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T S Higashi

Publications and source records attributed to T S Higashi.

9 recordsLinked to original sources
PubMed1996

[Fast two-compartment model analysis with 99mTc-GSA liver scintigraphy].

The use of numerical integration method (N. INT) was evaluated in determining parameters by two-compartment model analysis from liver scintigraphy. Among the 15 subjects, 14 had liver cirrhosis or chronic hepatitis, and one was normal. When using N.INT, the sum of two exponential functions on heart regression curve following intravenous injection of 99mTc-galactosyl human serum albumin (99mTc-GSA) was promptly calculated. The parameters obtained from N.INT, including transfer rate of 99mTc-GSA from extrahepatic blood to liver (k1), dissociation rate from liver to extrahepatic blood (k2), and excretion rate from liver to gallblader (k3), were significantly correlated with those obtained by the nonlinear least square method (NLS). k1/k2 was related with the maximum removal rate of 99mTc-GSA obtained from nonlinear five compartment model analysis (r2 = 0.705, n = 15) and also with the severity score of liver disease as classified by the First Department of Surgery, Mie University Medical School (r2 = 0.686, n = 13). In terms of the time required to obtain these parameters, including the blood retention rate of 99mTc-GSA at 15 min after injection (%ID15), N.INT was faster than the traditional method (NLS).

Aged↗
PubMed1996

[Quantitative analysis of 99mTc-GSA liver scintigraphy with graphical plot method].

99mTc-galactosyl human serum albumin (99mTc-GSA) is a newly developed receptor-binding agent, specific for the asialoglycoprotein receptor, which resides exclusively on the plasma membrane of mammalian hepatocytes. Liver scintigraphy using 99mTc-GSA was performed on 65 patients with liver diseases. Dynamic data were obtained by gamma camera during 20 minutes after the intravenous injection of 3 mg (185 MBq) of 99mTc-GSA. The maximum removal rate of 99mTc-GSA (denoted as P(2)) was measured by two methods: nonlinear five-compartment model analysis adopting the Michaelis-Menten constant for the transfer of 99mTc-GSA from hepatic blood to receptor, and a graphical plot using compartmental dose curves. The graphical plot could estimate easily the maximum removal rate in terms of two data points of 0 and 1 minutes without nonlinear least squares and numerical integration. The results indicated that the maximum removal rate was decided immediately after the intravenous injection of 99mTc-GSA. Although 99mTc-GSA is recognized to accumulate nonlinearly on the liver, the rate constant P(2)*(1/min) of transfer from hepatic blood to the receptor was estimated by graphical plot, assuming a linear five-compartment model. P(2)*Km, which was given by the product of the rate constant P(2)* and the Michaelis constant Km, was well correlated with P(2). Next, for 99mTc-GSA liver scintigraphy, we applied a Patlak plot that was applicable to the linear system, and the rate constant Ku of transfer from extrahepatic blood to the liver was estimated. From the results of graphical plot, it was theoretically shown that Ku represented P(2). This was confirmed by clinical data.

Adult↗
PubMed1995

Using Ga-67 scintigraphy in prostatic abscess.

The use of Ga-67 scintigraphy (Ga) in prostate inflammatory diseases may be restricted by the difficulty in distinguishing between the accumulation of Ga-67-citrate (Ga-citrate) in the lesion and feces. The diagnosis of prostatic abscess has been mainly made by other radiologic methods without scintigraphic studies and no finding of Ga has been reported. This patient demonstrated that coordinating the findings of Ga-citrate accumulation can be helpful in making a prompt diagnosis of a possibly fatal prostatic abscess, especially in those patients with poorly defined clinical symptoms and high risk factors.

Abscess↗
PubMed1995

[The image diagnoses on renal diseases; techniques of CT, MRI and ultrasound].

The accuracy on diagnosing a renal disease greatly depends on what the method is used for examination. Among those clinical using radiologic images, the techniques of new developed CT, MRI and ultrasonography were discussed. Their diagnostic advantages, shortages and the findings on using these techniques to detect the renal diseases were also discussed respectively.

Humans↗
PubMed1995

[A study of acquisition time using compartment analysis with 99mTc-GSA liver scintigraphy].

99mTc-galactosyl human serum albumin (99mTc-GSA) is a newly developed receptor-binding agent specific for the asialoglycoprotein receptor, which resides exclusively on the plasma membrane of mammalian hepatocytes. Liver scintigraphy using 99mTc-GSA was performed on 13 patients with liver disease. Dynamic data were obtained by gamma camera during 40 min after the intravenous injection of 3 mg (185 MBq) of 99mTc-GSA. Heart and liver time activity curves with acquisition times of 40,30 and 20 min were created, and two different compartment analyses were examined. One was a nonlinear five-compartment model adopting the Michaelis-Menten type for the transfer of 99mTc-GSA from hepatic blood to receptor, and the other was a linear five-compartment model assuming a linear rate constant (P(2)*) for the transfer of 99mTc-GSA. The maximum removal rate obtained by the nonlinear model, P(2), was found to be independent of the change in acquisition time, while the maximum removal rate obtained by the linear model, P(2)*.Km, which was given by the product of P(2)* and the Michaelis constant Km, increased with shortening acquisition times from 40 to 20 min. For both models, the liver blood flow rate decreased with shortening acquisition time. The maximum removal rate and liver blood flow rate obtained by the linear model were significantly correlated with those obtained by the nonlinear model. It was concluded that linear model with an acquisition time of 20 min was applicable to liver scintigraphy with 99mTc-GSA.

Adolescent↗
PubMed1993

[The consideration and performing of pretesting of contrast medium: surveying in Kanagawa].

The pretesting of contrast medium is world widely recognized to be an invaluable method to predict the adverse reactions. It was still required to perform on patients who shall have a contrast examination until recently in Japan. In May of 1990 the contrast drug package insert was reviewed and a statement of "there is no known method to predict the adverse reactions" was included. Although two reports suggested that the percentage of not performing the pretesting was increasing gradually since then, the clinical communications between institutes did not support the truth. This study investigated the problem by surveying the area in Kanagawa-ken neighboring to Tokyo and revealed that: 1. The percentage of non-performing the pretesting is high in radiologist and urologist (both are 40%) but low in other physicians (18%). 2. The risky performances of pretesting in the area without emergent equipment are occurring daily. 3. The percentage of the approval to abandon the pretesting increased significantly (from 46% to 89% with p < 0.01) after the accurate information on pretesting was given. 4. To prevent the tragedy caused by risky performance, actively contacting with and offering the information are necessary.

Contrast Media↗
PubMed1990

The delayed adverse reactions of low osmolar contrast media.

A computer scale survey to inspect the occurrence of delayed symptoms (adverse reactions) associated with the intravenous injection of low osmolar contrast medium (LOCM) was carried out. Of the recovered 1070 questionnaires, 290 had the delayed symptoms. Excluding 59 patients having the same symptoms in the past one year without contact with the contrast medium, the overall incidence of the delayed adverse reaction is 22.8% (231/1011). The delayed symptoms include arm pain (6.0%), headache (3.6%), itching (2.3%), rash (1.5%), general fatigue (1.4%), gastrointestinal symptoms, etc. Though the chi-square test had shown significance of the occurrence of the delayed symptoms for the group with a past history of drug allergy and nasal allergy (p less than 0.05), the delayed symptoms were mainly distributed in the middle-aged female to indicate that the sexuality is the cause of the foresaid significance. Furthermore, the incidence of the objective delayed symptoms such as rash in the group who had accepted more than two examinations is lower than the incidence in the group who accepted only one examination in the survey period. The disagreement to the fact that the repeated usage of the contrast medium is the risk factor to increase the incidence of the adverse reactions indicates the contrast medium may not be the only cause for the occurrence of the delayed symptoms, e.g. other factors such as sexual and psychological factors etc. may play a more important role than the contrast medium under this type of survey.

Adolescent↗
PubMed1990

Müllerian duct cyst: ultrasonographic and computed tomographic spectrum.

A Müllerian duct cyst (MDC) is the persistent remnant of the Müllerian duct. Reports of symptomatic cases are rare, signs and symptoms include perineal pain, dysuria, infertility, hematuria and genital inflammation. The prevalence of MDC has been previously reported as 4% of newborns and 1% in adult males. Herein we report six cases encountered in the past year. Our detection percentage was 1% and is compatible with the reported values. The imaging evaluation of symptomatic and asymptomatic patients with MDC is discussed as well as the apparent discrepancy between the number of previously reported cases and the reported prevalence.

Adolescent↗