Role of diffusion weighted magnetic resonance imaging and spectroscopy in the diagnosis and follow-up of hepatolenticular degeneration.

OBJECTIVE: To explore the changes of different brain metabolites during hepatolenticular degeneration using diffusion weighted magnetic resonance imaging (DWI) and magnetic resonance spectroscopy (MRS) in patients with hepatolenticular degeneration and study the correlation of apparent diffusion coefficient(ADC) values and MRS with the different pathological changes.

METHODS: Totally 53 patients with hepatolenticular degeneration were enrolled in this study and divided into DWI high-signal group (n=31) and DWI low-signal group (n=22). Magnetic resonance scan, DWI, and spectroscopy were performed before treatment and 4 months after treatment. The changes of ADC value, N-acetyl aspartate (NAA)/creatine (Cr) ratio, and choline (Cho)/Cr ratio were recorded.

RESULTS: Before treatment, the NAA/Cr ratio was significantly higher in the DWI high-signal group than in DWI low-signal group (P=0.002), whereas ADC value and NAA/Cr ratio were significantly lower (P=0.004, P=0.014, respectively). After treatment, the NAA/Cr ratio was still significantly higher in the DWI high-signal group (P=0.036), while the differences of ADC value and Cho/Cr ratio showed no statistical deference (P>0.05). In the DWI high-signal group, the ADC value and NAA/Cr ratio were significantly elevated after treatment (P=0.006, P=0.008), whereas the Cho/Cr ratio showed no significant change (P>0.05). In the DWI low signal group, NAA/Cr ratio was significantly increased after treatment (P=0.015), while the ADC value and Cho/Cr ratio showed no significant change (P>0.05).

CONCLUSIONS: DWI combined MRS imaging can be used to evaluate the microscopic structure and metabolic changes during copper deposition and thus, compared with the conventional magnetic resonance imaging provide more information on metabolism. Therefore, they can be useful tools in the early diagnosis and efficacy evaluation of hepatolenticular degeneration.