Early Periventricular Leukomalacia: MRI and Ultrasonographic Correlation on First one Month of Life

PURPOSE: To compare the findings of early periventricular leukomalacia on MR imaging and on US. MATERIALS AND METHODS: MR imaging was performed in 17 neonates in whom well-demarcated increased periventricular echogenicity was seen on sonography. One more patient was included during the same period because MR imaging of this patient showed a periventricular lesion not suspected on previous US. Initial sonography was performed within 6 days of birth and was followed up between one week and one month later. MR images were obtained within the first month of life. RESULTS: Twelve of 17 neonates showed abnormal periventricular signal intensities on MR imaging. Follow up sonography revealed cystic changes in two cases and heterogeneous hyperechogenicities in three. All patients except the two with cystic changes showed normal periventricular echogenicity on final sonography, On MR imaging,11 cases showed multifocal periventricular increased signals on T1-weighted images, and two cases showed mainly decreased signals representing cysts. Positive findings were more evident on T1-weighted than on T2-weighted image. CONCLUSION: on T1-weighted imaging, the characteristic finding of early periventricular leukomalacia was multifocal periventricular hyper or hypointensities, and hyperintense lesions were more common than hypointense. In the diagnosis of early noncystic periventricular leukomalacia, MR imaging was more objective than US.

Cerebral Fat Embolism Syndrome: Clinical, CT and MR Findings

PURPOSE: CT and MR findings of cerebral fat embolism syndrome(CFES) have been rarely reported, because its diagnosis had been made on the basis of only clinical features in the majority of the cases. The purpose of this study is to describe the clinical, CT, and MR findings in six patients of CFES. MATERIALS AND METHODS: Brain CT and MR findings were retrospectively analyzed in six patients with CFES that was diagnosed on the basis of clinical and MRI findings. All six patients had long bone fractures and showed typical delayed clinical manifestations 2-3 days later. Both CT and MRI were examined in all of six patients. Initial CT scan was performed within 48 hours after trauma in all patients, andfollow-up CT scan was done in 2-11 days in two patients. MRI was done within 2-7 days after trauma in three patients, and 13 days, 18 days, and 45 days in other three patients. Follow-up MRI studies were performed in 2-60 weeks in four patients. Clinical and laboratory findings were analyzed retrospectively with medical records. CT and MRI findings were evaluated with regard to presence or absence of diffuse brain swelling and focal abnormalities of signal intensity(density). RESULTS: CT scans obtained within 2 days after trauma showed diffuse cerebral swelling in five patients and normal findng in one patient. On Tl-weighted MRI, diffuse cerebral swelling was shown in three cases and high signal spots suggesting cerebral petechial hemorrhage were noted in both caudate nuclei and thalami in two cases. On T2-weighted images, high signal spots which were shown on Tl-weighted image were not visible. In all of six cases, multiple lesions of high signal were observed mainly in the cerebral white matters, cerebellum and brain stem, probably representing ischemia/infarct or edema. On the follow-up MRI studies performed within a period from weeks to one month after trauma, the size and the number of the lesions were significantly decreased and these findings were well corresponded with clinical course. CONCLUSION: MR findings' of CFES include diffuse cerebral swelling, petechial hemorrhage and mi- croinfarcts, which characteristically improved in short period. In cases suspected of having CFES, MRI is more useful than CT for initial and follow-up studies because of its high detection rate of lesions and correspondence with clinical course.