Intelligence and Medial Temporal Lobe Function in Older Adults: A Functional MR Imaging-Based Investigation • D.M. Yousem, M.A. Yassa, C. Cristinzio, I. Kusevic, M. Mohamed, B.S. Caffo, and S.S. Bassett
In this interesting prospective study, the influence of intelligence and education on cortical activation of the temporal lobes was studied. The authors recruited 38 adults and subjected them to auditory paradigms thought to activate the medial temporal lobes. Results of fMRI were then correlated with IQs and educational levels (assuming there is a relationship between both). All subjects had normal IQs and time spent in education varied widely. The degree of activation did not correlate with IQs or levels of education, implying these need not be taken into consideration when designing fMRI studies.
Diffusion Tensor Imaging Shows Different Topographic Involvement of the Thalamus in Progressive Supranuclear Palsy and Corticobasal Degeneration • A. Erbetta, M.L. Mandelli, M. Savoiardo, M. Grisoli, A. Bizzi, P. Soliveri, L. Chiapparini, S. Prioni, M.G. Bruzzone, and F. Girotti
Progressive supranuclear palsy and corticobasal degeneration have different imaging, pathologic, and, at times confusing, clinical features. In this study, the investigators decided to use diffusion tensor imaging to assess possible microstructural abnormalities in the thalami and their cortical connections in these 2 diseases. After measuring fractional anisotropy in several thalamic, white matter, and cortical locations, they found that in PSP, anisotropy was elevated in the anterior thalami but decreased in white and superficial gray matter. In CBD, FA was asymmetrically elevated only in the motor thalami but was also high in many regions of white matter and cortex. They suggest DTI may be used to differentiate these 2 movement disorders.
Added Value and Diagnostic Performance of Intratumoral Susceptibility Signals in the Differential Diagnosis of Solitary Enhancing Brain Lesions: Preliminary Study • H.S. Kim, G.-H. Jahng, C.W. Ryu, and S.Y. Kim
The quest to find yet another MR imaging sequence that may differentiate solitary metastasis from primary brain tumors continues. In this article, the authors evaluated the added value of susceptibility abnormalities seen inside brain masses in 64 patients. They subjectively attempted to predict the nature of the masses based on the susceptibility effects as seen on SWI and then quantitatively evaluated their results. In 67% of cases they used the SWI findings to successfully distinguish tumoral from non-tumoral lesions. Malignant lesions, such as glioblastoma multiforme and metastases, had the highest percentages of signal abnormalities and could not be separated. SWI was able to separate GBM from lymphoma in 100% of instances.
Fellows’ Journal Club
Temporal Association of Annular Tears and Nuclear Degeneration: Lessons from the Pediatric Population • A. Sharma, M.S. Parsons, and T.K. Pilgram
The fact that annular tears precede degeneration of the nucleus pulposus in adults is well known, but the authors of this article state that this sequence of events is not clear in children. Based on the hypothesis that tears precede degeneration even at a young age, they studied all lumbar disks in 26 children who had spinal MR imaging. They looked at the association between annular tears and nuclear MR imaging changes. Although we radiologists have always been taught that children are not little adults, in this case they seem to be: degenerated disks generally had accompanying annular tears while degenerated disks with intact annuli were seen in only 3% of patients.
Prevalence of Hippocampal Malrotation in a Population without Seizures • R.P. Gamss, S.E. Slasky, J.A. Bello, T.S. Miller, and S. Shinnar
If you have a busy epilepsy unit in your hospital, you are probably doing coronal imaging looking for mesial temporal sclerosis and finding a significant number of malrorated hippocampi. Many believe that malrotation of the hippocampus is a developmental aberration that is not associated with symptoms. In this study, the authors looked for unilateral malrotations in nearly 500 MR imaging studies that included coronal images of the temporal lobes done in patients without seizures. Only 6 individuals had malrotated hippocampi and thus they concluded that malrotation must be a pathological finding when seen.
Anterior-Segment Retinoblastoma Mimicking Pseudoinflammatory Angle-Closure Glaucoma: Review of the Literature and the Important Role of Imaging • R.R. Saket and M.F. Mafee
Now and then I include a Case Report as a reading recommendation for the fellows and this is such an occasion. When one sees enhancement of the anterior segment of the eye in a child with a retinoblastoma, one should assume that the tumor has extended into the aqueous chamber. This is generally seen in fairly advanced tumors and usually precludes more conservative therapy. Fortunately, in some of these children this enhancement is nothing more than reactive neovascularity. When enhancement is seen only in the anterior eye segment—as in this case—the differential diagnosis changes, but, as demonstrated by the authors, retinoblastoma can also occur in this location.