Cerebral perfusion in children: detection with dynamic contrast-enhanced T2*-weighted MR images.

Cerebral perfusion dynamics were assessed with dynamic contrast material-enhanced T2*-weighted magnetic resonance (MR) imaging in 33 subjects aged 3-20 years. Group A (n = 20) had sickle cell anemia without clinical evidence of cerebrovascular disease. Group B (n = 13) consisted of 12 patients with cerebrovascular disease and homozygous sickle cell anemia and one patient without that anemia. All subjects underwent conventional MR imaging and a dynamic study in which a spoiled gradient-echo pulse sequence was used to generate images (acquisition time, 2.5 seconds) during injection of a compact bolus of gadopentetate dimeglumine (0.1 mmol/kg). For qualitative analysis, the dynamic images were displayed in cine mode. Group A demonstrated symmetric sequential region patterns of loss of signal intensity within 10 seconds of injection. Group B exhibited signal loss asymmetries that corresponded to cerebrovascular lesions on conventional MR images. Quantitative analysis enabled estimation of hemodynamic parameters, including relative cerebral blood volume, relative cerebral blood flow, and mean transit time. This method of assessment of cerebral perfusion dynamics complements conventional MR imaging.