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A recent technology innovation is boosting potentials of chemical enhanced oil recovery (EOR) application to harsher field conditions, whereas it was possible for limited conditions under the past classic EOR screening criteria (Taber. et al. 1997). To proceed with such a chemical EOR application, nobody doubts an importance of water management; however, most of the technical discussions focus on injection while lesser on production. Therefore, this paper recaps the recent innovation of chemical EOR and reminds the importance of water management from a viewpoint of production treatment in particular for realistic operatability. Finally, our current progress of technology acquisition is introduced with a brief roadmap plan. [ABSTRACT FROM AUTHOR]

During the oil production process, oily waste water is coproduced at a rate several times that of oil. This water is known as produced water. Treatment levels and technologies are selected based on disposal method or reutilization objectives, environmental impacts, economics, and other such factors. For the treatment of produced water, the treatment system equipped with nitrogen microbubble flotation in conjunction with anthracite filtration and activated carbon adsorption was designed and examined. Polymer flooding is being used as an enhanced oil recovery (EOR) method in Oman. The quality of polymer flood produced water (PFPW) is different from produced water (PW) without polymer, it was clarified that aluminum sulfate (AS) is more effective than poly-aluminum chloride (PAC) as a flocculant. Based on the examination results, a 50 m3/day capacity pilot plant was designed, fabricated, and utilized to conduct produced water treatment trials, good oil removal was confirmed in all tests. It was also confirmed that this accompanied water treatment water could be used as irrigation water for agriculture by performing necessary higher order treatment. As a result, it was considered that the development as a new water source in the Middle East, where water resources are scarce, could be expected. [ABSTRACT FROM AUTHOR]

In general, a diesel engine does not have ignition system and it can ignite by self-ignition. It has pros that engine manufactures can consist engine components less than normal gasoline engines. However, diesel engines emit more particle matter (PM) rather than normal gasoline engine, so that diesel engines should have diesel particulate filter (DPF) to accumulate them even if it is in not only a exhaust gas but also an engine oil region. In this study, the authors clarified the possibility of PM accumulation method by using an alternating electric field applying between a metal needle and a plate to coagulate them as large particles more than 0.8 μm. The important parameters were an electric field intensity, frequency and applying time. The FESEM observation results indicated that approximately 100 nm-sized particles coagulated to be a large particle. Then, EDS analysis revealed that the particle did not include conventional engine additives such as zinc, molybdenum and calcium. Those results clearly indicated that the alternative electric field method can accumulate nano-sized PM.

The urine cytology test is one of the most important tools for the diagnosis of malignant urinary tract tumors. This test is also of great value for predicting malignancy. However, the sensitivity of this test is not high enough to screen for malignant cells. In our laboratory, we were able to attain a high sensitivity of urine cytology tests after changing the preparation method of urine samples. The differences in the cytodiagnosis between the two methods are discussed here. From January 2012 to June 2013, 2,031 urine samples were prepared using the conventional centrifuge method (C method) ; and from September 2013 to March 2015, 2,453 urine samples were prepared using the filtration method (F method) for the cytology test. When the samples included in category 4 or 5, were defined as cytological positive, the sensitivities of this test with samples prepared using the F method were significantly high compared with samples prepared using the C method (72% vs 28%, p＜0.001). The number of cells on the glass slides prepared by the F method was significantly higher than that of the samples prepared by the C method (p＜0.001). After introduction of the F method, the number of f alse negative cases was decreased in the urine cytology test because a larger number of cells was seen and easily detected as atypical or malignant epithelial cells. Therefore, this method has a higher sensitivity than the conventional C method as the sensitivity of urine cytology tests relies partially on the number of cells visualized in the prepared samples.

In Japan, ultralow-nicotine cigarette brands with ventilation holes on the cigarette filters have been widely marketed to smokers. The use of these cigarette brands leads to compensation smoking. Menthol cigarette brands that have a cooling and numbing effect are also sold. In 2013, smokeless tobacco products similar to the Swedish snus, which is banned for sale in the European Union except in Sweden, were released in Japanese markets. These tobacco products have "toxicity," have a "ventilation filter," are "attractive," and promote "dependence." Tobacco smoke and smokeless tobacco are classified into "Group 1: Carcinogenic to humans" by the International Agency for Research on Cancer (IARC). The purpose of Articles 9 and 10 of the World Health Organization Framework Convention on Tobacco Control (WHO FCTC) is to regulate the contents of tobacco products as well as to regulate tobacco product disclosures. The implementation of some other articles has gradually advanced in Japan. However, that of Articles 9 and 10 is late. Japanese governmental authorities are being urged to immediately implement Articles 9 and 10.

The adsorption of Bevacizumab, Trastuzumab, Rituximab, Nedaplatin, Vincristine sulfate, Nogitecan hydrochloride, Actinomycin D and Ramosetron hydrochloride to 0.2 μm endotoxin-retentive in-line filters was evaluated with pediatric doses by UV spectrophotometry. The results indicated that some drug adsorption was shown with Nogitecan hydrochloride, Actinomycin D and Ramosetron hydrochloride, and good recovery was shown with the other five drugs. For the three drugs which showed some losses, drug recovery was investigated at multiple test doses. The approximation formula for each drug adsorption was recorded as Y=100-A/X (X: dose (mg), Y: recovery rate (%), A: a constant for individual drug). The results showed there was high correlation between the reciprocal of test drug dose and the recovery rate. Furthermore, in the cases where adsorption to the filter were observed, it was found that it was possible to determine the relationship between dose and the recovery rate from a filterability test with one point pediatric dose. Since the recovery rate obtained from the approximation formula with multiple doses and that calculated from the prediction formula with one point pediatric dose were almost the same, then it was concluded that it is not necessary to conduct the filterability tests with multiple doses. We have shown that using UV spectrophotometry and carrying out a filterability test using one point pediatric dose is relatively easy method and reduces the effort and expense. This method for analysis of drug adsorption is extremely useful when using in-line filters with infusion therapy.

Objective: The tobacco tax in Japan was increased in October, 2010. Subsequently, the quantity of sales of domestic cigarette products decreased temporarily. However, smokers could import cigarettes directly through the internet. Because of the high value of the yen and the low price of foreign cigarettes, an individual could import cigarettes easily; however, the contents and emissions from privately imported cigarettes have not been investigated yet. In this study, we carried out a comparative analysis of domestic and privately imported cigarettes., Methods: Privately imported cigarettes from five brands and domestic cigarettes from the brand "Mild Seven" were selected for the study. For the fillers of the cigarettes, the levels of nicotine and tobacco-specific nitrosamines (TSNAs) were determined by methods that are usually used for cigarette products. For the mainstream smoke, the levels of tar, nicotine, carbon monoxide, and TSNAs were also determined by the methods used for cigarettes., Results: The average nicotine and TSNA levels in the fillers of the domestic cigarettes were 15.1 ± 0.19 mg/g and 1,920 ± 85.1 ng/g, respectively. The amounts of nicotine and tar in the mainstream smoke from the privately imported cigarettes were lower than those from the domestic cigarettes. However, the levels of TSNAs in the mainstream smoke from the privately imported cigarettes were higher than those from the domestic cigarettes., Conclusions: The amounts of TSNAs in the fillers of and mainstream smoke from the privately imported cigarettes were higher than those from the domestic cigarettes. Japanese smokers should be careful about consuming privately imported cigarettes because there is a variation in the amount of hazardous constituents in these cigarettes, even when they are from the same brand.

A new direct-conversion detector for DR mammography has improved the detectability of microcalcifications and masses. Each optimized exposure condition (target/filter combination and tube voltage) was defined through comparison of physical values and visual evaluation on breast specimens using the innovative DR mammography. The contrast-to-noise-ratios (CNRs) of PMMA phantoms of various thicknesses were obtained under a variety of exposure conditions whose average glandular doses (AGDs) were made consistent. Fifty breast specimens were irradiated under these combinations. Visual evaluation was conducted on the images, whose histograms were controlled for consistency. In the phantoms with thicknesses of 20 mm or more, tungsten/rhodium had the highest CNRs of the targets/filters such as molybdenum/molybdenum and molybdenum/rhodium. For visualizing microcalcifications and masses on breast specimens of thicknesses of 35 mm and below, molybdenum/molybdenum was the best. Nevertheless, to obtain better image quality, molybdenum/rhodium was superior for 35-55 mm thickness, and tungsten/rhodium was superior for 55 mm and above under the same AGD, enabling accurate and efficient diagnosis. The study showed that the exposure conditions differ for obtaining the highest CNR using phantoms and those under which breast specimen images allow the most accurate and efficient diagnosis. In addition, image evaluations of the breast specimens allowed optimization of exposure conditions that are closer to those of the actual diagnosis using mammography.

Exposure indicators of digital radiography systems have been termed by manufacturers individually. The International Electrotechnical Commission (IEC) provided a concept of exposure index (EI) that unified the exposure indicators in order to recognize the deviations from the intended exposure. Although the IEC determined the calibration conditions between the exposure indicator and the air kerma at the detector surface, the tolerance was described was limited concerning the beam conditions. The purpose of this study is to evaluate the calibration error regarding the geometry and the added filtrations. The relative errors of calibrations based on the IEC condition were derived using the value of exposure indicators at EI value of 200, 500 and 1000 for field size of 10×10 cm, 20×20 cm, 30×30 cm and 43×43 cm, and source-image receptor distance (SID) of 100 cm, 120 cm, 150 cm and 200 cm. The beam qualities using added filtrations of 0.5 mm Cu+2 mm Al, 0.6 mm Cu and 21 mm Al were adjusted to RQA 5. The air kerma at the detector surface over the clinical use ranged from 0.18 to 26.3 µGy. Consequently, the relative errors for the calibrations were less than 6% at a field size of more than 10 × 10 cm and at SID of more than 100 cm with all added filtrations.

Our study was involved with entrance surface dose reduction and irradiation field by the filter use of PCI, and insertion in place of an effective compensating filter to maximize entrance surface dose reduction, which we verified. The radiation dosimetry put a 6cc ion chamber on the back side of the thorax phantom, and changed the filter of the four corners (a: upper left, b: upper right, c: lower right, d: lower left) of the monitor confirmed with fluoroscopy [(0) no filter, (1) one filter, (2) two filters]. The angle of C arm was assumed to be eight directions and 0 degrees adopted by this hospital. It was compared with a corrective rate of which one was no filter. Next, the presence of filter and irradiation field overlaps on the area in monitor in the angle of C arm was verified by this hospital's classic example. As for corrective rate, (1) becomes 0.41 and (2) become 0.25 at fluoroscopy, (1) becomes 0.26 and (2) become 0.16 at exposure. Irradiation field overlaps on the area (+) compensating filter (-) was many with d of RAO/CAU, a of RAO and c of CAU at left CAG, c of LAO at right CAG, b of LAO/CRA (left CAG), b of CRA (right CAG) and a and d of RAO (right CAG) at both CAG. Irradiation field overlaps on the area (+) compensating filter (+) was many with b of CRA at left CAG, a of LAO/CRA at right CAG, b of CRA (left CAG) and b of RAO (right CAG) at both CAG. When the compensating filter is used the entrance surface dose reduction effect was great. If automatic exposure control protects the part of irradiation field overlaps on the area in the range without operating excessively, the radiological risk can be reduced, and it is conceivable as useful clinical setting.

The half-value layer (HVL) is an important index of the image quality or radiation risk in mammography. Radiation risk of the breast tissue is evaluated with the average glandular dose. The HVL index is indispensable for the average glandular dose computations. We investigated the influence of multiple factors that affect HVL value, such as thickness or purity of the aluminum attenuator, detector material of dosimeter, fluctuation of X-ray output, detector location in X-ray field and so on, for accurate average glandular dose computations. We found some aluminum plates about 20% thicker than nominal thickness. The HVL values between seven filter sets were different in about 5% at the maximum. In addition, we reduced a fluctuation of X-ray output with dose monitoring. Then, the standard deviation of HVL value decreased from 1.114% to 0.105%. HVL value obtained from a solid-state detector was statistically thicker than that measured by ionization chamber. It has been reported that there was a difference in the half-value layer under the influence of a heel effect by location of the measurement. Accompanied with alternation of detector location, HVL value of PCM (Konica Minolta) had a significant difference, while Novation (Siemens) and Senographe 2000D (GE) had no change.

Invasive aspergillosis (IA) is a major cause of morbidity and mortality among the immunocompromised, especially those undergoing hematopoietic stem cell transplantation. With spore inhalation the usual infection route, such subjects must be protected from environmental spore contamination, necessitating measures such as high-efficiency particulate air (HEPA) filtration. In April 2006, we implemented a new transplantation unit with HEPA filtration. We retrospectively evaluated its efficacy for hospitalized transplantation unit subjects whose sera were tested for aspergillus galactomannan antigen between April 2004 and March 2007. Subjects numbered 265 (973 samples) categorized as definite, probable, or possible. The earliest IA onset date was when symptoms, positive radiological findings, or positive galactomannan antigen tests occurred, based on revised European Organization for Research and Treatment of Cancer/Invasive Fungal Infections Cooperative Group and National Institute of Allergy and Infectious Diseases Mycoses Study Group (EORTC/MSG) definitions. We classified cases when IA occurred over 10 days after admission as hospital-acquired. No such cases were detected after November 2005 and IA incidence decreased significantly after the new unit began being used. Results suggest that the new unit and HEPA filtration helped eliminate nosocomial IA.

We have studied AmBisome, which is amphotericin B containing liposomes, used in the treatment of mycosis. Any potential problems regarding the liposome formulation remain unknown because it is a new dosage form. AmBisome is useful in that it can decrease adverse reactions while maintaining a therapeutic effect. However, it is doubtful whether AmBisome is suitable in a busy clinical environment. For example, this formulation should be filtered with an established filter. We then carried out a questionnaire survey involving medical staff (doctors and nurses) to clarify the problems regarding the liposome formulation and its practical utilization. Most doctors were satisfied with the effect of AmBisome, but about 90% of nurses who had used the preparation answered that it was troublesome to use the filter. On the other hand, only 40% of doctors understood how to use the filter when AmBisome was made up; 14% of nurses also did not know how to use the filter. We thought this was because they were not shown how to use it; actually, 30% of doctors were shown the preparation method by medical representatives (MR), although no nurse received an explanation. The residual rate of amphotericin B on 100 used filter pieces differed 50-fold between the minimum and maximum values. AmBisome is effective as an antifungal agent. However, pharmaceutical companies must liaise with medical staff for its effective clinical use. We hope that such companies will have exchanges with medical staff to develop safe and simple medicines, and that liposomes will be effective for many patients.

Cerebrospinal fluid (CSF) filtration has been proposed as a new treatment for Guillain-Barré syndrome (GBS). The theory behind filtering the CSF is that soluble pathogenetic factors or inflammatory mediators including cytokines might be removed from a site where nerve conduction could be impeded or nerve root damage inflicted. There is no pathologic background to recommend continuing with CSF filtration in GBS. Interferon is an immunoregulatory cytokine that reduces relapse frequency in multiple sclerosis and ameliorates experimental autoimmune neuritis, an animal model of GBS. A trial showed that interferon beta-1a would be safe in patients with GBS, but the sample size was too small to detect anything other than a large effect.

A 30-year-old woman was admitted to our hospital to undergo simultaneous cesarean section and radical hysterectomy when the pregnancy became 30 weeks. An ultrasonic examination had found hypoechoic region at the cervix uteri. Because she wished autologous blood transfusion, 100 ml each of her own blood was obtained 3 times preoperatively. All the stored blood was returned to the patient through a filtering system (40 microm in the pore size) during surgery. However, we found paste-like agglutinates floating in the bags. We transfused the blood carefully while confirming that there were no agglutinates in the reservoir below the filter. The paste-like agglutinates were also found on the filter. By microscopic observation fibrin-like substances attached by blood cells were detected. When the autologous blood from pregnant women is returned, special care should be taken because the blood is likely to form agglutinates even though the blood test data are within normal ranges.

To more easily estimate accurate values of collimator scatter facor, S(c), we suggest a two-component saturation model that accounts for scatter from the primary collimator and flattening filter and from the collimator jaws. This model, which assumes an exponential distribution of scatter intensity, was tested by in-air measurements using a mini-phantom for 4 MV and 10 MV X-rays of a Clinac 2100 C/D linear accelerator. The results showed a good fit of this model to our measured data (R(2)>0.9993). When the measured value was divided into the primary collimator/flattening filter component and the collimator jaw component, as expected, the former component showed a rapid and full saturation curve with increased field size, while the latter showed an almost linearly increasing curve. Therefore, we think that this saturation model is useful for the estimation of S(c) and is applicable to monitor unit calculation for an asymmetric field.

Purpose: To evaluate the efficacy of measurement of secretory IgA (sIgA) in tears with tear sampling methods using filter paper, and to review sIgA measurement method for clinical application., Subjects and Methods: Subjects were divided into the following 4 groups: a healthy control group, 29 eyes of 29 subjects; a contact lens group, 15 eyes of 15 subjects; a dry eye group, 13 eyes of 13 subjects; and a herpes group, 6 eyes of 6 subjects. In all subjects the sIgA value in tears was measured. In addition, in eighteen eyes of 18 healthy control individuals, the tear sIgA value was measured three times, morning, noon, and night in one day, and the variation of tear sIgA value was checked. The tears were sampled by the Schirmer 1 method. Schirmer papers were eluted in 200 microl of 0.5 M NaCl and 0.5% Tween 20 in 0.05 M phosphate-buffered solution (pH 7.2). Tear sIgA value was measured by ELISA (enzyme-linked immunosorbent assay)., Results: Tear sIgA value was 1249.0+/-1025.0 microg/ ml in the healthy control group; 1057.4+/-1583.3 microg /ml in the contact len groups; 197.8+/-91.3 microg/ml in the dry eye group; and 759.7+/-467.8 microg/ml in the herpes group. There was no significant difference between the healthy control group and the contact lens group, or the control group and the herpes group. There was a significantly (p<0.0001) low value in the dry eye group in comparison with the healthy control group. In the 18 healthy control individuals, there was a tendency for the tear sIgA value collected at noon to be higher., Conclusion: Measurment of the changes in tear sIgA values caused by inflammation of the lacrimal gland is useful as a clinical test of lacrimal gland function.

Formaldehyde is a flammable, colorless and readily polymerized gas at ambient temperature, and is one of the major pollutants in indoor air. Medical students during their dissection course are exposed to formaldehyde, whose exposure is recently considered to be one of the causes of multiple chemical sensitivity. To understand the system that produces exposures and to plan for implementing control options, this study examined formaldehyde exposures that occurred in the gross anatomy laboratory. Formaldehyde in air was sampled by an active 2,4-dinitrophenylhydrazine (DNPH)-silica gel cartridge, extracted with acetonitrile and analyzed with an high performance liquid chromatograph-ultraviolet(HPLC-UV)detector. The geometric mean formaldehyde concentration was 20-93 ppb in the anatomy laboratory before starting the anatomy dissecting. After beginning the dissecting, however, the highest geometric mean concentrations were 1012-1380 ppb. Significant differences were observed during the exposed period for symptoms of "unusual thirst", "burning eyes", "itchy eyes", "bad feeling", "fatigue", etc. in comparison with the non-exposed period. These results show that medical schools should take more concrete measures to reduce exposure to formaldehyde.

Objective: To evaluate quantitative fitness of N95 filtering facepiece respirators (N95 Mask) using Mask Fitting Tester and improvement of fitness by instruction., Materials and Methods: One hundred and thirty-three health care workers working at our hospital were tested as to quantitative fitness of N95 Mask using Mask Fitting Tester Model MT-02, Roken type that counts particles more than 0.7 microm in diameter. Based on counting the number of particles more than 0.7 microm in diameter of the air inside and outside the mask, leakage rate is calculated. Permissible range of leakage rate is 10% or below. In case of leakage rate more than 10%, we instructed way of wearing N95 Mask or change a type of N95 Mask. We usually provide three types of N95 Mask., Results: Eighty-seven (65.4%) out of 133 health care workers achieved leakage rate 10% or below at the first test. Forty-six (34.6%) who did not achieve leakage rate 10% or below at the first test received instruction or changed a mask type. Twenty-one (15.8%) achieved desired value by instruction and 19 (14.3%) by changing a mask type. But 6 (4.5 %) could not achieve desired value in spite of instruction or changing to another type of masks available to us. Leakage rate changed from 20.5 +/- 10.9% (10.1-58.6) to 6.3 +/- 4.9% (0-29.5) by instruction or changing a type of mask (p < 0.001). At the first test, mask fitness is better in male than female, and worse in workers who always use N95 Mask at isolation ward or laboratory room than workers who usually do not use N95 Mask. Main problems were choice of mask, fitness to nose, incorrect use of headband., Conclusion: It is useful to evaluate N95 Mask quantitative fitness using Mask Fitting Tester Model MT-02, Roken type. At the first test, 34.6% of health care workers have large amount of leakage more than 10%, and by instruction or changing a mask type, most of them could achieve 10% or below. But 4.5% could not achieve desired value. On Infection control, it is important to test quantitative fitness of N95 Mask and to provide more than three types of N95 Mask.

The MM50 is a racetrack microtron capable of taking out photon beams and electron beams with energies of up to 50 MeV. It flattens the beam by the beam-scanning method, while the microtron MM22 utilizes a flattening filter. The head-scatter factors (hereafter called S(h)), which are important for evaluating the output of the photon beam of the MM50 and MM22, were measured using a mini-phantom and build-up cap. S(h) measured with the build-up cap showed the influence of contaminated electrons, whereas S(h) measured with the mini-phantom showed less influence, even for 50 MV photon beams. Compared with the MM22, the MM50 showed less change in S(h) according to field size and energy. The reason for this seemed to be that the MM50 has a smaller extra-focal region than other accelerators equipped with flattening filters and, therefore, can essentially be considered a point source by using the beam-scanning method without a flattening filter. This study demonstrated that photons scattered by the flattening filter used for beam flattening in typical medical accelerators mainly contribute to S(h).

We examined ADP-induced platelet aggregability in 45 patients by novel whole blood aggregometer based on the screen filtration pressure method. Platelet aggregation could be easily and immediately checked without preparing platelet rich plasma. This aggregometer was useful for determination of anesthetic methods for a patient with an anti-platelet therapy. However, PATI (platelet aggregately threshold index) demonstrated the lowest value 5 minutes after blood collection and the valve was stabilized at higher level for 30 to 120 minutes. Time-dependent change should be considered for assessment of platelet aggregability in a clinical study.

Filtration Leukocytapheresis(LCAP) is an alternative to thoracic duct drainage and LCAP using a centrifuge method with the advantages that it can be performed easily and inexpensively. Clinical trials revealed that LCAP is a safe and effective therapy for patients with drug-resistant rheumatoid arthritis(RA). Assessment of RA before and after LCAP showed a substantial and rapid improvement in tender joints counts, swollen joint counts, and patient's and physician's assessments. Careful analysis indicated that 64-80% of patients with RA showed > or = 20% improvement following LCAP therapy. Furthermore, we investigated the clinical evaluation of LCAP for RA over the 3 year-study period. Possible therapeutic mechanisms of LCAP on RA are summarized.

An added filter on the collimator of the X-ray tube is useful for reducing exposure dose in interventional radiology (IVR). During IVR, high-quality fluoroscopic images are needed around the target region, but the portion of the fluoroscopic image that shows catheter/guide wires need not to be of high quality. Thus, we constructed an additional filter (spot filter) consisting of a copper sheet with an open hole in the center. The spot filter is moved by a remote control technique and can be used in cases of neurological, cardiac, abdominal, and pelvic IVR. Using this filter, image quality was improved at the target region of the image intensifier, because scatter radiation was attenuated in the periphery. Although image quality was deteriorated in the periphery, there was no significant disadvantage for IVR. The spot filter would be effective in reducing exposure dose in cases where the image quality of the target region needs to be maintained and in prolonged fluoroscopy.

We measured X-ray absorption and scatter with an acrylic plate attached to the front of the X-ray beam limiting device. The acrylic plate played the role of an added filter, absorbing the low energy element of the X-ray beam and decreasing the surface dose to 4.3% of the extreme height as a result. However, the surface dose outside the irradiation field increased to 35.3% of the extreme height, and the scatter dose increased to 47.8% of the extreme height. An acrylic plate with the minimum thickness necessary should be used to decrease unnecessary exposure outside the irradiation field.

At cardiac catheterization, analog images obtained using cinefilm are translated into digital images, and images appearing on the CRT are filtered by a sharpen filter. We investigated the effect of the sharpening filter on vessel diameter as measured by quantitative coronary arteriography. We acquired images of a vessel phantom filled with contrast material using an X-ray image intensifier. Vessel diameters measured by quantitative coronary arteriography were 1 mm, 1.5 mm, 2 mm, 3 mm, 4 mm, and 6 mm. Results showed that vessel diameters were decreased when the sharpening filter was used and that more intense filtering decreased the measured diameter further. When the diameter of the vessel phantom was less than 4 mm, the diameter was smaller and the ratio of decrease was larger. Vessel diameters of 2 mm, 3 mm, 4 mm, and 6 mm measured a maximum of 2.9 smaller, while those of 1 mm and 1.5 mm measured a maximum of 9.2 smaller.

Maximum likelihood expectation maximization (ML-EM) image quality is sensitive to the number of iterations, because a large number of iterations leads to images with checkerboard noise. The use of median filtering in the reconstruction process allows both noise reduction and edge preservation. We examined the value of median filtering after reconstruction with ML-EM by comparing filtered back projection (FBP) with a ramp filter or ML-EM without filtering. SPECT images were obtained with a dual-head gamma camera. The acquisition time was changed from 10 to 200 (seconds/frame) to examine the effect of the count statistics on the quality of the reconstructed images. First, images were reconstructed with ML-EM by changing the number of iterations from 1 to 150 in each study. Additionally, median filtering was applied following reconstruction with ML-EM. The quality of the reconstructed images was evaluated in terms of normalized mean square error (NMSE) values and two-dimensional power spectrum analysis. Median filtering after reconstruction by the ML-EM method provided stable NMSE values even when the number of iterations was increased. The signal element of the image was close to the reference image for any repetition number of iterations. Median filtering after reconstruction with ML-EM was useful in reducing noise, with a similar resolution achieved by reconstruction with FBP and a ramp filter. Especially in images with poor count statistics, median filtering after reconstruction with ML-EM is effective as a simple, widely available method.

The purpose of this study is to develop a technique to detect lacunar infarct regions automatically in brain MR images. Our detection method is based on the definition of lacunar infarcts. After inputted images were binarized, we used feature values such as area, circularities and the center of gravity of candidate regions to extract isolated lacunar infarct regions. We also developed and used a new filter to enhance the signals of lacunar infarcts adjacent to some high intensity regions. 10 cases involving 81 sectional images were applied to our experiment. As a result, the sensitivity was 100% with approximately 1.77 false-positives per image. Our results are promising on the first stage, although it remains to improve on problems that to eliminate false-positives and automatically establish threshold value.

Mammography practiced for the detection of breast carcinomas requires an appropriate X-ray equipment which can meet the performance standard. Also it is necessary to meet the requirements for the exposure dose as well as image quality. Factors affecting the exposure dose are X ray equipment, especially target-filter combination, recording systems, compression of breast, structural characteristics of breast and etc. The current guidance for the mammography adopts 3mGy as a dose level for standard breast for a direction which is recommended by IAEA. However, the average glandular dose for the mammography was 1.5mGy according to the image evaluation survey of medical institution as of December, 2001. This figure is almost equal to the result given by the national survey conducted from 1997 to 1998. The exposure reduction depends on the technique of radiological technologists. It is needed for them to optimize affecting factors. When reducing breast thickness by at least 1cm, the exposure does can be reduced by 50%.

Leukocytes are important in the occurrence of reperfusion injury in coronary intervention for acute myocardial infarction (AMI). This study compared reperfusion injury caused by reperfusion using leukocyte-depleted blood (LD) and that by conventional angioplasty (control) through the reperfusion phenomenon including reperfusion arrhythmia and additional ST elevation during direct percutaneous transluminal coronary angioplasty (PTCA) in 41 patients with 21 left anterior descending artery (LAD) lesions and 20 right coronary artery (RCA) lesions. LD was prepared from 20 ml of venous blood, 20 ml of mixed blood and 60 ml of arterial blood from the patients (LD group; LAD-LD: n = 10, RCA-LD: n = 10) which was passed through a leukocyte removal filter. The blood was injected from the tip of the balloon catheter at 10 ml/min during inflation for 10 min before balloon deflation. The control group (LAD-control: n = 11, RCA-control: n = 10) underwent conventional angioplasty. The appearance of reperfusion arrhythmia [atrioventricular block (AVB) > II, accelerated idioventricular rhythm (AIVR), ventricular tachycardia (VT), ventricular fibrillation (Vf)] and measurements of STmax deviation before and after reperfusion, the differences of the STmax deviation (delta ST) and additional ST elevation (LAD: > or = 0.5 mV increase of sigma ST in lead V1-V6, RCA: > or = 0.3 mV increase of sigma ST in lead II, III and aVF) were studied. The appearance of reperfusion arrhythmias was as follows; LAD-LD: AVB 0, AIVR 1, VT 1, Vf 0, LAD-control: AVB 0, AIVR 4, VT 2, Vf 1, NS, and RCA-LD: AVB 0, AIVR 0, VT 0, Vf 0, RCA-control: AVB 2, AIVR 0, VT 1, Vf 0, NS. There was no reperfusion arrhythmia in the RCA-LD group. There was no significant difference in the appearance of reperfusion arrhythmias between the LAD-LD and LAD-control or RCA-LD and RCA-control groups. Before reperfusion the STmax deviation (mV) was LAD-LD 0.86 +/- 0.46 vs LAD-control 0.74 +/- 0.49 and RCA-LD 0.29 +/- 0.18 vs RCA-control 0.15 +/- 0.09 and after reperfusion LAD-LD 0.63 +/- 0.35 vs LAD-control 0.81 +/- 0.49 and RCA-LD 0.13 +/- 0.15 vs RCA-control 0.20 +/- 0.12, respectively. There were no significant differences between LAD-LD and LAD-control or RCA-LD and RCA-control groups. delta ST (mV) was LAD-LD 0.23 +/- 0.56 vs LAD-control 0.07 +/- 0.60, p = 0.09 and RCA-LD 0.16 +/- 0.12 vs RCA-control 0.06 +/- 0.14, p = 0.002, respectively. The number of patients with additional ST elevation soon after reperfusion was LAD-LD 3 vs LAD-control 10, p < 0.05 and RCA-LD 0 vs RCA-control 8, p < 0.001, respectively.

Posttransfusion graft-versus-host disease (PTGVHD) is characterized by a fatal alloimmune reaction induced by donor lymphocytes contaminated in blood products. It is generally accepted that gamma irradiation of the blood products prior to transfusion is a most efficacious and reliable means to prevent this reaction. In contrast, leukocyte reduction by a third generation, high performance filter has been reported to fail the prevention of PTGVHD. With the filter function being considerably improved recently, leukocyte reduction may be an alternative for gamma irradiation to prevent PTGV-HD.

Background: Mass screening program for prostatic cancer (PC) using prostate specific antigen (PSA) filter paper method was performed in an urban area of Kyoto in 1995., Methods: In the primary study, males more than the age of 55 years were examined by PSA (Delfia PSA kit) with blood samples on a filter paper. The cut-off values were set at 4 and 10 ng/ ml. Subjects whose PSA level ranged from 4.1 to 10.0 ng/ml (gray zone) were examined by digital rectal examination (DRE), transrectal sonography (TRS) and PSA density (PSAD; more than 0.15) in the secondary study, then the suspected subjects of PC underwent 6 sextant biopsies under interventional ultrasound. Subjects whose PSA level were more than 10.1 ng/ml were biopsied directly., Results: Of 3,749 males who took the annual health checkup system organized by the government, 2,387 males wished to submit this screening. Among them, 2,217 (92.9%) showed a negative PSA, 107 belonged to the gray zone and 43 had a PSA more than 10.1 ng/ml. Of these, 102 subjects underwent biopsy. PC was finally detected in 28 (1.2%). The positive predictive value for positive PSA and gray zone PSA was 46.3% and 8.4%, respectively. In the detected cancers, 17 cases (60.7%) belonged to Stage B, 5 (17.9%) to Stage C and 6 (21.4%) to Stage D., Conclusion: The results suggested that this system of mass screening program for PC combined with the annual health checkup was suitable for the future "national-level" screening.

A 40-year-old female, whose blood type was A, Rh+, was admitted to our hospital for kidney transplantation from her younger brother whose blood type was B, Rh+. Before the transplantation, we performed 4 sessions of double filtration plasmapheresis (DFPP) to remove the anti-B antibodies. The serum anti-B antibody titer lowered from X32 to X4. The kidney transplantation was carried out following the splenectomy. The warm ischemic time was 8 minutes and the cold ischemic time was 47 minutes. Five immuno-suppressive agents including cyclospolin, azathioprine, prednisolone, anti-lymphocyte globulin (ALG), and deoxyspergualin were administered in the initial period. Nine days after the transplantation, an acute rejection occurred, and 15 sessions of hemodialysis were needed. However, Methylprednisolone and OKT3 treatment resulted in recovery of the graft function. Seventy-four days after the transplantation, she was discharged with the serum creatinine concentration of 1.3 mg/dl. The DFPP before transplantation was useful to remove the anti-RBC antibody from the patient receiving an ABO incompatible kidney allograft.

We reported a case of Isaacs' syndrome with abnormal F response detected electrophysiologically. A 14-year-old female was admitted to Hirosaki University Hospital with complaints of progressive myokymia and muscle cramp. PHT and CBZ were partially effective, but discontinued for drowsiness. A neurological examination revealed prominent myokymia and muscle cramp in the legs. The myokymia were worsened by exercise, bathing and diet. An electrophysiological examination showed characteristic F-response; high amplitude, long duration and increased number of phases. The epidural nerve block brought about a disappearance of the myokymia and an improvement of the abnormal features of F response. After repeated double filtration plasmapheresis, the myokymia and abnormal features of F response were remarkably reduced. Although Isaacs' syndrome is thought to have a hyperexcitability at the site of distal peripheral nerve, we suggested that the hyperexcitability might exist at the site of proximal region, and that immunological mechanisms underlie the cause of myokymia and unusual F-response in this case.

99mTc-gas (TECHNEGAS) is a 99mTc-labeled micro-aerosol which is considered to have different behavior from 133Xe or 81mKr gas. In order to estimate contamination levels to room air arising from the use of 99mTc-gas, filtered expired air during administration and 1, 2, 3, 5, 10 min after the administration were collected in each polyethylene bag. Radioactivities of the polyethylene bags, used filter and the lung were measured with 3-head scintillation camera. The activity of the expired air diminished within 6-10 min and about 5% of whole discharged 99mTc-gas was released to room air. The activity of the used filter was two times of the lung. According to these results, it is recommended that the 99mTc-gas may be administrated in a exclusive room. The administrated patient and used filter must be remain in the exclusive room.

We studied the effect of double filtration and immunoadsorption plasmapheresis in Guillain-Barré syndrome retrospectively in 70 patients. Thirty three patients had plasmapheresis, of whom 23 had double filtration and 10 immunoadsorption. The rest of 37 patients consisted of a control group. Clinical disability was evaluated using the functional grading scale by Hughes. In patients having a maximum disability of grade 4 and 5, the double filtration plasmapheresis group showed statistically significant improvement at 3 months after the treatment. There was no significant difference in prognoses between the immunoadsorption plasmapheresis and control groups. In mildly-illed patients having grade 2 and 3, the prognoses were not different between the three groups. In Guillain-Barré syndrome, double filtration plasmapheresis, as well as well-established plasma exchange, had benefit for severely-illed patients.