf hinweist, dass die Messungen zuverlässig und reproduzierbar waren. Des Weiteren wurden die Patienten anhand von Magnetresonanztomographie-Befunden in verschiedene Gruppen eingeteilt, wobei eine signifikante Korrelation zwischen einer leeren Sella turcica und größeren Sehnervenscheidedurchmessers-Werten gefunden wurde. Insgesamt belegen die Ergebnisse dieser Studie die Zuverlässigkeit und Genauigkeit sowohl der Messung mittels Magnetresonanztomographie als auch der Messung mittels transorbitaler Sonographie des Sehnervenscheidedurchmessers bei Patienten mit idiopathischer intrakranieller Hypertension. Abstract: In this thesis, I deal with the study "Transorbital sonography and MRI reliability to assess optic nerve sheath diameter in idiopathic intracranial hypertension" and the fundamentals of optic nerve sheath diameter measurement in idiopathic intracranial hypertension. Idiopathic intracranial hypertension is characterized by increased intracranial pressure, manifesting in typical symptoms such as headaches, nausea, vomiting, papilledema, and visual impairment. The study included 23 patients with idiopathic intracranial hypertension, averaging 45.4 years old, with 70% being female. All included patients underwent both magnetic resonance imaging, transorbital sonography, and lumbar puncture. Several magnetic resonance imaging findings were associated with idiopathic intracranial hypertension, including the presence of an empty sella turcica, optic nerve protrusion, optic nerve tortuosity, optic nerve sheath distension, flattening of the posterior globe, and venous sinus stenosis. The main objective of the study was to compare optic nerve sheath diameter measurements using transorbital sonography and magnetic resonance imaging and to assess the inter-rater reliability of magnetic resonance imaging measurements by three neuroradiologists. In both magnetic resonance imaging and transorbital sonography, the optic nerve sheath diameter was measured for each eye 3 mm behind the Lamina cribrosa. Magnetic resonance imaging measurements were performed by three different neuroradiologists. Transorbital sonography was conducted by the doctoral candidate and a trained examiner. Optic nerve sheath diameter values were considered as dependent variables, and regression analysis was conducted to examine the comparability of the two methods. The results showed a strong correlation between optic nerve sheath diameter values measured by magnetic resonance imaging and transorbital sonography. We also conducted a correlation between cerebrospinal fluid opening pressure and optic nerve sheath diameter measured via transorbital sonography and magnetic resonance imaging. The results here showed no correlation. The inter-rater reliability among the neuroradiologists for magnetic resonance imaging measurements was high, indicating that the measurements were reliable and reproducible. Furthermore, patients were categorized into different groups based on magnetic resonance imaging findings, revealing a significant correlation between an empty sella and larger optic nerve sheath diameter values. Overall, the results of this study support the reliability and accuracy of both magnetic resonance imaging and transorbital sonography measurements of optic nerve sheath diameter in patients with idiopathic intracranial hypertension.

In this thesis, I deal with the study "Transorbital sonography and MRI reliability to assess optic nerve sheath diameter in idiopathic intracranial hypertension" and the fundamentals of optic nerve sheath diameter measurement in idiopathic intracranial hypertension. Idiopathic intracranial hypertension is characterized by increased intracranial pressure, manifesting in typical symptoms such as headaches, nausea, vomiting, papilledema, and visual impairment. The study included 23 patients with idiopathic intracranial hypertension, averaging 45.4 years old, with 70% being female. All included patients underwent both magnetic resonance imaging, transorbital sonography, and lumbar puncture. Several magnetic resonance imaging findings were associated with idiopathic intracranial hypertension, including the presence of an empty sella turcica, optic nerve protrusion, optic nerve tortuosity, optic nerve sheath distension, flattening of the posterior globe, and venous sinus stenosis. The main objective of the study was to compare optic nerve sheath diameter measurements using transorbital sonography and magnetic resonance imaging and to assess the inter-rater reliability of magnetic resonance imaging measurements by three neuroradiologists. In both magnetic resonance imaging and transorbital sonography, the optic nerve sheath diameter was measured for each eye 3 mm behind the Lamina cribrosa. Magnetic resonance imaging measurements were performed by three different neuroradiologists. Transorbital sonography was conducted by the doctoral candidate and a trained examiner. Optic nerve sheath diameter values were considered as dependent variables, and regression analysis was conducted to examine the comparability of the two methods. The results showed a strong correlation between optic nerve sheath diameter values measured by magnetic resonance imaging and transorbital sonography. We also conducted a correlation between cerebrospinal fluid opening pressure and optic nerve sheath diameter measured via transorbital sonography and magnetic resonance imaging. The results here showed no correlation. The inter-rater reliability among the neuroradiologists for magnetic resonance imaging measurements was high, indicating that the measurements were reliable and reproducible. Furthermore, patients were categorized into different groups based on magnetic resonance imaging findings, revealing a significant correlation between an empty sella and larger optic nerve sheath diameter values. Overall, the results of this study support the reliability and accuracy of both magnetic resonance imaging and transorbital sonography measurements of optic nerve sheath diameter in patients with idiopathic intracranial hypertension.