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On T2-weighted MR images, the pontine tegmentum frequently shows a signal of high intensity in neurologically healthy individuals. We examined whether the signal intensity of the pontine tegmentum normally differs from that of the pontine base. We evaluated the signal intensity of the pontine tegmentum and pontine base on T2-weighted images from 38 neurologically healthy subjects. The subjects included 29 adults (16 males and 13 females, age range 23-48 years, mean age 39.5 years) and 9 children (4 boys and 5 girls (age range 4-9 years mean age 6.5 years). We compared the contrast-to-noise ratio (CNR) between the tegmentum and the base in the upper pons, midpons and lower pons, and evaluated the signal intensity ratio of the tegmentum to the base. The CNR was significantly higher for the tegmentum than the base at each level of the pons (P<0.0001), and the signal intensity ratio of the tegmentum to the base in the upper pons was significantly higher in children than in adults (P<0.005). On T2-weighted images, a high signal intensity of the pontine tegmentum is frequently seen in neurologically healthy subjects. This finding should not be considered abnormal, particularly in children.

Purpose: To evaluate MR findings at subacute and chronic stages after neonatal periventricular-intraventricular hemorrhage (PIVH), and to determine the clinical significance of follow-up MR., Material and Methods: Twenty-six children (estimated gestational age, 23-39 weeks; mean 29 weeks) with a history of previous PIVH underwent MR examination during their subacute and chronic clinical courses. PIVHs were initially detected with ultrasound examination in all cases. PIVH was divided into three grades (mild, moderate, and severe) according to the findings at the initial US studies, which were correlated to the MR findings., Results: Abnormal signal intensities related to hemorrhage were demonstrated in 10 of 21 patients (47.6%) on initial MR studies; the very low signal intensities on T2-weighted images found on the periventricular wall with a linear or a spotty shape had disappeared at one year after the initial US. The children with ventriculomegaly and periventricular leukomalacia (PVL) were increased in number on the follow-up studies., Conclusion: MR imaging provided valuable information about the consequences of neonatal PIVH such as developments of ventriculomegaly or PVL. It is noteworthy that hemorrhagic lesions could not be detected in half of the cases at the subacute or chronic stage of PIVH.

MR imaging of a patient with cortical blindness revealed areas of abnormal signal bilaterally in the lateral putamen and the striate cortices. The coronal T2-weighted image clearly demonstrated the selective involvement of the bilateral striate cortices. The differential diagnosis and the vulnerability of the striate cortex are discussed.

Purpose: To evaluate magnetic resonance (MR) signal intensities of orbital pseudotumors on short inversion time inversion-recovery (STIR) images and to predict the effect of treatment., Materials and Methods: Sequential MR examinations were performed in 17 patients with orbital pseudotumors, before and after treatment. All patients underwent MR imaging with T1- and T2-weighted spin-echo or fast spin-echo sequences, and STIR sequences with two 0.5-T systems. Quantitatively and qualitatively, the differences in signal intensities among three therapeutic response groups (good, mild, and no responses) were analyzed for each pulse sequence., Results: Quantitatively, both contrast and contrast-to-noise ratio on STIR images corresponded well to the results of response to therapy for all background markers; contrast and contrast-to-noise ratio values in the good response group were the largest, while those in the no response group were the smallest (P < .0001). Qualitatively, the signal intensities of the lesions in the good response group were interpreted as hyperintense to the cerebral cortex in 14 (93%) or 11 (73%) of 15 lesions by two observers, respectively, while in the no response group, both observers assessed 16 (89%) of 18 lesions as hypo- or isointense to the muscle (P < .0001)., Conclusion: STIR images showed a variety of signal intensities in the lesions, and the signal intensities on the STIR images helped predict the response to the therapy in orbital pseudotumors.