Prediction of final tumor response to preoperative chemotherapy by Tc-99m MIBI imaging at the middle of chemotherapy in malignant bone and soft tissue tumors: comparison with Tl-201 imaging.

The aim of this study was to assess the predictive power of 99mTc-MIBI scintigraphy performed in the middle of chemotherapy, for the final tumor response to chemotherapy, and compare it to that of (201)Tl in malignant bone and soft tissue tumors (MBST). Sixty-eight patients with MBST underwent 99mTc-MIBI and 201Tl scintigraphies at 15 min after tracer injection before the first, and after the third, chemotherapy cycles. After five cycles of chemotherapy and tumor resection, therapeutic effect was assessed by histopathology. Less than 90% and > or =90% necrosis were judged as poor and good response to chemotherapy, respectively. Tracers uptake ratios were calculated by dividing the lesion count density by that of the background. 99mTc-MIBI perfusion index was also calculated. The % reduction of the perfusion index (DeltaPI) and uptake ratios (DeltaUR) calculated by 100 x [(prechemotherapy value--postchemotherapy value)/prechemotherapy value] were compared with histologic response. The sensitivity, specificity, and accuracy for the prediction of effective chemotherapy in 99mTc-MIBI imaging were 80%, 95%, 88% in DeltaUR, and 74%, 74%, 74% in DeltaPI, respectively. The area under the receiver operator characteristic curve (A(z)) of the 99mTc-MIBI-DeltaUR (0.923) was significantly higher than that of DeltaPI (0.809, p = 0.025) but only marginally higher than that of the 201Tl-DeltaUR (0.865, p = 0.079). A(z) in 201Tl (0.865) was not significantly different from that of DeltaPI (0.809, p = 0.35). 99mTc-MIBI imaging performed in the middle of chemotherapy well predicts the final tumor response to chemotherapy in patients with malignant bone and soft tissue tumors.

Intraperitoneal radioimmunotherapy to treat the early phase of peritoneal dissemination of human colon cancer cells in a murine model.

BACKGROUND AND AIM: In patients with a high risk of peritoneal dissemination of colon cancer, a treatment adjuvant to surgical resection would improve their prognosis. We aimed to determine whether radioimmunotherapy employing radiolabelled monoclonal antibody would work in this situation. METHODS: A murine model of peritoneal dissemination was established in female Balb/c nu/nu mice by intraperitoneal injection of LS180 human colon cancer cells. Radioimmunotherapy with 7.4 MBq of a murine IgG1, anti-colorectal A7 monoclonal antibody, radiolabelled with (131)I by the chloramine-T method was conducted intraperitoneally on days 0, 3, 7 and 14 after cell inoculation, respectively. RESULTS: Radioimmunotherapy at any timing improved survival of mice as compared with those of non-treated mice and mice treated with a daily dose of 30 mg x kg(-1) of 5-fluorouracil for 4 consecutive days. The best improvement was obtained when radioimmunotherapy was conducted on day 0. CONCLUSION: These results indicate that intraperitoneal radioimmunotherapy may effectively kill colon cancer cells disseminated in the peritoneal cavity before formation of tumours and, therefore, may work as an adjuvant treatment to prevent peritoneal metastasis of colon cancer.

Myocardial damages in systemic sclerosis detected by gated myocardial perfusion SPECT and sympathetic imaging.

BACKGROUND: Cardiac involvement is an important factor for the appropriate management of systemic sclerosis (SSc). The possibility for detecting early myocardial damage was investigated using (99m)Tc methoxyisobutylisonitrile (MIBI) gated perfusion single photon emission computed tomography (SPECT) and (123)I metaiodobenzylguanidine (MIBG) sympathetic imaging. METHODS AND RESULTS: Twenty-three patients with SSc and 14 control subjects were studied. The severity of SSc was defined by disease type and semi-quantitative skin thickness scores. A myocardial perfusion study was performed using (99m)Tc MIBI exercise--rest study, and systolic and diastolic parameters were calculated from the volume curve of the gated SPECT. (123)I MIBG was evaluated by segmental defects, a heart-to-mediastinum ratio and washout rate (WR). No significant exercise-induced ischemia was observed and the left ventricular ejection fraction was within normal range in patients with SSc. However, diastolic function calculated by time to peak filling (TPF) in the early diastole was significantly prolonged in SSc compared with the control group (184+/-35 ms, 160+/-25 ms, p=0.030) and more rapid MIBG WR from the myocardium (18.2+/-7.0% vs 11.1+/-4.3%, p=0.0015). Compared with the control group, the severe group with either diffuse SSc or a skin thickness score >or=10 had more prolonged TPF/RR interval than the less severe group. Both diastolic and sympathetic abnormalities were observed in 7 (30%) patients, and 1 abnormality in 17 (74%) patients with SSc. CONCLUSIONS: In patients with SSc, either diastolic dysfunction or sympathetic derangement, or both were observed even without induced ischemia and normal ventricular contractility. Based on these subclinical early findings, further follow-up studies are recommended.

Fluctuation of adenosine concentration by modes of intravenous infusion based on mathematical simulation and experiments.

OBJECTIVE: Adenosine, which has been used for a myocardial perfusion scan, shows rapid clearance from blood because of its short half-life of <10 seconds. This simulation study evaluates influences of modes of radionuclide injection on ventricular adenosine concentration when one intravenous injection line is used. METHODS: Assuming that radionuclide injection is a unit impulse, time-activity curves were measured in the left ventricle (LV) and fitted by a gamma function. Typical patterns of concentration fluctuation when adenosine infusion was temporarily modified were calculated by the convolution integral of input function and unit impulse response. Variation of concentration was measured by experiments using continuous 99mTc injection and co-infusion of water via a three-way stopcock. Modes of co-infusion with various infusion speeds and volumes were examined. RESULTS: Intermission of adenosine infusion and rapid displacement by radionuclide co-injection significantly influenced the adenosine concentration in LV. Intermission of adenosine infusion for 2 seconds caused a 15% decrease in the adenosine concentration in the left ventricle. When a square-shaped input was assumed, a three-fold higher concentration of adenosine for 3 seconds created by radionuclide injection resulted in a +42% increase in the LV concentration. Based on a measured input function, radionuclide injection using three-way stopcock through one route caused a two- to three-fold increase in the steady concentration in the vein just after injection. When 0.5 ml of radionuclide was slowly co-injected, with three ways opened, it caused a relatively low fluctuation, creating a +34% to -47% change in concentration of LV. A flush of radionuclide with physiological saline significantly increased the adenosine concentration in LV, when short half-lives were assumed. CONCLUSION: An intravenous adenosine and radiopharmaceutical injection in the same line is feasible. However, the fluctuation of concentration depends significantly on the mode of injection. To minimize the fluctuation, a slow injection of a small volume of a myocardial imaging agent via a co-injection route, with three ways opened, is recommended.

Respiratory distress caused by radioiodine therapy in patients with differentiated thyroid cancer.

Respiratory distress accompanied by stridor is an uncommon complication of 131I radioiodine therapy for differentiated thyroid cancer that occurs within 48 hours of treatment. This report presents three cases with papillary thyroid carcinoma in which 131I therapy caused this acute complication. One of them had no apparent risk for this complication such as the existence of remnant thyroid tissue or laryngeal problems before the treatment. These cases remind physicians that 131I therapy is not a simple, riskless procedure.

99mTc-sestamibi to monitor treatment with antisense oligodeoxynucleotide complementary to MRP mRNA in human breast cancer cells.

OBJECTIVE: Technetium-99m sestamibi (MIBI) has been utilized to evaluate multi-drug resistance (MDR) phenomenon of malignant tumors and to predict chemotherapeutic effects on them. The current investigation examined the possibility of monitoring changes with respect to mRNA expression of multi-drug resistance associated protein (MRP) following antisense oligodeoxynucleotide (AS-ODN) treatment involving 99mTc-MIBI. METHODS: The human breast cancer MCF-7 cell line and its MDR-induced MCF-7/VP cell line were employed. Cell suspensions of the two cell lines at 1 x 10(4) cells/ml were inoculated in 24-well plates (0.2 ml/well) and incubated for one day. Antisense (AS) 20-mer phosphorothioate ODN complementary to the coding region of MRP mRNA and its sense (S) ODN were administered at final concentrations up to 25 microM, followed by a 5-day incubation. 99mTc-MIBI solution was added to each well and incubated for 30 min. Cellular 99mTc-MIBI uptake was corrected for protein concentration. MRP mRNA expression levels were analyzed via the reverse transcription polymerase chain reaction (RT-PCR). RESULTS: Cellular uptake of 99mTc-MIBI in MCF-7/VP cells was only 15% of that of MCF-7 cells. Following AS-ODN treatment at 25 microM for five days, 99mTc-MIBI uptake in MCF-7/VP cells increased 2.4-fold in comparison with non-treated control cells. 99mTc-MIBI uptake in MCF-7 cells was unaffected by AS-ODN administration. Sense ODN did not alter uptake in either cell line. RT-PCR confirmed reduction of MRP mRNA in MCF-7/VP cells following AS-ODN treatment. CONCLUSION: Effects of AS-ODN administration on MRP function can be monitored via assessment of cellular uptake of 99mTc-MIBI.

Effect of left ventricular function on diagnostic accuracy of FDG SPECT.

OBJECTIVES: Fluorine-18 fluorodeoxyglucose (FDG) SPECT has emerged as an alternative to dedicated PET imaging. However, it remains uncertain whether FDG SPECT is an as accurate for viability assessment as FDG PET in patients with severely reduced left ventricular function. The aim of the study was to assess the diagnostic accuracy of FDG SPECT in a head-to-head comparison with FDG PET, and divide the patients according to the severity of left ventricular dysfunction. METHODS: A total of 47 patients, with a history of myocardial infarction underwent FDG/perfusion (99mTc-sestamibi or 201Tl) SPECT as well as FDG/13N-ammonia PET. The patients were divided into 2 subgroups based on the left ventricular ejection fraction (LVEF) (35% cutoff). The left ventricular myocardium was divided into 13 segments, and each segment was classified as viable or scar using a semi-quantitative scoring system based on defect severity and the presence or absence of perfusion-FDG mismatch. RESULTS: Of the 47 patients studied, 23 had LVEF < 35% (low LVEF group; mean 25 +/- 7%), whereas the remaining 24 had LVEF > or = 35% (high LVEF group; mean 47 +/- 6%). In the low LVEF group, 213 segments (71%) were dysfunctional, as compared to 102 (33%) in the high LVEF group. The agreement for detection of viability between PET and SPECT in the low LVEF group was 82% (kappa 0.63), which was not different from the agreement in the high LVEF group (85%, kappa 0.66, p = 0.42 versus low LVEF group). CONCLUSIONS: The results indicate that FDG SPECT can be used for tissue viability assessment regardless of the severity of left ventricular dysfunction.

Binding with serum components favorably affects cellular uptake of 111In-oligonucleotide in a leukemia cell line.

PURPOSE: The influence of serum components on the intracellular uptake of an 111In-oligonucleotide (ODN) against mdr1 mRNA was investigated in the murine leukemia cell line, P388/S, and its mdr1-overexpressed P388/R. METHODS: 111In-ODNs naked and vectorized with lipids were analyzed for binding with serum components using high-performance liquid chromatography (HPLC). 111In-ODN was incubated in albumin and transferrin solutions. 111In-DTPA and 111In-mononucleotide were incubated in serum. Degradation of naked 111In-ODN was detected in phosphate buffered saline (PBS) and serum containing endonuclease S1. Cellular uptakes of naked and vectorized 111In-ODN in the above cells were examined with and without fetal calf serum (FCS). RESULTS: Time-dependent binding of naked and vectorized 111In- ODN with serum components was observed throughout 24 hours. Transchelation of 111In to transferrin was not detected. HPLC profiles of 111In-DTPA and 111In-mononucleotide did not change in serum. Degradation of 111In-ODN by S1 was less remarkable in serum than in PBS. Specific accumulation of vectorized 111In-ODN in P388/R cells was achieved in culture with and without 10% FCS. CONCLUSIONS: This study verified the intense binding of ODN with serum components, leading to no inhibition on ODN intracellular specific uptake. Binding with serum components protects 111In-ODN from degradation by endonuclease and thus may facilitate ODN transmembrane delivery.

Anti-angiogenic therapy and chemotherapy affect 99mTc sestamibi and 99mTc-HL91 accumulation differently in tumour xenografts.

BACKGROUND: Favourable effects of cytotoxic chemotherapy for tumours are characterized by the reduced accumulation of radiotracers such as 99mTc sestamibi (MIBI). Anti-angiogenic therapy is primarily cytostatic; consequently, its influence on tracer accumulation may differ from that of cytotoxic treatments. METHODS: Anti-angiogenic therapy employing 2-methoxyestradiol was administered in mice bearing subcutaneous xenografts of LS180 colon cancer cells. The effects of chemotherapy with 5-fluorouracil were examined as a cytotoxic counterpart. Treatments were conducted for 4 days from day 8. Distribution of 99mTc-MIBI and Tc-HL91, a hypoxic marker, was observed on days 8 and 12. Oxygen tension (PO2) in tumours was measured by a microelectrode. Cellular uptake of tracers was examined in vitro in normoxic and hypoxic conditions. RESULTS: 99mTc-MIBI accumulation decreased with increasing tumour weight when no treatment was conducted. Tumour growth was suppressed by anti-angiogenic therapy and chemotherapy. 99mTc-MIBI accumulation in tumours decreased after chemotherapy as compared to pre-therapeutic values, whereas accumulation of 99mTc-HL91 increased. In contrast, accumulation of tracers did not significantly change after anti-angiogenic therapy as compared to that observed pre-therapeutically. Tumour PO2 decreased with increasing tumour volume when no treatment was conducted. Chemotherapy reduced PO2 in tumours. PO2 in tumours treated with anti-angiogenic therapy was as high as that observed before treatment. 2-Methoxyestradiol or 5-fluorouracil did not significantly affect tracer accumulation in cells under both normoxic and hypoxic conditions in vitro. CONCLUSION: These findings indicate that scintigraphic assessment of therapeutic efficacy of anti-angiogenic therapy should be performed from a perspective distinct from that of cytotoxic treatment.

Dual-radionuclide simultaneous gastric emptying and bile transit study after gastric surgery with double-tract reconstruction.

OBJECTIVE: The physiology of gastrointestinal transfer function after proximal gastrectomy with bypass-tract reconstruction is not well understood. We applied a simultaneous dual-radionuclide method with a hepatobiliary imaging and gastric emptying study to evaluate physiologic alterations occurring after surgery. METHODS: Nineteen patients with early gastric cancer, including 9 preoperative control patients and 10 who had proximal gastrectomy and double-tract reconstruction surgery were examined by dual-radionuclide hepatobiliary and gastric emptying studies (99mTc PMT and 111In DTPA). Retention fraction in the stomach at 3 minutes (R3) and 60 minutes (R60) and gastric emptying half-time (GET) were calculated. Bile reflux and mixture of bile and food were also evaluated. RESULTS: The retention fractions of R3 and R60 were significantly lower in the double-tract reconstruction group than those in the preoperative group. GET differed significantly between the double-tract and preoperative groups (20.7 min +/- 7.1 min and 36.2 min +/- 11.0 min, p = 0.0018). The mixture of bile and food was not good in the double-tract reconstruction group (p = 0.014 vs. preoperative). Patients with a large residual stomach showed slower initial emptying (p = 0.0068) and a better mixture of bile and food (p = 0.058) compared to those with a small residual stomach. The bile reflux was not significantly increased after surgery. CONCLUSION: The dual-radionuclide gastrointestinal and hepatobiliary imaging was feasible and could demonstrate characteristic transit patterns of the foods and bile in the double-tract reconstruction procedure. A larger residual stomach, if possible, is desirable to provide better transfer and mixing of bile and foods.

Fusion of SPECT and multidetector CT images for accurate localization of pelvic sentinel lymph nodes in prostate cancer patients.

OBJECTIVE: The present study was performed to investigate the feasibility of fusion of images obtained by SPECT and multidetector CT (MDCT) for the accurate localization of sentinel lymph nodes in prostate cancer patients. METHODS: To facilitate the fusion of both SPECT and CT images, a pelvic MDCT scan was performed with 3 markers of small plastic bullets attached to the skin over the bilateral iliac crests and the ventral midline at the same height. SPECT was performed after the same locations were marked with needle caps containing (99m)Tc-pertechnetate. The images were superimposed by use of free software (MRIcro). The results of hot lymph node detection with fusion images were compared with those of surgery. RESULTS: The images could be successfully superimposed for all 11 patients examined. Surgeons accurately confirmed 27 (87.1%) of 31 regional lymph nodes on fusion images. CONCLUSION: Fusion of SPECT and MDCT images is useful for the precise localization of sentinel lymph nodes in prostate cancer patients.

Accuracy of cardiac PET imaging using post-injection transmission scan.

UNLABELLED: The purpose of this study was to investigate the accuracy of cardiac PET with post-injection transmission scans. METHODS: We performed a phantom study using 18F solution as well as 13N-ammonia PET study of ten patients. The average activities of no myocardial defect phantom model were estimated, and myocardial defect sizes of 12 phantom models were measured by pre- and post-injection transmission methods at various 18F activities. In 13N-ammonia PET at rest and during adenosine triphosphate (ATP) stress studies, measured defect sizes were compared between both methods. RESULTS: The ratios of average activity estimated by both methods (post/pre value) were almost 1.00 at each 18F activity and segment. Measured defect sizes by both methods showed an excellent correlation with true defect sizes (r = 0.98, p < 0.01 for pre vs. true value: r = 0.98, p < 0.01 for post vs. true value). The mean absolute errors of measurements were minimal up to 3.5% LV, and were similar between both methods. In 13N-ammonia PET, measured defect sizes by both methods also showed a good correlation (r = 0.97, p < 0.01). CONCLUSION: The results indicate that cardiac PET imaging with post-injection transmission scan provides information on myocardial tracer activity as well as myocardial defect size as does conventional pre-injection transmission method.

Characterization of cartilaginous tumors with 201Tl scintigraphy.

UNLABELLED: Histological diagnosis and grading of cartilaginous tumors are closely correlated with patient prognosis; consequently, they are essential elements. We attempted to clarify the characteristics of 201Tl uptake in various histological types of cartilaginous tumors and to assess its clinical value. METHODS: Twenty-two cases with histologically proven cartilaginous tumors (3 enchondromas, 15 conventional chondrosarcomas (grade I = 9, II = 5, III = 1), 3 mesenchymal chondrosarcomas, and 1 de-differentiated chondrosarcoma) were examined retrospectively. Planar 201Tl images were recorded 15 min following intravenous injection of 201Tl (111 MBq). 201Tl uptake in the tumor was evaluated visually employing a five-grade scoring system: 0 = no appreciable uptake, 1 = faint uptake above the background level, 2 = moderate uptake, 3 = intense uptake but lower than heart uptake and 4 = uptake higher than heart uptake. RESULTS: 201Tl uptake scores were 0 in 3 of 3 enchondromas, 9 of 9 grade I, and 4 of 5 grade II conventional chondrosarcomas. 201Tl uptake scores were 1 among 1 of 5 grades II and a grade III conventional chondrosarcoma. Mesenchymal chondrosarcoma and de-differentiated chondrosarcoma displayed 201Tl uptake scores of 2 or 3. CONCLUSIONS: Absence of elevated 201Tl uptake in cartilaginous tumors was indicative of enchondroma or low-grade conventional chondrosarcoma. However, in instances in which 201Tl uptake is obvious, high-grade chondrosarcoma or variant types should be considered.

Locoreginal radioimmunotherapy with 186Re-labeled monoclonal antibody in treating small peritoneal carcinomatosis of colon cancer in mice in comparison with 131I-counterpart.

The efficacy of locoregional radioimmunotherapy (RIT) in treating peritoneal tumors of colon cancer of <2 mm in diameter was examined at maximum tolerated doses, focusing the comparison between 186Re and 131I labeled to an anti-colorectal cancer IgG1. Estimated radiation doses to tumors were considerably higher with 186Re-RIT than with 131I-RIT. The advantage of 186Re-RIT decreased with decreasing tumor size, but 186Re-RIT delivered 1.6-times higher radiation to tumors of 1 mm. Consequently, 186Re-RIT attained better survival of mice than 131I-RIT or chemotherapy with 5-fluorouracil did. Therefore, locoregional 186Re-RIT may be an option in an adjuvant setting of colon cancer with high risk of peritoneal dissemination.

Time course of discordant BMIPP and thallium uptake after ischemia and reperfusion in a rat model.

UNLABELLED: Serial changes in fatty acid metabolism or use associated with acute ischemia and reperfusion were examined in rat hearts. METHODS: Male Wistar rats were subjected to occlusion of the left coronary artery for 20 min followed by reperfusion. After release of the occlusion, groups of animals were allowed to recover for intervals of 20 min (n = 9), 1 d (n = 9), 3 d (n = 6), 7 d (n = 6), or 30 d (n = 6). Hearts were excised 15-20 min after injection of 0.74 MBq of (125)I-15-(p-iodophenyl)-3-R,S-methylpentadecanoic acid (BMIPP) and 14.8 MBq of (201)Tl. One minute before resection, the left coronary artery was reoccluded and 185 MBq of (99m)Tc-sestamibi were injected to document the area at risk. Triple-tracer autoradiography was performed to assess tracer uptake. Uptake ratios of BMIPP and (201)Tl in the area at risk were calculated on the basis of the count density in the lesion divided by that in the normally perfused area. RESULTS: (201)Tl uptake did not change throughout the observation period (P = 0.25). In contrast, BMIPP uptake increased early in the acute phase (20 min and 1 d), decreased during the subacute phase (7 d), and subsequently recovered in the chronic phase (30 d). CONCLUSION: The present investigation clearly illustrated that BMIPP uptake is higher than (201)Tl uptake in the acute phase, that BMIPP uptake is lower than (201)Tl uptake in the subacute phase, and that BMIPP uptake and (201)Tl uptake are similar in the chronic phase. These results yield data essential to the precise interpretation of BMIPP images.

Electrocardiographic-gated dual-isotope simultaneous acquisition SPECT using 18F-FDG and 99mTc-sestamibi to assess myocardial viability and function in a single study.

PURPOSE: Dual-isotope simultaneous acquisition single-photon emission computed tomography (DISA SPECT) with 18F-fluorodeoxyglucose (FDG) and (99m)Tc-sestamibi appears attractive for the detection of viable myocardium because it permits simultaneous assessment of glucose utilisation and perfusion. Another potential benefit of this approach is that the measurement of left ventricular (LV) function may be possible by ECG gating. The aim of this study was to test the hypothesis that both myocardial viability and LV function can be assessed by a single ECG-gated 18F-FDG/(99m)Tc-sestamibi DISA SPECT study, based on comparison with 18F-FDG/13N-ammonia positron emission tomography (PET) and magnetic resonance imaging (MRI) as reference techniques. METHODS: Thirty-three patients with prior myocardial infarction underwent ECG-gated 18F-FDG/(99m)Tc-sestamibi DISA SPECT and 18F-FDG/13N-ammonia PET on a single day. Of these, 25 patients also underwent cine-MRI to assess LV function. The LV myocardium was divided into nine regions, and each region was classified as viable or scar using a semiquantitative visual scoring system as well as quantitative analysis. The global and regional LV function measured by gated SPECT was compared with the results of MRI. RESULTS: There was good agreement in respect of viability (90-96%, kappa 0.74-0.85) between DISA SPECT and PET by either visual or quantitative analysis. Furthermore, although both global and regional LV function measured by gated SPECT agreed with those by MRI, (99m)Tc-sestamibi showed a closer correlation with MRI than did 18F-FDG. CONCLUSION: In conclusion, ECG-gated DISA SPECT provides information on myocardial viability, as well as global and regional LV function, similar to that obtained by PET and MRI.

Failure of radioiodine treatment in Graves' disease intentionally caused by a patient: suspected Munchausen syndrome.

We experienced a case with Graves' disease in which radioiodine treatment failed probably because of intentional spitting out of capsules of radioactive iodide. Chemical analysis of the substances collected from the trash in the treatment room demonstrated that its profile was the same as that of the capsules for radioiodine administration. Measurement of the iodine concentrations in a blood sample obtained at 24 h after the administration of radioiodine indicated that the patient showed iodine excess. These findings suggest that this may be a case of Munchausen syndrome.

Significance of 123I-MIBG scintigraphy as a pathophysiological indicator in the assessment of Parkinson's disease and related disorders: it can be a specific marker for Lewy body disease.

Recently, reliable and clear evidence for the usefulness of 123I-MIBG scintigraphy in the diagnosis of Parkinson's disease (PD) has been accumulated and it has become increasingly popular as one of the most accurate means of diagnosing the disease. PD, one of the most common neurodegenerative disorders, is characterized by resting tremor, rigidity, bradykinesia or akinesia, and postural instability. The disease is characterized pathologically by distinctive neuronal inclusions called Lewy bodies in many surviving cells of dopaminergic neurons of the substantia nigra pars compacta and other specific brain regions. Furthermore Lewy body type degeneration in the cardiac plexus has been observed in PD. In PD, cardiac MIBG uptake is reduced markedly even in the early disease stages; therefore, MIBG imaging can be used as an indicator of the presence of PD rather than disease severity. Other parkinsonian syndromes such as multiple system atrophy, progressive supranuclear palsy, and corticobasal degeneration demonstrate normal cardiac MIBG uptake or only mild reduction of MIBG uptake, indicating that MIBG imaging is a powerful method to differentiate PD from other parkinsonian syndromes. Dementia with Lewy bodies (DLB) also shows severe reduction of MIBG uptake, whereas Alzheimer's disease (AD) demonstrates normal MIBG uptake, permitting differentiation of DLB from AD using MIBG scintigraphy. In pure autonomic failure, which shares similar pathological findings with PD and is thought to be associated with diffuse loss of sympathetic terminal innervation, cardiac MIBG uptake also decreases markedly. Considering all the data together, marked reduction of cardiac MIBG uptake seems to be a specific marker of Lewy body disease and thus extremely useful in the differentiation from other diseases with similar symptoms without Lewy bodies.

Left ventricular ejection and filling rate measurement based on the automatic edge detection method of ECG-gated blood pool single-photon emission tomography.

UNLABELLED: The objective of the present investigation was to determine the feasibility of assessing left ventricular systolic ejection and diastolic filling via the automatic edge detection method employing ECG-gated blood pool single-photon emission tomography (SPET GBP) data. METHODS: Thirty-five patients, who had undergone both SPET GBP and ECG-gated equilibrium blood pool scintigraphy by the planar method (planar GBP), were enrolled in this study. Planar GBP was performed with a single-headed gamma camera. From the left anterior oblique projection, data were acquired at 24 frames/cardiac cycle with ECG-gating during the equilibrium state. SPET GBP was conducted utilizing a triple-headed gamma camera, with 60 projection views over 360 degrees by 60 sec per view, in 16 frames/cardiac cycle. In each frame, left ventricular volume was determined by automatic edge detection employing a quantitative gated SPET program. Additionally, the time-volume curve was fitted by the 4th harmonics of Fourier transform. Ejection fraction (EF, %), peak ejection rate (PER, /sec), peak filling rate (PFR, /sec) and mean filling rate during the initial one-third of diastolic time (1/3 FRm) were calculated from the fitted curve. These parameters were also calculated with planar GBP data. RESULT: Left ventricular ejection and filling parameters were calculated by SPET GBP with the automatic edge detection program for all patient data. Correlation coefficients of EF, PER, PFR and 1/3 FRm between SPET and planar GBP were 0.91 (p < 0.001), 0.82 (p < 0.001), 0.78 (p < 0.001) and 0.74 (p < 0.001), respectively. CONCLUSION: Ejection and filling rates can be calculated using SPET GBP with the edge-detection software. These parameters displayed significant correlations with those values obtained via planar GBP. Additional studies are warranted to determine the reliability of parameters with SPET GBP.