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A new materials irradiation facility with improved control capabilities has been installed at the Kyoto University Reactor (KUR). Several deficiencies of conventional fission neutron material irradiation systems have been corrected. The specimen temperature is controlled both by an electric heater and by the helium pressure in the irradiation tube without exposure to neutrons at temperatures different from the design test conditions. The neutron spectrum is varied by the irradiation position. Irradiation dose is changed by pulling the irradiation capsule up and down during irradiation. Several characteristics of the irradiation field were measured. The typical irradiation intensity is 9.4×10 12 n/cm 2 s (>0.1 MeV) and the irradiation temperature of specimens is controllable from 363 to 773 K with a precision of ±2 K.

Unlike other herpesviruses, Epstein-Barr virus (EBV) has not yet been shown to infect macrophages. Six macrophage cultures were isolated from normal and affected samples. Nested polymerase chain reaction revealed the existence of the EBV genome in all these macrophages. EBV latent genes expression in all cultures were detected by mRNA in situ hybridization and immunofluorescence staining. Some cultures also expressed EBV replicative-infection proteins, while in other cultures induction of these proteins was demonstrated. These findings are the first to show expression of several latent and replicative-infection genes of EBV in macrophages, indicating that EBV proliferates in macrophages.

The p53 mutation has been found only in 0–6% of cervical carcinomas. In light of recent studies demonstrating that mutation of p53 gene was found in over 20% of the patients with vulvar carcinoma a disease of elderly women and a known human papillomavirus (HPV)-related malignancy, we analysed mutation of the p53 gene in 46 women with cervical carcinomas at the age of 60 or more (mean; 71 years, range; 60–96 years). The presence of HPV and its type were analysed by polymerase chain reaction (PCR)-based assay using the consensus primers for L1 region. Mutation of the p53 gene was analysed by PCR-based single-strand conformation polymorphism and DNA sequencing technique. Point mutation of the p53 gene was detected in 5 out of 46 (11%) cervical carcinomas: 1 of 17 (6%) samples associated with high-risk HPVs (HPV 16 and HPV 18) and 4 of 27 samples (15%) with intermediate-risk HPVs (P = 0.36) whereas no mutation was found in 2 HPV negative cases. The mutated residues resided in the selective sequence known as a DNA-binding domain. The immunohistochemistry revealed the overexpression in cancer tissues positive for p53 mutation. All of the observed mutations of the p53 gene were transition type, suggesting that the mutation may be caused by endogenous mutagenesis. Although falling short of statistical significance reduces the strength of the conclusion, data presented here imply that p53 gene mutation, particularly along with intermediate-risk HPV types, may constitute one pathogenetic factor in cervical carcinoma affecting elderly women. © 1999 Cancer Research Campaign

Closed patch testing and the nitrocellulose-replica method are performed as useful clinical methods for the evaluation of human skin irritation by cosmetics and topical medicaments. Comparison of the sensitivity between microscopic scoring by nitrocellulose-replica method and visual scoring by closed patch test in the detection of skin irritation, however, has not been well studied with statistical analysis. Here, we evaluated human skin irritation by carboxylic acids, alcohols, esters and aldehydes, with different chain length (C8-C18), using both methods. The results of closed patch testing showed that, although the score of skin irritation for carboxylic acids (C8, C12), alcohols (C8) and aldehydes (C8), tested at a concentration of 0.5 m-2.0 m, significantly increased with increasing concentration of the test compounds, ester compounds scarcely caused any irritation on the surface of the skin occluded. In addition, an increase of carbon chain length in the test compounds made it impossible to detect skin irritation. In contrast, the nitrocellulose-replica method could evaluate skin reactions against very weak irritants that gave no macroscopic alterations on the skin surface in the closed patch test. However, the scoring system is somewhat subjective and should be improved to make the analysis more objective.

The ability of radiographers to detect cancer on radiographs was compared to that of physicians to assess the competence of radiographers as film readers in gastric cancer screening. After obtaining permission for the screening and analysis of data, a test set of films from 100 patients who underwent gastric cancer screening using radiographic examination was evaluated. Films were selected from 137 744 patients and 197 cases of cancer. Screening was performed at the Osaka Cancer Prevention and Detection Center in Japan between April 2004 and March 2008. Eleven radiographers affiliated to the screening center and 37 physician readers scored the test set on a 4-point scale blinded to the other participants’ scores. Receiver operating characteristic (ROC) analysis was performed to evaluate the interpretation performance, and the area under the ROC curve (AUC) was defined as the ability of the radiographer or physician reader to detect cancer. The results showed that the average ability of radiographers to detect cancer (AUC, 0.82) was identical to that of physician readers (p = 0.96, Welch’s t test), suggesting that radiographers can assume the role of film readers in gastric cancer screening.

It has been reported that if the physician suspects cancer during standard mammography (craniocaudal and mediolateral oblique views), undertaking additional mammography under the physician’s order improves the diagnostic accuracy of breast cancer. The aim of our study was to determine whether additional mammography, as judged necessary by the radiographer, improves the diagnostic accuracy of breast cancer during mammography. Our Institutional Review Board approved the study. Mammography was performed at a single hospital in Osaka, Japan between June 2009 and March 2010. A total of 2636 individuals underwent mammography as workup. Of the 101 cases of cancer finally diagnosed, we examined a total of 75 cases were additional mammography had been undertaken. Three physicians certified as film readers by the Central Committee on Quality Control of Mammographic Screening in Japan, reinterpreted mammograms. The first reinterpretation involved only standard mammograms and the second included both standard and additional mammograms. Films were categorized by consensus on a five-point scale defining the degree to which cancer was suspected. To determine a category difference between standard mammograms alone, and both standard and additional mammograms, we used the Wilcoxon signed ranks test. A P value of

The purpose of this study was to investigate the potential benefits of additional x-rays in detecting gastric cancer during x-ray screening. We analyzed 151 gastric cancer cases among 136,450 individuals who underwent x-ray screening for gastric cancer. X-rays were performed by 10 radiographers at a single screening center in Japan from 2000 to 2002. Additional x-rays were taken based on the radiographer’s judgement in cases of suspected cancer lesions. During reinterpretation of the x-rays of cancer cases by 2 radiologists, we determined the number of cancer cases that were detected by standard x-rays alone. We next determined the number of cancer cases detected using both standard x-rays and additional x-rays. We then investigated whether additional x-rays increased the rate of cancer detection. The number of cancer cases detected by standard x-rays alone was 122 and the number of cancer cases detected by standard x-rays and additional x-rays was 151. We observed a significant increase in cancer detection with the use of additional x-rays when judged necessary by the radiographer (29 cases, P = 0.007, Wilcoxon signed..ranks test). No statistically significant correlation was observed between the number of additional x-rays performed and the increased rate of cancer detection due to additional xrays taken arbitrarily (rs = - 0.38, P = 0.28, Spearman’s rank correlation). We found that additional x-rays, performed when judged to be necessary by the radiographer during screening, can identify cases of cancer which are not detectable with the standard x-rays alone.

A new algorithm for canceling MRI artifact due to translational motion in the image plane is described. Unlike the conventional iterative phase retrieval algorithm, in which there is no guarantee for the convergence, a direct method for estimating the motion is proposed. In the previous approach, the motions in the readout (x-) direction and the phase encoding (y-) direction are estimated simultaneously. However the feature of each x- and y- directional motion is directional. By analyzing their features, each x- and y- directional motion is canceled by different algorithms in two steps. First, the authors notice that the x-directional motion corresponds to a shift of the x-directional spectrum of the MRI signal, and the nonzero area of the spectrum just corresponds to x-axis projected area of the density function. So the motion is estimated by tracing the edges of the spectrum, and the x-directional motion is canceled by shifting the spectrum in inverse direction. Next, the y-directional motion is canceled using a new constraint, with which the motion component and the true image component can be separated. The algorithm is shown to be effective by simulations. >

Non-contact micromanipulation is one of the fundamental techniques in micromachine technology. In the previous paper at MHS2000, a new manipulation technique was proposed to transport a particle three-dimensionally using an ultrasonic standing wave field generated by four transducers, whose sound beam axes were arranged to cross at a point with the same angle. There is a request from industry to operate a lot of flowing particles continuously. The present paper describes non-contact concentration of suspended particles in flow using acoustic radiation pressure in water. Using a standing wave field generated between a transducer and a reflector, it is possible to trap particles at nodes of the sound pressure distribution and to move their positions by changing the frequency. Thus, a standing wave field was generated in a wide area by a rectangle transducer along the flow route, and filtering of particles was tried. As a result, it was possible to draw particles to the reflector side or the transducer side by changing the frequency in repeat sweep mode. Namely, this method makes it possible to concentrate particles continuously.

When multiple mobile robots cooperate in carrying large objects, it is important for them to be located in appropriate positions. This paper describes optimal grasping positions of robots and regrasping procedure for carrying an object by cooperating multiple mobile robots. Regrasping action is performed by several exchanges of the robots, the number of which is more than the number of robots to be need of the load on the robots. Then, we propose a method for deciding the optimal grasping positions of them and optimal regrasping times by using the performance index. The regrasping procedure is decided in consideration of the intermediate situation between the initial situation and the optimal one. A numerical example shows the effectiveness of the proposed method.

The aim of this study was to evaluate whether low-dose high-pitch (6:1) multidetector-row helical high-resolution CT is appropriate for the evaluation of various pulmonary abnormalities, including faint opacities.Eleven autopsy lungs were scanned with a multidetector-row CT scanner using 2.5 mm x 4 beam collimation, effective slice thickness 3 mm, 6:1 pitch, 0.8 second gantry rotation speed, 20 cm Display FOV, high spatial frequency (bone) algorithm, and various radiation doses (120 kVp; 160, 80, 40, 24, and 8 mAs). The image quality of each CT set was assessed as adequate or inadequate for diagnosis by two independent observers. In addition, a wire phantom was scanned with the same parameters in order to describe the MTF curves.There was excellent agreement between the observers for the evaluation of image quality (kappa statistic, 0.84). The ratio of images evaluated as inadequate for 8 mAs and 24 mAs was significantly higher than that for 160, 80, and 40 mAs (p0.01: chi-square test). MTF curves of both 8 and 24 mAs were significantly inferior to those of 40, 80, and 160 mAs (p0.0 1, Friedman test), while the MTF curve of 40 mAs was relatively inferior to that of 160 mAs (p0.05, Friedman test).More than 40 mAs in combination with 120 kVp is preferable for the evaluation of details of lung parenchyma by high-pitch. multidetector-row helical high-resolution CT.

Purpose: To develop the detector for the four-dimensional dose distribution measurement. Methods: We made the prototype detector for four-dimensional dose distribution measurement using a cylindrical plastic scintillator (5 cm diameter) and a conical reflection grass. The plastic scintillator is used as a phantom. When the plastic scintillator is irradiated, the scintillation light was emitted according to absorbed dose distribution. The conical reflection grass was arranged to surround the plastic scintillator, which project to downstream the projection images of the scintillation light. Then, the projection image was reflected to 45 degree direction by flat reflection grass, and was recorded by camcorder. By reconstructing the three-dimensional dose distribution from the projection image recorded in each frame, we could obtain the four-dimensional dose distribution. First, we tested the characteristic according to the amount of emitted light. Then we compared of the light profile and the dose profile calculated with the radiotherapy treatment planning system. Results: The dose dependency of the amount of light showed linearity. The pixel detecting smaller amount of light had high sensitivity than the pixel detecting larger amount of light. However the difference of the sensitivity could be corrected from the amount of light detected in each pixel. Both of the depth light profile through the conical reflection grass and the depth dose profile showed the same attenuation in the region deeper than peak depth. In lateral direction, the difference of the both profiles was shown at outside field and penumbra region. We consider that the difference is occurred due to the scatter of the scintillation light in the plastic scintillator block. Conclusion: It was possible to obtain the amount of light corresponding to the absorbed dose distribution from the prototype detector. Four-dimensional dose distributions can be reconstructed with high accuracy by the correction of the scattered light.

This article describes pitfalls in the interpretation of multidetector-row helical CT (MDCT) images at the window width and level settings for lung parenchyma. On MDCT, linear artifacts, which look like black and white linear densities and are called "hurricane artifacts," radiate out from objects that have very different densities from their neighbors. For the evaluation of fine parenchymal details, a low table speed/slice collimation should be used. In fact, axial (step and shoot) scanning may be more effective for the evaluation of fine details. Since artifacts from vessels highly enhanced by contrast medium cause data blackout in the surrounding areas at high table speed/slice collimation, pulmonary parenchyma in such situations should be evaluated with unenhanced CT. Although multidetector-row helical CT is a promising tool for the evaluation of lung parenchyma, it is important to identify its shortcomings due to artifacts when interpreting images at the window width and level settings for lung parenchyma and to apply the appropriate methods for eliminating such artifacts.

The purpose of this study was to survey the usefulness of high-resolution CT (HRCT) for the evaluation of activity in acute and subacute non-infectious diffuse infiltrative lung diseases before and after corticosteroid treatment.Sequential HRCT images and chest radiographs obtained before and after treatment were retrospectively evaluated in 33 patients with acute or subacute noninfectious diffuse infiltrative lung diseases. All these patients were histologically confirmed to have pulmonary Inflammation and to have responded to treatment with corticosteroid. Radiographic and CT scores were correlated with the degree of dyspnea and the results of arterial blood gas analysis using Spearman's rank-correlation coefficient.On follow-up HRCT, the profusion score of areas with increased attenuation was significantly correlated with arterial oxygen tension (PaO2) (p=.003, r=-.53) and the alveolar-arterial oxygen tension difference (AaDO2) (p=.001, r=.57). No other correlation was found after treatment. Nodular and linear opacities were more commonly seen on follow-up chest radiographs and HRCT images than on initial ones.HRCT is useful for the evaluation of disease activity in acute and subacute noninfectious infiltrative lung diseases before and after treatment if paying special attention to the profusion of ground-glass attenuation. Even if pretreatment HRCT has not been performed, posttreatment HRCT should be examined.

Recently, there have been several reports describing patients with multiple myeloma complicated by consciousness disturbance due to hyperammonemia. Here we report a patient with multiple myeloma and hyperammonemia, who died after rapid progression of the disease. A 71-year-old man who had been diagnosed as having Bence Jones protein (kappa)-type multiple myeloma in 1996 was readmitted to our hospital in February 1997 because of worsening bone pain, renal dysfunction, and hypercalcemia. Bone marrow aspiration yielded an almost dry tap, and the bone marrow was found to be completely occupied by immature plasma cells. Although liver dysfunction was slight, the serum ammonia level was high and increased gradually. Despite treatment, the patient died due to cerebral embolism and progression of plasmacytic leukemia in October 1997. Peripheral blood sampled at the time of death showed a serum ammonia level of 204 micrograms/dl, and the myeloma calls were cultured using monolayered bone marrow stromal cells as feeder cells. This led to the successful establishment of a cell line. The level of ammonia in the supernatant was high, indicating that the cultured myeloma cells produced and released ammonia.

We report our experience with allogeneic peripheral blood stem cell transplantation (allo-PBSCT) following a nonmyeloablative conditioning regimen consisting of cytarabine (8 g/m2) and cyclophosphamide (120 mg/kg) in the treatment of 2 patients aged 50 and 55 years with refractory chronic myelomonocytic leukemia and chronic myeloid leukemia in accelerated phase, respectively. Our nonmyeloablative regimen was well tolerated by older patients at high risk of regimen-related toxicity by the conventional conditioning regimen but was immunosuppressive enough to achieve mixed chimerism. After allo-PBSCT, we monitored chimerism in these patients by fluorescence in situ hybridization using X- and Y-specific probes and polymerase chain reaction-based analysis of a variable number of tandem repeats. We found that full chimerism and graft-versus-leukemia (GVL) effects could be induced in these patients by donor lymphocyte infusions and withdrawal of posttransplantation immunosuppressive therapy. Our observations suggest that a nonmyeloablative conditioning regimen can establish mixed chimerism and that donor lymphocyte infusion may induce GVL effects in older patients at high risk of regimen-related toxicity.

Human bone marrow stroma (BST)-dependent myeloma sister cell lines MOLP-6 and MOLP-7 were established from the peripheral blood of a multiple myeloma (MM) patient with IgA kappa type MM (stage IIIB). The growth of the cell lines is constitutively dependent on BST cells; none of the cytokines tested nor the culture supernatant of the BST cells could support the growth. Both cell lines showed typical plasma cell morphology with abundant cytoplasm and one to four nuclei under Wright staining. The immunoprofiles of MOLP-6 and MOLP-7 correspond to that seen typically in primary MM cells: positive for cytoplasmic immunoglobulin (Ig) chains, a heavy and kappa light chains, CD9, CD28, CD40, CD44, CD45, CD56, and PCA-1; the cells were negative for surface Igs and various other B-cell, T-cell and myelomonocyte associated markers. Both cell lines also expressed adhesion molecules including HCAM (CD44), VLA-4 (CD49d/CD29), VLA-6 (CD49f/CD29), ICAM-1 (CD54), NCAM (CD56), LFA-3 (CD58) and L-selectin (CD62L). The doubling time of MOLP-6 and MOLP-7 was 48 and 168 hours, respectively. In addition to this growth characteristic, the maximum cell density of each cell line was obtained at 1.7 x 10(6) cells/ml and 9.7 x 10(5) cells/ml, respectively. The characteristics of each cell line may reflect intraclonal variation of the proliferative capacity. The MOLP-6 together with the MOLP-7 sister will be useful model systems for the investigation of the biology of myeloma.

The novel multiple myeloma (MM) cell line MOLP-5 and its homologous sister cell line B407, a lymphoblastoid cell line (LCL), were established from the peripheral blood of a 71-year-old Japanese patient with Bence-Jones kappa-type multiple myeloma (stage IIIB with hyperammonaemia and hypercalcaemia). The growth of MOLP-5 cells is constitutively dependent on bone marrow stroma (BST) cells; none of the cytokines tested nor the culture supernatant of the bone marrow stroma cells could support the growth of MOLP-5. Wright-Giemsa-stained MOLP-5 cells showed typical plasma cell morphology with abundant cytoplasm and one to three nuclei. The immunoprofile of MOLP-5 corresponds to that seen typically in primary MM cells: positive for cytoplasmic immunoglobulin (Ig) kappa light chain, CD28, CD29, CD38, CD40, CD44, CD49d, CD54, CD56, CD58, CD71, CD138 and PCA-1; the cells were negative for surface Ig and various other B-cell, T-cell and myelomonocyte-associated immunomarkers. Interleukin 6 (IL-6) receptor mRNA was found in the reverse transcriptase polymerase chain reaction (RT-PCR) analysis. IL-6 and IL-10 could induce cellular proliferation in short-term induction experiments. IL-6 or IL-10 production was not detected by specific enzyme-linked immunoabsorbent assay (ELISA). MOLP-5 cells expressed parathyroid hormone-related protein (PTHrP) at the mRNA level. Cytogenetic analysis showed the typical t(11; 14) chromosome abnormality. The novel MOLP-5 cell line together with the B407 B-LCL sister line will be useful model systems in the investigation of the biology of MM.

The objective of this study was to examine the feasibility of soft-copy (CRT) reading and suitable compression. Forty abdominal CT images with a space-occupying lesion (SOL) in liver and 40 normal images were selected for receiver-operating-curve (ROC) analysis. Each image was compressed by JPEG extended mode into 1/10 its original capacity, and then an expanded image was printed on film. Ten radiologists evaluated the presence of liver SOLs (primary and secondary tumors) on soft-copy (CRT) and hard-copy (film) images. Each radiologist reviewed four types of images (original and compressed hard-copy and original and compressed soft-copy images). Values of the area under the curve in the various ROC analyses were 0.858 (FILM) and 0.842 (CRT) for original images and 0.879 (FILM) and 0.846 (CRT) for compressed images. The results of ROC analysis showed better reading performance with hard-copy than soft-copy images, but the difference was not statistically significant. Compressed images showed a higher value (0.879) than original images (0.858), a difference that was statistically significant (p0.029) by the paired t-test but not by the jackknife method. The results indicate that soft-copy reading is a clinically acceptable alternative to hard-copy reading. We have had no difficulty in reading abdominal CT images compressed to 1/10 of the original size by the JPEG method. This study was supported in part by a grant from the Japanese Ministry of Health and Welfare.

Dose distribution images play important roles in the management of cancer patients. To date hard copies of these images have been stored and referred to by radiation oncologists as needed. In most cases, these images were not available to medical personnel outside the radiation oncology department. We have developed a mechanism in the hospital to access these dose distribution images via WWW (World Wide Web). A screen snapshot of a dose distribution image on the CRT of a treatment planning machine is copied to the WWW server and converted to a GIF image. Similarly, we can register dose volume histograms and digitally reconstructed radiographs on the WWW. Medical personnel throughout the hospital can access the images through the WWW browser. As a result, radiation oncologists are given detailed information on target definition in treatment planning by expert physicians. The system also helps co-medical staff in understanding dose distributions and predicting radiation injuries. At the same time, it actualizes an electronic archive of dose distribution images, which is a database for quick and reliable review, evaluation and comparison of treatment plans. This technique also furthers a close relationship among radiation oncologists, physicians, and co-medical personnel.

First, annual cost of electronic filing of medical images were calculated and compared with that of film storage in two hospitals under different conditions. Storage of medical images using a pixel size of 100 microns x 100 microns and 2-byte depth on the 130 mm, 650 MB magneto-optical disks costs with four times as much as the cost for film storage. However, 175 microns x 175 microns 12 bits combined with implementation of lossless compression would reduce the cost to a level equal to that for films storage. Doubled or tripled densities of MOD will improve the cost ever further. Second, the effectiveness of Hospital Information System/Radiological Information System (HIS/RIS) was evaluated. Examination time, film delivery time and the total turn-around time was markedly shortened by more than 23 hours on average. Our measurement method employing IC cards in pre-post HIS/RIS/PACS procedures is generally applicable to other hospitals. Third, to determine the optimal method of maximizing the efficacy of diagnostic imaging, 260 questionnaires were sent to the staff of 13 university hospitals. Every situation was described by both a radiologist and the physician who ordered the examination and received the reports and images. The level of technical efficacy and diagnostic accuracy of radiology strongly influenced the diagnostic thought processes of the physician.

Twenty-seven consecutive patients were examined by T2-(1,800/70 ms) and postcontrast T1-weighted (600/15) spin echo (SE) or dynamic (200/15) SE MR imaging to determine the usefulness of parasagittal MR imaging in assessing cervical invasion of endometrial carcinoma. The images were obtained in a direction parallel to the longitudinal axis of the uterus (parasagittal). The cervical epithelium, being hyperintense on the late phase dynamic and postcontrast T1-weighted SE images, had disappeared partially or totally in all 4 patients with cervical invasion. The enhanced cervical epithelium was completely seen in one patient with the tumor protruding into the cervical canal in a polyp-like form without cervical epithelial invasion. The same was also seen in the 22 patients with the tumor remaining in the corpus cavity. The enhanced parasagittal MR images facilitated the evaluation of the extent of the endometrial carcinoma.

Thirty-one cases of small hepatocellular carcinoma (HCC) under 3 cm in diameter underwent Spiral CT with bolus injection of contrast medium (Dynamic Spiral CT). Dynamic Spiral CT was compared with CT after intra-arterial injection of iodized oil (Lipiodol-CT). The detectability of 79 nodules of small HCC on early phase images of Dynamic Spiral CT was 49.4% (32.6% for those under 1 cm in diameter, 58.3% for 1-2 cm, 91.7% for 2-3 cm). The detectability of small HCCs above the hilum of the liver was better than that below the hilum. Five lesions were detected only on delayed CT images, but not on early phase CT images. Dynamic Spiral CT is useful for detecting hypervascular small HCCs, and both early phase and delayed CT images must be obtained.

We encountered a patient with multiple lymphangiomas of the mesentery and small intestine. Ultrasonography and computed tomography showed a mesenteric tumor composed of a solid component with a small cystic part. This unusual appearance made the differential diagnosis between lymphangioma and other intra-abdominal solid tumors difficult.

In the first study by the "Kinki Head and Neck Tumor Study Group," we performed a comparative study to investigate intergroup difference between a control group consisting of patients given radical treatment only, and a HCFU group consisting of patients receiving long-term administration of HCFU after radical treatment. We earlier reported that subsequent observations by stratification revealed a favorable tendency in the cumulative disease-free rate in Stage II and Stage III patients in the HCFU group. In the second study, the same methods of treatment as in the first study were compared in a prospective control study. No differences were found between the two groups in Stage II patients. In Stage III patients, however, the disease-free rate tended to increase significantly in the HCFU group as in the first study.

Dynamic 3-dimensional Fourier transformation (3 DFT)-FISP MR imaging was performed in 30 patients with 49 liver tumors (hepatocellular carcinoma 26, hemangioma 13, cholangiocellular carcinoma 2, metastatic liver tumor 8) to evaluate characteristic enhancement patterns. MR images of 3 DFT-FISP (TR/TE/flip angle/slab thickness/partition/slice thickness, 20 msec/8 msec/30 degree/21-75 mm/7 or 15/3-5 mm) were obtained before, just after (early phase), 1 min after (late phase 1) and 2-4 min after (late phase 2) the administration of 0.1 mmol/kg of Gd-DTPA. Twenty-three of the 26 (88%) hepatocellular carcinomas showed total hyperintense enhancement relative to surrounding liver parenchyma in the early phase, and isointense or total hypointense enhancement in the late phase. Eleven of 13 (85%) hemangiomas showed peripheral hyperintense enhancement in the early phase, and peripheral or total hyperintense enhancement in the late phase. Cholangiocellular carcinomas were enhanced gradually from the early to the late phase. Metastatic liver tumors showed doughnut-like ring enhancement in all 8 lesions in the early phase. We concluded that 3 DFT-FISP dynamic MR imaging was useful in the differential diagnosis of liver tumor.

PURPOSE: To delineate the appearance of normal Virchow-Robin spaces on routine spin-echo images and demonstrate the lenticulostriate arteries within them with a flow-sensitive fast low-angle shot (FLASH) pulse sequence. METHODS: Seventy subjects, free of cerebrovascular diseases and other neurologic disorders, ranging in age from 1 to 75 years, were examined. On a 1.5-T MR system, axial spin-echo images of 5 mm thickness were obtained in all subjects. In 45 of 70 subjects axial two-dimensional FLASH images of 3 mm thickness were continuously imaged. RESULTS: On T1- and spin density-weighted images Virchow-Robin spaces were detected as small foci of cerebrospinal fluid intensity around the anterior commissure in all subjects (100%), and in the basal ganglia at the level of the foramen of Monro in 40 (57%). T2-weighted images equally showed Virchow-Robin spaces around the anterior commissure but were less sensitive than T1- and spin-density weighted images at the level of the foramen of Monro (14%). Virchow-Robin spaces identified on T2-weighted images should be isointense with cerebrospinal fluid. However, one or two spaces in 11 younger subjects were hypointense relative to adjacent brain tissue. On FLASH images most Virchow-Robin spaces identified on spin-echo images were delineated as high-intensity foci, corresponding to lenticulostriate arteries. CONCLUSIONS: Normal Virchow-Robin spaces along the lenticulostriate arteries are frequently detected on spin-echo images. Their appearance, affected by the flow of associated lenticulostriate arteries, varies from hyper- to hypointensity to brain tissue on T2-weighted images. The two-dimensional FLASH sequence can demonstrate the flow of the arteries, thereby helping confirm that these are truly Virchow-Robin spaces.

PURPOSE: To investigate the effectiveness of MR angiography in conjunction with spin-echo imaging for evaluating vascular patency in patients with middle cerebral artery (MCA) stenosis or occlusion. METHODS: Seven patients with MCA stenosis or occlusion, verified with contrast angiography in five and correlated with transcranial Doppler sonography in two, were examined using two-dimensional and/or three-dimensional time-of-flight MR angiographic techniques as well as conventional spin-echo imaging. RESULTS: Of the seven patients, six demonstrated basal ganglionic and/or cortical infarct in the MCA territory. Except one case with minimal stenosis immediately distal to the MCA origin, all six cases with either severe stenosis or occlusion of the main trunk of the MCA showed the absence of normal flow voids using spin-echo imaging in the sylvian fissure on the affected side. However, it was not possible to discriminate between stenosis and occlusion. Although different mechanisms (ie, flow-induced spin dephasing for the 2-D technique and progressive spin saturation for the 3-D technique) were predominantly responsible for the loss of signal through the area of stenosis, both the 2-D and 3-D MR angiograms clearly depicted the compromised flow of the MCA: a focal discontinuity with decreased vessel caliber corresponded to stenosis, and nonvisualization of distal MCA branches represented occlusion. CONCLUSION: Either 2-D or 3-D time-of-flight MR angiography is a useful adjunct to conventional parenchymal spin-echo imaging for evaluating vascular patency in patients with MCA stenosis or occlusion, although it is important to recognize that each technique has a different basis for the loss of signal through the area of stenosis.

An experimental radiologic reporting system using oral presentations has been developed and tested. The rewritable and compact magneto-optical disk (MOD) is employed to store oral diagnostic reports together with read radiologic images. The MOD is 5.25 inches in diameter, has a 600 MB memory capacity, and is erasable, light and compact. Advantages of the system are simultaneous retrieval of oral reports by a radiologist and the images he or she interpreted, and the capability of media circulation in addition to the function of filing. Thus MOD has a multimedia function of both off-line communication and filing. When medical images are interpreted and oral presentations are registered, automatically digitized oral reports and digitized images are filed in the MOD. Referring physicians can get oral diagnostic reports and can see the images at the same time on a personal computer. Furthermore, integration with voice recognition capability is being tried in our experiment.

Our early experience using microSelectron HDR to treat cervical cancer patients at Osaka University Hospital is presented. From June 1991 through December 1992, a total of 20 patients (stage Ib, 6; stage IIa, 2; stage IIb, 5; stage IIIb, 6 and stage IVa, 1) with previously untreated invasive uterine cervical cancer and intact uterus were treated with high-dose rate intracavitary therapy administered with a microSelectron. For the treatment, a standard rigid applicator made of stainless steel for a microSelectron was used. Twenty to 30 Gy of external irradiation was administered to the whole pelvic field and 30 to 20 Gy to the central shielded field (total 50 Gy/5-6 weeks) for patients in stage II-IVa. For stage Ib, 40 Gy was delivered to the central shielded field. The 192Ir source had an activity of 370 GBq as of the measuring time. Source loading corresponded to the Manchester System for cervical cancer. Thirty-two or 30 Gy was administered at point A in four fractions over four weeks of intracavitary irradiation. Early primary tumor responses for all patients were complete. There have been two local recurrences in stage IIb and IIIb patients. Three patients in stages Ib, IIb, and IIIb developed para-aortic lymph node metastases, and two of them died from generalized metastasis. No acute radiation injury has been observed. One patient in stage IIb developed subileus five months after irradiation. From our early experience, it is concluded that microSelectron HDR can be used for cervical cancer patients as safely and effectively as our previously used high-dose rate machine.

MR images of the neck were prospectively studied in 19 patients with hyperparathyroidism. Fast low angle shot (FLASH) sequence was performed in addition to T1- and T2-weighted spin echo (SE) sequences. FLASH images were obtained with 320/12/20 degrees (TR/TE/flip angle) using presaturation technique. TE of 12 ms was chosen to eliminate high signal of fat tissue. In the evaluation of detectability, a combination of T1-weighted SE and FLASH images (T1WI + FLASH) was compared with a combination of T1- and T2-weighted SE images (T1WI + T2WI). MR imaging correctly depicted 20 of 30 abnormal glands on both T1WI + FLASH and T1WI + T2WI. FLASH imaging effectively eliminated high signal of fat tissue. Nineteen abnormal glands demonstrated higher signal than surrounding tissues on FLASH images, whereas 12 glands were high-intense on T2-weighted SE images. We conclude that FLASH imaging provides improved tissue contrast and anatomic delineation and, thus, may replace T2-weighted SE imaging in the neck.

Our early experience with Selectron MDR in treating cervical cancer patients at Osaka University Hospital is presented. From May 1991 through December 1992, a total of 22 patients (stage Ia, 1; stage Ib, 3; stage IIa, 1; stage IIb, 2; stage IIIb, 13 and stage IVa, 2) with previously untreated uterine cervical cancer and intact uterus were treated with mid-dose rate intracavitary therapy administered with a Selectron. A rigid applicator made of stainless steel for the Selectron was used for the treatment. The 137Cs source had an activity of 1.48 GBq as of reference time. Source loading corresponded to the Manchester System. Early tumor responses for all patients were complete. No acute radiation injury has been observed. There have been two local recurrences in stage IIIb patients. One of them developed para-aortic lymph node metastasis and died from distant metastasis. Another patient in stage IIIb had para-aortic and left supraclavicular lymph node metastasis and died from distant metastasis. Four patients developed rectal bleeding (grade 1, 3; grade 3, 1). One of them had been treated for aplastic anemia with steroid. The cause of grade 3 rectal bleeding was considered to be technical failure in intracavitary application. The remaining two patients recovered without treatment. From our early experience, it is concluded that Selectron MDR can be used for cervical cancer patients as safely and effectively as our previously used high-dose rate machine.

To assess whether regionally depressed myocardial uptake of beta-methyl-p-(123I)-iodophenyl-pentadecanoic acid (123I-BMIPP), is related to regional ventricular diastolic dysfunction in patients (pts) with hypertrophic cardiomyopathy (HCM), we carried out 123I-BMIPP myocardial SPECT and radionuclide ventriculography (RNV) at rest in 9 HCM pts (eight pts with asymmetric septal hypertrophy (ASH), and one patient with apical hypertrophy). The defects of 123I-BMIPP were semiquantitatively estimated by segmental analysis. Regional LV function was determined by sector analysis in RNV: regional peak filling rate (rPFR), regional time to peak filling rate (rTPFR), and early 1/3 filling rate (1/3 fil) were estimated in the LV septal and posterior sectors. Wall thickness was evaluated with M-mode echocardiography. As results, the defects of 123I-BMIPP myocardial SPECT, were found frequently in septal wall, but any defect was not recognized in all septum with significant hypertrophy. Also, the degree of septal hypertrophy was not significantly related to BMIPP defect score. However, the regional diastolic function (rPFR, rTPFR, 1/3 fil) in the septal lesions with 123I-BMIPP defects was decreased more than those without 123I-BMIPP defect in HCM. Furthermore, the relative regional diastolic dysfunction (the differences between rTPFR and 1/3 fil in the septum and in the posterior wall) was significantly related to BMIPP defect score. In conclusion, this results suggest that the decreased uptake of 123I-BMIPP is related to regional diastolic dysfunction more than wall hypertrophy.

From January 1967 through November 1991, a total of 135 patients with carcinoma of the major salivary glands (parotid: 95; submandibular: 39; sublingual: 1) were treated at our department. 40 patients had adenocarcinoma, 29 adenoid cystic carcinoma, 24 mucoepidermoid carcinoma and 16 squamous cell carcinoma. 100 patients were irradiated postoperatively and the remaining 35 were treated with radiation alone. Total radiation doses delivered were 50 Gy for the postoperative group and 50 to 66 Gy for the group receiving only radiation using a 60Co single portal with or without wedged paired or single electron portal boost. Actuarial five-year survivals after radiation therapy were 55% for the postoperative group and 26% for radiation only group (p = 0.0004). The local control rates for the postoperative group were 83% for adenocarcinoma, 81% for adenoid cystic carcinoma, 83% for mucoepidermoid carcinoma and 62% for squamous cell carcinoma. Corresponding figures for the radiation only group were 40% for adenocarcinoma, 38% for adenoid cystic carcinoma and 33% for mucoepidermoid carcinoma. Conventional irradiation techniques continue to play an important role because they offer superior local control for postoperative patients with carcinoma of the major salivary glands. However, the local control rates for the radiation only group were only 30 to 40%, so that new irradiation modalities such as provided by a high LET machine are needed for these patients.

Between December 1991 and August 1992, five patients with recurrent cancer in the pelvic area (four gynecological cancers and one rectal cancer) were treated at Osaka University Hospital with a remote afterloading interstitial implantation employing the template technique. External irradiation (40 to 50 Gy) was performed in four cases one to four weeks before brachytherapy. Interstitial high-dose-rate brachytherapy (24 to 40 Gy/four to eight fractions/two to four days) was performed twice a day. Three of the five patients achieved complete local tumor control. The remaining two patients obtained symptom relief. There were no complications serious enough to need surgical treatment. Moreover, this procedure is well tolerated and therefore an effective modality for elderly and frail patients.

To clarify the mechanism of appearance of low intensity band seen around the abdominal organ, we performed phantom study. The resected intestine, which filled with water and fixed in the salad oil, was obtained by spoiled GRASS MR imaging with variable TEs and fixed TR. On in phase image, low intensity band was seen in low frequency side of frequency encoding direction of surface of the intestine, and high intensity band in high frequency side. On out of phase image, low intensity band is seen all around the intestine. Our phantom study verified that the appearance of low intensity band on out of phase gradient echo image is due to both the misregistration and signal void caused by chemical shift artifact.

Portal circulation changes due to the progression of chronic liver disease and portal venous flow are also affected by pharmacotherapy. Thus, noninvasive measurement of effective portal venous flow (EPVF) is highly desirable. We evaluated EPVF under steady-state conditions using echo-Doppler flowmetry combined with per jejunal portal scintigraphy in 32 patients with chronic liver disease. After introduodenal administration of 37 MBq (1 mCi) of 123I-iodoamphetamine, scintigraphy of the pulmonary and hepatic regions was performed and a portosystemic shunt index (SI) calculated. EPVF was calculated as follows: EPVF = PVFx (1-SI/100). EPVF in chronic hepatitis, compensated cirrhosis and decompensated cirrhosis was 12.0 +/- 1.8 ml/min/kg, 10.3 +/- 1.6 ml/min/kg and 8.0 +/- 2.5 ml/min/kg, respectively. There were significant differences in EPVF between all groups, although PVF was similar in each group. EPVF correlated with liver function tests and was a better indicator of liver function than PVF. Measurement of EPVF may provide useful information in the management of patients with chronic liver disease.

In order to establish a noninvasive, quantitative method for measuring regional cerebral blood flow (rCBF) by N-isopropyl-p-[123I]iodoamphetamine (123I-IMP) SPECT, we attempted to employ continuous venous sampling instead of arterial sampling. Forty two patients with cerebrovascular diseases were classified into two groups, with (group II: n = 35) and without (group I: n = 7) hand warming. In group II, either hand was warmed, wrapping in a hot blanket (group IIA) or immersed in a 44 degrees C water bath (group IIB). In each patient, immediately after intravenous bolus injection of 222 MBq IMP, arterial and venous blood samples were collected continuously for 5 min from the radial artery and the cubital vein, respectively. By octanol extraction, IMP was divided into the unmetabolized and metabolized fraction. The ratio of 123I-IMP radioactivity of venous blood compared to arterial blood (pass ratio, referred as %PR) was calculated in three fractions, whole blood, unmetabolized, and metabolized fraction. By using these parameters, we assessed the possibility to estimate the amount of unmetabolized IMP fraction of arterial blood, usually used as an input function, from venous samples. In group I, %PR demonstrated a considerable variation between individuals (whole IMP, 47.5 +/- 24.6% (mean +/- SD): unmetabolized IMP, 46.0 +/- 24.5%: metabolized IMP, 51.8 +/- 27.4%). In group II, especially in group IIB, both increase of %PR value and the decrease in variation (whole, 77.9 +/- 5.6%: unmetabolized, 75.7 +/- 5.7%: metabolized, 86.7 +/- 8.7%) were observed, which permitted the further calculation based on the assumption that %PR value was constant in each IMP fraction (whole blood and unmetabolized fraction).(ABSTRACT TRUNCATED AT 250 WORDS)

Fourteen normal rats were received with percutaneous ethanol injection (PEI) in the subphrenic region of the liver, using a 22G fine needle, via the thoracic cage. The procedure was successful in all rats. Minor complications were observed in 3 rats: these included pneumothorax, hemorrhage, and pleural effusion. However all complications had disappeared in the follow up CT one week after the procedure. The transthoracic approach is a useful and safe method of PEI for the subphrenic region of the liver.