Various Magnetic Resonance Imaging Patterns of Chronic Subdural Hematomas: Indicators of the Pathogenesis?

Abstract

Magnetic resonance (MR) imaging can detect various patterns in chronic subdural hematomas. These patterns were compared to the computed tomography (CT) appearances and chemical analysis of the content in 60 hematomas from 44 patients. The hematomas could be classified into five types on both T 1 -and T 2 -weighted images: low, high, and mixed intensity, isointensity, and layered. Combining the T 1 -and T 2 -weighted images of all 60 hematomas revealed a total of 14 different imaging patterns. Combining the CT and MR imaging findings of 55 hematomas identified 25 different patterns. Analysis of the hematoma contents showed that hemolysis-related parameters, such as potassium, glutamate oxaloacetate transaminase, bilirubin, lactate dehydrogenase, and protein concentration, were markedly higher than in the peripheral blood, and there were significant correlations between these parameters. Mixed intensity hematomas were significantly thicker than the other types, and showed markedly higher values of hemolysis-related parameters. Factors affecting the CT and MR imaging findings, such as fresh bleeding, hemolysis, and hemoglobin changes, coexist in a hematoma to varying degrees, and these factors may interact with the age of the hematoma to produce the different patterns that are observed.

Evaluation of cortical brain parenchyma, by diffusion and perfusion mri, before and after chronic subdural hematoma surgery

“…Fibroblasts entering the region and resultant granulation tissue are thought to be responsible for the membrane formation. Intermittent, new hemorrhages, coagulation, and increased fibrinolysis from new and fragile neovascularization, which is formed particularly over the external membrane, generate hematoma growth (1,4,11). These mechanisms may be due to osmoticoncotic pressure differences, re-hemorrhage due to membrane capillary vulnerability, and fibrinolytic activation (2,3,7,8).…”

“…It is known that the amount of blood that accumulates in the subdural distance may gradually increase over time and may cause a mass effect. Pathophysiological mechanisms for this increase include osmotic-oncotic pressure differences, re-hemorrhage due to vulnerability of membrane capillaries, or fibrinolytic activation (2,4,11).…”

“…The structural characteristics of CSDHs can be examined using both CT and conventional MRI (4,6,13,15). However, both of these imaging modalitities are inadequate in evaluating microcirculatory changes likely to occur due to chronic pressure on tissues in the vicinity of the hematoma.…”

Age Determination and Medicolegal Assessment in Chronic Subdural Hematoma: Case Report

“…24 Ancak MRG özellikle BT'deki bilateral izodens ve çok katmanlı hematomlarda ve hematom ile diğer lezyonların ayırıcı tanısında önemli bilgi vericidir. 25 BT'de tespit edilen şüpheli küçük KSDH alanlarının doğrulanma-sında MRG kullanışlıdır. Genel olarak hematom kalınlığının hematom yaşı ile doğru orantılı olarak arttığı gözlenmiştir.…”

“…Genel olarak hematom kalınlığının hematom yaşı ile doğru orantılı olarak arttığı gözlenmiştir. 25 Ortalama hematom kalınlık ölçümlerinde BT ile MRG arasında yüksek oranda korelasyon tespit edilmiştir. 15 Subdural hematomlar, hematom yaşı açısından BT ve MRG'deki sinyal yoğunluğuna göre sınıflandırılabilir.…”