Related Experiment Video
Updated: Jan 21, 2026
Multifocal Electroretinograms
Published on: December 4, 2011
Cortical hypointensity in T2-weighted gradient-echo sequences in patients with progressive multifocal
P López Sala1, N Alberdi Aldasoro1, M V Zelaya Huerta2
1Servicio de Radiodiagnóstico, Complejo Hospitalario de Navarra, Pamplona, Navarra, España.
Introduction:
Progressive multifocal leukoencephalopathy is a demyelinating disease of the central nervous system caused by the reactivation of the JC virus. This opportunistic encephalopathy mainly affects immunodepressed patients with stage III HIV infection, although in recent years it has also been found in association with treatment with immunosuppressors such as natalizumab. MRI plays an important role in both the early diagnosis and follow-up of this disease. Recently, it has been reported that hypointensities in U-fibers and cortex adjacent to white-matter lesions characteristic of the disease can be identified on T2-weighted gradient-echo and susceptibility-weighted sequences in patients with progressive multifocal leukoencephalopathy.
Objective:
We aimed to analyze the presence and usefulness of cortical hypointensity on T2-weighted gradient-echo sequences in relation to the diagnosis of progressive multifocal leukoencephalopathy and to review the literature on the topic.
Material And Methods:
We analyze three cases of progressive multifocal leukoencephalopathy seen at our center in three patients with immunosuppression of different origins: one with stage III HIV infection, one with multiple sclerosis being treated with natalizumab, and one with rheumatoid arthritis being treated with rituximab.
Results:
In all three cases MRI showed the cortical hypointensity adjacent to the white-matter lesion in the T2-weighted gradient-echo sequence. In the patient with multiple sclerosis, this sign appeared earlier than the abnormal signal in the white matter. The patient being treated with rituximab was diagnosed postmortem and the pathology findings correlated with the MRI findings.
Conclusion:
The finding of cortical hypointensity on T2-weighted gradient-echo MRI sequences seems to support the diagnosis of progressive multifocal leukoencephalopathy, regardless of the type of immunosuppression, so this finding should routinely assessed in patients suspected of having this disease.
Related Concept Videos
01:06Echo
Imagine the sound is reflected back to the ears. Assuming that the source is very close to the human, the difference between hearing the two sounds—the emitted sound and the reflected sound—may be more than the minimum time for perceiving distinct sounds. If this is the case,...
01:26What is an Electrochemical Gradient?
The chemical gradient relies on differences in the abundance of a substance on the outside versus the inside of a cell and flows from areas of high to low ion concentration. In contrast, the electrical gradient revolves around an...
00:57Weighted Mean
For example, consider the number of goals scored in the matches of a tournament. While computing the average number of goals scored in the tournament, it may be more important to...
01:19Mass and Weight
01:25Atomic Weight
01:09Apparent Weight
Consider a person standing on a bathroom scale inside an elevator. If the scale is accurate at rest, its reading equals the...