Objective: A newly developed application for cerebral C-arm computed tomography perfusion imaging (C-arm CTP) using an angiography system was investigated.Case Presentation: C-arm CTP protocol continuously collects X-ray projection images during 10 back and forth C-arm rotations. From the collected data, cerebral blood flow (CBF), cerebral blood volume (CBV), mean transit time (MTT), and time to peak (TTP) images and multiphase vascular images are reconstructed. C-arm CTP images acquired in patients with acute and chronic major artery occlusion are presented.Conclusion: C-arm CTP using an angiography system is capable of evaluating perfusion parameters in real time, similar to conventional evaluation using multi-detector row CT perfusion (MD-CTP), suggesting its usefulness for examination of ischemic stroke in the angiographic suite.

Objectives: Dissecting aneurysms (DAs) truly localized at the posterior inferior cerebellar artery (PICA) are rare. In addition, bilateral dissecting aneurysms of PICA have never been reported in the literature to our knowledge. We report a case of bilateral DAs of the PICA presented with subarachnoid hemorrhage. Case presentation: A 41-year-old male was referred to the emergency care center of our institute due to sudden onset of posterior cervical pain and dizziness. He was neurologically intact with clear consciousness. CT showed subarachnoid hemorrhage (Fisher Grade 3), and cerebral angiography revealed DAs at anterior medullary segment to lateral medullary segment of bilateral posterior inferior cerebellar artery. He underwent parent artery occlusion (PAO) for the right lesion which showed increase in size during conservative treatment. In spite of negative result of preoperative balloon test occlusion of the right vertebral artery at the origin of the right PICA, he suffered acute infarction in the right cerebellum and medulla after PAO with temporary partial right Wallenberg syndrome and the right limb ataxia. The left lesion showed spontaneous decrease in size at 6 months follow-up angiography. Conclusions: An extremely rare case of bilateral DAs of the PICA is presented. Endovascular treatment for this lesion is feasible though more prudent preoperative evaluation is required.

Summary:When we treat a patient with progressing stroke, STA-MCA bypasses in the acute stage may be effective to minimize the lesion size. However, there was no evidence to support this hypothesis. The aim in this study is to investigate the potential risk and safety of acute stage bypass surgery to determine whether this treatment would be reasonable or not.Over a 4-year period, from April 1 2002 to August 1 2006, we performed 55 STA-MCA bypasses, 23 in the acute stage and 32 in the chronic stage. The chronic stage patients were based on the selection standards of JET study (Japanese EC-IC bypass Trial). Each case was examined by IMP or Xe SPECT within 2 weeks of bypass surgery. Where hyperperfusion was evident, cases were divided into one of 2 groups, according to the location of the hyperperfusion: Group A demonstrating it locally, and Group B demonstrating it hemispherically. Symptomatic cases were also divided into 2 groups according to the degree of severity, with the mild group exhibiting such symptoms as headaches or transient psychological disturbance, and the severe group reporting convulsions or conscious disturbance, etc. We examined the frequency of hyperperfusion syndrome and the safety of STA-MCA bypasses performed in the acute stages.Of the 23 acute stage bypasses, 7 cases (30.4%) were classified as Group A and 2 cases (8.7%) as Group B, affecting 9/23 cases, or 39.1% of the acute total. Of these, there were 3 mild symptomatic cases (13.0%), and 1 severe case (4.3%). Of the 32 chronic stage bypasses, 4 cases (12.5%) were classified as Group A and 1 case (3.1%) as Group B, affecting 5/32 cases, or 15.6% of the chronic total.Of these, there was 1 mild symptomatic case (3.1%), and 2 severe cases (6.3%). There were no hemorrhagic transformations. According to these results, acute stage bypasses did not differ significantly from chronic ones with regard to the occurrence of symptomatic cases. (p 0.435; Fisher exact method)