ObjectiveGadolinium ethoxybenzyl diethylenetriaminepentaacetic acid (Gd-EOB-DTPA) is a newly developed MR contrast agent. After intravenous injection, Gd-EOB-DTPA is gradually taken up by the hepatocytes and eventually excreted via the biliary pathway without any change to its chemical structure. Because of these characteristics, it can be used as a tracer for quantitative liver function testing. The purpose of this study is to develop a noninvasive method of quantitation of the hepatic function using Gd-EOB-DTPA through the deconvolution analysis.Materials and MethodsAdult New Zealand white rabbits (n = 10, average body weight = 3.5 kg) were used in the present study. Hepatic injury was induced to by the intragastric administration of carbon tetrachloride (CCl4) three times a week for three weeks. Liver enzyme (aspartate aminotransferase, AST; alanine aminotransferase, ALT) levels and the plasma indocyanine green (ICG) retention rate 15 minutes after an intravenous injection of ICG (ICG R15), was checked before and after the three-week administration of CCl4. At the end of experimental period, an observer "blinded" to the treatment given the rabbits performed the histological examination. MRI studies were performed before and after the three-week administration of CCl4 on a 1.5 T scanner using a human extremity coil. After intravenous bolus injection of Gd-EOB-DTPA (0.3 mL of Gd-EOB-DTPA freshly prepared in 2.7 mL of normal saline) through the ear vein, the 250 axial single level dynamic MR images were obtained using a fast low angle shot (FLASH, TR/TE = 11/4.2 msec, flip angle = 15, acquisition time 1 second, slice thickness = 5 mm, matrix = 128×128, field of view = 120 mm) sequence with 1.5 sec time intervals. The time-intensity curves were obtained at the abdominal aorta and the liver parenchyma that was devoid of blood vessels. Deconvolution analysis of the aortic (input function) and hepatic parenchymal (output function) time-intensity curves was performed with a modified Fourier transform technique to calculate the hepatic extraction fraction (HEF). The presence and type of hepatic injury were determined by the histopathologic examination and statistical analysis of the changes of the hepatic enzyme levels, the ICG R15 and Gd-EOB-DTPA HEF values between the time before and after CCl4 administration with Wicoxon signed rank test. Correlation between the Gd-EOB-DTPA HEF and the change of the ICG R15 were analyzed with Pearson's correlation coefficient.ResultsHistopathologic examination showed findings that were compatible with hepatic fibrosis caused by chronic liver injury. The initial blood biochemical studies before the administration of carbon tetrachloride showed that the mean AST and ALT levels were 39.8±5.2 IU/L and 59.1±11.7 IU/L, respectively. The AST and ALT levels increased to 138.4±50.5 IU and 172.0±71.6 IU/L, respectively, after the three week administration of CCl4. The ALT and AST levels were significantly increased after the three weeks of CCl4 administration (p = 0.018). The ICG R15 values w...
OBJECTIVE The optimal treatment strategy for patients with emergent large vessel occlusion (ELVO) due to underlying severe intracranial atherosclerotic stenosis (ICAS) is unclear. The purpose of this study was to compare treatment outcomes from intracranial angioplasty with or without stenting and intraarterial infusion of a glycoprotein IIb/IIIa inhibitor in patients with ELVO due to severe ICAS, and to investigate predictors of outcome after endovascular therapy in such patients. METHODS A total of 140 consecutive patients with ELVO attributable to severe ICAS underwent endovascular therapy at two stroke centers (A and B). Intracranial angioplasty/stenting was primarily performed at center A and intraarterial infusion of glycoprotein IIb/IIIa inhibitor (tirofiban) at center B. Data from both centers were prospectively collected into a database and retrospectively analyzed. RESULTS Overall, successful reperfusion was achieved in 95% (133/140) of patients and a good outcome in 60% (84/140). The mortality rate was 7.9%. Symptomatic hemorrhage occurred in 1 patient. There were no significant differences in the rates of successful reperfusion, symptomatic hemorrhage, 3-month modified Rankin scale score 0-2, and mortality between the two centers. Multivariate logistic regression analysis revealed the only independent predictor of good outcome was a history of previous stroke or transient ischemic attack (TIA) (odds ratio 0.254, 95% confidence interval 0.094-0.689, p = 0.007). CONCLUSIONS Both intracranial angioplasty/stenting and intraarterial infusion of a glycoprotein IIb/IIIa inhibitor are effective and safe in the treatment of underlying severe ICAS in acute stroke patients with ELVO. In addition, a lack of a history of stroke/TIA was the only independent predictor of good outcome after endovascular therapy in such patients.
Advanced age, male sex, and an aneurysm location requiring extensive arachnoid dissection (MCA aneurysms and multiple concomitant aneurysms at the MCA and ACoA) are all correlated with the occurrence of a subdural hygroma and CSDH after unruptured aneurysm surgery. The critical age affecting such an occurrence is 60 years.
A higher incidence of olfactory dysfunction was found in those patients in whom a contralateral pterional approach and a pterional approach for an AComA aneurysm were used. Another major risk factor was an age of 55 years and older.
Detailed visualization of peripheral pulmonary arteries is well within the scope of advanced CT techniques. Electron-beam CT has minor advantages in analyzing paracardiac arteries, probably because of reduction of motion artifacts and higher contrast enhancement. Further studies are needed to establish whether electron-beam CT allows a more confident diagnosis of emboli in these vessels.
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