Table 2.
MRI evaluation scales of the severity of preterm WMI.
| Miller et al.14 | Woodward et al.7 | Kidokoro et al.15 | Martinez-Biarge et al.10 | |
|---|---|---|---|---|
| Study | Prospective | Prospective | Prospective | Retrospective |
| Population (n) Gestational age (mean) BW (g) |
32 VLWB 29 weeks |
167 VLBW. Two cohorts. 27.3 weeks; BW 1014 27.1weeks; BW 948 |
Two cohorts 97 preterm (<30 weeks) (26.7 weeks; BW 949) 22 term healthy (39.1 week; BW 3285) |
82 (62 with 2 MRI studies) (29.8 weeks; BW 1453) |
| Period | 2000–2002 |
Two cohorts: 1998–2000 New Zealand; 2001–2002 Melbourne |
2007–2010 | 2003–2014 |
| Age MRI (PMA = postmenstrual age in weeks) |
Two sequential studies Early (31.9 weeks PMA) At term (36.5 weeks PMA) |
Term equivalent age | 36–42 weeks PMA |
138 sequential studies Early (0–2 weeks) Intermediate (2–6 weeks) TEAa (<16 weeks) |
| MRI acquisition | 1.5 T (T1 SE, T2 SE) | 1.5 T (T1, T2) | 3 T (T1, FSE T2) | 1.5 T (T1 IR, T2 DWI) |
| WM evaluation | Number and size of foci of hyperintensity on T1 |
Five variables (scores 1–3) 1. WM abnormality 2. Periventricular WM loss 3. Cystic abnormality 4. Ventricular dilatation 5. Thinning of corpus callosum |
Six variables (0–4) 1. Cystic lesions 2. Focal abnormality 3. Myelination delay 4. Thinning of corpus callosum 5. Dilated ventricles 6. Volume reduction |
Variables depending on MRI 0–2 weeks after birth: focal lesions (T1/DWI) 2–6 weeks after birth: focal or cystic lesions TEAa: focal (T1) or cystic, myelination, volume reduction |
| WMI global score |
1. Normal 2. Minimal: 3 or fewer foci <2 mm 3. Moderate: 3 or more foci or area >2 mm, but <5% of the hemisphere 4. Severe: >5% of the hemisphere |
1. Normal (scores 5 and 6) 2. Mild (scores 7–9) 3. Moderate (scores 10–12) 4. Severe (scores 13–15) |
1. No lesion (scores 0 and 2) 2. Mild (scores 3 and 4) 3. Moderate (scores 5 and 6) 4. Severe (score ≥7) (a score for gray matter and a global brain score are added) |
Four grades of WMI taking into account the moment of evaluation |
| Volume loss evaluation | No | Yes | Yes | Yes (TEAa) |
| Evaluation | Two blinded pediatric neuroradiologist | Two blinded investigators (neuroradiologist, neonatologist) | Single neonatal neurologist (inter- and intraobserver reliability in 20 studies >90%) | NR |
| Cortical gray matter evaluation | No |
1. Signal abnormality 2. Quality of gyral maturation 3. Size of subarachnoid space |
1. Signal abnormality 2. Delayed gyration 3. Dilated extracerebral CSF space |
No |
| Deep gray matter evaluation | No | No | Size and signal intensity of basal ganglia and thalami in an axial section | No |
| Cerebellum evaluation | No | No | Transcerebellar diameter and cerebellar signal intensity | No |
| Incidence of WMI |
56% with WMI: • 31% mild • 21.8% moderate • 3% severe |
72% with WMI • 51% mild • 17% moderate • 4% severe (49% with gray matter lesions) |
24% with WMI (24% with cerebellar injury) |
Selected population |
| Follow-up |
No (comparison with CUS findings only) |
Yes Moderate and severe WMI predicted adverse otucome |
No | No |
aTerm equivalent age.