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Biomedical subjects

M Kakishita

Publications and source records attributed to M Kakishita.

At least 19 recordsLinked to original sources

Extensive soft-tissue involvement of dermatomyositis detected by whole-body scintigraphy with 99mTc-MDP and 201TL-chloride.

The authors present a case of extensive soft-tissue radioactivity visualized on both 99mTc-MDP and 201Tl-chloride scintigrams in a patient with dermatomyositis and colon cancer. Incidentally, diffuse and intense uptake of 99mTc-MDP was observed in the shoulder girdles, anterior chest wall, psoas muscles, both proximal thighs and right lower limb, corresponding to the sites of symptomatic muscles, even though skin lesions were limited and no calcification was detected on radiographs. Moreover, 201Tl-chloride was also intensely accumulated in nearly the same sites as the symptomatic muscles as shown on the 99mTc-MDP bone scintigrams. Whole-body scintigraphy with 99mTc-MDP and 201Tl-chloride is a useful tool to detect occult muscle lesions with dystrophic calcification and hyperemia in dermatomyositis.

Calcinosis

Brain SPECT of Creutzfeldt-Jakob disease.

SPECT imaging with I-123 IMP or Tc-99m HMPAO was performed in two patients with Creutzfeldt-Jakob disease to evaluate abnormalities in brain perfusion. In the first patient, there was decreased perfusion of the left frontal, parietal, and temporal lobes. CT and MRI were negative. In the second patient, there was patchy perfusion and slightly decreased perfusion of the right hemisphere. MRI revealed slight brain atrophy and bilateral high intensity areas in the basal ganglia on T2 weighted images. Subsequent SPECT imaging revealed severely decreased perfusion of the entire brain. Subsequent MRI demonstrated severe brain atrophy.

Aged

Scintigraphic study of malignant melanoma with 123I-iodoamphetamine.

N-isopropyl-p-I-123-iodoamphetamine (123I-IMP) is extracted by the brain in proportion to regional blood flow. It is particularly useful in the clinical assessment of various pathological conditions related to altered cerebral flow. Moreover, it has been reported that 123I-IMP is avidly incorporated into melanin and melanotic melanoma. We evaluated 123I-IMP scintigraphy using either planar or single photon emission tomography (SPET) studies in 10 patients with malignant melanoma. The patients were classified into two groups according to the tumour site: Group A, six patients with primary or metastatic cutaneous malignant melanoma of the extremity with planar scintigraphy; Group B, four patients with primary malignant melanoma of other organs with planar scintigraphy and SPET. In Group A, tumour uptake was demonstrated in four of six patients; in Group B, three of four patients had tumour accumulation on SPET and planar scintigraphy. SPET revealed the exact tumour localization, even in the case of a tumour located in the lung. These results suggest that planar scintigraphy using 123I-IMP is useful in the detection of malignant melanoma. Furthermore, more clear tumour localization is possible with SPET, even in the case of a tumour located in the lung.

Aged

Simultaneous assessment of regional adrenergic activity and perfusion with 123I-MIBG and 201Tl in congestive heart failure.

Simultaneous assessment of regional adrenergic activity and perfusion with 123I-meta-iodobenzylguanidine (123I-MIBG) and 201Tl in various organs was performed in 13 patients with congestive heart failure (CHF) and 13 subjects without heart failure. In order to reduce the crosstalk of 201Tl to the 123I energy window to less than 5%, a dose of 123I-MIBG more than five times greater than that of 201Tl was administered following 201Tl scintigraphy. Regional uptake of 201Tl (%dose) was significantly increased in the heart (left ventricle) and lung (both P < 0.01) in the patients with CHF. The increased global cardiac uptake could have been related to the enlarged left ventricle. The patterns of regional uptake of 123I-MIBG (% dose) at 15 min were similar to those of 201Tl, suggesting that early 123I-MIBG uptake could in part depend on regional perfusion in both groups. At 3 h, regional uptake of 123I-MIBG was significantly increased in the heart, lung and kidney (all P < 0.01) in the patients with CHF. The delayed 123I-MIBG uptake indicates the degree of neuronal accumulation of the tracer, and therefore reflects adrenergic activity. Interestingly, the cardiac 123I-MIBG (adrenergic activity) to 201Tl (unit of perfusion) ratio decreased significantly in the heart (P < 0.01) but increased significantly in the kidney (P < 0.01) in the patients with CHF compared with the control group. Cardiac 123I-MIBG washout was also significantly increased in the CHF patients. Moreover, the cardiac 123I-MIBG:201Tl ratio was negatively correlated with plasma norepinephrine concentration (r = -0.74, P < 0.01), but positively correlated with LVEF (r = 0.60, P < 0.01). These data suggest that there may be impairment of both the neuronal uptake function and the vesicular storage function in the failing heart, and an increment in neuronal uptake function in the kidneys in patients with CHF. We suggest that dual-tracer scintigraphy is a useful non-invasive method for the simultaneous assessment of adrenergic activity and perfusion in various organs in patients with heart failure.

3-Iodobenzylguanidine

Concurrent detection of cholecystocolic fistula and hepatic abscess by hepatobiliary scintigraphy.

We report the case of a 58-year-old male with cholecystocolic fistula and hepatic abscess that were not diagnosed by routine radiologic examinations, but concurrently detected by hepatobiliary scintigraphy with 99mTc-PMT, and confirmed at operation. Hepatobiliary scintigraphy is noninvasive and useful in the detection of a biliary enteric fistula and lesions about related organs. Concurrent detection of cholecystocolic fistula and hepatic abscess on hepatobiliary series is of great clinical value in planning surgical intervention.

Biliary Fistula

Postgastrectomy osteomalacia with pseudofractures assessed by repeated bone scintigraphy.

A patient with osteomalacia secondary to vitamin D deficiency after gastrectomy for gastric cancer is presented. Initial bone scintigrams showed both asymmetric and symmetric focal areas of intense uptake due to pseudofractures reminiscent of bone metastases. Radiographs only confirmed the presence of pseudofractures at some, but not all, of the abnormal sites demonstrated by bone scintigraphy. At first, metastatic bone disease was suspected. However, the appearance of repeated bone scintigram was normalized after treatment with vitamin D. A diagnosis of osteomalacia was established. The present case serves to illustrate that symmetric focal lesions are important features of pseudofractures secondary to osteomalacia, and comparison with radiographs and repeated bone scintigraphy are necessary in distinguishing between bone metastases and pseudofractures.

Bone Neoplasms

The value of combined 99mTc-Sn-colloid and 99mTc-RBC scintigraphy in the evaluation of a wandering spleen.

Wandering spleen is the term commonly applied to splenic hypermobility that results from laxity or maldevelopment of its suspensory ligaments. It comes to medical attention usually as an abdominal mass, or when the spleen undergoes torsion. Diagnosis on clinical grounds alone is rarely made, and ultrasonography, CT and MRI findings have no specific characteristics for this condition. 99mTc-labeled colloid taken up by the spleen may provide a specific diagnosis. We report a case of wandering spleen, in which the preoperative diagnosis was made on the basis of sequential liver-spleen scintigraphy with 99mTc-Sn-colloid and blood-pool scintigraphy with 99mTc-RBC. This is a rare case, in which hypermobility was assessed by sequential 99mTc-Sn-colloid scintigraphy, and to our knowledge, is the first case in which 99mTc-RBC scintigraphy provided useful information on splenic blood volume and its location.

Adult

Sequential subtraction scintigraphy with 99mTc-RBC for the early detection of gastrointestinal bleeding.

To improve the early detectability of gastrointestinal (GI) bleeding, we have developed a new subtraction scintigraphic technique using in vivo labeled 99mTc red blood cells (RBC). Use of this new sequential subtraction method every 5 min makes it possible to detect early the bleeding site and calculate the bleeding rate. In phantom experiments, focal activity was detected on subtraction images at pump rates of more than 0.20 ml/min at any urethane thickness, but was negative on conventional scintigrams. The calculated pump rate by the subtraction method correlated well with the actual syringe pump rate (y = 1.07x - 0.02, r = 0.99, p < 0.01) in the case of an 8-cm urethane board as an abdominal wall. Twenty-four of 50 patients with suspected GI bleeding were confirmed to be positive within 24 hr. The subtraction method showed 15 true positive and 2 false positive cases within 60 min. On the other hand, the conventional scintigraphic method showed only 7 true positive and 1 false positive cases. Sensitivity of the subtraction method was 62.5%, which was significantly higher (p < 0.05) than that of the conventional scintigraphic method (29.2%). These results suggest that sequential subtraction scintigraphy with 99mTc-RBC is an effective method for the early detection of GI bleeding and shortening the examination time as compared with conventional scintigraphy.

Adolescent

Brain SPECT with neuro-Behçet disease.

A patient with neuro-Behcet disease is described. SPECT using Tc-99m HMPAO was performed to evaluate brain perfusion. The brain SPECT revealed decreased perfusion in the right frontal, parietal, temporal, and occipital lobes. MRI showed high intensity lesions in the white matter in the right periventricular centrum semiovale and frontal region on T2 weighted images. Gray matter abnormalities were evident on brain SPECT, but not on MRI. Brain SPECT using Tc-99m HMPAO may provide useful clinical information on regional cerebral cortical abnormalities associated with neuro-Behcet disease.

Behcet Syndrome

I-123 MIBG imaging of metastatic carcinoid tumor from the rectum.

I-131 MIBG, a specific radiopharmaceutical agent for scintigraphic imaging and treatment of pheochromocytoma and neuroblastoma may be useful for detection of apudomas. Scintigraphy with I-123 radiolabeled MIBG was performed in a patient with metastatic carcinoid tumor from the rectum. I-123 MIBG scintigraphic findings showed multiple areas of abnormal tumor uptake of hepatic and bone metastases from the rectal carcinoid. Bone scintigraphy demonstrated multiple metastatic lesions. Computed tomography revealed multiple solid tumors of the liver. This report describes accumulation of I-123 MIBG in the liver and bone metastases from the rectal carcinoid. Radioiodine MIBG scintigraphy may be useful for detecting metastatic lesions, for evaluating postoperative recurrence, and also for the treatment of the carcinoid tumor.

3-Iodobenzylguanidine

Whole-body 201Tl scintigraphy during one-leg exercise and at rest in normal subjects: estimation of regional blood flow changes.

To determine the effect of exercise intensity on regional blood flow in exercising and resting leg muscles and organs, we assessed relative changes in the regional distribution of 201Tl during one-leg ergometer exercise and at rest by whole-body scintigraphy as an estimate of regional blood flow changes in 10 healthy males. The regional 201Tl activity was expressed as a percentage of the whole-body activity, and relative changes in each region were compared to those at the anaerobic threshold (AT) and at peak exercise. In the legs, the distribution of 201Tl in the exercising thigh and calf increased significantly at the AT to 390.7 and 219.2% respectively of resting levels (both P < 0.01), but remained unchanged the resting thigh from rest to peak exercise. Conversely its distribution in the resting calf decreased significantly at the AT to 60.0% of the resting level (P < 0.01). However, there were no significant differences between AT and peak exercise. In the organs, the distribution of 201Tl in the lung, liver, spleen and kidneys decreased significantly at the AT to 88.4 +/- 10.4%, 67.0 +/- 11.5%, 62.4 +/- 11.8% and 67.0 +/- 8.6% respectively of resting levels (all P < 0.01). Redistribution of blood flow to the exercising leg occurs predominantly during mild to moderate exercise. Therefore, blood flow in the leg during strenuous exercise depends primarily upon an increase in cardiac output. The splanchnic organs are the major sources of redistribution.

Adult

[Assessment of tumor viability by 201Tl SPECT in VX-2 tumor-bearing rabbits after irradiation: comparison with X-ray CT and pathohistologic findings].

In order to evaluate 201Tl SPECT for the assessment of tumor viability after radiation therapy. Twenty rabbits were implanted with VX-2 tumor in the left femoral muscles and were classified into four groups as follows: normal control group (N), 20 Gy irradiated response group (A), 20 Gy irradiated non-response group (B), and 40 Gy irradiated group (C). Eight days after implantation, 201Tl SPECT and CT studies were performed to assess the changes in 201Tl uptake and tumor volume at 0, 1, 2, 3, and 4 weeks after single irradiation. Histologic specimens were also taken. In group N tumors continued to increase in volume, but 201Tl uptake showed a steady decrease after 2 weeks. In group A tumors continued to increase in volume, but 201Tl uptake showed a transient decrease at 2 weeks, then a steady increase. In group B tumors showed a transient increase in volume at 2 weeks, then a continuous decrease, but 201Tl uptake showed a continuous decrease throughout the study. In group C there was a continuous decrease both in volume and 201Tl uptake with the later more prominent. 201Tl uptake was decreased earlier than tumor volume both in group B and C, at one week that was significant (p < 0.01). 201Tl uptake by tumor reflects the burden of viable tumor on histology; therefore 201Tl SPECT is of great use in assessing the therapeutic effects on tumors.

Animals

Diffuse increased renal uptake on bone scintigraphy in acute tubular necrosis.

Acute renal failure after exercise with frank pain and patchy renal vasoconstriction is a clinical syndrome that occurs in young, previously healthy persons. The authors describe a 24-year-old man who had this syndrome. CT scan showed wedge-shaped contrast enhancement of both kidneys, which suggested patchy renal vasoconstriction. Tc-99m MDP imaging revealed diffuse increased uptake of both kidneys. After renal function was improved, Tc-99m MDP imaging showed normal uptake of both kidneys. Acute renal failure due to acute tubular necrosis was confirmed by renal biopsy. The authors conclude that Tc-99m MDP may be useful in evaluation of acute renal failure after exercise with flank pain and patchy renal vasoconstriction due to acute tubular necrosis.

Adult

Assessment of residual tumor viability in thymic carcinoma by sequential thallium-201 SPECT: comparison with CT and biopsy findings.

We present a case of 201TI accumulating thymic carcinoma, in which sequential CT scans demonstrated a steady decrease in tumor volume. The presence of a residual mass on CT scans after the completion of therapy presented the clinical dilemma of whether or not a viable tumor remained. Sequential 201TI SPECT images demonstrated a marked decrease in tumor uptake. At 2 wk after therapy, no significant accumulation of 201TI in the region of the residual mass was observed, indicating a lack of viable tumor. A biopsy specimen revealed no tumor cells. Sequential histopathologic findings were correlated well with the findings of 201TI SPECT rather than those of CT. Thallium-201 SPECT is of great clinical value in assessing tumor viability in the course of therapy.

Aged

Basilar artery migraine. Reversible ischemia demonstrated by Tc-99m HMPAO brain SPECT.

The authors present a case of basilar artery migraine in a 33-year-old woman who was initially misdiagnosed as having a cerebrovascular or mental disorder and subjected to MRI and cerebral angiography, which, however, did not show any pathologic findings. During admission to the university hospital, she lost consciousness. An emergency Tc-99m HMPAO brain SPECT showed a significant decrease of regional cerebral blood flow in the right temporal and occipital cortices, and right cerebellar hemisphere, where regional cerebral blood flow was decreased by 10-24% as compared to the left side. The second brain SPECT during a symptom-free phase showed the reversion of regional cerebral blood flow to normal in these areas. Basilar artery migraine was diagnosed by the finding of reversible ischemia in the territory of the right basilar artery on brain SPECT images and the clinical picture.

Adult

[MR evaluation of common femoral arterial flow: age-related changes and characteristics in obstructive arterial disease of lower extremities].

Flow velocity measurements of the common femoral arteries in 60 lower extremities of 30 healthy subjects and 12 lower extremities of 7 patients with arteriosclerosis obliterans (ASO) were performed by means of magnetic resonance imaging with a use of presaturation bolus tracking (PBT) method. Our PBT method can provide both precise determination of flow velocity and evaluation of flow patterns within 30 minutes in the clinical setting. In phantom study, MR flow velocity had good correlation with actual flow velocity (r = 0.997). 30 healthy volunteers were classified into three groups; group I (20-40 years), group II (41-60 years) and group III (61-80 years). Starting time of acceleration (STA) were shortened as the age progressed. Peak reverse velocity (PRV), maximum deceleration rate (MDR), peak forward velocity/mean velocity ratio (PFV/MV) and pulsatility index (PI) were significantly decreased in group III as compared to group I and group II. Although intraluminal flow profile showed almost uniform during acceleration time on MR images, flow profile became disproportioned and reverse flow was observed in the medial portion during deceleration time. These characteristic hemodynamics were recognized in all healthy subjects regardless to the different age group. In ASO, STA was prolonged and PFV, PRV, Maximum acceleration rate, MDR, PFV/MV, PI, Vascular sectional area, flow volume were significantly decreased (p < 0.001) as compared to the control healthy group III. As the result we obtained marked characteristics such as flattening of curves and disappearance of reverse flow in MR flow waveform. On MR images, disproportion of intraluminal flow profile, decreased flow velocities during acceleration time and disappearance of reverse flow (11 of 12 extremities) during deceleration time were observed.

Adult