Fast magnetic resonance imaging in steady-state precession (true FISP) in the prenatal diagnosis of a congenital brain teratoma

Teratomas are the most common congenital intracranial tumor. Although fetal magnetic resonance (MR) imaging is becoming more popular for prenatal diagnosis, only 2 cases of congenital intracranial teratoma have been reported, and these cases relied on half-Fourier single-shot turbo spin echo (HASTE) imaging. We report the first known case of congenital intracranial teratoma diagnosed by means of a fast imaging in steady-state precession (true FISP) MR sequence. True FISP can be obtained in almost 20 seconds and provides superior contrast resolution compared with HASTE.     

Does Tweeting Improve Citations? One-Year Results From the TSSMN Prospective Randomized Trial

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Early-life stress, corpus callosum development, hippocampal volumetrics, and anxious behavior in male nonhuman primates

Male bonnet monkeys (Macaca radiata) were subjected to the variable foraging demand (VFD) early stress paradigm as infants, MRI scans were completed an average of 4 years later, and behavioral assessments of anxiety and ex-vivo corpus callosum (CC) measurements were made when animals were fully matured. VFD rearing was associated with smaller CC size, CC measurements were found to correlate with fearful behavior in adulthood, and ex-vivo CC assessments showed high consistency with earlier MRI measures. Region of interest (ROI) hippocampus and whole brain voxel-based morphometry assessments were also completed and VFD rearing was associated with reduced hippocampus and inferior and middle temporal gyri volumes. The animals were also characterized according to serotonin transporter genotype (5-HTTLPR), and the effect of genotype on imaging parameters was explored. The current findings highlight the importance of future research to better understand the effects of stress on brain development in multiple regions, including the corpus callosum, hippocampus, and other regions involved in emotion processing. Nonhuman primates provide a powerful model to unravel the mechanisms by which early stress and genetic makeup interact to produce long-term changes in brain development, stress reactivity, and risk for psychiatric disorders.     

Facilitation of memory by contextual cues in patients with diencephalic or medial temporal lobe dysfunction

Item-context binding is crucial for successful episodic memory formation, and binding deficits have been suggested to underlie episodic-memory deficits. Here, our research investigated the facilitation of cued recall and recognition memory by contextual cues in 20 patients with Korsakoff's amnesia, 20 unilateral medial-temporal lobectomy (MTL) patients and 36 healthy controls. In a computerized task participants had to learn 40 nouns that were randomly combined with a photograph of an everyday scene. Korsakoff patients showed a general memory deficit in both the cued recall and the recognition condition. A less severe memory impairment was found in the patients with medial-temporal lobectomy. Contextual cues facilitated cued recall to an equal extent in unilateral temporal lobectomy patients and healthy controls. However, no facilitation was observed in Korsakoff patients, suggesting an impairment in item-context binding during cued recall tasks. In contrast to the presumed exclusive dependency of recognition memory on item information, all groups equally profited from the contextual cues in recognition tasks. Our findings show that unilateral lesions as with MTL result in normal binding of context and item information, while bilateral dysfunction of the hippocampal-diencephalic system results in impaired context and item binding.     

Intracranial subdural osteoma: A rare benign tumor that can be differentiated from other calcified intracranial lesions utilizing MR imaging

We report the magnetic resonance (MR) imaging characteristics of subdural osteoma and other benign calcified intracranial lesions to highlight imaging features that differentiate between these disease entities. A 63-year-old woman presented with progressively altered mental status. Non-contrast CT demonstrated a densely calcified right middle cranial fossa extra-axial mass. MR imaging of the lesion demonstrated T1 and T2 hypointensity without evidence of contrast enhancement, parenchymal abnormality, or connection to adjacent venous structures. Diffusion weighted imaging demonstrated markedly decreased signal intensity and artificially reduced diffusion on apparent diffusion coefficient map. Histologically, the tumor was predominantly composed of lamellar bone and small fragments of residual dura consistent with subdural osteoma. This case demonstrates that radiological examination can provide additional insight into the origin of intracranial osteomas (extradural versus subdural versus sinonasal) and help distinguish from other diagnostic considerations including benign meningeal ossification and calcified meningioma prior to surgical resection.