Diagnostic Specificity of Cerebral Magnetic Resonance Imaging for Punctate White Matter Lesion Assessment in a Preterm Sheep Fetus Model.

Recent studies, using magnetic resonance imaging (MRI) to assess white matter injury in preterm brains, increasingly recognize punctate white matter lesions (PWML) as the primary lesion type. There are some papers showing the relationship between the size and number of PWML and the prognosis of infants. However, the histopathological features are still unknown. In this study, we experimentally induced periventricular leukomalacia (PVL) in a sheep fetus model, aiming to find whether MRI can visualize necrotic foci (small incipient lesions of PVL) as PWML. Three antenatal insults were employed to induce PVL in preterm fetuses at gestational day 101-117: (i) hypoxia under intrauterine inflammation, (ii) restriction of artificial placental blood flow, and (iii) restriction of artificial placental blood flow after exposure to intrauterine inflammation. MRI was performed 3-5 days after the insults, and standard histological studies of the PVL validated its findings. Of the 89 necrotic foci detected in histological samples from nine fetuses with PVL, 78 were visualized as PWML. Four of the lesions detected as abnormal findings on MRI could not be histologically detected as corresponding abnormal findings. The diagnostic sensitivity and positive predictive values of histologic focal necrosis visualized as PWML were 0.92 and 0.95, respectively. The four lesions were excluded from these analyses. These data suggest that MRI can visualize PVL necrotic foci as PWML 3-5 days after the injury induction. PWML can spontaneously become obscure with time after birth, so their accurate diagnosis in the acute phase can prevent overlooking mild PVL.

Overview and considerations on MRI research of neonatal punctate white matter lesions / 西安交通大学学报(医学版)

The number of preterm neonates appears to remain high in China in recent years.These subjects are vulnerable to pathogenic factors and have brain lesions easily.Punctate white matter lesions(PWML)are very common(the incidence＞20%).The degeneration in the brain associated with PWML is harmful to the outcomes and hard to be detected.Early diagnosis and prediction of PWML are focuses for pediatric researchers.This paper describes the change patterns and spatial distributions associated with PWML.The factors of individual differences and development during the diagnosis and prognosis are discussed as well.Finally,the paper points out the core problems in developmental brain template construction,individualized diagnosis,and early prediction.

Signal classification by multimodal magnetic resonance imaging on neonatal punctate white matter lesions / 西安交通大学学报(医学版)

Objective To explore the significance of signal classification by multimodal magnetic resonance imaging(MRI)(including conventional MRI,diffusion imaging,and susceptibility-weighted imaging)on neonatal punctate white matter lesions(PWML).Methods Between March 2011 and February 2013,neonates with PWML who underwent 3.0T MRI examination were recruited.The routine protocols included T1 weighted imaging (T1WI),T2 weighted imaging(T2WI),diffusion tensor imaging(DTI),and 3D-enhanced susceptibility-weighted angiography(ESWAN).Apparent diffusion coefficient(ADC)map,magnitude image,and phase image were obtained from DTI and ESWAN,respectively.The signal of PWML was one-to-one observed on T1WI,T2WI, ADC map and magnitude image.The combined signals were classified and the number of cases of each type was counted.Results Totally 84 neonates with PWML were included(preterm/term,47/37).Seven signal types were found and classified into three groups: ① Type Ⅰ was the most,59 cases,accounting for 70.24%,with the performance of high-signal intensity on T1WI,low-signal intensity on T2WI,low-signal intensity on ADC map,and high-signal intensity on magnitude image. ② Type Ⅱ,7 cases,accounting for 8.33%,high-signal intensity on T1WI,low-signal intensity on T2WI,low-signal intensity on ADC map,and low-signal intensity on magnitude image.③ Type Ⅲ - Ⅶ,26 cases,accounting for 30.95%,high-signal intensity on T1WI,low/iso-signal intensity on T2WI,low/iso-signal intensity on ADC map,high/iso-signal intensity on magnitude image.There was no significant difference in the incidence of different signal types between preterm and full-term PWML neonates. Conclusion Magnetic resonance signal may reflect the characteristics of PWML lesions.Signal classification of PWML by multimodal magnetic resonance imaging is helpful in determining injury type and has certain significance in guiding clinical treatment.