Related Experiment Video
Updated: Apr 1, 2026
Diffusion Tensor Magnetic Resonance Imaging in the Analysis of Neurodegenerative Diseases
Published on: July 28, 2013
Impact of Postoperative Diffuse-Weighted Imaging Rim Restriction on Neurological Outcomes After Resection of Newly
Grazia Menna1,2, Nadeem N Al-Adli2, Jasper K W Gerritsen3
1Department of Neurological Surgery, Fondazione Policlinico Universitario Agostino Gemelli, Rome, Italy.
Background/Objectives:
Postoperative diffusion-weighted imaging (DWI) abnormalities, appearing as a rim of restricted diffusion around the surgical cavity, are frequently observed on early postoperative MRI in patients with glioma. This study aims to explore the evolution and impact of these DWI abnormalities on neurological outcomes.
Methods:
A retrospective cohort analysis was conducted on 303 patients who underwent initial resection for newly diagnosed isocitrate dehydrogenase-wildtype glioblastoma at the University of California, San Francisco, between 2017 and 2021. DWI abnormalities were classified according to severity: 0 (no rim restriction), 1 (thin/minimal rim restriction), 2 (moderate rim restriction), 3 (minimal region/sector [<1 cm3] of restriction), or 4 (moderate/large region or sector [>1 cm3] of restriction). DWI volumes were segmented and used to calculate median lesional apparent diffusion coefficient. Maximum perpendicular diameters of the restriction abnormality were measured manually. Multivariable regression models assessed associations with neurological outcomes.
Results:
Of the 303 patients analyzed, 11 (3.6%) patients exhibited no rim restriction (Grade 0), 247 (81.5%) patients had some contiguous, nonbulky DWI rim restriction (Grades 1-2), and 45 patients (14.9%) had thick contiguous, bulky (Grades 3-4) DWI restriction. Overall, all postoperative DWI abnormalities resolved within 6 months. Among the 17 patients (5.6%) who developed new or worsening deficits immediately postoperation or at discharge, only 3 (17.6%) had contiguous, bulky DWI restriction and 9 (52.9%) fully recovered at 6 months. Among the patients who did not recover (n = 8), 6 (75%) had DWI Grades 1 to 2 and 2 (25%) had DWI Grades 3 to 4 (P = .29). DWI volume and maximum DWI diameter were significantly associated with new/worsening deficits at all time points; however, neither DWI grade nor apparent diffusion coefficient were significantly associated with new/worsening deficits at any time point.
Conclusion:
DWI rim restriction is common after glioblastoma resection, and these changes uniformly resolve within 6 months of surgery. The severity of DWI abnormalities does not reliably predict postoperative deficit recovery.
Insights
Postoperative diffusion-weighted imaging (DWI) abnormalities after glioma surgery typically resolve within six months. The extent of these DWI changes does not reliably predict neurological recovery.
Area of Science:
- Neuroimaging
- Oncology
- Neurosurgery
Background:
- Postoperative diffusion-weighted imaging (DWI) abnormalities are common after glioma resection.
- These abnormalities manifest as a rim of restricted diffusion around the surgical cavity.
- Understanding their evolution and impact on neurological outcomes is crucial.
Purpose of the Study:
- To investigate the evolution of postoperative DWI abnormalities in glioma patients.
- To determine the association between DWI abnormalities and neurological outcomes.
- To explore the predictive value of DWI severity on patient recovery.
Main Methods:
- Retrospective cohort analysis of 303 patients with newly diagnosed isocitrate dehydrogenase-wildtype glioblastoma.
- Classification of DWI abnormalities into four grades based on severity and volume.
- Measurement of DWI volumes and maximum diameters; calculation of apparent diffusion coefficient.
- Multivariable regression models to assess associations with neurological outcomes.
Main Results:
- Most patients (81.5%) showed mild to moderate DWI rim restriction (Grades 1-2).
- All DWI abnormalities resolved within 6 months post-surgery.
- DWI volume and maximum diameter correlated with new/worsening deficits, but DWI grade and apparent diffusion coefficient did not.
- Severity of DWI abnormalities did not reliably predict recovery from deficits.
Conclusions:
- Postoperative DWI rim restriction is a frequent finding after glioblastoma resection.
- These imaging changes are transient, resolving within six months.
- The severity of DWI abnormalities is not a reliable predictor of neurological deficit recovery.
