Related Experiment Video
Updated: May 31, 2026
Brain Infarct Segmentation and Registration on MRI or CT for Lesion-symptom Mapping
Published on: September 25, 2019
Preoperative localization of intracranial lesions with MRI using marking pills
Sumiya Shibata1, Takeharu Kunieda, Hidemitsu Adachi
1Department of Neurosurgery, Kobe City Medical Center General Hospital, Japan. sshiba@kuhp.kyoto-u.ac.jp
Objective:
To describe a simple technique for preoperative surface localization of intracranial lesions.
Methods:
11 pills in total, including Alfarol (alfacalcidol) capsules, were affixed to a phantom with adhesive tape and a MRI scan was performed. The visibility of the pills and any spatial errors in determining their locations were evaluated. Between June 2006 and April 2009, we employed Alfarol capsules as a skin marker in MRI in clinical surgical cases.
Results:
Alfarol capsules, whose actual size is 5.6 mm in diameter, were identified as a hyperintense spot at a size of 4.2, 4.2, and 4.5mm in diameter in T1-weighted, T2-weighted, and FLAIR (fluid attenuated inversion recovery) sequence images, respectively. The size discrepancies were within 1.4 mm. The average spatial errors were 0.7, 0.6, and 0.7 mm in T1-weighted, T2-weighted, and FLAIR sequence images, respectively. Other pills were not identified in the MRI scans. During this 35-month period, 8 patients underwent preoperative MRI-guided localization at our institution. There were 5 men and 3 women in whom 8 biopsies were performed. In all cases, the result of the biopsy was positive and useful for the treatment that followed. No perioperative complications were encountered.
Conclusion:
Alfarol capsule can be used as an external skin marker. Our simple and inexpensive method is a useful addition to preoperative evaluation of superficial intracranial lesions.
