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.

99mTc-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.

Strontium-89 therapy and imaging with bremsstrahlung in bone metastases.

The bone-seeking radiopharmaceutical Sr-89 has been used as a palliative treatment for patients with bone pain caused by bone metastases. The authors report the results of nine patients (three with prostate cancer, four with breast cancer, one with thyroid cancer, and one with lung cancer) who underwent therapy with Sr-89 chloride for painful bone metastases, and evaluate Sr-89 imaging with bremsstrahlung. Two levels of dosage (1.5 and 2.2 MBq/kg) were used. Sr-89 imaging was performed in seven patients 1 week after injection. Abnormal uptake was seen in all and was consistent with the results of Tc-99m HMDP imaging. Six patients were assessed at 3 months and three patients toward the time they were terminal; 78% (seven of nine) derived some benefit. Two patients had a favorable clinical response and showed improvement on Tc-99m HMDP imaging.

[A significance of the washout of 123I-BMIPP in patients with vasospastic angina].

We investigated the washout of 123I-BMIPP from early and delayed SPECT in 28 patients with vasospastic angina from the standpoint of the intervals from the last angina attack. We divided myocardial wall into 13 segments from the early and delayed SPECT, and visually classified into four grades of defect score ranged from 0 (normal) to 3 (severe defect). Early and delayed severity scores were calculated as a total of defect scores in 3 vessel territories, and washout scores (WS) as (delayed severity score-- early severity score)/number of segments. WS of the group within 1 month from last angina attack was compared with the groups more than 1 month. In the territory of the right coronary artery, the group within 1 month showed significantly higher WS than groups more than 1 month (p < 0.05). In the other two territories, the group within 1 month showed higher WS than one of the groups more than 1 month, but the difference was not statistically significant. We considered that the washout of 123I-BMIPP may reflect the clinical course of vasospastic angina.

[The possibility of evaluation on inflammatory change at respiratory tract in chronic bronchial asthma using 67Ga scintigraphy].

67Ga scintigraphy was performed in 17 patients with chronic bronchial asthma to grasp the inflammatory change of respiratory tract. On 67Ga scintigraphy, abnormal accumulations were detected on lung fields in 6 cases (35.3%) of 17 cases. In 5 cases of these 6 cases, the defect areas which were pointed out on 81mKr ventilation scintigraphy were matched to the abnormal accumulation areas which were pointed out on 67Ga scintigraphy. In dynamics, the abnormal accumulation areas which were pointed out on 67Ga scintigraphy were matched to the defect areas which had been at all times pointed out on 81mKr ventilation scintigraphy. 67Ga scintigraphy was expected to be one of index to grasp the inflammatory change of respiratory tract in patients with chronic bronchial asthma.

[Evaluation of efficiency of a multi-crystal scintillation camera Digirad 2020tc Imager using a solid-state detectors].

Digirad 2020tc Imager is the movable scintillation camera, consisting of combining multi-crystal scintillators (CsI(Tl)) and photo-diodes. Total numbers of element are 4096, which are further divided into 16 x 16 modules. Each module contains 4 x 4 elements. We have examined Digirad 2020tc according to NEMA (National Electrical Manufactures Association), and the following results are obtained; the maximum count rate; 221 kcps, total system uniformity; 1.3% (integral uniformity), 0.9% (differential uniformity), system spatial resolution; 6.97 +/- 0.72 mm (the LEHR collimator to 99mTc source at 10 cm), intrinsic energy resolution; 12.8%, total system sensitivity; 3270.8 cpm/MBq (with LEHR collimator using 99mTc source at 10 cm). Further more, we determined the contrast of an imaging using the pin-hole (100 microns phi) 99mTc source in order to know the signal per noise (S/N) ratio among the pixels (S/N; 93.4 +/- 46.2 (first pixels)). Although the physical dimension of the camera has a smaller field of view, comparing with the standard camera, Digirad 2020tc has the equivalent characteristics as well as that of the standard camera and its field view is enough to measure the adult lung perfusion using a diverging collimator. We will further examine Digirad 2020tc with its movable portability and expect applications in nuclear medicine.

[Diagnostic value of urinary N-telopeptide of type I collagen in prostate cancer: comparison with bone scintigraphy].

The usefulness of a new biochemical marker of bone resorption, N-telopeptide of type I collagen (NTx), in the diagnosis of bone metastasis was assessed in 69 prostate cancer patients. Based on the bone scintigraphy findings, the patients were divided into a bone metastasis (+) group (n = 36) and a bone metastasis (-) group (n = 33). The urinary NTx level was significantly higher in the bone metastasis (+) group than in the bone metastasis (-) group (95.5 +/- 18.5 nM BCE/mM Cr vs. 63.3 +/- 7.9 nM BCE/mM Cr). There was a tendency for greater variability in urinary NTx levels during a 2 month-period in the bone metastasis (+) group than in the bone metastasis (-) group. The urinary NTx level of the 6 patients who were clinically staged as (4+) according to the extent of disease (EOD) grading system was 211.4 +/- 96.9 nM BCE/mM Cr, and was significantly higher (p < 0.05) than in the (-) group. However, there was not a significant difference in urinary NTx levels between the (1+) to (3+) groups and the (-) group. In conclusion, measuring urinary NTx levels in useful in diagnosing bone metastasis in view of the fact that it is a simple and noninvasive procedure. While it is not as sensitive as bone scintigraphy, it may be used to supplement bone scintigraphy.

[Evaluation of clinical utility of 99mTc-MIBI scintigraphy in the localization of thyroid, breast and lung/mediastinum tumors--a report of multicenter phase III clinical trials].

Phase III clinical study in 136 patients diagnosed or strongly suspected of thyroid, lung/mediastinum or breast cancer was performed to determine clinical utility of 99mTc-MIBI in the localization of tumors, and the results in 135 were evaluated. Except taste peculiar in 43 patients and nausea in one, no adverse events were reported. Seven abnormal changes in vital signs and 27 in clinical laboratories were noted, which were all judged as having no or unlikely relationship to the agent. Out of 177 malignant lesions, 156 (88%) were detected with 99mTc-MIBI regardless of their histology or location. Of 6 benign tumors, 3 were detected. Fifteen sites of false positive in 11 malignant tumor patients and 5 sites in 6 patients with non-tumor disease were observed. Our study indicates that 99mTc-MIBI is a safe and excellent agent for the localization of tumors. Especially, the fact that 99mTc-MIBI detected remote metastatic lesions with high sensitivity is a great advantage over the other conventional imaging modalities.

[Assessment of cerebral benzodiazepine receptor distribution in anxiety disorders by 123I-iomazenil-SPECT: comparison to cerebral perfusion scintigraphy by 123I-IMP].

123I-Iomazenil (123I-IMZ) and 123I-IMP imaging were performed in 5 patients with anxiety disorder (PAD) and 6 normal volunteers (NV). On 123I-IMZ delayed imaging, the 2 PAD showed abnormally decreased findings. In anxiety disorder, decreased accumulation on 123I-IMZ delayed images was seen in left hippocampus and parahippocampal gyrus in one patient, in right frontal and temporal lobe and left occipital pole in the other. Compared with NV, PAD had lower 123I-IMZ uptake on delayed image in right upper and left lower frontal cortices, indicating the involvement of the benzodiazepine receptor complex in anxiety disorder. Compared with grading for anxiety disorder with Hamilton anxiety scale (HAS) and delayed to early count ratios of 123I-IMZ, negative correlation (R < -0.7) was recognized hippocampus and parahippocampal gyrus, frontal and occipital cortices. Compared between HAS and the count ratio to the cerebellum on 123I-IMP image, positive correlation (R > 0.7) was recognized in the hippocampus, the parahippocampal gyrus, the lower outer temporal cortex and the lower frontal cortex.

[Assessment of cerebral benzodiazepine receptor distribution in epilepsy by 123I-iomazenil-SPECT].

123I-Iomazenil (123I-IMZ) and 123I-IMP imaging were performed in 8 epileptic patients (EP) in the interictal phase and 6 normal volunteers (NV). On 123I-IMZ delayed imaging, the 8 EP showed abnormally decreased findings. Two EP showed decreased perfusion in the same region on 123I-IMP imaging. 123I-IMZ imaging for the detection of epileptic foci showed relatively high specificity compared with EEG recording. On 123I-IMZ early images, the count ratio of the right lower frontal cortex was lower the cerebellar cortex in EP was lower than that in NV. On 123I-IMZ delayed images, the count ratio of the bilateral occipital and the right upper and lower frontal cortices to the cerebellar cortex in EP was lower than that in NV. On 123I-IMZ delayed images, the count ratio of the right upper frontal cortex to the occipital cortex in EP was lower than that in NV. On 123I-IMZ delayed images, the count ratio of the left lower frontal cortex to the occipital cortex in EP was higher than that in NV. These results pointed to the involvement of the benzodiazepine receptor complex in epilepsy.

[Comparative study of 201Tl and 99mTc-MIBI in breast tumor].

A comparative study of 201Tl and 99mTc-MIBI was performed in 39 breast tumors. 201Tl scintigraphy was carried out in 24 breast tumors and 99mTc-MIBI scintigraphy in 15. The sensitivity of 201Tl for malignant tumors was 100% (22/22), but specificity was 0% (0/2). On 99mTc-MIBI scintigraphy, the sensitivity for the malignant tumors was 83.3% (10/12) and specificity was 100% (3/3). 99Tc-MIBI might be more useful for the diagnosis of breast tumors, because the tumor/background ratio of 99mTc-MIBI was significantly higher than that of 201Tl. In addition, 201Tl scintigraphy and 99mTc-MIBI scintigraphy showed the same degree of accuracy (93.3%) in diagnosis of lymph node reached. Moreover, when either US and 201Tl or 99mTc-MIBI scintigraphy was positive for lymph node metastasis, accuracy of detection of lymph node metastasis became 94.4%. A combined study of US and scintigraphy might improve the accuracy for diagnosis of lymph node metastasis.

[Autoradiographic study of myocardial fatty acid metabolism in diabetic mouse using 125I-BMIPP].

The existence of diabetic cardiomyopathy has been substantiated in patients with diabetes mellitus. In this study we evaluated two mice with diabetes mellites (DM) and two control mice to determine whether the fatty acid metabolism of the myocardium is abnormal when 125I-BMIPP is used. 125I-BMIPP of 0.74 MBq (20 microCi) was injected, and 30 min later, the mice were slaughtered. Heart, lungs, liver, spleen and kidneys were removed. After freezing the heart, myocardium was sliced into 20 micron sections using a cryostat. Each slice was placed in contact with an imaging plate for autoradiography. A bioimaging analyzer was used to analyze the data. The percent injected dose/g of heart was lower in the DM group than in the control group (11.6 +/- 0.49 vs 18.3 +/- 1.27). Each slice of the DM group also had fewer counts than slices in the control group (p < 0.05 or p < 0.01). These results indicated that fatty acid metabolism in the myocardium was less in the DM group than in the control group.

Redistribution in I-123 N-isopropyl-p iodoamphetamine single-photon emission computed tomography in cerebrovascular disease and the effects of rehabilitation.

We performed N-isopropyl-p (I-123) iodoamphetamine (IMP) single-photon emission computed tomography (SPECT) on 28 patients with severe cerebrovascular disease before rehabilitation, and compared the degree of redistribution and the assessment of activities of daily living (ADL). We calculated a redistribution (RD) ratio in the central and peripheral parts of the lesions: RD ratio (c) and RD ratio (p). We classified the patients into four groups based on the degree of redistribution: complete: both RD ratio (c) and (p) > or = 75; peripheral: RD ratio (c) < 75, RD ratio (p) > or = 75; incomplete: both RD ratio (c) and (p) < 75 and at least one of RD ratio (c) or (p) > or = 25; no redistribution: both RD ratio (c) and (p) < 25. We assessed the ADL using the modified Barthel index (BI). deltaBI was defined as BI after rehabilitation-BI before rehabilitation (BIpost-BIpre). The deltaBI of the four groups were as follows: complete-redistribution group (40.8 +/- 22.8), peripheral-redistribution group (40.0 +/- 15.8), incomplete-redistribution group (27.2 +/- 22.6), no-redistribution group (8.8 +/- 12.3). The deltaBI of the complete and peripheral redistribution groups were significantly higher than that of the no-redistribution group. However, deltaBI was almost the same in the complete- and peripheral-redistribution groups. This suggests that the effect of rehabilitation might be closely related to the viability of the peripheral part of the lesion.

[Relationship between redistribution rate (RD rate) of 123I-IMP SPECT and prognosis by Barthel index in cerebral infarction].

A comparative study of RD rate and the Barthel index was performed in 26 patients who had cerebral infarction. On 123I-IMP SPECT, the RD rate was calculated as follows, RD rate = (I-II)/I x 100(%). (I = (B-A)/B, where A is the mean count of the low density area (LDA) on brain CT on the early image and B the mean count of the opposite portion of LDA on the early image. II = (B'-A')/B', where A' is the mean count of the LDA on the delayed image and B' is the mean count of the opposite portion of the LDA on the delayed image. delta Barthel index (delta B. I.) was defined as follows: delta B. I. = B. I. (post-rehabilitation)-B. I. (pre-rehabilitation). In the group with B. I. (pre rehabilitation) < 85, the RD rate and delta B. I. were well correlated. In the group with B. I. (pre-rehabilitation) > or = 85, the RD rate and delta B. I. were not correlated. This result suggests that the RD rate might be useful in predicting prognosis and selecting the principle of therapy.