© Pol J Radiol, 2010; 75(3): 47-50 Jurkiewicz J et al – Usefulness of magnetic resonance imaging with SWI… A of the cerebellum, venous malformations, as well as amy- loid angiopaties and radiotherapy [9–11]. In order to limit the risk of the aforementioned complications, neurosurgical modifications of anatomical hemispherectomy or functional hemispherectomy are applied [12]. In the case presented by us, the operation consisted in a selective resection of a massive tumor destroying the pos- terior part of the left hemisphere. Due to a slow growth of the tumor mass, there appeared some atrophic lesions of the brain in that region, connected with compression exert- ed by the tumor. There was a large asymmetry between the hemispheres. Due to the tumor growth and widening of the brain ventricles, the size of the brain increased, leading to an excessive increase in the circumference of the child’s head (macrocrania). After resecting the large tumor mass and opening the ventricle of the brain, the internal hydro- cephalus resolved and there appeared a significant dispro- portion between the brain size and the volume of the skull. This led to a substantial subarachnoid fluid collection and created conditions similar to the ones observed in patients after anatomical hemispherectomies. A very important factor predisposing to the presented com- plication was the presence of the extensive bone defect in the cranial vault in the left parietal-temporal-occipital region. This caused abnormal fluctuations in the intracra- nial pressure, depending on the body position and patient’s activity status. Periodically, the child experienced distur- bances in blood coagulation connected with the introduced radio-/chemotherapy, which contributed to the appearance of the aforementioned posthemorrhagic complications. At present, due to the development of the state-of-the-art neurosurgical techniques, cerebral hemosiderosis, being solely the consequence of surgeries, is diagnosed very rarely. B C Figure 2. (A) SWI sequence, (B) transverse planes and (C) sagittal plane: laminar loss of signal intensity around the brain stem, cerebrum and cerebellum, which indicates hemosiderin deposition. Hemorrhage inside the posterior horn of the right lateral ventricle. A rapid development of different diagnostic methods, including the MRI, contributes not only to a better plan- ning of neurosurgical procedures, but also to a more precise recognition of postoperative complications. An example for that would be the introduction of MRI imaging with SWI sequence. This is a 3D gradient-echo sequence with a very high spatial resolution. This type of imaging was primarily used for visualization of the venous system, as it applies the pragmatic properties of deoxyhemoglobin running in veins [13]. Soon, it turned out that SWI uses the differences in magnetic susceptibility of tissues which cause differ- ences in phases between regions including paramagnetic 49