Abstract

Objectives:Adult patients with intracranial hemorrhage (ICH) are often young but receive serial cranial computer tomography (CCT). To lower their cumulative radiation dose risks, we evaluated applicability of low dose cranial CT (LD-CCT) in the follow-up of ICH patients compared to an initial standard dose cranial CT (SD-CCT). Methods:53 ICH patients underwent initial SD-CCT (350 mAs/120 kV) and follow-up LD-CCT (either 220 or 240 mAs/120 kV). Iterative reconstruction used for both dose levels was increased by one factor for LD-CCT. Image quality parameters [visual impression (VI), gray matter (GM)/white matter (WM) differentiation, edema, ICH, cerebrospinal fluid spaces (CSF), postoperative changes, basal cisterns] were retrospectively assessed independently by an experienced neuroradiologist and neurosurgeon. Significance level was set at p < 0.05. Results:Both raters accredited both LD-CCT protocols (220 and 240 mAs) to be equivalent to SD-CCT for display of ICH, CSF and basal cisterns. The SD-CCT was rated significantly better (p < 0.01) concerning VI, GM/WM differentiation and imaging of edema by the neuroradiologist only. Conclusions:IR based LD-CCT with a dose reduction up to almost 40% are applicable for ICH follow-up concerning findings requiring immediate therapeutic intervention. However, LD-CCT quality deficits regarding GM/WM differentiation and hypodense lesions exclude stroke assessment.

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