Shigeyuki Ogi

Usefulness of radio-guided surgery using Technetium-99m. Methoxyisobutylisonitrile for primary and secondary hyperparathyroidism

The efficacy of technetium-99m methoxyisobutylisonitrile (99mTc-MIBI)-guided surgery for detecting abnormal parathyroid glands in patients with secondary hyperparathyroidism (2-HPT) was evaluated and compared with the results from the same examination in patients with primary hyperparathyroidism (1-HPT). The results were also compared with those found by ultrasonography (US) and preoperative 99mTc-MIBI scintigraphy was also made. At operation 99mTc-MIBI accumulated in 64 nodules of 15 cases of 2-HPT, and all of 60 parathyroid swellings were detected (true-positives 60, sensitivity 100%, accuracy 94%). In the cases of 1-HPT, 99mTc-MIBI revealed 11 hot nodules in 10 cases, and the evaluation was true-positive 10, sensitivity 100%, and accuracy 91%. US and preoperative 99mTc-MIBI scintigraphy in patients with 2-HPT had a sensitivity of 75% and 67% and an accuracy of 70% and 66%, respectively. The usefulness of 99mTc-MIBI-guided surgery for detecting abnormal parathyroid tissue in 2-HPT patients was similar to that in 1-HPT patients but was superior to US and preoperative 99mTc-MIBI scintigraphy. Intraoperative 9mTc-MIBI for patients with 2-HPT is effective and makes the surgery easier, especially when the parathyroid glands are ectopic or when a few glands are markedly enlarged but the other glands are atrophied.

The usefulness of radio-guided surgery in secondary hyperparathyroidism

Recent reports have shown that radio-guided surgery with an intraoperative gamma probe (IGP) is useful for identifying parathyroid adenomas. The aim of this study was to evaluate the usefulness of IGP mapping in patients with secondary hyperparathyroidism. Seven patients with secondary hyperparathyroidism underwent technetium-99m methoxyisobutylisonitrile (Tc-99m MIBI) scintigraphy immediately before undergoing surgical resection of all parathyroid tissues. We compared the sensitivity of Tc-99m MIBI scintigraphy alone with that of the combination of Tc-99m MIBI scintigraphy and IGP mapping. The sensitivity of the combination of Tc-99m MIBI scintigraphy and IGP mapping was 100% (28 of 28 lesions) and was significantly higher than that of Tc-99m MIBI scintigraphy alone (71.4%, 20 of 28 lesions). The combination of the Tc-99m MIBI scintigraphy and IGP mapping has increased sensitivity for identifying parathyroid lesions during parathyroidectomy in patients with secondary hyperparathyroidism.

Influence of hilar deposition in the evaluation of the alveolar epithelial permeability on 99mTc-DTPA aerosol inhaled scintigraphy

PurposeWe investigated whether hilar radioaerosol deposition affects the clearance rate of technetium-99m-labeled diethylenetriaminepentaacetic acid (99mTc-DTPA) from peripheral alveolar regions.Materials and methodsA total of 38 patients underwent 99mTc-DTPA inhalation lung scintigraphy. Six region of interest (ROI) patterns were adopted: ROI 1 was outlined around the entire hemithorax, and ROIs 2–6 were outlined around the hemithorax but excluded square ROIs of different size in the hilar region. Half-times (T½) were calculated with time-activity curves using onecompartment and two-compartment analyses. The T½ of ROIs 1–5 were plotted against the T½ of ROI 6, and regression lines were obtained with the least-squares method. The absolute values of the differences between surveyed values and regression line were calculated. The Wilcoxon test for trend and a single linear regression model were used to determine statistical significance.ResultsThere were significant reductions in the absolute values of the differences between surveyed values and regression line from ROIs 1–5 by one-component analysis and the fast component of two-compartment analysis (P < 0.001).ConclusionOur results suggest that the deposition of radioaerosol in the hilar region affects the clearance rate of 99mTc-DTPA from the alveoli in damaged lungs. The hilar region should be excluded from ROIs when alveolar epithelial permeability is evaluated.

Use of digirad 2020tc Imager, a multi-crystal scintillation camera with solid-state detectors in one case for the imaging of autografts of parathyroid glands.

Abstract99mTc-methoxy-isobutyl-isonitrile (99mTc-MIBI) scintigraphy with Digirad 2020tc ImagerTM (2020tc), which was a multi-crystal scintillation camera with solid-state detectors was performed for patients with secondary hyperparathyroidism having autografts of parathyroid glands in the right arm. With the 2020tc camera, three abnormal accumulations were found in the right arm. The images obtained with this camera were superior in resolution to those obtained with a conventional NaI crystal gamma camera (ZLC7500, Siemens, Germany). The next day, resection of autografts of parathyroid glands was done. Four hyperplastic parathyroid glands were resected and all were hyperplastic in pathological findings.

The role of renal scintigraphy in renal arteriovenous malformation treated by transcatheter arterial embolization

A 41-year-old woman was hospitalized because of gross hematuria. She was found to have a renal arteriovenous malformation and was treated with transcatheter arterial embolization (TAE). Renal scintigraphy with Tc-99m mercaptoacetyltriglycine was performed before and after TAE. Renal scintigraphy was useful for evaluating renal function in this patient.

A case of ganglioneuroma in which131I-6ß-iodomethyl-19-norcholest-5(10)-en-3ß-ol scintigraphy showed high uptake in the adrenal gland leading to a misdiagnosis

We experienced a case in which131I-6ßiodomethyl-l9norcholest-5(10)-en-3ß-ol (131I-adosterol) scintigraphy showed high uptake in the right adrenal gland. We diagnosed functional cortical adenoma because of the finding of131I-adosterol scintigraphy. However, no positive findings for the existence of cortical adenoma were obtained in other examinations and we performed right adrenalectomy. Unexpectedly, pathological finding showed the right adrenal gland was occupied with a large ganglioneuroma. This is an instructive case in which131I-adosterol scintigraphy showed abnormal high uptake in the adrenal gland, in spite of the fact that the adrenal gland was occupied by a tumor derived from adrenal medulla.

125I-iomazenil-benzodiazepine receptor binding during psychological stress in rats.

Objective: We investigated the changes in125I-iomazenil (125I-IMZ) benzodiazepine receptor (BZR) binding with psychological stress in a rat model.Methods: Six male Wistar rats were placed under psychological stress for 1 hour by using a communication box. No physical stress was not received. 1.85 MBq of125I-IMZ was injected into the lateral tail vein and the rat was killed 3 hours later. Twenty-micrometer-thick sections of the brain were collected and % injected dose per body weight (%ID/BW) of eleven regions (frontal, parietal, temporal, occipital cortices, caudate putamen, accumubens nuclei, globus pallidus, amygdala, thalamus, hippocampus and hypothalamus) were calculated by autoradiography. The %ID/BW of rats which were placed under psychological stress was compared with that of 6 control rats.Results: The %ID/BW of rats which were placed under psychological stress diffusely tended to show a reduction in125I-IMZ-BZR binding. A significant decrease in BZR binding was observed in the hippocampus of the rats which were placed under psychological stress.Conclusion:125I-IMZ-BZR binding tended to decrease throughout the brain.

Usefulness of intraoperative 99mTc-MIBI-guided detection for recurrent sites in secondary hyperparathyroidism: A case-controlled study

PURPOSE (99m)Tc-Methoxyisobutylisonitrile ((99m)Tc-MIBI)-guided surgery for the detection of abnormal parathyroid glands in primary hyperparathyroidism (1-HPT) has gained popularity as an effective technique. However, in secondary hyperparathyroidism (2-HPT), the efficacy of this method remains controversial, especially for the recurrence sites of 2-HPT. METHODS (99m)Tc-MIBI-guided surgery was performed for 28 recurrent sites of transplanted parathyroid tissue in 4 patients, and the detection rates of this method were compared with the results of preoperative ultrasound (US) examination and computed tomography (CT) scanning. RESULTS The results of (99m)Tc-MIBI-guided surgery for regions of recurrence were a sensitivity of 100% (28/28) and an accuracy of 100% (29/29), compared with preoperative US and CT which had a sensitivity of 92.9% (26/28) and 0% (0/28), and an accuracy of 89.7% (26/29) and 0% (0/28), respectively. CONCLUSIONS Intraoperative (99m)Tc-MIBI-guided surgery can identify recurrent parathyroid tissues of 2-HPT more precisely than preoperative US examination or CT scanning, and makes the surgery easier to perform.

Effects of diazepam on125I-iomazenil-benzodiazepine receptor binding and epileptic seizures in the El mouse

ObjectiveTo investigate changes in free benzodiazepine receptor density in response to repeated, long-term administration of diazepam in epilepsy, we assessed125I-iomazenil (125I-IMZ) binding in a mouse model.MethodsEl mice were divided into two groups of 12 mice each which received either no diazepam (EI(D[-]) group) or 2 mg/kg of diazepam per week (EI(D[+]) group). Nine ddY mice were used as a control. Once each week from the age of 5 to 19 weeks, the El mice received stimulation to produce epileptic seizures 20 minutes after receiving intraperitoneal injections. At 20 weeks of age, a total dose of 0.37 MBq of125I-IMZ was injected in all mice and their brains were rapidly removed 3 hours later. The incidence of epileptic seizures at the age of 19 weeks and the autoradiograms of the brain were compared.ResultsThe incidence of epileptic seizures in response to weekly stimulation was significantly lower in the E1(D[+]) group than in the E1(D[-]) group (p < 0.001). The percent injected doses of125I-IMZ per gram of tissue in the cortex, hippocampus and amygdala were significantly lower in the E1(D[+]) group than in the E1(D[-]) group (p < 0.05).ConclusionThe results suggest that diazepam binds competitively to125I-IMZ as an agonist to free benzodiazepine receptor sites in the cortex, hippocampus and amygdala and shows anticonvulsant effect in El mice.