Search

Purpose To enhance the utility of acceleration time (AcT) in the diagnosis of internal carotid artery (ICA) stenosis, we assessed the value of AcT measurements with different waveform patterns. Methods Ninety-three patients with acute atherothrombotic cerebral infarction were enrolled, and they underwent both carotid ultrasonography and digital subtraction angiography (DSA). AcT was determined by a conventional procedure (using the first peak point or the bending point) and the peak systolic velocity (PSV) procedure. The AcT ratio was calculated as (AcT of ICA)/(AcT of the ipsilateral common carotid artery). We evaluated the correlation of stenosis rate as assessed by the North American Symptomatic Carotid Endarterectomy Trial method using DSA (DSA-NASCET) with the AcT of ICA (ICA-AcT), the AcT ratio measured by the conventional procedure (conventional AcT ratio), and the AcT ratio measured by the PSV procedure (PSV AcT ratio). The area under receiver operating characteristic curves (AUC) for DSA-NASCET was calculated based on the ICA-AcT and AcT ratio. Results Forty-five vessels had 50% or greater ICA stenosis. DSA-NASCET was positively correlated with the conventional AcT ratio (r = 0.723), conventional ICA-AcT (r = 0.638), and PSV AcT ratio (r = 0.245). The corresponding AUCs for ICA stenosis ≥ 50% were 0.971, 0.886, and 0.572, respectively. Conclusion We demonstrated the usefulness of the conventional procedure for diagnosing stenosis of ICA origin using AcT and showed that the AcT ratio was a more beneficial parameter than AcT.

Background: Vertebral artery stump syndrome (VASS) develops into recurrent posterior circulation ischemic stroke after ipsilateral vertebral artery (VA) occlusion at its origin. Case Description: The patient was a 46-year-old man with the right posterior cerebral artery occlusion. We used a recombinant tissue plasminogen activator (rt-PA) and then performed mechanical thrombectomy using a stent retriever. Angiography revealed left VA occlusion and stagnant flow to the left VA from the right deep cervical artery; therefore, we diagnosed VASS. Within 24 h of the rt-PA injection, the symptoms had dramatically improved, and so we avoided additional antithrombotic agents. Only 13 h later, the patient developed a basilar artery occlusion and died in spite of a repeated mechanical thrombectomy. Conclusion: Vigilance against early (and sometimes fatal) recurrent stroke induced by VASS is required.

Purpose The acceleration time (AcT) ratio of the internal carotid artery (ICA) is increased in ICA stenosis. However, there are few reports that have directly compared the AcT ratio to digital subtraction angiography (DSA) findings. Methods We evaluated 177 vessels with DSA and carotid artery ultrasonography. The AcT ratio was calculated as AcT of the ICA (ICA–AcT)/AcT of the ipsilateral common carotid artery (CCA). We evaluated the correlation of DSA–NASCET stenosis with the origin of the ICA or the peak systolic velocity (ICApsv) in the stenotic region, ICApsv/peak systolic velocity of the CCA (CCApsv), ICA–AcT, and AcT ratio. Sensitivity and specificity for stenosis ≥ 70% were calculated based on the ICApsv, ICApsv/CCApsv, ICA–AcT, and AcT ratio. Results Using NASCET criteria, 34 vessels had 70% or greater stenosis. DSA–NASCET showed a significant positive correlation with ICApsv, ICApsv/CCApsv, ICA–AcT, and AcT ratio (p

A 56-year-old man noted sudden onset of headache, fever, right pupil-spared oculomotor nerve palsy and consciousness disturbance. Swelling of pituitary with T1 high intensity on brain MRI suggested the diagnosis of pituitary apoplexy. Considering significant decrease of pituitary anterior lobe hormone and central diabetes insipidus, high dose of hydrocortisone was administered. Eight days after onset, consciousness level and headache improved. On day 30, brain MRI revealed the reduction of mass size, and on day 46, photophobia and double vision disappeared. Following the rapid response to steroid and disappearance of pituitary lesion, pituitary apoplexy was probably caused by panhypophisitis. Thin-slice brain MRI confirmed the compression of oculomotor nerve at inlet zone of cavernous sinus, suggesting the mechanism of oculomotor palsy was perfusion impairment of feeding artery.

Context is defined as information that represents the environment surrounding us. A system to provide services to users using context is called a context-aware system (CAS), and it has been widely studied. However, many conventional CASs are not flexible. As conventional CASs cannot be freely customized by end-users, they lack adaptability to environments, making them difficult to use in various environments. To solve this problem, we propose a user-oriented context-aware system architecture (U-CASA) for building ad-hoc smart rooms. This architecture allows end-users to install various IoT sensor devices to the target environment and to make it a smart room. The end-user can also freely customize the system settings and can link various contexts to a variety of services. In order to evaluate the proposed architecture, we built two ad-hoc smart rooms based on U-CASA. As a result of the demonstration experiment with behavior scenarios, we confirmed that two smart rooms can perform properly and can provide services despite their different environments.

Background: Carotid endarterectomy (CEA) has been the standard preventive procedure for cerebral infarction due to cervical internal carotid artery stenosis, and internal shunt insertion during CEA is widely accepted. However, troubleshooting knowledge is essential because potentially life-threatening complications can occur. Herein, we report a case of cervical internal carotid artery injury caused by the insertion of a shunt device during CEA. Case Description: A 78-year-old man with a history of hypertension, diabetes, and hyperuricemia developed temporary left hemiplegia. A former physician had diagnosed the patient with a transient cerebral ischemic attack. The patient’s medical history was significant for the right internal carotid artery stenosis, which was severe due to a vulnerable plaque. We performed CEA to remove the plaque; however, there was active bleeding in the distal carotid artery of the cervical region after we removed the shunt tube. Hemostasis was achieved through compression using a cotton piece. Intraoperative digital subtraction angiography (DSA) revealed severe stenosis at the internal carotid artery distal to the injury site due to hematoma compression. The patient underwent urgent carotid artery stenting and had two carotid artery stents superimposed on the injury site. On DSA, extravascular pooling of contrast media decreased on postoperative day (POD) 1 and then disappeared on POD 14. The patient was discharged home without sequela on POD 21. Conclusion: In the case of cervical internal carotid artery injury during CEA, hemostasis can be achieved by superimposing a carotid artery stent on the injury site, which is considered an acceptable troubleshooting technique.

DCBA(Drift Chamber Beta-ray Analyzer) experiment is aiming to search for neutrinoless double beta decay (0νββ). The DCBA detector is a momentum analyzer to measure individual electron energy from double beta decays. Since 0νββ is extremely rare, the detector must be low background and accommodate a lot of decays source. And also the excellent energy resolution is required at the Q-value to distinguish 0νββ from two-neutrino double beta decay (2νββ). The DCBA detector consists of drift chambers, a magnet and cosmic-ray veto counters. A test prototype DCBA-T2 has been constructed and operated with natural Mo source containing 9.6% 100Mo in order to solve operation problems. Another new prototype called DCBA-T3 is under construction at KEK. DCBA-T3 will have better performance than DCBA-T2 in view points of the energy resolution and the source accommodation volume. The results of the DCBA-T2 test operation and the DCBA-T3 status are described together with the future plan temporarily called Magnetic Tracking Detector (MTD), which is designed based on the experiences of DCBA-T2 and T3.