Comparison of the Efficiency of Fractional Anisotropy or Relaxation Time T2* in the Early Diagnosis of 6-Hydroxydopamine-Induced Rat Model of Parkinson's Disease

Dongye An ¹, Yansheng Chen ¹, Xiaoxia Zhang ¹

⁰First Hospital of Qinhuangdao, Qinhuangdao, China.

Bulletin of Experimental Biology and Medicine +

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January 9, 2026

View abstract on PubMed

Summary

Transverse relaxation time T2* measurement is more effective than fractional anisotropy (FA) from diffusion tensor imaging (DTI) for early Parkinson's disease (PD) diagnosis. Both MRI methods showed increased diagnostic accuracy over time in a rat model.

Area Of Science

Neuroimaging
Biomedical Engineering
Neurology

Background

Fractional anisotropy (FA) in diffusion tensor imaging (DTI) and transverse relaxation time T2* in T2*-weighted imaging (T2*WI) are key MRI methods for Parkinson's disease (PD) diagnosis.
The comparative effectiveness of DTI and T2*WI for early PD detection remains unclear.

Purpose Of The Study

To compare the sensitivity and specificity of DTI (measuring FA) and T2*WI (measuring T2*) for the early diagnosis of Parkinson's disease (PD).

Main Methods

A rat model of PD was created using 6-hydroxydopamine (6-OHDA) injection into the substantia nigra (SN).
MRI scans were performed weekly for 6 weeks to measure FA and T2* in the SN.
Receiver Operating Characteristic (ROC) curves were utilized to evaluate diagnostic sensitivity and specificity.

Main Results

Both FA and T2* values showed significant differences between lesioned and control SNs at specific time points.
Diagnostic effectiveness, indicated by Youden's indices and Area Under the ROC Curve (AUC), increased over the 6-week period.
T2* measurement demonstrated higher diagnostic effectiveness (90% sensitivity, 95% specificity, AUC=0.9450) compared to FA (100% sensitivity, 70% specificity, AUC=0.9075) at 6 weeks post-injection.

Conclusions

T2*-weighted imaging is more effective than DTI for the early diagnosis of Parkinson's disease.
Both FA and T2* parameters show improved diagnostic accuracy for PD in later stages of the disease model.

Keywords:

Parkinson’s disease Sprague-Dawley rats fractional anisotropy receiver operating characteristic curve relaxation time T2*