Biomedical subjects

N Tonami

Publications and source records attributed to N Tonami.

At least 37 records · Page 2Linked to original sources

PubMed2001

Nuclear imaging of bone tumors: thallium-201 scintigraphy.

(201)Tl scintigraphy provides important information for the management of patients with bone tumors. Although the role for staging the disease of bone tumors and for differentiation of benign from malignant lesions is limited, (201)Tl scintigraphy reflects the disease activity after treatment and it should be used to determine the treatment response and for early diagnosis of recurrence. Baseline study is essential for future reference to evaluate the response to preoperative chemotherapy and to detect recurrence after surgery. Sequential (201)Tl scintigraphy before and after treatment is useful in assessing the grade of response of the tumor to chemotherapy. The early prediction of chemotherapeutic effect by (201)Tl scintigraphy during treatment will affect the management of patients who do not respond to the therapy. This is of special importance to determine whether the patient needs an amputation or a limb-salvage surgery.

Antineoplastic Agents↗

PubMed2001

Technetium-99m-tetrofosmin would be a substrate for multidrug resistance-associated protein (MRP): comparison between a leukemia cell line with high MRP gene expression and its parental cell line.

UNLABELLED: The kinetics of cellular accumulation and retention of technetium-99m-tetrofosmin (99mTc-TF) were investigated in wild type HL60/WT cell line and in its doxorubicin-resistant HL60/DOX cell line with multidrug resistance-associated protein (MRP), but without P-gp overexpression, to determine whether 99mTc-TF is a substrate for MRP. METHODS: The accumulation and washout of 99mTc-TF were observed in both cell lines at 37 degrees C. The effect of verapamil on the kinetics was also assessed. RESULTS: 99mTc-TF net accumulation was significantly lower in HL60/DOX (1.35 +/- 0.23%) than in HL60/WT (12.79 +/- 0.47%) at 60 min (P < 0.001). Three minutes after exchanging the incubation solution to the tracer-free medium, only 18.20 +/- 0.34% of 99mTc-TF remained in HL60/DOX, whereas 84.74 +/- 0.65% did in HL60/WT (P < 0.001). In the presence of 10 microM verapamil, 99mTc-TF net accumulation in HL60/DOX was 302% of the control and the washout was significantly delayed. CONCLUSION: 99mTc-TF would be a substrate for MRP and 99mTc-TF may be used as a functional imaging agent of MRP in vivo.

ATP Binding Cassette Transporter, Subfamily B, Mem↗

PubMed2001

Thymic lesions in patients with myasthenia gravis: characterization with thallium 201 scintigraphy.

PURPOSE: To assess thallium 201 ((201)Tl) single photon emission computed tomography (SPECT) for evaluation of thymic lesions associated with myasthenia gravis (MG), including lymphoid follicular hyperplasia (LFH) and thymoma. MATERIALS AND METHODS: (201)Tl SPECT and computed tomography (CT) were performed preoperatively in 46 patients with MG who had undergone thymectomy. SPECT was conducted 15 (early image) and 180 (delayed image) minutes after (201)Tl injection. Results were visually assessed, and (201)Tl uptake ratios (thymic lesion count density/lung count density) were measured for quantitative analysis. Uptake was analyzed among the normal thymus, LFH, and thymoma patient groups. RESULTS: Histopathologic results indicated a normal thymus, LFH, and thymoma in 19, 16, and 11 patients, respectively. Mean uptake ratios in the normal thymus, LFH, and thymoma were 0.96 (95% CI: 0.90, 1.03), 1.14 (95% CI: 1.04, 1.25), and 1.87 (95% CI: 1.56, 2.25), respectively, on early images and 1.09 (95% CI: 1.00, 1.18), 1.65 (95% CI: 1.48, 1.85), and 2.03 (95% CI: 1.65, 2.50), respectively, on delayed images. Thymoma showed more intense (201)Tl accumulation than did the normal thymus (P <.001) and LFH (P <.001) on early images. Both thymoma (P <.001) and LFH (P <.001) displayed more intense uptake than did the normal thymus on delayed images. CONCLUSION: (201)Tl SPECT can enable differentiation between normal thymus, LFH, and thymoma in patients with MG.

Adult↗

PubMed2001

Diastolic dysfunction in patients with systemic sclerosis detected by gated myocardial perfusion SPECT: an early sign of cardiac involvement.

UNLABELLED: Diagnosis of cardiac involvement is important for the management of patients with systemic sclerosis (SSc). This study was undertaken to determine the significance of gated myocardial perfusion SPECT in patients with SSc and whether diastolic function measured by gated SPECT is an early sign of cardiac complications. METHODS: Thirty-four patients with SSc and 16 control patients were studied using exercise nongated and resting gated myocardial perfusion SPECT. The SSc was classified by the modified Rodnan total skin score (TSS) into high-TSS (score > or = 10; n = 18) and low-TSS (score < 10; n = 16) groups. Gated SPECT was performed using 99mTc-methoxyisobutylisonitrile with 16 frames per cardiac cycle and quantitatively analyzed by QGS software and Fourier filtering of the volume curve. The parameters of ejection fraction (EF), peak filling rate (PFR), one-third mean filling rate, and time to PFR (TPFR) were calculated. RESULTS: A slight perfusion abnormality was observed in four and five patients in the low-TSS and high-TSS groups, respectively (not statistically significant). A decreased resting EF less than 55% was found in no and two patients in the low-TSS and high-TSS groups, respectively. TPFR was 166 +/- 22, 168 +/- 38, and 216 +/- 82 ms (P = 0.05, high-TSS group versus low-TSS group; P = 0.04, control group versus high-TSS group) and TPFR/R-R interval was 0.18 +/- 0.02, 0.19 +/- 0.04, and 0.26 +/- 0.09 (P = 0.01, high-TSS group versus low-TSS group; P = 0.005, control group versus high-TSS group) for the control, low-TSS, and high-TSS groups, respectively. CONCLUSION: Diastolic function can be evaluated by gated myocardial perfusion SPECT. Significant diastolic abnormalities were shown even in patients with normal perfusion and systolic function and were related to the severity of SSc.

Coronary Circulation↗

PubMed2001

Methylxanthine sensitization of human colon cancer cells to 186Re-labeled monoclonal antibody.

UNLABELLED: Tumor cells lacking the functional p53 suppressor gene may arrest at the G2 phase of the cell cycle after exposure to ionizing radiation, resulting in increased radioresistance. Methylxanthines (MTXs), such as pentoxifylline (PTX) or caffeine (CAF), can inhibit the G2-phase checkpoint arrest of damaged cells and thus radiosensitize them. However, the effect of MTX in cells irradiated with low-dose-rate beta-emission is not well understood. METHODS: A clonogenic assay was performed with LS180 human colon cancer cells lacking the functional p53 suppressor gene. Cells were irradiated with increasing concentrations of 186Re-mercaptoacetyltriglycine (186Re-MAG3)-labeled A7 monoclonal antibody against colorectal cancer (0-925 kBq/mL) at 37 degrees C in 5% CO2 for 24 h in the presence or absence of PTX (0-2 mmol/L) or CAF (0-5 mmol/L). The enhancement ratio (ER) with MTX was calculated as a ratio of 50% cell-killing concentration of 186Re-MAG3-A7 in control cells to that in cells treated with PTX or CAF. The cell cycle distribution was analyzed with a flow cytometer. RESULTS: The concentration of 50% cell kill was 474 kBq/mL 186Re-MAG3-A7. Both PTX and CAF dose dependently enhanced the cytotoxicity of 186Re-MAG3-A7: ERs of 0.5 mmol/L PTX, 2 mmol/L PTX, 1 mmol/L CAF, and 5 mmol/L CAF were 1.50, 2.18, 1.54, and 2.63, respectively. Flow cytometry showed that the percentage nonirradiated cells in the G2/M phase of the cell cycle was 11.3% +/- 1.66%. On the other hand, cells exposed to 186Re-MAG3-A7 accumulated in the G2/M phase of the cell cycle (40.2% +/- 1.46%), which was inhibited by the presence of 1 mmol/L PTX (19.8% +/- 8.12%) or 2 mmol/L CAF (26.9% +/- 6.21%). CONCLUSION: Cellular modulation of the cell cycle with PTX and CAF radiosensitized LS180 colon cancer cells exposed to 186Re radiation.

Antibodies, Monoclonal↗

PubMed2001

(99m)Tc-sestamibi retention characteristics during pharmacologic hyperemia in human myocardium: comparison with coronary flow reserve measured by Doppler flowire.

UNLABELLED: The aim of the study was to investigate the increase in myocardial (99m)Tc-methoxyisobutylisonitrile (sestamibi) retention in humans during pharmacologic vasodilation. METHODS: For calculation of the increase in (99m)Tc-sestamibi retention during hyperemia, baseline and adenosine triphosphate (ATP)-induced hyperemic stress sestamibi studies were performed using a same-day rest-stress protocol. On the injection of sestamibi, left ventricular dynamic data were obtained for 90 s. The increase in sestamibi retention from baseline to hyperemia was calculated by the formula [abstract: see text] where Cm(h)(t) and Cm(b)(t) are myocardial counts on the tomographic image, and Cb(b)(tau) and Cb(h)(tau) are the left ventricular blood-pool counts during the first transit of sestamibi at baseline and during hyperemia, respectively. Coronary flow increase during intravenous ATP stress was measured using intracoronary Doppler flow guide wire and compared with the scintigraphic results of 28 measurements in 22 patients. RESULTS: Sestamibi retention increased as coronary flow velocity increased but plateaued at >2.5-3 times baseline flow velocity. The relationship between the increase in sestamibi retention (Y) and the increase in flow (X) is expressed as follows: Y = 0.44 + 0.60X - 0.068X(2) (r = 0.82). CONCLUSION: In humans, the increase in (99m)Tc-sestamibi myocardial retention underestimates coronary flow reserve, particularly at high flow rates. Knowledge of these tracer retention characteristics will contribute to a more comprehensive understanding of the manner and interpretation of stress sestamibi imaging.

Adenosine Triphosphate↗

PubMed2001

Accuracy of ventricular volume and ejection fraction measured by gated myocardial SPECT: comparison of 4 software programs.

UNLABELLED: Gated myocardial perfusion SPECT has been used to calculate ejection fraction (EF) and end-diastolic volume (EDV) and has correlated well with conventional methods. However, the comparative accuracy of and correlations across various types of gated SPECT software are not well understood. METHODS: Mathematic phantoms of cylindric-hemispheric hybrid models, ranging in volume from 34 to 266 mL, were generated. The clinical cases consisted of 30 patients who participated in a radionuclide angiography and gated blood-pool (GBP) study in addition to undergoing (99m)Tc-sestamibi gated SPECT. Four kinds of software, Quantitative Gated SPECT (QGS), the Emory Cardiac Toolbox (ECT), 4D-MSPECT, and Perfusion and Functional Analysis for Gated SPECT (pFAST) were used to compute EF and EDV, and the results were analyzed by multiple comparisons tests. Patients were classified into 4 groups (i.e., no defect, small defect, large defect, and small heart) so that factors affecting variation could be analyzed. RESULTS: In mathematic models > or = 74 mL, volume error was within +/-15%, whereas for a small volume (34 mL), QGS and 4D-MSPECT underestimated the volume and pFAST overestimated it. The respective intra- and interobserver reproducibility of the results was good for QGS (r = 0.99 and 1.00), ECT (r = 0.98 and 0.98), and 4D-MSPECT (r = 0.98 and 0.98) and fair for pFAST (r = 0.88 and 0.85). The correlation coefficient for EF between gated SPECT and the GBP study was 0.82, 0.78, 0.69, and 0.84 for QGS, ECT, 4D-MSPECT, and pFAST, respectively. The correlation coefficient for EDV between gated SPECT and the GBP study was 0.88, 0.89, 0.85, and 0.90, respectively. Although good correlation was observed among the 4 software packages, QGS, ECT, and 4D-MSPECT overestimated EF in patients with small hearts, and pFAST overestimated the true volume in patients with large perfusion defects. Correlation coefficients among the 4 kinds of software were 0.80-0.95 for EF and 0.89-0.98 for EDV. CONCLUSION: All 4 software programs showed good correlation between EF or EDV and the GBP study. Good correlation was observed also between each pair of quantification methods. However, because each method has unique characteristics that depend on its specific algorithm and thus behaves differently in the various patient subgroups, the methods should not be used interchangeably.

Coronary Circulation↗

PubMed2001

Phantom studies for estimation of defect size on cardiac (18)F SPECT and PET: implications for myocardial viability assessment.

UNLABELLED: SPECT with (18)F-FDG has emerged as an alternative to dedicated PET for the assessment of myocardial viability. However, whether FDG SPECT can reliably quantify the extent of viable and scarred myocardium is uncertain. The aim of this study was to investigate whether SPECT with an (18)F-labeled agent would provide information on defect size similar to that provided by dedicated PET. METHODS: Imaging was performed using an elliptic cylinder chest phantom with simulated bone, lung, mediastinum, liver, and heart. (18)F was administered into the myocardium, mediastinum, right and left ventricular cavities, and liver. Plastic inserts (n = 11) ranging in size from 2% to 60% of the myocardium were used to simulate transmural myocardial infarctions. The chest phantom was imaged with a dedicated PET camera and with a double-head SPECT camera equipped with ultra-high-energy collimators. Both SPECT and PET data were analyzed using a semiquantitative polar map approach. Defects were quantified using various cutoff thresholds ranging from 30% to 80% of peak activity and were expressed as a percentage of the left ventricular myocardium. Defect size as measured by SPECT or PET was compared with true defect size. RESULTS: The measured SPECT defect size was highly variable depending on the cutoff used, whereas PET defect size was relatively constant over the range of cutoffs tested. The mean absolute difference between measured and true defect sizes was minimal at a cutoff of 50% of peak activity for both SPECT (3.3% +/- 3.3%) and PET (2.7% +/- 2.5%). For this threshold, both SPECT and PET measurements showed an excellent correlation with true defect size (r = 0.98 for SPECT and 0.99 for PET). The correlation between SPECT and PET measurements was also excellent (r = 0.99; P < 0.01). CONCLUSION: If an appropriate threshold is used to define a defect, SPECT with an (18)F-labeled agent can accurately measure defect size similarly to the manner of PET.

Fluorodeoxyglucose F18↗

PubMed2001

[Improvement of 99mTc-pyrophosphate scintigraphy in detection of acute myocardial infarction: combined with 99mTc-tetrofosmin].

BACKGROUND: 201Tl and 99mTc-pyrophosphate (PYP) dual scintigraphy is daily used in the detection of acute myocardial infarction (AMI). However, 201Tl is not available on emergent situation. We proposed a new method for detection of AMI combined 99mTc-PYP with 99mTc-tetrofosmin (TF). METHODS: 99mTc-PYP (740 MBq) was administered to 25 patients with AMI, and 3.5 hours later, planar imaging (PYP planar) and SPECT were performed (PYP-SPECT). Immediately after cessation of PYP-SPECT, 99mTc-TF (370-740 MBq) was injected and 5 minutes later SPECT was performed in the same position (TF-SPECT). PYP-SPECT and TF-SPECT were reconstructed in the same geometric status to permit superimpose of PYP-SPECT and TF-SPECT images. Two experts and 2 beginners of nuclear medicine physician interpreted the images in three ways; PYP planar image only, PYP-SPECT, and PYP-SPECT with TF-SPECT. RESULTS: PYP-SPECT combined with TF-SPECT shows 100% detectability of the AMI lesions, which is significantly higher than other two methods in both experts and beginners. CONCLUSION: PYP-SPECT combined with TF-SPECT is a powerful method for detection of AMI.

Aged↗

PubMed2001

[Quantitative evaluation of esophageal scintigraphy in systemic sclerosis].

BACKGROUND: Esophageal involvement by systemic sclerosis (SSc) is frequent. The purpose of this study was to evaluate esophageal motility disorders quantitatively. METHODS: We investigate esophageal scintigraphy in 22 patients with SSc. Esophageal scintigraphy was obtained with swallowing physiological saline in supine position, and swallowing soup in supine and sitting positions. Data was acquired with 0.5 sec per frame for 192 frames in the anterior view. We employed a condensed image as a visual evaluation, half-life and retention rate as a quantitative evaluation, which were obtained from time-activity curves generated from regions of interest on the whole esophagus. The half-life and retention rate were compared with classification of Barnett, stages of SSc, and modified Rodnan total skin score (TSS). RESULTS: No significant differences were seen in classification of Barnett and the stages of SSc. No significant difference was seen between swallowing water and soup in the supine position. The retention rate was significantly prolonged in the supine position than in the sitting position. The retention rate of soup study in the sitting position correlated with TSS (r = 0.61). CONCLUSION: Esophageal scintigraphy in the sitting position is useful in evaluation of esophageal motility in SSc.

Adult↗

PubMed2000

Regional cerebral blood flow in male schizophrenic patients performing an auditory discrimination task.

Regional cerebral blood flow (rCBF) was measured in 11 schizophrenic patients amid 10 normal controls, both at rest and while performing an auditory discrimination task. Single photon emission computed tomography with technetium-99m hexamethylpropylene amine oxime was used for quantitative evaluation of rCBF. The schizophrenic patients showed greater rCBF in the temporal and parietal regions at rest than the controls, but no abnormalities were found in frontal perfusion. During task performance. on the other hand, the patients showed a reduced frontal rCBF. whereas there was no group difference in rCBF in the temporal and parietal regions. In addition, the left> right hemisphere asymmetries of rCBF observed in the controls during task performance were not present in the patients. although there was no group difference in hemisphere laterality in rCBF at rest. These findings suggest that the employment of a cognitive task for neuroimaging studies is useful for detecting abnormalities of brain activation. such as hypofrontality and altered hemisphere laterality. in patients with schizophrenia.

Adult↗

PubMed2000

Dye- and gamma probe-guided sentinel lymph node biopsy in breast cancer patients: using patent blue dye and technetium-99m-labeled human serum albumin.

BACKGROUND: Sentinel lymph node (SLN) biopsy is a promising method for the diagnosis of the axillary nodal status. We examined the availability of the SLN biopsy using two mapping procedures: the dye- and gamma probe-guided method, and preoperative lymphoscintigraphy by gamma camera imaging. METHODS: We enrolled 48 patients with breast cancer. Technetium-99m-labeled human serum albumin was injected into the subdermal tissue above the primary tumor or biopsy cavity, and preoperative gamma camera imaging was performed. After induction of general anesthesia, patent blue dye was injected into the peritumoral area prior to the surgical procedure. A handheld gamma-detection probe was used to assist in SLN detection. Careful dissection was performed to identify blue-stained afferent lymphatic vessels and nodes. An SLN was defined as any blue and/or radioactive node, and was excised. After SLN biopsy, axillary lymph node dissection of level I, II, and III was completed, in order to confirm the diagnostic ability of the SLN biopsy. RESULTS: Intraoperative SLN identification of axillary lesions was successful in 43 of 48 patients (90%). The dye- and gamma probe-guided method was successful in 25 patients (52%), the dye-guided method alone succeeded in 11 patients (23%), and the gamma probe-guided method alone succeeded in 7 patients (15%). Preoperative lymphoscintigraphy revealed axillary focal accumulations in 29 of 48 patients (60%). All patients who underwent successful preoperative SLN identification by lymphoscintigraphy had successful intraoperative SLN identification. A diagnostic accuracy of 95%, a sensitivity of 89%, and a specificity of 100% were achieved in the diagnosis of axillary metastasis. Internal mammary SLNs were identified in four patients intraoperatively, but we could not detect cancer metastasis in the internal mammary SLNs. CONCLUSIONS: The dye-guided and gamma probe-guided methods were complementary. Preoperative lymphoscintigraphy was useful to predict intraoperative SLN identification. Further study is necessary to assess the role of SLN biopsy of the internal mammary lymph nodes.

Adult↗

PubMed2000

Thallium-201 SPECT with triple-headed gamma camera for differential diagnosis of small pulmonary nodular lesion 20 mm in diameter or smaller.

AIM: Although thallium-201 (201Tl) has been used for the diagnosis of lung cancer, its detectability of small pulmonary nodules is not known. The aim of this study was to evaluate the ability of 201Tl SPECT for the differential diagnosis for the pulmonary nodules 20 mm in diameter or smaller. METHODS: 201Tl SPECT was performed in 31 patients suspected of having primary lung cancer. The final diagnosis was established by histology, and tumor size was 10 to 20 mm in diameter. Twenty of 31 patients had malignant tumors, including squamous cell lung cancer (n = 5), adenocarcinoma (n = 14) and small cell lung cancer (n = 1), but in none of them was there mediastinal lymphnode involvement. RESULTS: Ten of 20 malignant tumors and 1 of 11 benign lesions demonstrated significant 201Tl uptake, so that the positive predictive value, negative predictive value, sensitivity and specificity for the diagnosis of lung cancer were 90.9% (10/11), 50.0% (10/20), 50.0% (10/20) and 90.9% (10/11), respectively. CONCLUSION: These data suggest that sensitivity for detecting lung cancer 20 mm or less in diameter may be insufficient, but even in patients with small pulmonary nodules, a positive 201Tl result is highly predictive of lung cancer.

Adenocarcinoma↗

PubMed2000

Increased uptake of 99mTc-HL91 in tumor cells exposed to X-ray radiation.

99mTc-HL91, a hypoxic marker, may be a predictor of tumor response to radiotherapy and an indicator of tumor oxygenation in the course of treatment. In this study, serial changes in 99mTc-HL91 uptake were observed in the normoxic condition in a human bladder cancer cell line exposed to a single dose or a fractionated dose of 10 Gy with an x-ray beam. The uptake per cell increased during cell growth retardation induced by the irradiation. This finding indicates that 99mTc-HL91 uptake is affected by injury to cells due to radiation; it may therefore be difficult to correctly assess the tissue oxygenation status during radiotherapy with 99mTc-HL91.

Cell Division↗

PubMed2000

Detecting meningeal carcinomatosis from breast cancer with thallium-201 SPECT.

Thallium-201 (201Tl) scintigraphy is one of the imaging methods used in the detection of various tumors including brain metastasis. We evaluated a patient with meningeal carcinomatosis from breast cancer by using 201Tl single-photon emission computed tomography (SPECT). Meningeal spread of a tumor was noted on enhanced CT. SPECT revealed tumor localization in meningeal carcinomatosis. These results suggest that SPECT with 201Tl may be useful in detecting meningeal carcinomatosis from breast cancer.

Breast Neoplasms↗

PubMed2000

Gliosarcoma with thallium-201 SPECT.

Thallium-201 (201Tl) chloride scintigraphy is the imaging method use for the detection of various tumors including glioblastoma, but only limited information on 201Tl uptake in gliosarcoma is available. We investigated a patient with gliosarcoma by means of 201Tl single-photon emission computed tomography (SPECT) and MRI. SPECT imaging revealed high 201Tl uptake in the tumor, which was closely correlated with contrast-enhancement on MRI. These results suggest that SPECT with 201Tl may be useful for detecting gliosarcoma and provide physiological information on this tumor.

Adult↗

PubMed2000

Gated SPET quantification of small hearts: mathematical simulation and clinical application.

Quantification of gated single-photon emission tomography (SPET) in small hearts has been considered to be inaccurate. To evaluate the validity of gated SPET in a small chamber volume, mathematical simulation and clinical application to paediatric patients were performed. Myocardium with various chamber sizes from 14 ml to 326 ml was generated assuming an arbitrary resolution (6.9-15.7 mm in full-width at half-maximum), noise and zooming factors. The cut-off frequency of the Butterworth filter for preprocessing was varied from 0.16 to 0.63 cycles/cm. The chamber volume was calculated by quantitative gated SPET software (QGS). The patients, aged 2 months to 19 years (n=27), were studied by gated technetium-99m methoxyisobutylisonitrile or tetrofosmin SPET. Image magnification as large as possible was performed during data acquisition to include the whole chest using 1.25-2.0 zooming. Based on the simulation study, an underestimation of the chamber volume occurred below a volume of 100 ml. The degree of underestimation for a 37-ml volume was 49% without zooming, but it improved to 3% with 2x zooming. Filters with a higher cut-off frequency, better system resolution and hardware zooming during acquisition improved quantitative accuracy in small hearts. For the subjects under 7 years old (n=7), quantification of volume and ejection fraction (EF) was possible in 72% of the patients. In those over 7 years old, gated SPET quantification was feasible in all cases. The correlation between gated SPET end-diastolic volume (SPET EDV) and both echocardiographic end-diastolic dimension (EDD) and echocardiographic EDV was good (r=0.84 between SPET EDV and echo EDD, r=0.85 between SPET EDV and echo EDV, P<0.0001 for both). The correlation between gated SPET EF and both echocardiographic fractional shortening (FS) and echocardiographic EF was fair (r=0.69 between SPET EF and echo FS, r=0.72 between SPET EF and echo EF, P<0.0001 for both). In conclusion, quantification of gated SPET of small hearts can be improved by means of a SPET filter with a high cut-off frequency, high system resolution and appropriate zooming. Gated SPET should be attempted not only in patients with small hearts but also in paediatric patients.

Adolescent↗

PubMed2000

Peripheral sympathetic dysfunction in patients with Parkinson's disease without autonomic failure is heart selective and disease specific. taki@med.kanazawa-u.ac.jp.

UNLABELLED: The study was undertaken to investigate by means of iodine-123-labelled metaiodobenzylguanidine (MIBG) scintigraphy the peripheral sympathetic function in patients with Parkinson's disease (PD) without autonomic failure and in patients with related neurodegenerative diseases with parkinsonism. Seventy patients (33 men and 37 women, mean age 63+/-9.7 years) with parkinsonism and ten control subjects underwent MIBG scintigraphy. Of these 70 patients, 41 were diagnosed as having idiopathic PD, 9 multiple system atrophy (MSA), 6 progressive supranuclear palsy (PSP) and 2 corticobasal degeneration (CBD); the remaining 12 were diagnosed as having neurodegenerative disease with parkinsonism (P-nism) that did not meet the diagnostic criteria of any specific disease. Cardiac planar and tomographic imaging studies and subsequent whole-body imaging were performed 20 min and 3 h after the injection of 111 MBq MIBG. The early MIBG heart to mediastinum (H/M) ratio in PD (1.61+/-0.29) was significantly lower than that in the control group (2.24+/-0.14, P<0.01), P-nism (2.15+/-0.31, P<0.01), MSA (2.08+/-0.31, P<0.05) and PSP (2.30+/-0.24, P<0.01). The delayed H/M ratio in PD (1.47+/-0.34) was also significantly lower than that in the control group (2.37+/-0.14, P<0.01), P-nism (2.13+/-0.38, P<0.01), PSP (2.36+/-0.36, P<0.01) and MSA (2.17+/-0.36, P<0.01). In patients with PD, early and delayed H/M ratios were significantly decreased in disease stages I, II and III (established using the Hoehn and Yahr criteria) as compared with control subjects, and there were no significant differences among the stages. Only PD showed a significantly higher washout rate (WR) than that in the control subjects (27%+/-8.0% vs. 11%+/-4.2%, P<0.01). Early and delayed uptake ratios of the lung, parotid gland, thyroid gland, liver and femoral muscles in each of the patient groups were not significantly different from those in control subjects. Only the early and delayed uptake ratios of the lower leg muscles in MSA were significantly lower than those in the control group (P<0.05). IN CONCLUSION: In patients with PD without autonomic failure, only cardiac MIBG uptake was severely reduced in the earliest phase of the disease (stage I). Parkinsonian syndromes other than PD did not demonstrate significant reduction in MIBG uptake in any organs except for the lower legs in MSA. In patients with PD without autonomic failure, reduction in MIBG uptake occurs selectively in the heart; this is considered to be a specific finding for PD and useful for the differential diagnosis of the parkinsonian syndromes.

3-Iodobenzylguanidine↗