Each intracranial aneurysm in this study had at least one spiral flow. The WSS was lower and OSI was higher at the apex of the spiral flow than the whole aneurysmal wall.

Purpose:To visualize the hemodynamics of the intracranial arteries using time-resolved three-dimensional phasecontrast (PC)-MRI (4D-Flow). Materials and Methods:MR examinations were performed with a 1.5T MR unit on six healthy volunteers (22-50 years old, average ϭ 30 years). 4D-Flow was based on a radiofrequency (RF)-spoiled gradient-echo sequence, and velocity encoding (VENC) was performed along all three spatial directions. Measurements were retrospectively gated to the electrocardiogram (ECG), and cine series of three-dimensional (3D) data sets were generated. The voxel size was 1 ϫ 1 ϫ 1 mm, and acquisition time was 30 -40 minutes. 4D data sets were calculated into time-resolved images of 3D streamlines, 3D particle traces, and 2D velocity vector fields by means of flow visualization software. Results:We were able to see the 3D streamlines from the circle of Willis to the bilateral M2 segment of the middle cerebral arteries (MCAs). Time-resolved images of 3D particle traces also clearly demonstrated intracranial arterial flow dynamics. 2D velocity vector fields on the planes traversing the carotid siphon or the basilar tip were clearly visualized. These results were obtained in all six volunteers. Conclusion:4D-Flow helped to elucidate the in vivo 3D hemodynamics of human intracranial arteries. This method may be a useful noninvasive means of analyzing the hemodynamics of intracranial arteries in vivo.

BACKGROUND AND PURPOSE:The stiffness of intracranial tumors affects the outcome of tumor removal. We evaluated the stiffness of 4 common intracranial tumors by using MR elastography and tested whether MR elastography had the potential to discriminate firm tumors preoperatively.

With the elastic belt, miscalculation of the pancreatic stiffness was reduced. MRE showed differences of stiffness between normal pancreas and pancreatic lesions.

A 31-year-old man presented with a ruptured right extracranial vertebral artery aneurysm associated with neurofibromatosis type 1, manifesting as acute onset of right neck and shoulder pain, and right supraclavicular mass. Three-dimensional computed tomography angiography showed a large aneurysm involving the right extracranial vertebral artery associated with a pseudoaneurysm. The aneurysm was successfully treated by transarterial endovascular trapping with detachable coils. Extracranial vertebral artery aneurysm is rare, but the mortality of ruptured cases is extremely high, so early diagnosis and early treatment are important. The present case shows that endovascular treatment was very effective.

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Pseudo-continuous arterial spin labeling (PCASL) can measure tumor blood flow (TBF) reliably. We investigated meningioma TBF using PCASL and assessed for any correlation with histopathological microvascular density (MVD) and the World Health Organization (WHO) classification. Conventional MRI with contrast T1-weighted images and PCASL were acquired with a 3 T scanner before surgery in 25 consecutive patients with meningiomas. Using the PCASL perfusion map, the mean and maximum TBF were calculated from regions of interest placed in the largest cross-sectional plane of each tumor. Tissue sections from 16 patients were stained with CD31 to evaluate MVD and were assigned a WHO classification. The TBFs were statistically compared with MVD and the histopathological meningioma subtypes. There were 16 meningothelial meningiomas, four angiomatous meningiomas, two fibrous meningiomas, one transitional meningioma, and two atypical meningiomas. We observed significant correlation between MVD and both mean and maximum TBF (p < 0.05). The mean and maximum TBF ((mean)TBF, (max)TBF) in angiomatous meningiomas are significantly higher than that in non-angiomatous meningiomas (p < 0.05). PCASL is useful in assessing meningioma vascularity, and in differentiating angiomatous meningiomas from non-angiomatous meningiomas.