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Biomedical subjects

K Hisada

Publications and source records attributed to K Hisada.

At least 91 records · Page 5Linked to original sources
PubMed1993

99mTc colloid and 99mTc IDA imagings in diffuse hepatic disease.

Ninety-six patients with various diffuse hepatic diseases were observed using both 99mTc colloid and 99mTc iminodiacetic acid (IDA), focusing on the potential etiologies of the disease process as well as its chronicity and severity. The presence of acute hepatic disease was more sensitively depicted with 99mTc IDA than with 99mTc colloid. In chronic hepatic disease, on the other hand, 99mTc colloid and 99mTc IDA demonstrated a similar sensitivity. The potential etiology of the disease process (differential diagnosis) and the chronicity of the disease could be evaluated better with 99mTc colloid. Among the patients with different stages of liver cirrhosis, however, 99mTc IDA significantly discriminated the severity of the hepatic disease. These results suggest that 99mTc IDA may be used to determine the degree of functional disorder in acute hepatic disease and evaluate the severity of diffuse hepatic disease, whereas 99mTc colloid can effectively evaluate the potential etiology and chronicity of the disease.

Colloids↗
PubMed1993

123I-labelled BMIPP fatty acid myocardial scintigraphy in patients with hypertropic cardiomyopathy: SPECT comparison with stress 201Tl.

123I-labelled 15-(p-iodophenyl)-3-(R,S)-methylpentadecanoic acid (BMIPP) myocardial single photon emission computed tomography (SPECT) was performed in 17 patients with hypertrophic cardiomyopathy, and was compared with 201Tl exercise stress myocardial perfusion SPECT images. Fourteen patients showed asymmetrical hypertrophy, and three demonstrated apical hypertrophy. SPECT was performed 20 min and 3 h after injection of 111 MBq 123I-BMIPP at rest. Exercise stress 201Tl SPECT was performed at 10 min and 3 h after injection and was compared with BMIPP imaging. In 13 patients BMIPP accumulation in the hypertrophied area in the 20 min image was lower than that of 3 h 201Tl uptake. Interestingly, six patients demonstrated 201Tl redistribution in the region where the uncoupling of BMIPP uptake at 20 min and 201Tl accumulation at 3 h after exercise was observed. These findings suggest that impaired fatty acid metabolism or utilization in hypertrophic myocardium and ischaemia or impaired coronary flow reserve may be one of the causes of the abnormality of fatty acid accumulation.

Adult↗
PubMed1993

Evaluation of suspected malignant pulmonary lesions with 201Tl single photon emission computed tomography.

201Tl single photon emission computed tomography (SPECT) was evaluated in 170 patients suspected of having a malignant pulmonary lesion greater than 20 mm in diameter on the surgical specimen. Delayed SPECT (at 3 h after injection) visualized all of the 147 malignant pulmonary lesions and 16 of the 23 (69.6%) benign pulmonary lesions, and generally exhibited the lesion more clearly than the early SPECT images (at 15 min after injection). There was no significant difference in delayed ratio (uptake ratio of the lesion to the normal lung on delayed scan) among the various histological groups except between the adenocarcinoma and large cell carcinoma groups (P < 0.05), and no difference was noted between the malignant and benign lesions. However, in retention index (degree of retention in the lesion) a significant difference was noted between the malignant and benign lesions (P < 0.01), although there was no significant difference in this index among malignant different histology groups. These results indicate that this method is useful for visualizing malignant pulmonary lesions greater than 20 mm in diameter to exclude the possibility of malignancy in the lesions when no abnormal 201Tl accumulation is observed. When the lesion shows abnormal 201Tl accumulation, the retention index seems to help differentiate malignant from benign lesions.

Adenocarcinoma↗
PubMed1993

Diffuse cerebral hypoperfusion in epileptic patients observed from quantitative assessment with single photon emission computed tomography using N-isopropyl-(iodine-123)-p-iodoamphetamine.

Quantitative assessment of regional cerebral blood flow (rCBF) in the bilateral cerebral and cerebellar cortices was performed in 15 epileptic adult patients receiving chronic high-dose antiepileptic drug therapy and 22 normal volunteers matched for sex and age, using single photon emission computed tomography with N-isopropyl-(iodine-123)-p-iodoamphetamine. The entire averaged rCBF value in the epileptic patients, i.e. 52.8 +/- 13.7 ml/10 g/min (range: 25-78 ml/100 g/min), was significantly lower as compared with that in the normal subjects, i.e. 69.1 +/- 14.2 ml/100 g/min (range: 46-102 ml/100 g/min). Six of the 15 patients showed absolute rCBF values less than the minimum of the normal range, i.e. 46 ml/100 g/min, in all or most of the measured brain tissues. There was a significant correlation between the diffuse cerebral hypoperfusion and simultaneous ingestion of phenytoin and phenobarbital. The possible effects of antiepileptic drugs on rCBF are discussed.

Adult↗
PubMed1993

Probable cerebellar abnormality on N-isopropyl-(iodine-123)-p-iodoamphetamine single photon emission computed tomography scans in an epileptic patient receiving long-term high-dose phenytoin therapy.

Quantitative assessment of regional cerebral blood flow (rCBF) was performed in a 22-year-old man with intractable temporal lobe epilepsy on long-term high-dose phenytoin (PHT) therapy, using single photon emission computed tomography (SPECT) with N-isopropyl-(iodine-123)-p-iodoamphetamine. In all the SPECT scans repeated three times with changes in the PHT dose, absolute rCBF values were lower in most of the cerebral and cerebellar regions measured, as compared with 5 normal subjects matched for sex and age, and 22 normal subjects including the 5 men. Both the cerebellar to frontal rCBF ratio and cerebellar to cerebral rCBF ratio in the patient persistently showed low values, probably reflecting abnormal relative cerebellar hypoperfusion, whereas X-ray computed tomography and magnetic resonance brain imaging showed no abnormal findings. However, this probable cerebellar abnormality on SPECT was to some degree reversible with decreases in the PHT dose. These results suggest the utility of SPECT scans for early detection of cerebellar abnormalities known to be often present in epileptic patients, and imply a risk of long-term high-dose PHT therapy.

Adult↗
PubMed1993

Efficacy of sulthiame (Ospolot) on motor partial seizure status during sleep in a patient with motor cortex epilepsy.

An 18-year-old female patient with a particular form of intractable motor cortex epilepsy, in which motor partial seizure status occurred only during sleep every night, was reported focusing on the drastic efficacy of sulthiame on the seizure status. Moreover, the present study demonstrated that single photon emission computed tomography (SPECT) and pulse oximetry examinations, both of which were performed in the ictal state, were useful for the regional diagnosis of the epileptic focus and observations of the seizure frequency, respectively. The therapeutic effect, epileptic picture and clinical examinations described here appear to be relatively rare in the literature, and therefore, this case report may be of clinical significance.

Adult↗
PubMed1993

[Evaluation of early kinetics of 123I-BMIPP in patients with ischemic heart disease].

Early kinetics of 123I-BMIPP was evaluated in 200 left ventricular myocardial segments from 10 patients with old myocardial infarction, employing dynamic SPECT. Dynamic SPECT acquisition was performed from 2 minutes to 14 minutes after injection of 123I-BMIPP. Conventional static SPECT with 123I-BMIPP (BM-S) at 20 min after injection and delayed image from stress 201Tl SPECT (Tl-RD) were visually evaluated by dividing each myocardial segment into the following four groups, NL (the segments with normal radioactivity in BM-S and Tl-RD), Tl < BM (the segments with reduced radioactivity in Tl-RD compared with BM-S), Tl > BM (the segments with reduced radioactivity in BM-S compared with Tl-RD) and Tl = BM < NL (the segments with equally reduced radioactivity in BM-S and Tl-RD). In the dynamic SPECT, washout rate (WR) from 2-4 to 12-14 minutes images was calculated. The WR of Tl > BM group (12.9 +/- 15.5% (mean +/- SD), 55 of 200 segments) was significantly higher than those of NL (-8.6 +/- 11.9%, 95 of 200 segments), Tl = BM < NL (-0.6 +/- 16.0%, 45 of 200 segments) and Tl > BM (-4.4 +/- 9.2%, 5 of 200 segments) groups. This high WR of Tl > BM group may reflect "back diffusion" from myocardium in early phase after injection of 123I-BMIPP.

Adult↗
PubMed1993

[Quantitative analysis of brain perfusion using radionuclide angiography with 99mTc-HMPAO].

A noninvasive simple method for quantitative radionuclide angiography with 99mTc-dl-hexamethyl propylene amine oxime (99mTc-HMPAO). The method of graphical analysis was employed for the evaluation of the unidirectional influx constant (Ku) from the blood to the brain for the tracer. The Ku values were standardized to represent objective and comparable values, brain perfusion indices (BPI), among studied subjects by setting the ratio of ROIbrain size to ROIaorta size to 10. The mean +/- SD of the whole-brain BPI values for the 41 normal controls was 11.15 +/- 2.61, and biphasic reduction with advancing age was observed. The mean of the whole-brain BPI of 7.95 with SD of 2.35 in 103 patients with cerebrovascular disorders was significantly lower than that in normal controls. The right to left ratio of BPI showed wider dynamic range than that of the total counts of SPECT. This technique is quite easy to apply as an adjunct to SPECT and may be helpful in the quantitative evaluation of brain perfusion in routine clinical studies.

Adult↗
PubMed1993

Myocardial perfusion imaging and dynamic analysis with technetium-99m tetrofosmin.

Technetium-99m tetrofosmin is a new myocardial perfusion imaging agent that accumulates rapidly and shows slow clearance from the myocardium. Dynamic acquisition and SPECT imaging were performed in a total of 26 patients. Using exercise-rest protocol, the single-photon emission computed tomography (SPECT) findings of 130 myocardial segments were classified as infarction, ischemia and partial filling and compared to those with 201Tl. Complete concordance of findings was obtained in 108 segments (83%) between images with 99mTc tetrofosmin and 201Tl. Partial filling was observed in 24 segments with 201Tl and 14 segments with tetrofosmin, showing a greater number of ischemic regions in 201Tl. However, in comparison with coronary arteriography (n = 19), overall sensitivity and specificity for detecting coronary artery stenosis (> or = 75%) was 15 of 25 (0.60) and 27 of 32 (0.84), respectively, which did not differ significantly from those of 201Tl, which was 18 of 25 (0.72) and 27 of 32 (0.84), respectively. Graphic analysis that assumes unidirectional transfer of the tracer was applied to initial dynamic changes and uptake constant k and distribution volume V were computed. Multiple vessel disease and congestive heart failure showed a low perfusion index (k/V), and may be used in this type of tracer with unidirectional uptake. This preliminary study in the clinical trial showed the usefulness of 99mTc tetrofosmin as a myocardial perfusion imaging agent.

Coronary Angiography↗
PubMed1993

[Evaluation of renal function using 99mTc-MAG3: comparison with 123I-OIH and 99mTc-DTPA].

The utility of 99mTc-mercaptoacetyltriglycine (MAG3) with studied clinically. In the renography obtained with 99mTc-MAG3, the abdominal aorta and the common iliac arteries were clearly visualized in the vascular phase. Due to less background activity and high target to background ratio, the quality of 99mTc-MAG3 image was superior to that of 123I-OIH or 99mTc-DTPA image. The parameters on the renogram including Tmax, T2/3, and T1/2 were compared. The correlation of Tmax and T2/3 or T1/2 were not significant between 99mTc-MAG3 and 123I-OIH. Another parameter of C20/Cmax, where C20 and Cmax are renal activities at 20 min after injection and at Tmax respectively, showed an excellent correlation between 99mTc-MAG3 and 123I-OIH. Using C20/Cmax, pattern of renogram can be characterized numerically. Concerning about the relation between C20/Cmax and renogram pattern, standard renogram pattern showed the C20/Cmax value of less than 0.4, while hypofunctioning pattern showed more than 0.5. The correlation coefficient between the renal uptake of 99mTc-MAG3 and 123I-OIH was 0.880 with a correlation plot: "Y = 1.16X-0.043", where X and Y represent renal uptake of 99mTc-MAG3 and 123I-OIH, respectively. It can be concluded that 99mTc-MAG3 is useful renal imaging agent as an alternative to 123I-OIH, in order to evaluate the proximal tubular function and calculate ERPF.

Adult↗
PubMed1993

[Central type benzodiazepine receptor and cerebral blood flow in experimental chronic brain infarction--evaluation using a double-tracer autoradiography technique].

Double tracer autoradiography was performed to measure regional cerebral blood flow (rCBF) and the binding of central type benzodiazepine receptors (BZR) in infarction by means of permanent occlusion of the unilateral middle cerebral arteries (MCA) in rat. Iodine-125 Iomazenil and 99mTc-HMPAO was used to label BZR and rCBF respectively. In the chronic phase of infarction 21 to 28 days after occlusion (5 rats), rCBF in the left MCA territory was decreased to 62% of the sham control (4 rats), while BZR was more decreased to 45% of the control. In remote areas from the MCA lesion, the ipsilateral thalamus showed 28% decrease of BZR as compared to the control, though the decrease of rCBF was not significant. Iomazenil distribution may represent neuron density or BZR density on a neuron, since central type BZR is reported to be located on neurons. These results suggest that central type BZR imaging is more useful tool for the evaluation of brain tissue viability and transneuronal degeneration than rCBF imaging in brain infarction.

Animals↗
PubMed1993

[Assessment of congenital heart disease by a thallium-201 SPECT study in children: accuracy of estimated right to left ventricular pressure ratio].

The characteristics of correlation between the right-to-left ventricular systolic pressure ratios (RVp/LVp) and the thallium-201 right-to-left ventricular (201Tl R/L) count ratios was investigated in children with various congenital heart diseases. High-resolution three-headed SPECT system equipped with either parallel-hole or fan-beam collimators was used. In a total of 102 patients, the correlation between RVp/LVp and 201Tl R/L average count ratios was good in both planar (r = 0.89, p = 0.0001) and SPECT studies (r = 0.80, p = 0.0001). Quantitative analysis of myocardial uptake by SPECT demonstrated the characteristic pattern of each disease as well as the differences in the right ventricular overload types. When the linear regression analysis was performed in each heart disease, ventricular septal defect showed most excellent correlation. Complex heart anomalies also showed positive correlation (r = 0.51, p = 0.05) with RVp/LVp, and it can be used to estimate right ventricular pressure. After surgical treatment of tetralogy of Fallot and pulmonary stenosis, the decrease of 201Tl R/L count ratio was in accordance with improvement of right ventricular overload. We conclude that 201Tl SPECT study can be a good indicator for estimation of right ventricular pressure.

Adolescent↗
PubMed1993

Probable cerebellar abnormality on 123I-IMP SPECT scans in epileptic patients with long-term high-dose phenytoin therapy. Based on observation of multiple cases.

Quantitative assessment of regional cerebral blood flow (rCBF) in the bilateral cerebral and cerebellar cortices was performed in 13 epileptic patients receiving long-term high-dose phenytoin (PHT) therapy, using single photon emission computed tomography (SPECT) with N-isopropyl-(iodine 123) p-iodoamphetamine. In 4 of the 13 patients, both the cerebellar to frontal rCBF ratio and cerebellar to cerebral rCBF ratio showed low values as compared with those in 22 normal subjects matched for sex and age, probably reflecting abnormal relative cerebellar hypoperfusion. None of the 4 patients showed any abnormal findings on X-ray computed tomography or magnetic resonance brain imaging. The patients with a history of acute PHT intoxication tended to show the abnormal relative cerebellar hypoperfusion. These results suggest the utility of SPECT scans for early detection of cerebellar abnormalities known to be often present in epileptic patients, and imply a risk of long-term high-dose PHT therapy.

Adult↗
PubMed1993

Quantitative assessment of regional cerebral blood flow with 123I-IMP in normal adult subjects.

Quantitative assessment of regional cerebral blood flow (rCBF) in the bilateral cerebral and cerebellar cortices was performed in 22 normal adult subjects consisting of an early twenties group (5 men and 9 women, 20-22 years) and middle age group (3 men and 5 women, 41-52 years), using single photon emission computed tomography (SPECT) with N-isopropyl-(iodine 123) p-iodoamphetamine. Absolute rCBF values in each region in the 22 subjects ranged from 46 to 102 ml/100 g/min (mean 69.1, standard deviation 13.7 ml/100 g/min). The absolute rCBF values were significantly higher in women than in men, and in the early twenties group than in the middle age group. In addition, based on each absolute rCBF value, the interhemispheric asymmetry, anterior to posterior ratio and cerebellar to frontal ratio in rCBF were calculated. These results may be useful as indexes for detecting organic and functional brain abnormalities in various neuropsychiatric diseases.

Adult↗
PubMed1992

[Evaluation of the internal mammary nodes by lymphoscintigraphy and ultrasonography in patients with breast cancer].

The efficacy of lymphoscintigraphy and ultrasonography was evaluated in the detection of internal mammary lymph node (IMN) metastases in patients with breast cancer. On histological examination of IMN, 10 patients had metastases (positive group) and 47 did not (negative group). On lymphoscintigraphy, lack of uptake in the parasternal region of the affected side was classified as abnormal. The frequency of this abnormal finding was not significantly different between both groups. On sonography, the thickness of the sonolucent internal mammary area was measured. The thickness of the affected side was 6 mm or more in two patients of the positive group and only one of the negative group. A thickness of over 6 mm on the affected side was statistically significant (p less than 0.05). The difference in thickness between the affected side and the healthy side was 3 mm or more in four patients of the positive group, and was less than 3 mm in all patients of the negative group. A difference in thickness of more than 3 mm between the two sides was extremely significant (p less than 0.001). In conclusion, sonography is valuable in detecting IMN metastases, while lymphoscintigraphy is not useful. Sonography is recommended as an efficient diagnostic modality for IMN metastases.

Adult↗
PubMed1992

A quantitative approach to technetium-99m hexamethylpropylene amine oxime.

A non-invasive, simple method for the quantitative evaluation of brain perfusion is presented using intravenous radionuclide angiography with technetium-99m hexamethylpropylene amine oxime (99mTc-HM-PAO). Graphical analysis was employed for the evaluation of the unidirectional influx constant (ku) of the tracer from the blood to the brain. The ku values were standardized to provide objective and comparable values, brain perfusion indices (BPI), among studied subjects by setting the ratio of ROIbrain size to ROIaorta size at 10. The whole-brain BPI values for the normal control subjects showed a significant negative correlation with advancing age (r = -0.632, P = 0.0204, n = 13). The mean of the whole-brain BPI of 7.0 (SD = 1.4) in 20 patients with cerebrovascular disorders was significantly lower than that of 10.6 (SD = 1.5) in 13 normal control subjects. The BPI measurements showed only minimal intra- and interobserver variability. Changes of the ratio of ROIaorta size and ROIbrain size did not significantly influence the BPI values. Hemispherical BPI values in 19 subjects (n = 38) showed highly significant correlations with the hemispherical mean cerebral blood flow values obtained from Xenon-133 single photon emission tomography (SPET) (r = 0.926, P = 0.0001 for the early picture method and r = 0.932, P = 0.0001 for the sequential picture method). This technique is easy to apply as an adjunct to SPET and may be helpful in the quantitative evaluation of brain perfusion in routine clinical studies.

Adult↗