[Computed Tomography: Simple Yet Indispensable].

Although frequently regarded as a routine diagnostic modality, computed tomography (CT) has substantial clinical significance. As of 2024, Japan had 14,898 CT units, corresponding to 107 scanners per one million people, over four times the mean among OECD countries. With its well-established infrastructure and fewer accessibility barriers than magnetic resonance imaging or nuclear medicine, CT is a crucial first-line modality in daily clinical practice. However, its convenience occasionally leads to vaguely designated "screening" examinations without sufficient clinical context, representing suboptimal resource use. This review aims to highlight the importance of rigorous, contextually appropriate interpretation of head and cervical spine CT imaging and discuss strategies for its optimal integration into clinical decision-making.