[Systematization of methylation procedure and application to 11C-labeled compounds].
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Benzamides↗
Biomedical subjects
I Kanno
Publications and source records attributed to I Kanno.
Clinical value of PET with 18F-fluorodeoxyglucose and L-methyl-11C-methionine for diagnosis of recurrent brain tumor and radiation injury.
We studied 15 patients clinically suspected to have recurrent brain tumor or radiation injury, using positron emission tomography (PET) with 18F-fluorodeoxyglucose (18FDG) and L-methyl-11C-methionine (11C-Met). PET with 11C-Met (Met-PET) clearly delineated the extent of recurrent brain tumor as focal areas of increased accumulation of 11C-Met, and was useful for early detection of recurrent brain tumor. PET with 18FDG (FDG-PET) showed focal 18FDG-hypermetabolism in one patient with malignant transformation of low grade glioma, and demonstrated its usefulness for evaluation of malignant transformation. 18FDG-hypometabolism was observed in all patients with radiation injury, but was also found in one patient with recurrent malignant brain tumor. 11C-Met uptake in 3 patients with radiation injury was similar to that of the normal cortical tissue. FDG-PET can be used to initially exclude recurrent brain tumor which is seen as 18FDG-hypermetabolism. The combined use of Met-PET in addition to FDG-PET can improve the accuracy of differentiation of recurrent brain tumor with 18FDG-hypometabolism from radiation injury.
Adolescent↗
[Estimation of 3 rate constants of the 3 compartments model in PET measurement by a weighted integral method--simulation of estimation errors].
A simulation study to evaluate the errors in rate constants of the three compartment model using the weighted integral method was performed. Ten combinations of 7 kinds of weight functions, the errors were tested in 18F fluorodeoxyglucose (18FDG) study. The error factors arising in PET measurement were statistical noise, cerebral blood volume, time shift and scanning time of PET measurement. Errors in each rate constant were within the range of 10 percent and those in k1k3/(k2+k3) within 1 percent. The weighted integral method was confirmed to be a faster method than the conventional least squares method within a reasonable error range.
Body Fluid Compartments↗
[The changes of cerebral blood flow and metabolism of normal brain tissue after surgery, radiation, and chemotherapy in brain tumor patients: evaluated by position emission tomography].
The changes of cerebral blood flow (CBF) and metabolism of normal brain tissue after surgery, radiation, and chemotherapy in brain tumor patients were measured by positron emission tomography (PET). The subjects consisted of 6 men and 3 women, and were from 11 to 62 years old. Those were four patients with glioblastomas, one patient with malignant oligodendroglioma, one patient with astrocytoma grade II, one patient with astrocytoma grade III, one patient with pontine glioma, one patient with pineal germinoma. Seven patients were operated and pathohistologically diagnosed. Two patients with pineal germinoma and pontine glioma were not operated and radiologically diagnosed. Of 7 operated patients, first PET was performed before operation in 3 patients, and from 10 to 16 days after operation in 4 patients. Following first PET, the patients were treated with irradiation (1 case), or with both irradiation and chemotherapy (8 cases). The total radiation dose for tumor was from 59 to 61 Gy distributed in a period of 6-8 weeks. Whole brain irradiation was performed up to 30 or 40 Gy, with a remaining dosimetry (20-30 Gy focused on the tumor field. Chemotherapy consisted of intravenous administration of ACNU and oral administration of FT-207. Second PET was performed 1 month after therapy (9 cases), and third PET was performed from 4 to 24 months after therapy (6 cases). Fourth PET was performed in 2 patients (22 and 35 months after therapy), and fifth PET was performed in one patient (35 months after therapy).(ABSTRACT TRUNCATED AT 250 WORDS)
Adolescent↗
[3-dimensional imaging of regional cerebral blood flow by means of emission computed tomography].
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Amphetamines↗
[Brain glucose metabolism in a patient with Creutzfeldt-Jakob disease measured by positron emission tomography].
Sequential measurements of local cerebral glucose metabolism were performed in a case with Creutzfeldt-Jakob disease. The diagnosis was based on the characteristic clinical symptoms and EEG. Cerebral glucose metabolism (CMRGlc) was measured by positron emission tomography (PET) and 18F-fluorodeoxyglucose. CMRGlc was decreased to about 45% of the normal value. At that time, X-ray CT revealed little brain atrophy. The decrease of CMRGlc was prominent in cerebral cortices, but the metabolic decrease was slight in striatal body, cerebellum, and brainstem. The motor cortex and occipital lobe showed relatively preserved metabolism among the cerebral cortices. Six months after the first PET measurement, X-ray CT showed marked brain atrophy. Decrease of cerebral glucose metabolism advanced furthermore. However, the progress of the decrease was relatively small in the basal ganglia, brainstem, and cerebellar nucleus. These findings differ from the findings that was known by pathological study. These results suggest that measurement of CMRGlc by PET is useful for the early detection and for understanding of the pathophysiology of this disease.
Brain↗
[Compartment analysis of 123I-IMP brain SPECT].
To clarify the kinetics of N-isopropyl [123I]p-iodoamphetamine (IMP) in the brain, 2-compartment analysis was applied for brain SPECT with 57-minute dynamic scan in 9 subjects. The model consisted of blood component and brain tissue component. Two transfer rate constants were defined; k1 showed the rate from the blood to the brain tissue, and k2 was that of back diffusion. The late scan was performed 210 minutes after the tracer injection. Suitable k values best fitting to the dynamic data were determined for all regions of interest. Predicted regional cerebral activity at 210 minutes using 57-minute dynamic data was well agreed with measured activity. These showed the kinetics of IMP in the brain was well described by the 2-compartment model. The partition coefficient (k1/k2 ratio) was as large as about 35, and almost constant in the various brain structures including hypoperfused areas. These findings indicated that the initial IMP images reflected the reasonable CBF distribution, which gave relatively reliable CBF values even if using microsphere model.
Amphetamines↗
[Quantitative evaluation of myocardial blood flow and myocardial fluoro-deoxyglucose uptake determined by PET before and after aorto-coronary bypass operation in patients with ischemic heart disease].
Absolute myocardial blood flow (MBF) and myocardial FDG uptake (MFU) in the fasting state were determined in 5 patients who underwent aorto-coronary bypass operation, using O-15 water, F-18 fluoro-deoxyglucose and dynamic PET before and after the operation. In the patent graft region, MBF was increased from 0.59 +/- 0.17 ml/min/g to 0.77 +/- 0.14 ml/min/g (p less than 0.05). Mean MBF was increased from 0.69 +/- 0.22 ml/min/g to 0.83 +/- 0.18 ml/min/g (p less than 0.05). MFU in the fasting state was significantly decreased in high MFU region compared with low MFU region (p less than 0.005). Quantitative evaluation of MBF and MFU before aorto-coronary bypass operation was quite useful to determine adequate indication of the operation.
Aged↗
[Positron emission tomography in acute disseminated encephalomyelitis: a case report].
Sequential positron emission tomography (PET) and single photon emission tomography (SPECT) were performed in an 11-year-old girl who was clinically diagnosed as acute disseminated encephalomyelitis (ADEM). She had fever, stupor, loss of sight and left hemiparesis on admission to our hospital. X-ray CT (XCT) demonstrated a hypodense lesion in the right fronto-parietal white matter. In the 1st PET study, CBF and CMRO2 were reduced in both hemispheric white and gray matter, particularly in the right fronto-parietal lesion. The XCT abnormality was improved in the subsequent scan when the patient had improved except visual disturbance. When visual disturbance was worsened again, and a new hypodense lesion was appeared in the left frontal white matter on XCT, the 2nd PET study was performed. CBF and CMRO2 were recovered except the left frontal white and gray matter. SPECT study was also performed and the image was almost similar to CBF image of PET scan. The changes and distributions of CBF and CMRO2 were related to her symptoms and clinical course. Reduced CBF and CMRO2 of whole brain is thought to be characteristic of ADEM. From the experiences of this case, PET measurements is useful for the understanding of neuronal functional abnormalities of ADEM, and is more useful for the detection of recovery or relapsing process than XCT.
Acute Disease↗
[A fast technique to estimate local cerebral blood flow and partition coefficient using dynamic PET of H(2)15O: a new approach to weighted integration method based on time integration of Kety-Schmidt equation].
We developed a new technique for fast estimation of local cerebral blood flow and partition coefficient based on time integration of Kety-Schmidt equation. This technique has two advantages concerning statistical noise. Firstly, it does not need a Ci(T) image which contains high statistical noise because of low activity in brain. Secondly, statistical noise is minimized by time integration of Kety-Schmidt equation before multiplied by weighting function. The error analyses in flow and partition coefficient caused by statistical noise were performed using computer simulation, and dynamic PET human study using H(2)15O bolus injection. Both simulation and PET study indicated that uncertainties of flow and partition coefficient were confirmed to be lower in this technique than in the original weighted integration method.
Brain↗
[Value of 11C-methionine and PET in the diagnosis of low grade gliomas].
Ten patients with low grade glioma were examined with positron emission tomography (PET) using 11C-methyl-L-methionine (11C-Met). In 4 cases, follow-up study was performed after radiation therapy. 11C-Met uptake index was calculated by sequential arterial blood sampling and PET image on 45 minutes after injection. The tumor was clearly seen in the images, and uptake index in the tumor lesion was higher than that in the normal cortex. The uptake of 11C-Met was observed in a recurrent lesion that was confirmed by operation. 11C-Met uptake indices were decreased in the tumor lesions after radiation therapy. From these results PET with 11C-Met is a useful clinical tool for diagnosis of low grade gliomas.
Adolescent↗
A determination of the regional brain/blood partition coefficient of water using dynamic positron emission tomography.
In order to investigate the validity of the single compartment model in measuring CBF with the use of 15O-labeled water (H2 15O), dynamic positron emission tomography (PET) was performed following bolus injection of H2 15O. Careful attention was paid to accuracy in the measurement system (especially for the input function). In the region of the putamen, which includes the smallest mixture of gray and white matters in addition to the smallest contamination of cerebrospinal fluid (CSF) spaces, the partition coefficient obtained was 0.88 +/- 0.06 (ml/g). The discrepancy from the prediction estimated from the brain/blood water content ratio was only 7%. This finding suggests that there is no more complicated model than the usual single compartment one to describe the physiological behaviour of 15O water. On the other hand, in the other cortical regions, the discrepancy was larger (e.g., about 12% for the insular cortex and 26% for the frontal cortex) than in the region of the putamen, and a significant fit-interval dependence was observed in the calculated parameters. These observations suggest a significant effect of tissue heterogeneity and/or contamination with nonperfusable spaces in actual clinical PET data.
Blood-Brain Barrier↗
[Studies on bacterial agents in acute diarrheal disease (1985-1987)].
A three-year epidemiological study (from January 1985 to December 1987) was carried out on sporadic cases of acute diarrhea. A total of 2889 fecal specimens in Cary-Blair transport medium were examined for bacterial enteric pathogens, and 832 strains of fifteen species were isolated from 739 specimens, 73 patients having two or more pathogens. C. jejuni shared 51.7%, Salmonella spp. 18.3%, V. parahaemolyticus 10.3%, and Aeromonas spp. 15.7% of total fecal specimens. Isolation rates of C. jejuni and Salmonella spp. in children under the age of fifteen years (19.3%, 6.4%) were higher than those of older years (9.8%, 3.9%), respectively. Isolation of C. jejuni decreased to 24% (12/50) during 2-4 days storage at room temperature in Cary-Blair transport medium, which showed the necessity of rapid plating for isolation of C. jejuni from fecal specimens. Incidence of A. caviae in children up to ten years of age was significantly higher as compared with those of other Aeromonas species. Desoxycholate-hydrogen sulfide-xylose-agar (DHXA) was used for direct plating technique and for plating after enrichment with alkaline peptone water (without NaCl), which was found suitable as an enrichment medium for Aeromonas spp. Enterohemorrhagic E. coli (EHEC) O157:H7 was isolated from 3 patients by using desoxycholate-hydrogen sulfide-sorbitol-agar (DHSA).
Acute Disease↗
[Requirement for radiation shields of transportation pipe for on line inhalation gases from compact cyclotron in positron emission tomography].
In the unit housing of a compact cyclotron and positron emission CT (PET), positron emitting gas such as 15O, 11C, C15O2, C15O etc. is supplied from a cyclotron to a PET room through a transportation pipe with an appropriate shield to reduce positron annihilation radiation. Using lead or concrete shield blocks with various thicknesses, radiation leakage through the shield was measured by an ionization chamber type survey meter during continuous and constant supply of 15O gas of 1.85 GBq/min concentration which is the maximum dose for clinical use. The leakage radiation measured was 213.7, 56.0, 15.3, 5.0 muSv/week for lead shield with 1, 2, 3, and 4 cm thickness, respectively, and 193.3, 30.5 and 5.1 muSv/week for concrete shields with thickness of 10, 20, and 30 cm, respectively. The present study shows that to keep less than 300 muSv/week, which is the permissible dose rate of the boundary zone around the radiation controlled area by Japan Science and Technology Agency, it is required to use more than 8 mm thick lead shield or 7 cm thick concrete for continuous supply of 1.85 GBq/min 15O gas.
Carbon Dioxide↗
[Mucormycosis in paranasal sinuses].
Paranasal sinus mucormycosis is a rare and often fatal condition that occasionally occurs in patients with debilitating disease. Five mucormycosis cases with paranasal sinus involvement are reported. Two also complicated diabetes mellitus. These diabetic patients rapidly developed meningitis after the onset of symptoms. One case was soon operated upon and necrotic masses with fungus were excised. Despite i.v. amphotericin B administration, two patients lost their consciousness in a few days, relapsed into coma and died. In these cases, the infection originated from the ethmoidal sinus and directly spread towards the orbit and brain. The remaining three cases with mucormycosis had operations after the initial diagnosis of sinusitis. All of the three patients are alive and well. The combination of an excisional operation and antifungal therapy resulted in favorable response. High resolution CT scanning is valuable both in planning treatment and monitoring the response to therapy.
Adult↗
[Vascular responses in cerebrovascular "Moyamoya" disease--evaluated by positron emission tomography].
We investigated cerebral blood flow and metabolism, and cerebral vascular response in 9 patients with cerebrovascular Moyamoya disease or unilateral Moyamoya phenomenon using positron emission tomography (PET). The subjects consisted of 5 men and 4 women, and were from 9 to 60 years old. Five patients had bilateral occlusion in the carotid fork with Moyamoya vessels (fulfilled the criteria of cerebrovascular Moyamoya disease), and four patients had unilateral Moyamoya phenomenon. The PET scanner used was the HEADTOME III, of which spatial resolution in clinical use was 10 mm full width at half-maximum (FWHM) in the image plane. Cerebral blood flow (CBF), cerebral metabolic rate of oxygen (CMRO2), cerebral oxygen extraction fraction (OEF), and cerebral blood volume (CBV) were measured in resting state by the 15O-labelled gases steady state method in every patient and 22 normal controls (17 men and 5 women, and from 26 to 64 years old). Consecutively cerebral vascular responses were measured by H215O autoradiographic method in resting state, hypercapnia, hypocapnia, and hypertension. Forced hypercapnia, hypocapnia, and hypertension were achieved by 7% CO2 inhalation, hyperventilation, and venous infusion of angiotensin II, respectively. CMRO2 of the whole brain was significantly lower in patients than in normal controls (p less than 0.05), and CBV of the lentiform nucleus significantly increased in patients (p less than 0.01). This reflected Moyamoya vessels in the basal ganglionic regions. In 3 of 5 patients with bilateral Moyamoya vessels, CBF and CMRO2 in the symptomatic cerebral hemisphere were lower than that in the nonsymptomatic hemisphere.(ABSTRACT TRUNCATED AT 250 WORDS)
Adolescent↗
[Radiation dose distribution of gamma and beta+-rays during O-15-labeled gas steady state measurement].
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Beta Particles↗
[Design concepts and preliminary performances of stationary-sampling whole-body high-resolution positron emission tomography: HEADTOME IV].
Design concepts and preliminary performances of a stationary sampling high-resolution whole-body positron emission tomograph, HEADTOME IV, were reported. The system comprises four layers of detector ring which consists of 768 BGO crystals with 3 mm width, 96 photomultiplier tubes arrayed on 825 mm circle. A sufficiently fine sampling-interval allows data sampling without scan motion along the transaxial plane. But an axial motion (Z-motion) is installed to interlace between adjacent planes. Preliminary performance characteristics were an in-plane resolution of 4.5 mm in full width at half maximum (FWHM), an axial resolution of 9.5 mm in FWHM, sensitivities of 14 and 24 kcps/(microCi/ml) for direct and cross planes, respectively, with 20 cm diam. cylindrical flood phantom. A large scale cache memory prepared for each plane allows a realtime correction for the deadtime and the radionuclide decay, and a realtime calculation of the rate constants using the weighted integral method.
Brain↗