AJNR. American journal of neuroradiology
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AJNR Am J Neuroradiol · Aug 2006
Comparative Study3T 1H-MR spectroscopy in grading of cerebral gliomas: comparison of short and intermediate echo time sequences.
Echo time (TE) can have a large influence on the spectra in proton MR spectroscopy ((1)H-MR spectroscopy). The purpose of this study was to comparatively assess the diagnostic value of 3T single-voxel (1)H-MR spectroscopy with short or intermediate TEs in grading cerebral gliomas. ⋯ Metabolite ratios were significantly different between short and intermediate TE. Cho/Cr and LL/Cr ratios at either TE were similarly useful in differentiating high-grade gliomas from low-grade gliomas. If only a single spectroscopic sequence can be acquired, short TE seems preferable because of poor lactate inversion at intermediate TE on 3T single-voxel (1)H-MR spectroscopy.
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AJNR Am J Neuroradiol · Aug 2006
Comparative StudyProton MR spectroscopy in neonates with perinatal cerebral hypoxic-ischemic injury: metabolite peak-area ratios, relaxation times, and absolute concentrations.
Results from cerebral proton (1)H-MR spectroscopy studies of neonates with perinatal hypoxic-ischemic injury have generally been presented as metabolite peak-area ratios, which are T1- and T2-weighted, rather than absolute metabolite concentrations. We hypothesized that compared with (1)H-MR spectroscopy peak-area ratios, calculation of absolute metabolite concentrations and relaxation times measured within the first 4 days after birth (1) would improve prognostic accuracy and (2) enhance the understanding of underlying neurochemical changes in neonates with neonatal encephalopathy. ⋯ Metabolite concentrations, in particular [NAA], enhance the prognostic accuracy of cerebral (1)H-MR spectroscopy-[NAA] was the only measurable to discriminate among all (control, normal/mild, and severe/fatal outcome) groups. However, peak-area ratios are more useful prognostic indicators than concentration ratios because they depend on metabolite concentrations and T2s, both of which are pathologically modulated. Concentration ratios depend only on the concentrations of the constituent metabolites. Increased Cr T2 may provide an indirect marker of impaired cellular energetics, and similarly, NAA T2 may constitute an index of exclusively neuronal energy status. Our recommendation is to collect data that enable calculation of brain metabolite concentrations. However, if time constraints make this impossible, metabolite peak-area ratios provide the next best method of assigning early prognosis in neonatal encephalopathy.
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AJNR Am J Neuroradiol · Aug 2006
Procedural complications of coiling of ruptured intracranial aneurysms: incidence and risk factors in a consecutive series of 681 patients.
To report the incidence of procedural complications of coiling of ruptured intracranial aneurysms leading to permanent disability or death in a consecutive series of 681 patients and to identify risk factors for these events. ⋯ Procedural complication rate of coiling of ruptured aneurysms leading to disability or death is 5.9%. In this series, the use of a temporary supporting balloon in the treatment of wide-necked aneurysms was the only risk factor for the occurrence of complications.
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AJNR Am J Neuroradiol · Aug 2006
Comparative StudyPain response in the first trimester after percutaneous vertebroplasty in patients with osteoporotic vertebral compression fractures with or without bone marrow edema.
Presence of bone marrow edema (BME) in osteoporotic vertebral compression fractures (VCF) detected by MR imaging as selection criterion for percutaneous vertebroplasty (PV) is speculative. To clarify significance of BME in VCF, we assessed pain response after PV in patients with VCF with full BME versus patients with VCF with absent BME. ⋯ Pain decrease after PV in patients with VCF is more frequently observed when full BME is present. Because 71% of patients with VCF with absent BME responded favorably on pain, PV should not be withheld based on absence of BME alone.
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AJNR Am J Neuroradiol · Aug 2006
Endovascular treatment of intracranial vertebral artery dissections with stent placement or stent-assisted coiling.
Endovascular treatment with stent placement or stent-assisted coiling was recently introduced as an alternative to parent artery occlusion in intracranial vertebral artery dissections. We describe the efficacy and limitations of this method. ⋯ Intracranial vertebral artery dissections were acceptably treated with stent placement or stent-assisted coiling, and the patency could be preserved at follow-up. However, the efficiency of stent placement alone for intracranial vertebral artery dissecting aneurysm was limited. Stent-assisted coil embolization or double stent placements are a viable alternative for complete occlusion of dissecting aneurysms.