Quantification of image contrast of infarcts on computed tomography scans
| Autor: | Antoni Grzanka, Andrzej Urbanik, Robert Chrzan, Radoslaw Kazmierski, Ryszard Gomolka, Wieslaw L. Nowinski |
|---|---|
| Rok vydání: | 2017 |
| Předmět: |
Adult
Brain Infarction Male Time Factors Statistics as Topic Contrast Media Computed tomography computer.software_genre 030218 nuclear medicine & medical imaging Brain Ischemia Lesion 03 medical and health sciences 0302 clinical medicine Voxel Hounsfield scale Medicine Humans Radiology Nuclear Medicine and imaging Longitudinal Studies Stroke Aged Retrospective Studies Aged 80 and over Analysis of Variance Brain Imaging medicine.diagnostic_test business.industry Ischemic infarct General Medicine Middle Aged medicine.disease Image contrast Computer-aided diagnosis Female Neurology (clinical) medicine.symptom Nuclear medicine business Tomography X-Ray Computed computer 030217 neurology & neurosurgery |
| Zdroj: | The neuroradiology journal. 30(1) |
| ISSN: | 2385-1996 |
| Popis: | Introduction Accurate identification of infarcts in non-contrast computed tomography (NC-CT) scans of the brain is fundamental in the diagnosis and management of patients with stroke. Quantification of image contrast properties at the boundaries of ischemic infarct regions in NC-CT can contribute to a more precise manual or automatic delineation of these regions. Here we explore these properties quantitatively. Methods We retrospectively investigated 519 NC-CT studies of 425 patients with clinically confirmed ischemic strokes. The average and standard deviation (SD) of patients’ age was 67.5 ± 12.4 years and the average(median)±SD time from symptoms onset to NC-CT examination was 27.4(12)±35.7 h. For every scan with an ischemic lesion identified by experts, the image contrast of the lesion vs. normal surrounding parenchyma was calculated as a difference of mean Hounsfield Unit (HU) of 1–5 consecutive voxels (the contrast window width) belonging to the lesion and to the parenchyma. This contrast was calculated at each single voxel of ischemic lesion boundaries (previously delineated by the experts) in horizontal and vertical directions in each image. The distributions of obtained horizontal, vertical and both contrasts combined were calculated among all 519 NC-CTs. Results The highest applicative contrast window width was identified as 5 voxels. The ischemic infarcts were found to be characterized by 6.60 HU, 8.28 HU and 7.55 HU mean values for distributions of horizontal, vertical and combined contrasts. Approximately 40–50% of the infarct boundary voxels were found to refer to the image contrast below 5 HU. Conclusion Low image contrast of ischemic lesions prevents accurate delineation of the infarcts in NC-CT. |
| Databáze: | OpenAIRE |
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