Related Experiment Video
Updated: Feb 9, 2026

Automated Midline Shift and Intracranial Pressure Estimation based on Brain CT Images
Published on: April 13, 2013
Proton range shift analysis on brain pseudo-CT generated from T1 and T2 MR.
Giampaolo Pileggi1,2, Christoph Speier2,3, Gregory C Sharp2
1a Department of Experimental and Clinical Medicine , Magna Graecia University of Catanzaro , Catanzaro , Italy.
This study demonstrates the feasibility of using MRI-generated pseudo-CT (pCT) for proton therapy planning. This approach avoids planning CT scans, enabling better target definition and online adaptive therapy possibilities.
Area of Science:
- Medical Physics
- Radiotherapy
- Medical Imaging
Background:
- Magnetic Resonance (MR) imaging offers superior soft tissue contrast compared to Computed Tomography (CT) but lacks electron density information crucial for radiotherapy dose calculations.
- This study investigates the use of pseudo-CT (pCT) generated from T1w/T2w MR images for proton therapy planning.
Purpose of the Study:
- To assess the feasibility of using MR-derived pCT for proton treatment planning.
- To compare proton range accuracy between standard CT and pCT.
Main Methods:
- MR and CT data from 14 glioblastoma patients were analyzed.
- Pseudo-CT images were generated using conversion libraries based on MR tissue segmentation.
- Proton therapy plans were created on pCT and transferred to CT for range shift (RS) and gamma-index analysis.
Main Results:
- The generated pCT showed a mean absolute error and bias of 124 ± 10 and -16 ± 26 Hounsfield Units (HU), respectively.
- The median range shift (RS) between pCT and CT was 0.5 mm (IQR: 1.4 mm), with a maximum absolute value of 4.4 mm.
- 40 out of 42 analyzed beams met the clinical acceptance threshold for RS, with deviations primarily due to segmentation errors.
Conclusions:
- Generating pCT from T1w/T2w MR images is feasible for proton therapy planning.
- This method eliminates the need for a planning CT, potentially improving target definition and enabling online adaptive radiotherapy.
- Further methodological refinement is needed to enhance the accuracy of MRI-to-HU conversion.
More Related Videos
Related Concept Videos
Proton (¹H) NMR: Chemical Shift
Absorption signals of all the protium nuclei...
¹H NMR Chemical Shift Equivalence: Homotopic and Heterotopic Protons
¹H NMR Chemical Shift Equivalence: Enantiotopic and Diastereotopic Protons
In chiral compounds such as 2-butanol, replacing the methylene hydrogens at C3 produces a pair of...
Range
15.9; 16.1; 15.2; 14.8; 15.8; 15.9; 16.0; 15.5
Measurements of the amount of soda in a 16-ounce can vary since different subjects record these measurements or since the exact amount - 16 ounces of liquid, was not...
¹H NMR: Long-Range Coupling
In alkenes, spin information is communicated via σ–π overlap, as seen in allylic (four-bond) and homoallylic (five-bond) couplings. These coupling interactions are stronger when the σ bond is parallel to the alkene...
Qualitative Analysis
For instance, group IV...

