Related Experiment Video
Updated: May 30, 2026
Functional Magnetic Resonance Imaging (fMRI) of the Visual Cortex with Wide-View Retinotopic Stimulation
Published on: December 8, 2023
Assessment of cortical visual impairment in infants with periventricular leukomalacia: a pilot event-related FMRI
Bing Yu1, Qiyong Guo, Guoguang Fan
1Department of Radiology, Shengjing Hospital of China Medical University, Shenyang, China.
Insights
Event-related functional MRI (fMRI) can assess visual impairment in infants with periventricular leukomalacia (PVL). Abnormal blood oxygenation level-dependent (BOLD) signals and delayed hemodynamic response functions (HRFs) in the visual cortex correlate with visual deficits.
Area of Science:
- Neuroimaging
- Pediatric Neurology
- Visual Neuroscience
Background:
- Periventricular leukomalacia (PVL) is a common cause of cerebral palsy in premature infants.
- Cortical visual impairment (CVI) is a frequent complication of PVL, impacting visual development.
- Accurate assessment of CVI in infants is crucial for early intervention.
Purpose of the Study:
- To evaluate the utility of event-related functional magnetic resonance imaging (ER-fMRI) for assessing CVI in infants with PVL.
- To correlate fMRI findings with clinical measures of visual acuity.
Main Methods:
- ER-fMRI was performed on 24 infants with PVL and 12 age-matched controls during visual stimulation.
- Data analysis involved Statistical Parametric Mapping (SPM2) and MarsBar for region of interest analysis.
- Time to peak (TTP) of hemodynamic response functions (HRFs) and the number of activated voxels were quantified.
- Pearson correlation analysis compared fMRI data with Teller Acuity Cards (TAC) results.
Main Results:
- Control infants showed typical blood oxygenation level-dependent (BOLD) signal in the primary visual cortex (PVC).
- Infants with PVL exhibited varied patterns of abnormal or absent PVC activation.
- The number of activated occipital voxels significantly correlated with TAC-evaluated visual impairment (p < 0.001).
- Mean TTP of HRFs was significantly delayed in PVL infants compared to controls.
Conclusions:
- ER-fMRI is a valuable tool for assessing CVI in infants with PVL.
- BOLD signal characteristics and activation patterns provide important insights into visual pathway integrity.
- fMRI findings correlate with clinical visual assessments, aiding in diagnosis and management.
Objective:
We wanted to investigate the usefulness of event-related (ER) functional MRI (fMRI) for the assessment of cortical visual impairment in infants with periventricular leukomalacia (PVL).
Materials And Methods:
FMRI data were collected from 24 infants who suffered from PVL and from 12 age-matched normal controls. Slow ER fMRI was performed using a 3.0T MR scanner while visual stimuli were being presented. Data analysis was performed using Statistical Parametric Mapping software (SPM2), the SPM toolbox MarsBar was used to analyze the region of interest data, and the time to peak (TTP) of hemodynamic response functions (HRFs) was estimated for the surviving voxels. The number of activated voxels and the TTP values of HRFs were compared. Pearson correlation analysis was performed to compare visual impairment evaluated by using Teller Acuity Cards (TAC) with the number of activated voxels in the occipital lobes in all patients.
Results:
In all 12 control infants, the blood oxygenation level-dependent (BOLD) signal was negative and the maximum response was located in the anterior and superior part of the calcarine fissure, and this might correspond to the anterior region of the primary visual cortex (PVC). In contrast, for the 24 cases of PVL, there were no activated pixels in the PVC in four subjects, small and weak activations in six subjects, deviated activations in seven subjects and both small and deviated activations in three subjects. The number of active voxels in the occipital lobe was significantly correlated with the TAC-evaluated visual impairment (p < 0.001). The mean TTP of the HRFs was significantly delayed in the cases of PVL as compared with that of the normal controls.
Conclusion:
Determining the characteristics of both the BOLD response and the ER fMRI activation may play an important role in the cortical visual assessment of infants with PVL.
