Kim Annink

243 7.0T MRI in neonates artificial ear, led to an acoustic noise level of 58dB(A). If they were both well placed on the ear by using the elastic head band, this decreased to 47.8dB(A). Feasibility of MRI Twelve infants have been included with a median gestational age of 28.2 weeks (range 25.0-41.7), median birthweight of 1127 gram (range 585-4570), median postnatal age at MRI of 95 days (range 31-114) and a median weight at MRI of 3322 gram (range 2715-6335). The clinical indications for the MRI scans were: MRI at term equivalent age because of preterm birth before 28 weeks of gestation (n=7); MRI at term (equivalent) age because of white matter injury (n=2); follow-up MRI at three months of (corrected) age because of a thalamic hemorrhage (n=1) or hemorrhage in the temporal lobe (n=1); follow-up MRI at six weeks because of an arterial ischemic stroke (n=1). Temperature, heart rate, peripheral oxygen saturation and comfort scales were stable before, during and after MRI. No serious adverse events related to the MRI occurred. MRV at 7.0T provided good visibility of the different veins and sinuses i.e. the superficial cerebral veins could be followed in detail (Figure 4A+G). Also SWI at 7.0T was feasible and showed details of the deep venous circulation, i.e. the deep medullary veins (Figure 4B+H). Single-shot T2-weighted imaging (T2WI) at 7.0T demonstrated good grey and white matter contrast. In one patient with a perinatal arterial stroke, perivascular spaces were seen at 7.0T that were not visible at 3.0T (Figures 4C+I). Otherwise, no clinically relevant additional findings were reported by the radiologist (ML) at 7.0T. The grey and white matter differentiation at T1-weighted imaging (T1WI) was suboptimal at 7.0T (Figures 4E+K) MRA showed more peripheral arteries at 7.0T and little noise was visible at 7.0T making it more easy to see the thickness and curves of the arteries (Figures 4D+J). MRS was of improved quality. For example, the patient shown in Figure 4F+L had an SNR of 19 at 7.0T compared to 6 at 3.0T. It was possible to correctly fit more metabolites with a Cramer–Rao lower-bound <20% at 7.0T, such as N-acetylaspartylglutamate, taurine and glycine. 11