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Objective: To evaluate the clinical usefulness of lingual nerve repair surgery in patients diagnosed with sensory impairment of the lingual nerve after impacted lower molar surgery treated at the Department of Oral and Maxillofacial Surgery, Tokyo Dental College, Japan. Patients and Methods: This prospective study reviewed the cases of 6 patients who were treated between 1998 and 2002. Of 6 patients, 3 underwent lingual nerve repair surgery. These patients were interviewed about their subjective symptoms with regard to their sensory perception, and were subjected to examinations of their sensory threshold values using a Semmes-Weinstein pressure anesthesiometer and taste perception using filter paper disk and whole-mouth methods. Results: Although patients whose lingual nerve had been divided showed almost no postsurgical taste recovery in the filter paper test, sensory perception was found to be on the way to recovery. Further, none of the patients showed deterioration in their condition as compared with their presurgical condition. Conclusion: In case of suspicion of lingual nerve severing or serious nerve injury, immediate nerve repair surgery is recommended.

Primary canine oral mucosal epithelial cells were cultured on temperature-responsive dishes and cell culture inserts to fabricate transplantable epithelial cell sheets. When 3T3 feeder layers and fetal bovine serum were eliminated from dish culture, the harvested cell sheets became significantly more fragile. In contrast, when epithelial cells were cultured on inserts having submicron-scale pores, cell sheet fragility was eliminated. Keratin expression profiles showed no differences among the harvested cell sheets, but the expression of p63, a putative stem/progenitor marker, was strongly dependent on the presence of 3T3 feeder layers and serum. These results suggest that the maintenance of stem/progenitor cells is influenced by the apical/basal supply of nutrients as well as culture supplements.

To exclude bacteria- or animal-derived factors from cultured fabrication of transplantable epithelial cell sheets, primary human oral mucosal epithelial cells were seeded on temperature-responsive culture inserts having submicron-scale pores. Supplying culture medium containing human autologous serum to both apical and basal sides of human epithelial cells allows these cells to grow to confluence. These proliferating cells created stratified epithelial layers even when 3T3 feeder layers and fetal bovine serum were eliminated from culture. Normal keratin expression profiles were obtained with these cells, and basal and midlayer cells expressed p63, a putative stem/progenitor marker. These results suggest that temperature-responsive culture inserts can be useful in clinical settings that require the exclusion of xenogeneic factors.

Altered microsatellite DNA in the blood of cancer patients may provide a novel means for tumor detection. Such alterations are a major characteristic of many types of tumor especially those associated with head or neck cancer. Moreover, recent evidence suggests that senescent tumor cells release DNA into the circulation, which is subsequently carried by the blood and thus enriched in the serum and plasma. We tested 10 head and neck cancer patients (5 with malignant melanomas (MM) and 5 with adenoid cystic carcinomas (ACC)) by polymerase chain reaction (PCR)-based microsatellite analysis of DNA from white blood cells and paired plasma samples. Our goal was to amplify two microsatellite markers, D1S243 and D19S246, which sometimes show microsatellite alterations in head and neck cancer patients. However amplification of fragments from three loci in the plasma samples proved impossible, probably due to the small amounts of DNA isolated. We used multiple displacement amplification (MDA) to amplify genomic DNA from the plasma samples. Two microsatellite fragments were amplified from whole genome amplified DNA. Among 5 heterozygote samples, 3 showed the same pattern in DNA samples from both blood cells and plasma but 2 showed loss of heterozygosity (LOH). Although further study is necessary to confirm whether the LOH found in this study reflects alteration in circulating tumor cell DNA, application of whole genome amplification may allow DNA analysis from limited amounts of such DNA and provide a minimally invasive diagnostic procedure and useful aid in therapy.

自然の磁場信号は非常に電気伝導度の高い海水の影響で減衰が大きいため，海底での MT 探査では一般的に長周期のデータのみを扱い，深部のマントル構造を主なターゲットとしていた。プレート間巨大地震発生域の調査といった地殻構造を得るためには，より短周期の 1 秒から 1000 秒の周期帯が重要となる。しかしながら，それらに適した海底電位差磁力計が国内に存在せず，地殻構造調査を行うことが困難であった。そのため，我々は機動性に優れた小型の海底電位差磁力計の開発を行い，実海域での動作試験とデータ取得に成功した。一方で，人工電流源を用いた探査は，MT 法よりもさらに浅い構造をより詳細に得るのに非常に有効な手法である。我々は，150m の電極ケーブルを曳航体に取り付けて調査を行う曳航式海底電気探査装置を開発し，その実海域試験を通してその有効性を確かめた。本稿では，我々が開発した OBEM と曳航式海底電気探査装置について述べ，その実海域試験の結果について述べる。

To standardise regenerative medicine using cultured cells, the use of serum-free, chemically defined media will be necessary. We have reported that IL-1α inhibits the growth of epithelial cells in culture and that recombinant IL-1 receptor antagonist (IL-1RA) significantly promotes epithelial cell growth in no feeder layer condition. In this study, we examined inhibitors of calpain, a cysteine proteinase that plays crucial roles in various cellular functions, including IL-1α maturation and secretion. The culturing of epithelial cells in serum-free media supplemented with a membrane-permeable calpain inhibitor significantly promoted growth while suppressing IL-1α maturation and secretion. By contrast, non-membrane-permeable calpain inhibitor treatment did not have these effects. Interestingly, immunoblotting analysis revealed that immature, untruncated, IL-1α expression was also downregulated by cell-permeable calpain inhibitor treatment, and the difference in IL-1α gene expression increased from day 2 to day 6. Although IL-1RA has been reported to promote epithelial cell growth, we detected no synergistic promotion of epithelial cell growth using a calpain inhibitor and IL-1RA. These findings indicate that calpain inhibitors promote epithelial cell proliferation by inhibiting IL-1α maturation at an early phase of epithelial cell culture and by suppressing the positive feedback-mediated amplification of IL-1α signalling.

Purpose: This study examined the mechanisms of osteoclast-mediated bone invasion in a model of oral squamous cell carcinoma (OSCC). C3H/HeN mice were inoculated with SCC VII cells into the masseter region to establish an animal model of mandibular invasion by OSCC. Experimental Design: The mice were divided into three groups: a control group, given daily s.c. injections of saline; group 1, given 2 μg per mouse per day of the bisphosphonate YM529; and group 2, given 10 μg per mouse per day of YM529. After 3 weeks of treatment, the lesions were studied by micro-computed tomography. After tartrate-resistant acid phosphatase (TRAP) staining, the osteoclasts were easily identified, and the percentages of the area occupied by osteoclasts were calculated by computer for each sample. The tumors were analyzed by RT-PCR to determine the mRNA expression of interleukin-6 (IL-6), parathyroid hormone–related protein (PTHrP), tumor necrosis factor-α (TNF-α), receptor activator of nuclear factor-κB (RANK), RANK ligand (RANKL), and osteoprotegerin. Results: SCC VII cells rapidly multiplied in the masseter muscle of the mice. Bone invasion was evident only in the control group on micro-computed tomography. On TRAP-stained slices, the percentages of osteoclasts in groups 1 and 2 were significantly lower than that in the control group. The mRNA expressions of IL-6, PTHrP, THF-α, and RANK decreased as the concentration of YM529 increased. Conclusions: We conclude that various cancer-derived cytokines play important roles in the invasion of bone by OSCC. YM529, a third-generation bisphosphonate, can suppress osteoclast-mediated bone invasion by OSCC. The mechanism of this effect might involve inhibition of cytokines such as IL-6, PTHrP, TNF-α, and RANK by YM529.

We investigate the role of the bulk Compton-scattering process in the internal shock model. We numerically show that the radiation field created by internal shocks does not affect the efficiency of the energy conversion in the shocks even if fireball outflows have highly nonuniform velocity distributions. However, the bulk Compton-scattering produces an additional high energy component especially when variability in the outflows arises because of a modulation of the mass injected into a constant energy flow. We show that an isotropic energy of $10^{50-51}$ ergs could be radiated in the range of 100MeV-GeV through the scattering process, provided that the shell's Lorentz factor varies between 10 and $10^4$.

Abbreviations: CBF, cerebral blood flow; CT, computed tomography; CTA, comuted tomography angiography; FLAIR, fluid-attenuated inversion recovery; IMP, -isopropyl[123I]-p-iodoamphetamine; MRA, magnetic resonance angiography; RI, magnetic resonance imaging; RCVS, reversible cerebral vasoconstriction synrome; SAH, subarachnoid hemorrhage; SPECT, single photon emission computed omography. ∗ Corresponding author at: Department of Neurosurgery, Nippon Medical School, -1-5 Sendagi, Bunkyo-ku, Tokyo 113-8603, Japan. Tel.: +81 3 3822 2131; ax: +81 3 5685 0986. E-mail addresses: shunchan.ryouchan@gmail.com, s00-078@nms.ac.jp, 00-080@nms.ac.jp (F. Matano).

In the age of traction system made of inverter and ac traction motors, distributed traction system with pure electric brake of regenerative mode has been recognised very advantageous. This paper proposes a new system as the lowest life-cycle cost system for high performance rapid transit, a new architecture and optimum parameters of power feeding system, and a new running method of trains. In Japan, these components of this proposal, i.e. pure electric brake and various countermeasures of reducing loss of regeneration have been already popular but not as yet the new running method for better utilisation of the equipment and for lower life-cycle cost. One example of what are proposed in this paper will be made as Tsukuba Express, which is under construction as the most modern commuter railway in Greater Tokyo area.

Invasion of the mandible by lower gingival squamous cell carcinoma is an important clinical problem. A previous study suggested that bone destruction associated with carcinoma invasion was mediated by osteoclasts rather than by carcinoma cells. However, the mechanisms involved remain unclear. This study focused on the role of various cytokines in activating osteoclastic bone resorption. We microscopically examined 38 specimens of lower gingival carcinoma and classified them into an invasion group (23 cases) and noninvasion group (15 cases). The specimens were examined immunohistochemically with antibodies to parathyroid hormone-related protein (PTHrP), tumor necrosis factor (TNF)-α, interleukin (IL)-1 α, 1 β, 6, 11, 18, and TGF-β. In the invasion group, the numbers of PTHrP, TNF-α, IL- 6, and IL-11 positive cells were significantly higher than those in the noninvasion group (P

Acoustic cavitation bubbles are useful for enhancing the heating effect in high-intensity focused ultrasound (HIFU) treatment. Many studies were conducted to investigate the behavior of such bubbles in tissue-mimicking materials, such as a transparent gel phantom; however, the detailed behavior in tissue was still unclear owing to the difficulty in optical observation. In this study, a new biological phantom was developed to observe cavitation bubbles generated in an optically shallow area of tissue. Two imaging methods, high-speed photography using light scattering and high-speed ultrasonic imaging, were used for detecting the behavior of the bubbles simultaneously. The results agreed well with each other for the area of bubble formation and the temporal change in the region of bubbles, suggesting that both methods are useful for visualizing the bubbles.

We have been studying a real-time detection method for tissue changes induced by high-intensity focused ultrasound (HIFU) treatment using ultrasonic RF signals. It has been difficult to track the target region when the tissue to be treated deviates from the imaging plane along the elevation axis of the probe. In this study, a new 1.5-dimensional (1.5D) prototype phased array probe consisting of transducer elements along both the lateral and elevation axes was developed to track tissue motion along the elevation axis of the probe, and the elevational displacement range where the tracking is effective was investigated. The complex cross-correlation coefficient based on a block matching algorithm was applied to 2.5D volumetric RF images acquired by the 1.5D probe and the displacement vector along the elevation axis was calculated. From the results, it was found that the effective tracking range using this prototype probe was up to 3 mm, about 3 times that of a conventional 1D imaging probe. The proposed 1.5D phased array probe has the potential to track target tissue with intrafractional motion.

Background To prevent severe esophageal stenosis after aggressive endoscopic submucosal dissection (ESD), our group previously reported an efficient treatment using cell sheets that had been fabricated from patient cells. However, this transplantation procedure had not been easy for every endoscopist and needed to be improved to derive the full effect of epithelial cell sheets. Objective To develop an endoscopic device that enables easy and effective cell sheet transplantation and to evaluate its performance and clinical feasibility. Design Animal study. Setting Animal experimentation laboratory. Intervention Three pigs underwent circumferential esophageal ESD while under general anesthesia. A total of 12 cell sheets were endoscopically transplanted to the ESD site; 6 cell sheets were transplanted by using an endoscopic device that we developed, and 6 cell sheets were transplanted by using the conventional method. Main Outcome Measurements Procedure time, transplanted area on the ESD site, transplantation success rate, and monitoring of adverse events or incidents. Results The device allowed successful transplantation of all cell sheets with a shorter procedure time than with the conventional method (4.8 ± 0.8 minutes vs 13.3 ± 5.7 minutes, respectively) ( P = .005) and onto a larger area (111.3 ± 56.3 mm 2 vs 41.8 ± 4.2 mm 2 , respectively) ( P = .023) with a higher success rate (100% vs 83%, respectively). No adverse incidents were monitored in each method. Limitations Animal study, small sample. Conclusion A newly designed endoscopic cell sheet transplantation device would be useful.

Acute intracerebral hemorrhage (ICH associated with mild anemia is commonly observed on radiological examination and there are several reports of ruptured aneurysms occurring with ICH but without accompanying subarachnoid hemorrhage. However the relationship among computed tomography (CT magnetic resonance imaging (MRI and intraoperative findings of ICH caused by ruptured cerebral aneurysm in patients with severe chronic anemia has been rarely reported and is poorly understood. Here we report atypica lr adiological and intraoperative findings of acute ICH caused by ruptured cerebral aneurys mi n ap atient with severe chronic anemia. A 64‑year‑old man with anemia was admitted to our hospital after he experienced left hemiparesis and a disturbance of consciousness. At a referring institution he showed evidence of macrocytic anemia (white blood cell count 9000 μL; red blood cell count 104�10 4 μL; hemoglobin 4.0 g dL; hematocrit 12.2%; and platelet count 26.6�10 4 μL. Both CT and MRI showed a right frontal ICH. The outer ring of the hematoma appeared as low‑density area on CT a low‑intensity area on T1‑weighted MRI and a high‑intensity area on T2‑ weighted MRI with a serous component. The patient received a blood transfusion and underwent surgical removal of the hematoma the following day. The white serous effusion visualized with CT and MRI was identified as a blood clot in the hematoma cavity. The blood that leaks from blood vessels appears as a high‑intensity area on CT because it undergoes plasma absorption in a solidification shrinkage process and is therefore concentrated. Although we did not examine the white effusion to determine if serous components were present we speculated that the effusion may have contained serous components. Therefore we removed the part of the effusion that appeared as a low‑density area on CT. The presence of ICH without subarachnoid hemorrhage suggested the possible adhesion and rupture of a previous aneurysm. Therefore ICH appeared as a mixed density area on CT because bleeding may have occurred several times. Because radiological findings of ICH caused by ruptured cerebral aneurysm in patients with severe chronic anemia are similar to those of ICH and cerebral edema we suggest that the atypical radiological findings of ICH caused by ruptured cerebral aneurysm in patients with severe chronic anemia should be carefully evaluated especially when surgery is indicated. (J Nippon Med Sch 2014; 81: 264―268

Aberrant DNA methylation could potentially serve as a biomarker for colorectal neoplasms. In this study, we assessed the feasibility of using DNA methylation detected in bowel lavage fluid (BLF) for colorectal cancer screening. A total of 508 BLF specimens were collected from patients with colorectal cancer (n = 56), advanced adenoma (n = 53), minor polyp (n = 209), and healthy individuals (n = 190) undergoing colonoscopy. Methylation of 15 genes (miR-1-1, miR-9-1, miR-9-3, miR-34b/c, miR-124-1, miR-124-2, miR-124-3, miR-137, SFRP1, SFRP2, APC, DKK2, WIF1, LOC386758, and ZNF582) was then analyzed in MethyLight assays, after which receiver operating characteristic (ROC) curves were analyzed to assess the diagnostic performance of BLF methylation. Through analyzing BLF specimens in a training set (n = 345), we selected the three genes showing the greatest sensitivity for colorectal cancer detection (miR-124-3, 71.8%; LOC386758, 79.5%; and SFRP1, 74.4%). A scoring system based on the methylation of those three genes (M-score) achieved 82% sensitivity and 79% specificity, and the area under the ROC curve (AUC) was 0.834. The strong performance of this system was then validated in an independent test set (n = 153; AUC = 0.808). No significant correlation was found between M-score and the clinicopathologic features of the colorectal cancers. Our results demonstrate that DNA methylation in BLF specimens may be a useful biomarker for the detection of colorectal cancer. Cancer Prev Res; 7(10); 1002–10. ©2014 AACR.

We have developed a technique for endoscopic transplantation of cultured autologous oral mucosal epithelial cell sheets to an esophageal ulcer following endoscopic submucosal dissection (ESD). The epithelial cell sheets successfully prevented esophageal stricture after ESD. Key technology is that epithelial cell sheets cultured from oral mucosal tissue and attached proteins can be harvested using cell sheet technology and can be transplanted to a wound site without the use of adhesive material. This regenerative procedure can promote the epithelialization of ulceration safely and effectively. In the near future, the development of advanced endoscopic treatment of regenerative medicine shows promise.

The prognosis of advanced squamous cell carcinoma (SCC) of the external auditory canal and middle ear remains poor. Carbon ion radiotherapy (C-ion RT) has shown promise for locally advanced head and neck cancer. Therefore, we evaluated the safety and efficacy of C-ion RT for locally advanced SCC of the external auditory canal and middle ear.The cases of 13 patients with advanced (T3 and T4) SCC of the external auditory canal and middle ear who received C-ion RT as the primary treatment were reviewed.The median follow-up for all patients and the 7 surviving patients was 12 and 32 months, respectively. The 1-year and 3-year local control and overall survival (OS) rates were 72% and 54% and 70% and 40%, respectively. Severe temporal bone necrosis was observed in 2 patients.C-ion RT is effective and generally safe for locally advanced SCC of the external auditory canal and middle ear.

The feed-forward charge/discharge control scheme of energy storage systems (ESS's) for DC electric railways takes advantage of the fact that the track and speed profiles are already available for all runs of trains before they take place. Using the track and speed profile information, the capacity of the ESS's can be best utilised to obtain maximal effects. This idea can be used for both onboard and stationary ESS's. However, the effect of introducing feed-forward charge/discharge control to stationary ESS's is not as significant as the onboard ESS's, and it is expected to be difficult to prepare and maintain the feed-forward data required to implement such a scheme. In this paper, the authors propose the fuzzy feed-forward control for stationary ESS's, which is expected to make such preparation and maintenance of feed-forward data easier while improving the overall performance of the charge/discharge control.

Purpose: Contrast-enhanced T1-weighted black-blood fast spin-echo MR imaging (BB-FSE) was performed to suppress enhancing venous signal and flow artifacts in the brain without sacrificing the T1-weighted imaging contrast. Material and Methods: Twenty-five MR imaging sections (17 transverse and 8 coronal images) in 15 patients with various brain diseases were obtained by contrast-enhanced T1-weighted SE and BB-FSE images. Results: In contrast-enhanced T1-weighted BB-FSE images, venous signal was significantly less and T1-weighted contrast of the brain was more evident. No differences in flow artifacts were found between the two imaging techniques. The interobserver agreements were good for the venous signal and flow artifacts using both techniques. Conclusion: Contrast-enhanced T1-weighted BB-FSE imaging reduced the venous signal in the brain with maintaining T1-weighted contrast. This novel MR technique can be used when the suppression of enhancing venous signal is expected to improve the depiction of enhancing lesions in the brain.

Object. The authors confirm the usefulness of extravasation detected on three-dimensional computerized tomography (3D-CT) angiography in the diagnosis of continued hemorrhage and establishment of its cause in patients with acute intracerebral hemorrhage (ICH).Methods. Thirty-one patients with acute ICH in whom noncontrast and 3D-CT angiography had been performed within 12 hours of the onset of hemorrhage and in whom conventional cerebral angiographic studies were obtained during the chronic stage were prospectively studied. Noncontrast CT scanning was repeated within 24 hours of the onset of ICH to evaluate hematoma enlargement.Findings indicating extravasation on 3D-CT angiography, including any abnormal area of high density on helical CT scanning, were observed in five patients; three of these demonstrated hematoma enlargement on follow-up CT studies. Thus, specificity was 60% (three correct predictions among five positives) and sensitivity was 100% (19 correct predictions among 19 negatives). Evidence of extravasation on 3D-CT angiography indicates that there is persistent hemorrhage and correlates with enlargement of the hematoma.Regarding the cause of hemorrhage, five cerebral aneurysms were visualized in four patients, and two diagnoses of moyamoya disease and one of unilateral moyamoya phenomenon were made with the aid of 3D-CT angiography. Emergency surgery was performed without conventional angiography in one patient who had an aneurysm, and it was clipped successfully.Conclusions. Overall, 3D-CT angiography was found to be valuable in the diagnosis of the cause of hemorrhage and in the detection of persistent hemorrhage in patients with acute ICH.

Persistent sciatic artery is a rare but potentially significant vascular anomaly that is associated with a high incidence of aneurysm formation and limb-threatening ischemic complications. The diagnosis of persistent sciatic artery has usually been made by conventional angiography. We report a case of occluded and patent persistent sciatic arteries in which multidetector-row computed tomographic angiography allowed a definitive diagnosis of this rare vascular condition.

Malignant mucosal melanoma (MMM) of the head and neck is rare and has a poor prognosis. Additionally, MMM has long been regarded as radioresistant. We recruited 106 patients with MMM of the head and neck who were treated with carbon ion radiotherapy (C-ion RT) and concomitant chemotherapy. The 5-year local control and overall survival rates of all patients were 80.6 and 54.0 %. The median survival time was 64.8 months. The most common acute toxicities were mucositis (grade 3, 21.7 %) and skin reactions (grade 3, 0.9 %); no reactions worse than grade 3 were observed. Furthermore, the most common adverse events associated with dacarbazine, nimustine hydrochloride, and vincristine sulfate (DAV) chemotherapy were myelotoxicity and liver dysfunction. C-ion RT is a safe and effective treatment for MMM of the head and neck because of good local control and acceptable toxicity. In addition, the overall survival rate was better than the rates associated with conventional radiation therapy and surgery with concomitant chemotherapy.

The typical neuroimaging features of primary central nervous system lymphoma (PCNSL) have been described as single or multiple intra-axial, homogenous, contrast-enhancing lesions with marked perilesional edema and restricted diffusion, usually contacting the cerebrospinal fluid surface. Necrosis, peripheral enhancement, hemorrhages, and calcifications are unusual. Recently, some of our patients with PCNSL have had atypical neuroimaging features even before treatment. In this article, we review the neuroimaging characteristics of PCNSL in immunocompetent patients and analyzed how imaging findings over the last 10 years differ from those from more than 10 years ago. Neuroimaging findings suggest that PCNSL is a disease that affects the entire brain. Although some imaging findings are characteristic of PCNSL, the frequency of atypical findings on conventional neuroimaging is increasing. Atypical neuroimaging findings do not rule out PCNSL, even in immunocompetent patients.

There has been an upsurge in regenerative medicine in recent years. In particular, because oral mucosal epithelial cells can be obtained noninvasively, cultured epithelial cell sheets have been used in a number of ectopic transplantations. Additionally, the verification of the properties of experimental animals' cultured cells has accelerated the application of regenerative medicine. In the present study, the properties of oral mucosal epithelial cells were compared between six animal species. The human and pig epithelia were relatively thicker than the epithelia of the other species. The colony-forming efficiency of the rat was the highest, followed by those of the dog, human, rabbit, and pig, whereas the colonies of the mouse cells were all paraclone and uncountable in the colony-forming assay. We also found that the rabbit and pig cells proliferated poorly and were unable to form cell sheets without feeder layers. In contrast, even in the absence of feeder layers and cholera toxin, cultured dog and mouse cells formed contiguous sheets, when the cell seeding density was high. These results indicate that interspecies variation is considerable in oral mucosal epithelial cells and that specific experimental animal or human cells must be chosen according to the intended use.

AIM Replacement of aneurysm clips or temporary parent artery occlusion during aneurysm clipping (AC) carries the risk of inducing postoperative neurologic deficits. When studying the risk of surgical complications associated with cerebral aneurysms, patients with similar conditions should be compared to eliminate the influence of rupture and location of aneurysm. MATERIAL AND METHODS We used 3.0-Tesla (3.0T) magnetic resonance diffusion-weighted imaging (DWI) and magnetic resonance angiography (MRA) to analyze surgical complications after AC. A total of 42 AC procedures for 40 unruptured and 2 delayed-phase ruptured MCA aneurysms were evaluated. RESULTS In six patients, temporary parent artery occlusion was performed. Asymptomatic hyperintensities were observed on DWI of three patients. In one patient, an asymptomatic lesion was most likely caused by a small contusion that occurred during dissection of an aneurysm attached to the brain surface. In two patients, asymptomatic cortical lesions were caused by brain surface contusions due to lacerations of the open dura. No symptomatic hyperintensities on DWI were observed after surgery. No fixed ischaemic neurologic deficits resulted from AC. CONCLUSION Although some postoperative abnormalities were observed with 3.0T DWI, we found clipping of MCA aneurysms to be a safe procedure with a low risk of ischaemic complications.

Nearly three decades ago, I spent a kind of sabbatical year in Bioacoustic Research Laboratory, University of Illinois, which was supervised by Professor Floyd Dunn. Human knowledge and technologies on acoustic cavitation were significantly limited at that time compared to now. As the result, acoustic cavitation was considered to be avoided even in therapeutic applications of ultrasound. However, I was thinking that it should be utilized and had discussions with him on it, who was the expert on bioeffects of ultrasound including those induced by cavitation. Human technologies on acoustic cavitation have been advanced since then mainly in two aspects: 1) ultrasonic as well as optical observation of cavitation microbubbles at a high frame rate, and 2) generation of a short ultrasonic pulse at extremely high amplitude. A high speed camera had made possible to observe that a short extremely high-amplitude pulse can generate cavitation microbubbles localized near the ultrasonic focal point without inducing the...

Cavitation bubbles can accelerate high-intensity focused ultrasound (HIFU) treatments thermally, chemically, and mechanically. Acoustic generation of cavitation bubbles requires extremely high-intensity or long duration time enough to form a standing-wave field. We have proposed and investigated the ultrasound sequence of a high-intensity short pulse, named as trigger pulse, followed by a relatively lower intensity and longer duration burst, named as heating burst, mainly for the cavitation-enhanced ultrasonic heating. Trigger pulses are used to generate cavitation bubbles then form cavitation clouds. The acoustic power of trigger pulses is more than hundreds of W and the duration is less than 100 μs to avoid effects of standing-wave components. Cavitation bubbles induced by trigger pulses continuously oscillate with heating bursts. The sequence was repeated 3—15 s. Cavitation clouds formation by trigger pulses was observed with a high-speed camera. The temperature measured by thermocouple and tissue coag...

Photoacoustic (PA) signal is highly dependent on the structure of the target. In the present study, PA imaging system with parabolic array transducer for multi-angle detection is developed and the skin vasculature is observed. The transducer was consisted of 256 ch 1-3-composite elements with the center frequency of 10 MHz. The diameter was 42.4 mm and the opening angle was 90 degree. A hole was made in the center of the transducer for transmission of the laser. PA signal was acquired by a programmable ultrasound data acquisition system with the sampling frequency of 60 MHz. A diode laser with the wavelength of 532 nm, pulse width of 8 ns, pulse energy of 5 mJ, and repetition frequency of 10 Hz was equipped for generation of PA signal. Three dimensional image was reconstructed by delay-and-sum beamforming of PA signals received by all channels. The frame rate for displaying x-y, y-z, and x-z images was 10 Hz, and the full width at half maximum (FWHM) of the x-z image was 70 μm. 3D structure of the skin ca...

Ultrasound image-guided High Intensity Focused Ultrasound (HIFU) has been become one of the potential surgical techniques for the treatment of the malignant tumor. The ultrasound image during the treatment is severely corrupted by the reflected HIFU wave because HIFU and imaging transducers are simultaneously activated. In our previous study, a new method to selectively eliminate only HIFU noise during the treatment was suggested, but it cannot sufficiently reduce the HIFU noise when the HIFU exposure is phase-modulated with a period less than a few milliseconds. In this study, a new method to selectively eliminate the HIFU noise even when the HIFU exposure is modulated with a certain modulation period. In this study, “multiple HIFU exposure” with a certain modulation period was employed. The focus of HIFU was moved every 25μs sequentially for six positions with spacing proper for thermal conduction. the RF signals of the same modulation period were received with (RF2) and without (RF1) transmitting an im...

During high-intensity focused ultrasound (HIFU) treatment, tissue change, and acoustic cavitation as its precursor, should be monitored both in and outside the HIFU focal zone, to ensure the intended therapeutic effect and to prevent potential adverse effects, respectively. Unlike boiling-induced bubbles, cavitation-generated microbubbles are difficult to detect with conventional B-mode imaging because their life is significantly shorter than the typical image repetition period. An image repetition period less than a few milliseconds is required to detect them. This can only be accomplished by high-frame-rate imaging with plane or diverging waves. In-vivo as well as ex-vivo experimental results evidencing the effectiveness of such imaging to detect cavitation-generated microbubbles will be shown in this paper. A number of researches are underway to ultrasonically detect HIFU-induced tissue change, which occurs at much lower temperature than boiling. During echo data acquisition for detecting such tissue c...

Objectives Bowel cleansing is necessary before colonoscopy, but is a burden to patients because of the long cleansing time and large dose volume. A low-volume (2 L) hypertonic polyethylene glycol-ascorbic acid solution (PEG-Asc) has been introduced, but its possible dehydration effects have not been quantitatively studied. We compared the efficacy and safety including the dehydration risk between hypertonic PEG-Asc and isotonic PEG regimens. Design This was an observer-blinded randomised study. Participants (n=310) were allocated to receive 1 of 3 regimens on the day of colonoscopy: PEG-Asc (1.5 L) and water (0.75 L) dosed with 1 split (PEG-Asc-S) or 4 splits (PEG-Asc-M), or PEG-electrolyte solution (PEG-ES; 2.25 L) dosed with no split. Dehydration was analysed by measuring haematocrit (Ht). Results The cleansing time using the hypertonic PEG-Asc-S (3.33±0.48 hours) was significantly longer than that with isotonic PEG-ES (3.05±0.56 hours; p

Cavitation bubbles are known to enhance the heating effect of high-intensity focused ultrasound (HIFU). In our previous study, the use of a “triggered HIFU” sequence consisting of a high-intensity pulse and a relatively low-intensity burst was proposed as an effective method to utilize the effect of cavitation bubbles. However, the duration of each component in the sequence has not been optimized. In this study, optical imaging was carried out to observe the behavior of cavitation bubbles in a gel phantom during the triggered HIFU exposure. Ultrasound imaging using the pulse inversion method was also conducted to detect the behavior of the bubbles. The results suggest that the oscillation of cavitation bubbles become inactive as the duration of HIFU burst exposure increases to the order of 10 ms. It was also suggested that ultrasonic imaging has potential use for detecting a change in the oscillation of cavitation bubbles for optimizing a triggered HIFU sequence.