[Falx images on CT scan (author's transl)]

Area of Science:

• Neuroradiology
• Medical Imaging

Background:

• Falx images on CT scans are typically associated with falx calcification or brain atrophy.
• However, falx images are frequently observed in normal pediatric CT scans, suggesting other factors influence their visualization.

Purpose of the Study:

• To evaluate the incidence and characteristics of falx images on CT scans in relation to age, sex, CT slice level, and other intracranial structures.
• To determine if falx images indicate calcification or are related to specific pathological conditions.

Main Methods:

• Retrospective analysis of CT scans from 964 normal and abnormal cases.
• Evaluation of falx image incidence based on CT slice level, patient age, sex, and comparison with visualized pineal body, habenula, and choroid plexus.
• Correlation with clinical conditions such as brain edema and brain atrophy.

Main Results:

• Higher slice levels showed a greater incidence of falx images.
• Incidence peaked in the second decade and increased with age, with no significant sex difference.
• Falx image incidence relative to other structures changed with age: falx > pineal/habenula > choroid plexus (under 10 years); pineal/habenula > choroid plexus >= falx (11-20 years); pineal/habenula > choroid plexus > falx (over 21 years).
• Brain edema cases had a higher incidence of falx images, unlike brain atrophy cases.
• No significant difference in CT numbers was found between falx regions with and without visible falx images.

Conclusions:

• Falx images on CT scans are common and do not solely indicate calcification.
• Their visualization is influenced by age, CT slice level, and brain edema.
• Age-related changes in the relative prominence of falx and other brain structures on CT are observed.