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Biomedical subjects

K Hamamoto

Publications and source records attributed to K Hamamoto.

At least 109 records · Page 6Linked to original sources
PubMed1990

[Multiple myeloma causing obstructive jaundice by extramedullary plasmacytoma after Bence Jones protein loss--an autopsy case report].

A 63-year-old man was admitted to our hospital with a chief complaint of general malaise in March 1986. A diagnosis of Bence Jones protein (kappa) type of multiple myeloma was made from increased atypical plasma cells in the bone marrow, urinary BJP (kappa) and osteolytic lesions. Urinary BJP (kappa) was decreased by MP and VENP therapies. In April 1987, he visited us again with the complaint of pain on the left shoulder. An examination revealed multiple osteolytic lesions and bilateral pleural effusion containing atypical plasma cells. Jaundice was developed at the end of July 1987. An ultrasound examination revealed a hypoechoic mass in the area of pancreatic head. The effusion was gradually increased without response to the treatment. He died of respiratory failure on July 31, 1987. On autopsy, extramedullary plasmacytoma was found in the head of pancreas. It was a rare case of multiple myeloma in which pleural effusion and multiple plasmacytomas, and finally obstructive jaundice were developed although urinary BJP (kappa) was reduced by treatment.

Bence Jones Protein↗
PubMed1990

[A case of a gastric cancer patient with high serum pepsinogen levels at relapse].

A rare case of a 68-year-old female cancer patient with an extremely high serum level of pepsinogens (PG) at relapse is presented. She had stage 3 Borrmann 3 type gastric cancer which was a poorly differentiated adenocarcinoma. Her postoperative serum PG levels had been within normal limits (23.0 ng/ml for PG-I and 3.2 ng/ml for PG-II), but at the time of the peritoneal relapse they were 5,630 ng/ml and 3,380 ng/ml, respectively. After was chemotherapy initiated, her serum PG levels decreased in parallel with an improvement of her clinical status. Immunohistochemical examination with monoclonal antibodies revealed PG-I and PG-II production in the primary and the metastatic lesions.

Adenocarcinoma↗
PubMed1989

[Single photon emission computed tomography (SPECT) with N-isopropyl-p-(123I) iodoamphetamine in partial epilepsy--evaluation of delayed image].

Thirty eight patients with partial seizures in the interictal phase were studied using single photon emission computed tomography performed 30 min. (early image) and 4-4.5 hrs. (delayed image) after an injection of 111 MBq (3 mCi) N-isopropyl-p(123I) iodoamphetamine (IMP). Five types of distribution changes were observed on IMP-SPECT between the early and delayed images. Eight patients, Type 1, exhibited an unchanged distribution of IMP between the early and delayed images. Fifteen patients, Type 2, showed a smaller area of low uptake on the IMP-SPECT (delayed image) compared to that on the IMP-SPECT (early image)-redistribution. The Type 3 patients exhibited an initial uptake area on the IMP-SPECT (early image) which later became a lower uptake area on the IMP-SPECT (delayed image)-reversed redistribution. This type was further classified into three categories according to the initial uptake pattern including (a) Type 3A, 3 patients with increased uptake area, (b) Type 3B, 6 patients with normal uptake area, and (c) Type 3C, 6 patients with decreased uptake area. With Type 2, the epileptic findings on the present interictal electroencephalography (EEG) were shown in 11 of 15 patients. However, we could not find any other remarkable correlation among these 5 types and the clinical factors (the types of seizures, the X-CT findings, the present interictal EEG data, the present frequency of seizures, and the intervals from the last seizure). In 2 patients with Type 3B who suffered from simple partial seizures, a region of the normal distribution on the IMP-SPECT (early image) became a lower uptake area on the IMP-SPECT (delayed image), corresponding topologically to the ictal symptoms. In this experience, we determined that the IMP-SPECT (delayed image) could be useful in patients with the epileptic lesions unable to be detected on the IMP-SPECT (early image).

Adolescent↗
PubMed1989

[Visualization of epileptic lesions using single photon emission computed tomography (SPECT) with N-isopropyl-p-(123I) iodoamphetamine after intravenous loading of bemegride--report of a case].

Single photon emission computed tomography (SPECT) was performed 30 minutes and 4 hours after injection of 111 MBq (3 mCi) N-isopropyl-p-(123I) iodoamphetamine (IMP) which was injected 5 minutes after the completion of intravenous bemegride loading. A 31-year-old female with simple partial seizures evolving to complex partial seizures evolving to generalized tonic-clonic convulsive seizures with a history of hospitalization, suffering from low-grade fever, generalized convulsive seizures, and impaired consciousness at the age of 27 years was studied. Angiographic examinations, X-CT, MRI, CSF examinations, and interictal neurological examinations were normal. She suffered from clonic convulsions in her right shoulder and arm, and hallucinations and dysmnesia which were characteristic of temporal lobe epilepsy. More recently she suffered from impaired consciousness once or twice a month. While the controlled IMP-SPECT study was normal, the IMP-SPECT study examined after the activation by intravenous bemegride loading showed the pattern of a regional increased uptake of IMP in the epileptic lesions corresponding with the epileptic symptoms, and a surrounding border of decreased uptake which might be the inhibition of surrounding neuronal activity and metabolism. In conclusion, the bemegride loading IMP-SPECT study could be a potential diagnostic method in patients with seizures whose epileptic lesions were not determined by the conventional methods or in whom the surgical interventions were considered, by reason of its capability to demonstrate positively the epileptic lesions.

Adult↗
PubMed1989

[Diagnostic value of the reflux sign in cholescintigraphy after administration of a gallbladder contracting agent--a comparison with X-ray cholangiography].

This study reviewed 25 patients with the reflux sign in cholescintigraphy to assess its diagnostic value in evaluating biliary passage. After at least 4-hour fasting 5 mCi of 99mTcPMT or p-butyl IDA was injected intravenously and serial images were recorded before and after intramuscular injection of 10 micrograms of ceruletide diethylamine (caerulein). The reflux sign was determined positive when increased radioactivities in the left hepatic duct (minor reflux; MIR) or more peripheral intrahepatic ducts (major reflux; MAR) were recognized after injection of caerulein. The reflux sign was found in 28 of 237 (12%) studies. Direct and/or indirect X-ray cholangiograms were available in 25 (MIR; 15, MAR; 10). They included common bile duct (CBD) stone in 4, dilated CBD in 4, biliary dyskinesia (BD) in 4, chronic pancreatitis (CP) in 4, gallbladder (GB) stone in 3, duodenal ulcer (DU) in 2, CBD adenoma, pancreatic pseudocyst (PP), duodenal diverticle (DD), and acute cholangitis (AC) in 1 each. Their serum bilirubin levels were within normal limit in all but 2 at the time of cholescintigraphy. Transit time of radionuclides to the duodenum was found prolonged more than 60 min in 17 (68%) patients and persistent pooling in the CBD was found in 8 (28%) patients on scintigrams. The diameter of the CBD on X-ray cholangiogram was ranged 4 to 17 mm. Dilated CBD of more than 10 mm was found in 13 (52%) patients and apparent stenosis of the CBD in 6 (24%) patients. MAR seemed to correspond to increased diameter of the common hepatic more than 2 mm after caerulein injection in DIC. No abnormal findings in X-ray cholangiography was found in 10 (40%) patients including 3 with BD, 2 with GB stone, 2 with DU, 1 each with CP, PP, and AC. All those patients demonstrated MIR. We concluded that major reflux (MAR) sign was helpful in detecting an incomplete obstruction of the CBD, especially in patients with slightly to mildly dilated CBD.

Adult↗
PubMed1989

SPECT volume measurement using an automatic threshold selection method combined with a V filter.

The volume measurement of various organs by single photon emission computed tomography (SPECT) has generally been performed by summing up the voxels lying within the outer edge of the organ determined by thresholding as a function of the maximum reconstructed counts within a volume of interest. The optimum threshold level, however, is influenced by various factors. To eliminate this problem, Mortelmans et al. (1986) proposed to use an automatic threshold selection method (ATSM) based on discriminant criteria and to correct the errors induced by the imperfect system response using the method based on linear regression analysis, which has some problems in practical application. We tried to use ATSM combined with a V filter. The correlation coefficient (r) and the regression equation between the true (x) and the calculated volume (y) obtained by experimentation using 22 phantoms with a volume ranging between 26 ml and 380 ml were as follows: r = 0.994 and y(ml) = 1.015 x +1.09 using ATSM combined with a V filter, while r = 0.993 and y(ml) = 1.110 x +30.55 using only ATSM. The relative error between the true and the calculated volumes decreased significantly (P less than 0.01) from 37.7% +/- 26.9% to 5.5% +/- 4.2%. The results suggest that ATSM combined with a V filter is useful for correcting the errors caused by an imperfect system response, and is available and reliable for SPECT volume determination even when the organ volume is small.

Filtration↗
PubMed1989

A unified computer program for assessment of attenuation correction and data acquisition methods in single photon emission computed tomography (SPECT).

A computer based simulation program was developed to assess the usefulness of various attenuation correction algorithms and data acquisition methods in single photon emission computed tomography (SPECT) in a unified approach. The program analytically calculated projection ray sums from a mathematical model with various distributions of activities and either uniform or non uniform attenuation coefficients by using the line integrals including the effect of attenuation. Data acquisition starting at arbitrary angles, various acquisition angles, including a 180 degree scan and a non circular orbit of a gamma camera, including an elliptical orbit can readily be taken into consideration in our simulation program. To simulate non circular orbit data acquisition, the resolution dependence on the object distance from the collimator surface was incorporated into the simulation. This computer based simulation program allows various combinations of attenuation correction algorithms such as hybrid methods, and data acquisition methods can be evaluated under a large number of study conditions. The usefulness of this computer based simulation program is shown with several representative examples.

Algorithms↗
PubMed1989

A measurement of regional portal blood flow with Xe-133 and balloon catheter in man.

This investigation was undertaken to measure regional portal blood flow of the liver. The measurement was performed by injecting 133Xe into the proper hepatic artery through a balloon catheter and then occluding the proper hepatic artery with an inflated balloon. Data were collected using a gamma camera, and washout curves were generated. They were analyzed by the initial slope method and Kety Schmidt equation. The average regional portal blood flows were: 59.31 +/- 13.04 ml/100 g per min, 58.71 +/- 14.14 ml/100 g per min and 37.12 +/- 10.11 ml/100 g per min in hospital controls (11), patients with chronic hepatitis (10) and those with liver cirrhosis (56), respectively. In the patients with cirrhosis, the regional portal blood flow was significantly reduced (P less than 0.01). The reproducibility of this method was satisfactory. The measurement of regional portal blood flow will be useful to evaluate underlying liver injuries and determine indications of a transcatheter arterial embolization of the liver.

Catheterization↗
PubMed1989

Alleviation of gallbladder complications by treatment of hepatic arterial embolization with caerulein.

Transcatheter arterial embolization (TAE) with the concurrent use of caerulein was assessed for the purpose of preventing gallbladder complications often seen after TAE of hepatic carcinoma. Ninety-six cases with primary hepatic carcinoma, who had undergone TAE in the right hepatic arterial region over the past 4 years, were divided into three groups: 22 cases for which embolization was possible on a selective basis by passing the catheter to the peripheral side beyond the bifurcated region of the cystic artery; 40 cases who had undergone TAE in which caerulein was not administered, from the central side of the bifurcated region of the cystic artery; and 34 cases given 20 micrograms caerulein 15-30 min before TAE. A comparison was made using the abdominal pain, pyrexia, rate of leukocytosis and the US findings of the gallbladder as the indices of the gallbladder complications. As a result, it became evident that it was possible to prevent or alleviate gallbladder complications if caerulein were administered before TAE in cases where the embolizing substances were infused in the right hepatic artery from the central side of the bifurcated region of the cystic artery. It was conclusively shown that the gallbladder blood flow decreases if the organ is contracted by caerulein, which in turn causes a decrease in the inflow of the embolizing substances whereby complications are alleviated.

Adult↗
PubMed1989

Assessment of hepatic excretory function in chronic liver disease by hepatobiliary scintigraphy.

Hepatobiliary scintigraphy was performed in 23 normal subjects and 47 patients with chronic liver disease (chronic hepatitis; n = 27, liver cirrhosis; n = 20) to evaluate its availability as a test of liver function. After intravenous administration of Tc-99m N-pyridoxyl-5-methyl-tryptophan, the data were acquired for 60 min and the time-activity curves of ROIs (the heart and liver) were generated. In two compartment model simulation, the early blood clearance rate (kl), late blood clearance rate (km), hepatic uptake rate (ku) hepatic excretion rate (ke), and hepatic excretion T 1/2 were calculated. There was no significant difference in those four k values in normal and chronic hepatitis. However, in liver cirrhosis each of them, except km, was lower than in normal subjects. The kl value correlated closely with the indocyanine green plasma clearance test, whereas the ke and T 1/2 values were closely correlated with the level of serum bilirubins. Only hepatobiliary scintigraphy showed the excretory function of the liver quantitatively and the ke value was helpful in detecting hepatic excretory dysfunction early in chronic liver disease before serum bilirubins increased.

Adolescent↗
PubMed1989

Radiation-induced oesophageal stricture in a case of Bloom's syndrome.

A case of Bloom's syndrome with lung cancer treated by radiation therapy is described. Squamous cell carcinoma of the lung responded well to a tumour dose of 50.4 Gy. The most serious complication of therapy was an oesophageal stricture induced by only 30.6 Gy to the mediastinum. Brief reviews of radiation-induced oesophageal stricture and radiosensitivity in Bloom's syndrome are presented.

Adult↗
PubMed1989

A unified design algorithm of two-dimensional digital filters for radioisotope image processing.

A unified design algorithm of two-dimensional digital filters for radioisotope image processing based on the Fourier-Bessel transform and the weighted least-squares method is described. The algorithm presented here can treat the various kinds of two-dimensional digital filters in a unified approach. Design examples are presented and several graphs are included to show the relationships between the design parameters as an aid in practical applications. The application of the method in radioisotope image processing is also presented. Several low-pass, Wiener and band-pass filters were designed using the method and applied to some clinical data in nuclear medicine including SPECT images. The digital filter design technique proposed here is considered to provide a powerful tool for extraction of additional qualitative information and improvement of the quality of nuclear medicine images both in research and in routine clinical work.

Algorithms↗
PubMed1989

[A case of mitochondrial encephalomyopathy with cardiomyopathy due to decreased complex I and IV activities].

We reported a girl with mitochondrial encephalomyopathy, who had various neuromuscular symptoms including dilated cardiomyopathy, generalized convulsions, myoclonus, muscular weakness and growth retardation. Lactate levels in the serum and CSF were elevated. Muscle biopsy showed scattered ragged-red fibers, and complex I (NADH-CoQ reductase) and complex IV (cytochrome c oxidase) were markedly reduced. Although she was treated with coenzyme Q, DL-carnitine and sodium succinate, she died of progressive congestive heart failure at 9 10/12 years of age.

Cardiomyopathy, Dilated↗
PubMed1989

Reflux sign in cholescintigraphy after administration of a gallbladder contracting agent.

This study reviewed 12 patients with the reflux sign in cholescintigraphy to assess its diagnostic usefulness in evaluating biliary passage. The reflux sign was determined by appearance or increase of the radioactivity in peripheral intrahepatic bile ducts after intramuscular injection of 10 micrograms of ceruletide diethylamine (caerulein). Of the 12 patients, there were common bile duct (CBD) stone in four, chronic pancreatitis in two, biliary dyskinesia in two, papillary adenoma of the CBD, dilated CBD, papillitis, and juxtapapillary duodenal diverticulum in one each. Cholangiographically, dilated caliber of the CBD more than or equal to 12 mm was found in five and equivocal caliber of 8 to 11 mm was in the remaining seven. Apparent stenosis of the CBD was found in four with dilated CBD. There were two patients who had CBD stone with equivocal caliber of the CBD. The reflux sign seems to be a sensitive finding indicating the presence of biliary dysfunction, and would be helpful for the detection of incomplete obstruction of the CBD or CBD stone, especially in a patient with equivocal caliber of the CBD.

Adult↗