Usefulness of Silent MR Angiography for Intracranial Aneurysms Treated with a Flow-Diverter Device.

BACKGROUND AND PURPOSE: The flow-diverter device has been established as a treatment procedure for large unruptured intracranial aneurysms. The purpose of this study was to compare the usefulness of Silent MR angiography and time-of-flight MRA to assess the parent artery and the embolization state of the aneurysm after a flow-diverter placement. MATERIALS AND METHODS: Seventy-eight large, unruptured internal carotid aneurysms in 78 patients were the subjects of this study. After 6 months of treatment, they underwent follow-up digital subtraction angiography, Silent MRA, and TOF-MRA, performed simultaneously. All images were independently reviewed by 2 neurosurgeons and 1 radiologist and rated on a 4-point scale from 1 (not visible) to 4 (excellent) to evaluate the parent artery. The aneurysmal embolization status was assessed with 2 ratings: complete or incomplete occlusion. RESULTS: The mean scores of Silent MRA and TOF-MRA regarding the parent artery were 3.18 ± 0.72 and 2.31 ± 0.86, respectively, showing a significantly better score with Silent MRA (P < .01). In the assessment of the embolization of aneurysms on Silent MRA and TOF-MRA compared with DSA, the percentages of agreement were 91.0% and 80.8%, respectively. CONCLUSIONS: Silent MRA is superior for visualizing blood flow images inside flow-diverter devices compared with TOF-MRA. Furthermore, Silent MRA enables the assessment of aneurysmal embolization status. Silent MRA is useful for assessing the status of large and giant unruptured internal carotid aneurysms after flow-diverter placement.

Non-Contrast-Enhanced Silent Scan MR Angiography of Intracranial Anterior Circulation Aneurysms Treated with a Low-Profile Visualized Intraluminal Support Device.

BACKGROUND AND PURPOSE: The Low-Profile Visualized Intraluminal Support Device comprises a small-cell nitinol structure and a single-wire braided stent that provides greater metal coverage than previously reported intracranial stents, as well as assumed strong susceptibility artifacts. This study aimed to assess the benefits of non-contrast-enhanced MRA by using a Silent Scan (Silent MRA) for intracranial anterior circulation aneurysms treated with Low-Profile Visualized Intraluminal Support Device stents. MATERIALS AND METHODS: Thirty-one aneurysms treated with Low-Profile Visualized Intraluminal Support Device stents were assessed by using Silent MRA, 3D TOF-MRA, and x-ray DSA. The quality of MRA visualization of the reconstructed artery was graded on a 4-point scale from 1 (not visible) to 4 (excellent). Aneurysm occlusion status was evaluated by using a 2-grade scale (total occlusion/remnant [neck or aneurysm]). Weighted κ statistics were used to evaluate interobserver and intermodality agreement. RESULTS: The mean scores ± SDs for Silent MRA and 3D TOF-MRA were 3.16 ± 0.79 and 1.48 ± 0.67 (P < .05), respectively, with substantial interobserver agreement (κ = 0.66). The aneurysm occlusion rates of the 2-grade scale (total occlusion/remnant [neck or aneurysm]) were 69%/31% for DSA, 65%/35% for Silent MRA, and 92%/8% for 3D TOF-MRA, respectively. The intermodality agreements were 0.88 and 0.30 for DSA/Silent MRA and DSA/3D TOF-MRA, respectively. CONCLUSIONS: Silent MRA seems to be useful for visualizing intracranial anterior circulation aneurysms treated with Low-Profile Visualized Intraluminal Support Device stents.

Isolation and characterization of C-reactive protein and serum amyloid P component from bovine serum.

C-reactive protein (CRP) and serum amyloid P component (SAP), which are known as acute phase reactants in human and many other animals, were purified from cow sera. Affinity chromatography using HE agarose gel was the most effective method to isolate both CRP and SAP from a large volume of bovine serum. Separation of CRP and SAP from the mixed preparation could be performed by DEAE-cellulose column chromatography, gel permeation HPLC using TSK-G3000SW or affinity chromatography using phosphorylcholine derivatives of bovine serum albumin-conjugated Toyopearl HW 65. Bovine CRP and SAP were identified as genuine CRP- and SAP-class proteins by their cross reactivities with anti-human CRP and anti-human SAP, respectively, and by their homology in amino acid compositions compared with those of human CRP and SAP, respectively. Bovine CRP moved slower than beta-globulin, and bovine SAP moved in the beta-globulin region in agarose gel electrophoresis. Both of them gave single bands in native polyacrylamide gel electrophoresis (PAGE). Bovine CRP and SAP molecular weights were estimated to be 100,600 and 109,500 daltons respectively, by sedimentation equilibrium analysis. Bovine CRP showed 23K dalton subunits by sodium laurylsulfate-PAGE and bovine SAP showed 28K and 32K dalton subunits, both of which were glycosylated and had identical amino acid compositions, indicating that both CRP and SAP molecules are pentamers. In fact, they appeared to have pentameric disk-like configurations in electronmicroscopical examination.