MRI in cerebral intraventricular hemorrhage: analysis of 50 consecutive cases.

MRI of intraventricular haemorrhage (IVH) has not been studied formally. We aimed to describe the degradation rate and patterns shown on 1.5 T MRI in IVH, comparing them to other coexisting brain hemorrhage. We studied 50 consecutive cases using T1-, proton-density, and T2-weighted images. IVH was seen in two forms: layered (free-flowing in ventricles) (37 cases) and/or clotted (31). Both were best shown by proton-density image. Layered IVH was seen in the dependent portions of the lateral ventricles with fluid ("blood-CSF") levels, degrading more slowly than both clotted IVH and intraparenchymal hemorrhages (IPH) (acute blood products persisting for several more days; P < 0.05). Clotted IVH degraded at a rate comparable to IPH. IVH cleared rapidly and did not form hemosiderin. Subarachnoid hemorrhage (SAH) cleared faster and was less conspicuous than IVH. Hypertensive (22), aneurysmal (11), traumatic (2), idiopathic (9), or vascular malformation-related (6) IVH were seen. IVH coexisted with IPH (30) or SAH (12), or both (12). The high rate of layering with blood-CSF levels in IVH is most likely due to different densities of blood components and CSF and the fibrinolytic capability of the latter. Delayed degradation of layered IVH probably reflects high intraventricular oxygen and glucose content. Further study is necessary to determine if MRI characteristics of IVH are helpful in excluding other intraventricular diseases such as neoplasia and pyocephalus.