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Naofumi Hayabuchi

Publications and source records attributed to Naofumi Hayabuchi.

At least 37 records · Page 2Linked to original sources
PubMed2005

Usefulness of whole PTH assay in patients with renal osteodystrophy--correlation with bone scintigraphy.

OBJECTIVE: Intact parathyroid hormone (PTH) assay has recently been reported to be effective in evaluating both 1-84 PTH (whole PTH) and inactive 7-84 PTH. Inactive 7-84 PTH is considered to be increased in hemodialysis patients and to prevent the effects of 1-84 PTH, and intact PTH is considered to overestimate the PTH activity in these patients. As such, a whole PTH assay has recently been developed. The purpose of this study was to examine the usefulness of a whole PTH assay using the bone to soft tissue (B/ST) ratio on bone scintigraphy. METHOD: Twenty-five hemodialysis patients were included in our study. In all patients, bone scintigraphy and a blood test [whole PTH, intact PTH, alkaline phosphatase (ALP), calcium (Ca), and phosphorus (P)] were performed. Regions of interest (ROIs) were drawn around the cranium, lumbar vertebrae, left femoral neck, and soft tissue of the medial left thigh to obtain the B/ST ratio. RESULTS: The B/ST ratio of the cranium and left femoral neck correlated with whole PTH and intact PTH. In particular, the B/ST ratio of the cranium correlated most significantly with the value of whole PTH. Whole PTH levels correlated with intact PTH levels (r = 0.891, p < 0.0001). CONCLUSION: Our data indicate that a whole PTH assay may be useful in evaluating PTH activity using the B/ST ratio. The B/ST ratio of the cranium may reflect the bone metabolism of hemodialysis patients.

Adult↗
PubMed2005

Assessment of therapeutic effect in patients with secondary hyperparathyroidism using bone scintigraphy.

OBJECTIVE: The semi-quantitative method of bone scintigraphy [bone to soft tissue (B/ST) ratio] has been used in diagnosing and evaluating systemic metabolic bone diseases. The aim of this study is to evaluate of the therapeutic effect of secondary hyperparathyroidism (SHP). METHODS: The subjects were ten hemodialysis patients with SHP. Seven patients underwent parathyroidectomy (PTX), and 22-Oxacalcitoriol (derivative of 1,25-dihydroxyvitamin D3) (OCT) was given to three patients. Bone scintigraphy and blood tests [intact parathyroid hormone (PTH), alkaline phosphatase (ALP), calcium (Ca), phosphorus (P), bone alkaline phosphatase (BALP), and deoxypridinoline (DPYD)] were performed before and after treatment. Regions of interest were drown around cranium, lumbar vertebrae, femoral neck and soft tissue of left medial thigh to calculate the B/ST ratio. RESULT: The B/ST ratios of cranium, lumbar vertebrae, and femoral neck were reduced significantly after PTX (cranium, p = 0.0079, lumbar vertebrae, p = 0.0282, femoral neck, p = 0.0252). Intact PTH, ALP, Ca, P, BALP and DPYD levels were reduced significantly after PTX (intact PTH, p = 0.003, Ca, p = 0.0005, P, p = 0.0393, ALP, p = 0.0051, DPYD, p = 0.0232, BALP, p = 0.0324). After OCT administration, the B/ST ratio of each bony region showed tendency to diminish, although not significantly. Intact PTH levels were reduced significantly, although ALP, BALP, and DPYD levels were not. Ca and P levels were increased significantly because of the medicinal action of OCT. CONCLUSION: The B/ST ratio of cranium may be non-invasive method and have potential in evaluating the therapeutic effect of SHP.

Adult↗
PubMed2005

Esophagectomy: is it necessary after chemoradiotherapy for a locally advanced T4 esophageal cancer? Prospective nonrandomized trial comparing chemoradiotherapy with surgery versus without surgery.

The need for surgery after chemoradiotherapy for a T4N0-1M0 squamous cell carcinoma in the thoracic esophagus was evaluated. A series of 53 patients were enrolled in this prospective nonrandomized trial from among 124 patients with an esophageal cancer assessed as T4 in Kurume University Hospital from 1994 to 2002. After the first chemoradiotherapy cycle, which consisted of radiotherapy in a total dosage of 36 Gy and chemotherapy using cisplatin (CDDP) and 5-fluorouracil (5FU), the patients each decided, after being informed of the efficacy of the chemoradiotherapy, whether to undergo surgery. All patients, including those who had undergone surgery and those who had not, later underwent a second chemoradiotherapy cycle consisting of radiotherapy in a total dosage of 24 Gy and chemotherapy using CDDP and 5FU, as far as practicable. Among the responders to the first chemoradiotherapy cycle, there was no significant difference in the long-term (5-year) survival rate between the 18 patients who underwent esophageal surgery and the 13 patients who did not (23% vs. 23%). Among the nonresponders, the 11 patients who underwent surgery showed a tendency toward longer survival than the five patients who had had no surgery. The nonresponders had 1- and 2-year survival rates of 64% and 33%, respectively. The corresponding rates for the 5 nonsurgical patients who completed the two chemoradiotherapy cycle were 20% and 20%, respectively. For a T4N0-1M0 squamous cell carcinoma in the thoracic esophagus, full-dosage chemoradiotherapy (definitive chemoradiotherapy) is preferred for responders to a half-dose of chemoradiotherapy as much as esophagectomy, whereas esophagectomy may be preferred for nonresponders.

Antineoplastic Combined Chemotherapy Protocols↗
PubMed2005

Output of radiopharmaceutical nuclides of known injected doses from a municipal sewage treatment system.

The concentrations of (99m)Tc, (123)I, (67)Ga, and (201)Tl of the discharge water and the sewage sludge from Kurume Central Sewage Treatment Plant were determined once a week for 2 mo. The radiopharmaceutical doses injected into the patients for all of four hospitals that use nuclear medicines in the service area of the plant were also surveyed. Approximately 1.5% of the (99m)Tc, 1.5% of the (123)I, 4.3% of the (67)Ga, and 0.41% of the (201)Tl of the injected doses were detected in the discharged water from the plant. The behavior of these radionuclides in the sewage treatment system was analyzed using a compartment model. The analyses suggest that the average residence times in storage tanks and drainage pipes before entering the plant were 9.5 h for (99m)Tc, 81 h for (123)I, 120 h for (67)Ga, and 480 h for (201)Tl.

Gallium Radioisotopes↗
PubMed2005

Rhabdomyolysis induced by psychotropic drugs.

A 41-year-old man experienced continuous convulsions, unconsciousness, and a high temperature. His laboratory findings revealed an increase in serum creatine phosphokinase, serum myoglobulin, and urinary myoglobulin levels. He had taken many psychotropic drugs as treatment for schizophrenia and was very dehydrated. Because a diagnosis of rhabdomyolysis was suspected, Tc-99m HMDP bone scintigraphy was performed. It showed diffusely increased soft tissue uptake in his shoulder girdles, vertebral area, psoas iliac muscles, and gluteofemoral muscles, leading to a diagnosis of rhabdomyolysis. Bone scintigraphy is useful in making an early diagnosis and evaluating the location and degree of muscle injury in rhabdomyolysis.

Adult↗
PubMed2005

Microdosimetric evaluation of the 400 MeV/nucleon carbon beam at HIMAC.

Microdosimetric single event spectra were determined as a function of depth in an acrylic phantom for the carbon beam at HIMAC using a tissue equivalent proportional counter (TEPC) coupled to a scintillation counter system. The fragments produced by the carbon beam were identified by the deltaE-time of flight distribution obtained from two scintillation counters which were positioned at the up- and down-stream of the TEPC. Lineal energy distribution for the carbon beam and its five fragments, namely, proton, helium, lithium, beryllium, and boron ions, were measured in the lineal-energy range of 5-1000 keV/microm at five phantom depths between 0 and 230 mm. The dose distribution for the carbon beam and its fragments were obtained separately. The relative biological effectiveness (RBE) of the carbon beam in the phantom was calculated using a response function. The maximum RBE for the carbon beam was found to be about 5 near the Bragg peak. It was observed to rapidly decrease for Bragg peaks occurring at deeper positions in the phantom. The dose from the beam fragments accounted for about 30% to the total dose, however, its contribution to the RBE was less than 17%.

Carbon↗
PubMed2005

Hilar and suprapancreatic cholangiocarcinoma: value of 3D angiography and multiphase fusion images using MDCT.

OBJECTIVE: We evaluated the feasibility of creating 3D and multiphase fusion images of cholangiocarcinoma. The 3D rendering of the biliary tree provide valuable information for planning surgery, including the location of the obstruction and its relationship to the surrounding vessels. CONCLUSION: Our data emphasize that 3D and multiphase fusion images may be an accurate and routinely applicable tool for the diagnosis and therapeutic management of patients with biliary system abnormalities.

Bile Duct Neoplasms↗
PubMed2005

Pulmonary sarcoidosis: comparison of findings of inspiratory and expiratory high-resolution CT and pulmonary function tests between smokers and nonsmokers.

OBJECTIVE: The purpose of our study was to compare the high-resolution CT and pulmonary function test findings of smokers and nonsmokers with pulmonary sarcoidosis. MATERIALS AND METHODS: Full inspiratory and expiratory high-resolution CT of the thorax and pulmonary function tests were performed in 46 patients (23 smokers and 23 lifelong nonsmokers) with histologically proven sarcoidosis. The median interval between high-resolution CT and pulmonary function tests was 8 days (range, 0-27 days). High-resolution CT findings were categorized into six patterns, and the overall extent of each pattern was scored independently (high-resolution CT score). Correlation between each high-resolution CT score with each pulmonary functional parameter was performed using Spearman's rank correlation and stepwise multiple regression analysis. RESULTS: Air trapping on expiration (45/46 patients, 98%) and small nodules on inspiration (all 46 patients, 100%) were the most common findings. Smokers had a greater extent of emphysema than nonsmokers (p = 0.002). No significant difference was seen in the extent of air trapping, consolidation, ground-glass attenuation, reticular opacities, or small nodules between smokers and nonsmokers. On Spearman's rank correlation, the extent of air trapping negatively correlated with forced vital capacity in smokers (p < 0.05) but not in nonsmokers. The extent of small nodules negatively correlated with forced vital capacity and positively correlated with the ratio of forced expiratory volume in 1 sec to forced vital capacity in nonsmokers (p < 0.05, both) but not in smokers, respectively. On stepwise multiple regression analysis, the extent of air trapping on CT was independently associated with decreased forced vital capacity (p < 0.05), and cigarette smoking was the main determinant of decrease in maximum midexpiratory flow and forced expiratory flow at 50% of vital capacity (p < 0.01). CONCLUSION: Cigarette smoking confounds the correlation between the CT and pulmonary function test findings in patients with sarcoidosis. Therefore, smoking history must be taken into account when correlating the extent of parenchymal sarcoidosis on CT with functional impairment.

Adult↗
PubMed2005

[Usefulness of diffusion-weighted MRI in differentiating benign from malignant musculoskeletal tumors].

PURPOSE: To evaluate the usefulness of diffusion-weighted MRI in distinguishing different components and in differentiating benign from malignant musculoskeletal tumors. MATERIALS AND METHODS: Fifty-seven patients with musculoskeletal tumors underwent MR at our institution from October 1999 to April 2002. We evaluated 57 tumors (9 bone tumors and 48 soft tissue tumors). All tumors were classified into 8 groups (myxomatous, fibrous, cystic, cartilaginous, fatty components, hematomas, other benign tumors, and other malignant tumors). MR examinations were performed with a 1.5-Tesla system. Diffusion-weighted single-shot EPI images were obtained in all patients. Apparent diffusion coefficients (ADCs) were calculated by using b factors of 0 and 1,000 sec/mm2. RESULTS: ADC values of myxomatous, cystic, and cartilaginous components were significantly higher than those of other tumors. In cartilaginous tumors, malignant tumor ADC values (2.33 +/- 0.44) were higher than those of benign tumors (2.13 +/- 0.13). However, there was no significant difference between benign and malignant tumors. Except for high-intensity components on T1-weighted imaging and low or homogeneously very high intensity components on T2-weighted imaging, there was a significant difference in ADC between malignant (1.35 +/- 0.40) and benign (1.97 +/- 0.50) tumors. CONCLUSION: Within the limited number of cases, there was a significant difference in ADC between malignant and benign tumors.

Adolescent↗
PubMed2004

Primary central nervous system lymphoma in Japan 1995-1999: changes from the preceding 10 years.

PURPOSE: Previously, we conducted a nationwide survey of primary central nervous system lymphoma (PCNSL) treated between 1985 and 1994 in Japan. In the present study, we conducted further investigations of PCNSL patients treated between 1995 and 1999 to clarify possible changes with time in the clinical features, treatment, and outcome of this disease. METHODS: Thirteen Japanese institutions were surveyed, and data on 101 patients with histologically-confirmed PCNSL were collected. These data were compared with those of 167 patients treated at the same institutions between 1985 and 1994. RESULTS: Regarding patient and tumor characteristics, the proportion of patients with good performance status (PS) was significantly higher in the group treated during 1995-1999 than in that treated during 1985-1994, but other characteristics were not significantly different. Regarding treatment, more patients in the more recent period (66%) received systemic chemotherapy than those in the preceding period (53%, P = 0.049). For all patients, including those who did not complete radiotherapy, the median survival time was 17 months and 30 months in patients treated between 1985 and 1994 and those treated between 1995 and 1999, respectively, and the 5-year survival rate was 15% versus 31% (P = 0.0003). In both patient groups, higher age and tumor multiplicity were associated with poor prognosis in multivariate analysis. In patients treated between 1995 and 1999, those who received systemic chemotherapy showed significantly better prognosis than those who did not (P = 0.0049), but the difference was not significant in multivariate analysis (P = 0.23). CONCLUSIONS: The high survival rates observed in the present survey are comparable with those of recent prospective studies employing intensive chemoradiotherapy. The improvement in prognosis appeared to result, at least in part, from the increase in the proportion of patients with better PS. Since the clinical feature and treatment outcome of patients with PCNSL can thus change with the era, historical control data should not be used in comparing different treatment modalities.

Adolescent↗
PubMed2004

A clinical assessment of the relationship between bone scintigraphy and serum biochemical markers in hemodialysis patients.

BACKGROUND: Renal osteodystrophy is a metabolic bone disease and a common complication of end-stage chronic renal failure and maintenance dialysis treatment. In this study, we examined the correlation between quantifying bone scintigraphy and serum biochemical markers in hemodialysis patients. METHODS: Bone scintigraphy with technetium-99m-hydroxy-methylene-diphosphonate (99mTc-HMDP) was performed on 28 patients on maintenance hemodialysis. Bone scintigraphy was performed using a standard protocol and was quantified by setting regions of interest (ROIs) over selected regions. The bone-to-soft-tissue ratio (B/ST ratio) at each region was calculated in all patients. The B/ST ratios were then compared with serum biochemical markers. RESULTS: The B/ST ratio for the skull correlated well with serum bone-specific alkaline phosphatase (BAP) (r = 0.735, p < 0.001), serum deoxypyridinoline (DPD) (r = 0.806, p < 0.001) and intact parathyroid hormone (intact PTH) (r = 0.701, p < 0.001). The B/ST ratio for the lumbar spine correlated with intact PTH (r = 0.387, p < 0.05) but not with serum BAP or serum DPD. The B/ST ratio for the femoral neck correlated with serum DPD (r = 0.431, p < 0.05) and intact PTH (r = 0.449, p < 0.05) but not with serum BAP. CONCLUSIONS: Our data suggest that quantitative bone scintigraphy is a sensitive and useful method for evaluating bone metabolism in hemodialysis patients. The B/ST ratio for the skull may reflect changes of bone metabolism in hemodialysis patients.

Adult↗
PubMed2004

Bronchioloalveolar carcinoma with fluctuating extent of consolidation on chest radiography.

We report a case of bronchioloalveolar carcinoma that required approximately 1 year to diagnose due to alternating periods of exacerbation and improvement of abnormal opacity on chest radiography. It is important to consider the diagnosis of bronchioloalveolar carcinoma when consolidative opacities simulating pneumonia show an alternating pattern of worsening and improvement.

Adenocarcinoma, Bronchiolo-Alveolar↗
PubMed2004

Pneumoconiosis in rush mat workers exposed to clay dye "sendo" dust: clinical, radiologic, and histopathologic features in seven patients.

STUDY OBJECTIVES: The purpose of this study was to describe the clinical, chest radiographic, high-resolution CT, and histopathologic features of clay dye "sendo" dust pneumoconiosis in seven rush mat ("tatami") workers. PATIENTS: Seven patients with a history of occupational exposure to sendo dust and radiographic changes suggestive of pneumoconiosis were retrospectively reviewed. RESULTS: The duration of exposure ranged from 15 to 45 years (median, 30 years). Three patients had cough, and four patients had abnormal pulmonary function test results. Chest radiographs showed nodular opacities < 3 mm in diameter (types p and q) in all patients. The standard International Labor Office profusion score ranged from 0/1 to 1/1 (median, 1/0). High-resolution CT demonstrated small nodular opacities (types p and q) in all seven patients. In four patients, high-resolution CT demonstrated branching centrilobular structures, airway ectasia, airway wall thickening, and emphysematous changes. None of the patients had conglomerate nodules, large opacities, honeycombing, pleural effusion, or lymphadenopathy. Microscopic examination of the specimens obtained by open lung biopsy or transbronchial lung biopsy revealed nodular fibrosis with accumulation of dust-laden macrophages, but no silicotic nodules. Needle-like particles of 1 to 20 microm in length were evident among the dust deposits, and birefringent crystals were identified under polarizing microscopy. Four of seven patients showed intra-alveolar fibroblastic foci similar to Masson bodies, accompanied by dust deposition. CONCLUSION: Rush mat workers' sendo dust pneumoconiosis is caused by dust containing free silica. The radiographic and high-resolution CT findings consist of small nodular opacities < 3 mm in diameter and bronchial and bronchiolar abnormalities.

Aged↗
PubMed2004

[Fundamental study of magnetization transfer contrast (MTC) effect: optimization of MT pulse condition using experimental phantom].

Magnetization transfer contrast (MTC) was evaluated by changing the off-set frequency and pulse intensity of MTC with the spoiled gradient echo (SPGR) sequence (T2*-weighted image) using an experimental phantom that included olive oil, protein, fiber, collagen, and pure water. The intensity of pure water reached a constant level just above the off-set frequency (1200 Hz) regardless of MT pulse power. The contrast-to-noise ratio (CNR) in each of the phantom materials was maximal at the MT pulse power of 2500 degrees (equivalent flip angle). The CNR and image noise obtained by body coil were inferior to those obtained with an extremity coil. In clinical application, the MTC effect on chondrosarcoma was higher (MT ratio, ROI-1:0.448, ROI-2:0.382) than those of other cases in this study. Since the image contrast was improved between the malignant fibrous histiocytoma (MFH, MT ratio, ROI-1:0.282, ROI-2:0.289) and peripheral tissues, extraskeletal extension could be observed more easily than without MTC imaging. In conclusion, the effects of MTC might be in providing useful information, in presuming composed tissues, differential diagnoses, and extent to the surrounding structures because of changing the image contrast to surrounding tissues corresponding to the rate of included bound water.

Bone Neoplasms↗
PubMed2004

Conformity of carotid stents with vascular anatomy: evaluation in carotid models.

BACKGROUND AND PURPOSE: Conformity between self-expanding Wallstents and vascular anatomy is limited. Because of a lack of longitudinal flexibility, straightening effects on vascular curves occur and may result in stent-induced kinking. Our purpose was to evaluate the conformity of self-expanding stents with the course and endoluminal surface of silicone models of the normal human carotid artery. METHODS: Five different types of self-expanding carotid stents were implanted into simplified pulsatile perfused silicone models of the carotid bifurcation. The models embody elastic properties of the vessel wall similar to those of normal human arteries. All stents had the same nominal diameter and length and bridged the external carotid artery origin as well as a consecutive curve at the initial segment of the internal carotid artery. Conventional radiographs of the model were compared before and after stent placement to record changes of shape and course of the silicone artery. Dehiscences between stent filaments and arterial wall were measured on digital subtraction angiograms of the model. RESULTS: Implantation of braided Wallstents or the Expander with continuous filaments induced considerable straightening effects on the bifurcation angle, as well as on the curves of the internal carotid artery. Segmented designs of modular nitinol stents complied better with vascular tortuosity and showed improved adaption between stent and the endoluminal surface of the model. CONCLUSION: Model experiments show that segmented nitinol stents improve the conformity between the prosthesis and vascular anatomy, and confirm new carotid stent concepts as an alternative to the Wallstent.

Alloys↗
PubMed2004

[Angiography].

The clinical usefulness of three dimensional images was widely recognized. The three dimensional digital subtraction angiography (3D-DSA) well demonstrated anatomical structures of cerebral arteries with high special resolution. This 3D observation allowed high quality planning for aneurysmal coil packing and neck clipping. Because of the bony structure and curvy arterial anatomy in the skull base region, 3D-CTA and MRA was sometimes distureved the demonstration of the anatomical relationship adjacent to the aneurysm. However, 3D-DSA not only demonstrated arterial anatomy, but also analyzed of vascular structure, quantifiably. And it was useful in radiation dose reduction by reduction of DSA exposure number. We believe that 3D-DSA should provided useful information for planning of surgical and endovascular treatment in the field of cerebro-vascular disease.

Angiography, Digital Subtraction↗
PubMed2004

[Early-stage carcinoma of the external auditory canal treated by intracavitary irradiation with HDR 192Ir-RALS: a case report].

We report a case of early-stage carcinoma of the external auditory canal treated by intracavitary irradiation with high-dose-rate (HDR) 192Ir-RALS after 40 Gy by external irradiation. We made an applicator that was inserted into the external auditory canal for the intracavitary irradiation, using a 9 Fr silicone catheter and resin. The total intracavitary radiation dosages were 20 Gy/8 Fr/4 weeks. No severe side effects were noted, and the tumor disappeared. RALS may be indicated for early carcinoma of the external auditory canal for its efficacy and lack of side effects.

Brachytherapy↗