AJNR. American journal of neuroradiology
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AJNR Am J Neuroradiol · Nov 2007
Imaging characteristics of dacryocystocele diagnosed after surgery for sinonasal cancer.
A dacryocystocele forms when tears accumulate within the lacrimal sac as a result of an obstruction more distally in the lacrimal drainage apparatus, which may occur as a complication of sinonasal surgery. The purpose of this study was to define the imaging characteristics of a postoperative dacryocystocele occurring after surgery for sinonasal cancer and to review the anatomy of the nasolacrimal drainage apparatus. ⋯ Dacryocystocele after surgery for sinonasal cancer has a characteristic appearance on CT and MR imaging. Familiarity with this complication of sinonasal surgery and its appearance on imaging will enable radiologists to avoid misinterpreting dacryocystocele as a recurrent tumor or another process.
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AJNR Am J Neuroradiol · Nov 2007
Sixty-four-row multisection CT angiography for detection and evaluation of ruptured intracranial aneurysms: interobserver and intertechnique reproducibility.
The purpose of this work was to assess intertechnique and interobserver reproducibility of 64-row multisection CT angiography (CTA) used to detect and evaluate intracranial aneurysms. ⋯ Sixty-four-row multisection CTA is an imaging method with a good interobserver reproducibility and a high sensitivity and specificity for the detection and the morphologic evaluation of ruptured intracranial aneurysms. It may be used as an alternative to DSA as a first-intention imaging technique in patients with SAH.
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AJNR Am J Neuroradiol · Oct 2007
Improved identification of intracortical lesions in multiple sclerosis with phase-sensitive inversion recovery in combination with fast double inversion recovery MR imaging.
Accurate detection and classification of purely intracortical lesions in multiple sclerosis (MS) are important in understanding their role in disease progression and impact on the clinical manifestations of the disease. However, detection of these lesions with conventional MR imaging remains a challenge. Although double inversion recovery (DIR) has been shown to improve the sensitivity of the detection of cortical lesions, this sequence has low signal-to-noise ratio (SNR), poor delineation of lesion borders, and is prone to image artifacts. We demonstrate that intracortical lesions can be identified and classified with greater confidence by the combination of DIR with phase-sensitive inversion recovery (PSIR) images. ⋯ Reliable detection and classification of intracortical lesions in MS are greatly improved by combined use of PSIR and DIR.
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AJNR Am J Neuroradiol · Oct 2007
ReviewRadiation dose-reduction strategies for neuroradiology CT protocols.
Within the past 2 decades, the number of CT examinations performed has increased almost 10-fold. This is in large part due to advances in multidetector-row CT technology, which now allows faster image acquisition and improved isotropic imaging. The increased use, along with multidetector technique, has led to a significantly increased radiation dose to the patient from CT studies. ⋯ Neuroradiologists are familiar with factors that affect patient dose such as pitch, milliamperes, kilovolt peak (kVp), collimation, but with increasing attention being given to dose reduction, they are looking for additional ways to further reduce the radiation associated with their CT protocols. In response to increasing concern, CT manufacturers have developed dose-reduction tools, such as dose modulation, in which the tube current is adjusted along with the CT acquisition, according to patient's attenuation. This review will describe the available techniques for reducing dose associated with neuroradiologic CT imaging protocols.
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AJNR Am J Neuroradiol · Oct 2007
Diffusion tensor MR imaging tractography of the pyramidal tracts correlates with clinical motor function in children with congenital hemiparesis.
Children with congenital hemiparesis have greater asymmetry in diffusion parameters of the pyramidal tracts compared with control subjects. We hypothesized that the asymmetry correlates with the severity of hemiparesis and that diffusion metrics would be abnormal in the affected tracts and normal in the unaffected tracts. ⋯ Asymmetry in fractional anisotropy, transverse diffusivity, and mean diffusivity, as well as the degree of abnormality in the actual values of the affected pyramidal tracts themselves, correlates with the severity of motor dysfunction in infants and children with congenital hemiparesis from different causes. This suggests that abnormalities detected by diffusion tensor MR imaging tractography in the affected pyramidal tract are related to the functional ability of the affected pyramidal tract, regardless of the etiology of motor dysfunction.