Analysis of iron deposition in the brain lesions of patients with multiple sclerosis by three dimensional enhanced T2-star weighted angiography

Abstract

Objective To explore the values of 3D enhanced T2-star weighted angiography (ESWAN) in detecting iron deposition of the brain in patients with multiple sclerosis ( MS).Methods Conventional MRI and 3D ESWAN were performed in 22 patients with released-remitting MS(RR-MS) and in 22 age- and gender-matched normal controls.Both the magnitude images and phase images were available after post processing of the original ESWAN data post processing.The expanded disability status scale (EDSS) scores of the patients were from 0 to 8.5,and the course of disease were between 0.5 year and 15 years.The manifestation of MS lesions was evaluated on conventional MR images and ESWAN images by two experienced radiologists with blind methods.The phase values were measured for MS lesions between the semioval center and periventricular white matter and the corresponding regions in the normal control group were measured as well The Wilcoxon rank test was used to compare the differences of phase values between MS patients and normal controls,and the Spearman rank correlation analysis were used to analyze the correlations among the phase values of MS lesions,EDSS scores and course of disease of MS patients.Results ( 1 ) MS lesions were observed on magnitude images and phase images,respectively and together.Two hundred and thirteen(32.8％ )lesions were detected on both the magnitude images and phase images,164 (25.2％)lesions were detected on the magnitude images only,and 273 (42.0％) lesions were detected on the phase images only.A total of 650 lesions were observed on the ESWAN,which showed more 42 lesions than conventional images(608).Among 486(273 + 213 )lesions observed on the phase images,205 (31.5％) lesions were homogeneously hypointense,45 (6.9％ ) lesions showed hypointense ring,and 236 (36.4％ ) lesions were inhomogeneously hypointense.(2) “ Penetrating veins” were showed in 424 (65.2％ ) periventricular lesions.The “penetrating veins” showed dilated and prolonged in 198 (30.5％ ) acute lesions,thin and short in 208 (32.9％ ) chronic lesions.However,the “penetrating veins” of 12 ( 1.8％ ) chronic lesions in 5 stable MS patients were expanded and prolonged slightly.( 3 ) The average phase value of the lesions ( - 0.05 ± 0.08) in patients with RR-MS was significantly lower than that of corresponding to regions (0.06 ± 0.05 ) in the normal control group( Z = 22.30,P ＜ 0.01 ).(4) The phase values of MS lesions were significantly correlated to the EDSS and course of disease of patients with RR-MS (r = -0.98,0.99 respectively,P ＜ 0.01 ).Conclusion ESWAN can be helpful in the evaluation and quantification of abnormal iron deposition in MS lesions,which provides important values for the pathogenesis and pathological study for MS patients. Key words: Multiple sclerosis; Magnetic resonance imaging; Iron