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BACKGROUND AND PURPOSE: Conventional MR imaging techniques cannot produce optimal images of bone structures because bone has little water and a very short T2 life span. The aim of this study was to investigate the clinical feasibility of skull MR imaging using the zero TE sequence in patients with head trauma by assessing its diagnostic image quality and quantitative measurement compared with CT images. MATERIALS AND METHODS: Thirteen enrolled patients with head trauma were assessed using brain CT and skull MR imaging. Image quality was graded on a 5-point Likert scale to compare the 2 modalities. To evaluate quantitative analyses between the 2 imaging modalities, we measured skull thickness and normalized bone tissue signal. Interobserver reliability was assessed using weighted statistics and the intraclass correlation coefficient. RESULTS: Both imaging techniques clearly depicted skull fractures in all 13 patients. The mean scores for skull MR imaging and CT were 4.65 Ϯ 0.56 and 4.73 Ϯ 0.45 (P ϭ .157), respectively, with substantial interobserver agreement (P Ͻ .05). The 2 imaging modalities showed no difference in skull thickness (P ϭ .092) and had good correlation (r 2 ϭ 0.997). The mean value of normalized bone tissue signal among the 3 layers of the skull was relatively consistent (P ϭ .401) with high interobserver agreement (P Ͻ .001). CONCLUSIONS: Zero TE skull MR imaging has diagnostic image quality comparable with that of CT images. It also provides consistent results on the quantitative measurement of cortical bone with CT images.

BACKGROUND Flow visualization in time-of-flight magnetic resonance angiography (TOF MRA) is limited for treated intracranial aneurysms owing to magnetic susceptibility and radiofrequency shielding. OBJECTIVE To assess the clinical usefulness of noncontrast-enhanced magnetic resonance angiography (MRA) using a silent scan (silent MRA) as a follow-up imaging modality in patients with treated intracranial aneurysms. METHODS A total of 119 patients with 126 treated aneurysms underwent silent MRA and TOF MRA during the same scan session. Two neuroradiologists independently assessed overall image quality and visualization of the treated site using a 5-point Likert scale to compare the 2 image sets. We used receiver operating characteristic (ROC) curve analysis to investigate the diagnostic performance of the 2 MRA methods in evaluating aneurysm occlusion. Interobserver reliability was also assessed using weighted kappa statistics. RESULTS The overall image quality scores of silent MRA and TOF MRA were 4.04 ± 0.22 and 4.64 ± 0.48, respectively (P < .001), and interobserver agreement was substantial (P < .001). For the treated site, the score of flow visualization on silent MRA was higher than that on TOF MRA, 3.94 ± 0.94 vs 2.59 ± 1.37 (P < .001), with substantial interobserver agreement (P < .001). ROC curve analysis showed that silent MRA was superior to TOF MRA in diagnostic performance (area under the curve [AUC] = 0.962; 95% CI: 0.931-0.982 vs AUC = 0.843; 95% CI: 0.792-0.886; P < .001). CONCLUSION Silent MRA can be useful to evaluate treated intracranial aneurysms during follow-up without radiation exposure and use of contrast material. It is characterized by higher diagnostic performance and superior visualization for the treated site.