Related Experiment Video
Updated: Aug 16, 2026
High-resolution In Vivo Manual Segmentation Protocol for Human Hippocampal Subfields Using 3T Magnetic Resonance Imaging
Published on: November 10, 2015
MRI volumetry of the hippocampus: the effect of slice thickness on volume formation
M P Laakso1, K Juottonen, K Partanen
1Department Neuroscience and Neurology, University Hospital, Finland.
Abstract:
The hippocampus is a mesial temporal lobe structure of complex shape and the main locus of temporal lobe epilepsy and also affected early in Alzheimer's disease. Magnetic resonance imaging of the hippocampus has been found to be a helpful diagnostic tool for these conditions. Measurement of hippocampal volumes has been found to be not only the most accurate approach to evaluation of the hippocampal pathology, but the most demanding and time consuming as well. One of the factors contributing to this is the slice thickness-the thinner the slice, the more time is required. On the other hand, it has been hypothesized, that the use of thick slice would result in volume aberrations due to, for example, the volume averaging effect. We therefore measured the volumes of the hippocampus on coronal slices in 10 healthy, young control subjects using slice thicknesses of 1, 3 and 5 mm, and evaluated the effect of the slice thickness on the volume formation. No significant difference between the volumes of the hippocampus using different thicknesses was found. Therefore, it appears that use of the thick slices would not necessarily introduce systematic bias to the volumetric measurement. Yet, we do not feel compelled to advise the use of "thick" slices either, since the use of "thin" slices seems the most authoritative and less vulnerable to being affected by a single false estimate.
Insights
Thick slices in MRI scans do not significantly alter hippocampal volume measurements. However, thin slices are still recommended for more reliable and accurate results in diagnosing conditions like epilepsy and Alzheimer's disease.
Area of Science:
- Neuroimaging
- Radiology
- Anatomy
Background:
- The hippocampus is crucial for memory and implicated in neurological disorders.
- Magnetic Resonance Imaging (MRI) is vital for diagnosing hippocampal pathologies.
- Accurate hippocampal volume measurement is essential but time-consuming.
Purpose of the Study:
- To investigate the impact of MRI slice thickness on hippocampal volume measurements.
- To determine if thicker slices introduce systematic bias in volumetric analysis.
Main Methods:
- Hippocampal volumes were measured in 10 healthy subjects using MRI.
- Coronal slices with thicknesses of 1 mm, 3 mm, and 5 mm were analyzed.
- The effect of slice thickness on volume was evaluated.
Main Results:
- No statistically significant differences in hippocampal volumes were observed across the tested slice thicknesses (1, 3, and 5 mm).
- Thicker slices did not appear to introduce systematic bias into the volumetric measurements.
Conclusions:
- Using thicker slices for hippocampal MRI may not necessarily introduce systematic bias.
- Thin slices are still preferred for hippocampal volume measurement due to greater accuracy and reduced vulnerability to errors.
