Summary
When peripheral blood is serially diluted with saline solution, the bloody colour is determined by the derivative of haemoglobin. Solutions over 105/mm3 red cells or 0.5 g/dl haemoglobin are represented as being sanguineous. This is the lower limit for a subdural haematoma, because the name itself requires at least a bloody appearance of its contents. Diluted blood solutions less 0.5×104 red cells or 15 mg/dl haemoglobin are macroscopically translucent or watery clear. Solutions between bloody and translucent are xanthochromic. If the contents of a subdural collection is watery clear or xanthochromic, it must be called an effusion or hygroma.
The haemoglobin in haematomas is the most important factor determining the attenuation values in the CT scan. Protein, iron or calcium ions have only minimal concentration in haematomas and are neglegible for attenuation values of haematomas in the CT scan. The lightest sanguineous solution, that is a haematoma, corresponds to 15 Hounsfield's units measured by the CT scan.
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References
Amendola, M. A., Ostrum, B. J., Diagnosis of isodense subdural hematomas by computed tomography. Am. J. Roentgenol.129 (1977), 693–697.
Bergström, M., Ericson, K., Levander, B.,et al., Variation with time of the attenuation values of intracranial hematomas. J. Comput. Assist. Tomogr.1 (1977), 57–63.
Bergström, M., Ericson, K., Levander, B.,et al., Computed tomography of cranial subdural and epidural hematomas: Variation of attenuation related to time and clinical events such as rebleeding. J. Comput. Assist. Tomogr.1 (1977), 449–455.
Forbes, G. S., Sheedy, P. F., Piepgras, D. G.,et al., Computed tomography in the evaluation of subdural hematomas. Radiol.126 (1978), 143–148.
Grumme, T., Lanksch, W., Kazner, E.,et al., Zur Diagnose des chronischen subduralen Hämatoms in Computer-Tomogramm. Neurochirurgia19 (1976), 95–103.
Ito, H., Komai, T., Yamamoto, S., Fibrin and fibrinogen degradation products in chronic subdural hematoma. Neurologia medico-chirurgica15 (1975), 51–55.
Ito, H., Komai, T., Yamamoto, S., Fibrinolytic enzyme in the lining walls of chronic subdural hematoma. J. Neurosurg.48 (1978), 197–200.
Ito, H., Yamamoto, S., Komai, T.,et al., Role of local hyperfibrinolysis in the etiology of chronic subdural hematoma. J. Neurosurg.45 (1976), 26–31.
Kao, M. C., Sedimentation level in chronic subdural hematoma visible on computerized tomography. J. Neurosurg.58 (1983), 246–251.
Kim, K. S., Hemmati, M., Weinberg, P. E., Computed tomography in isodense subdural hematoma. Radiol.128 (1978), 71–74.
New, P. F. J., Aronow, S., Attenuation measurements of whole blood and blood fractions in computed tomography. Radiol.121 (1976), 635–640.
Schurr, P. H., Subdural hematomas and effusions in infancy. Develop. Med. Child Neurol.11 (1969), 108–111.
Weir, B., Gordon, P., Factors affecting coagulation: Fibrinolysis in chronic subdural fluid collections. J. Neurosurg.58 (1983), 242–245.
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Ito, H., Maeda, M., Uehara, T. et al. Attenuation values of chronic subdural haematoma and subdural effusion in CT scans. Acta neurochir 72, 211–217 (1984). https://doi.org/10.1007/BF01406871
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DOI: https://doi.org/10.1007/BF01406871