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ABSTRACT: Objective: The purpose of this study is to evaluate effect of attenuation correction technique on18F-fluoride positron emission tomography (PET).Methods: We performed PET scans after the injection of 185 MBq18F-fluoride on 32 patients from October 20th, 2004 to April 13th, 2005. We calculated bone-to-muscle ratios for the images
with and without attenuation correction. We placed regions of interest (ROIs) on normal bone accumulation in 22 patients.
The exclusion criteria were bone metastasis, Paget's disease, and rheumatoid arthritis. Several regions were chosen for ROI
placement: skull, cervical vertebra, mandible, scapula, thoracic vertebra, rib, humerus, lumbar vertebra, radius, ulna, pelvis,
femoral head, femoral shaft, tibia, and fibula. The count ratios of normal bones to gluteus muscle were calculated as bone-to-muscle
ratios. The count ratios of abnormal skeletal lesions to gluteus muscles were calculated as bone-to-muscle ratios, while the
count ratios of abnormal skeletal lesions to normal bones were calculated as bone-to-bone ratios.Results: PET images without attenuation correction showed significantly higher mean bone-to-muscle ratios than those with attenuation
correction (p<0.05) for all normal bones except the femoral head and lumbar vertebrae. For abnormal bones, bone-to-muscle
ratios without attenuation correction were significantly higher than those with attenuation correction (p<0.005). The same
statistical significance was found for bone-to-bone ratios (p<0.005).Conclusions: The attenuation correction technique is not necessary to conduct the visual interpretation of18F-fluoride PET images. The bone-to-muscle ratio analysis without attenuation correction may be of use to differentiate malignant
from benign disease processes.
Annals of Nuclear Medicine 04/2012; 21(2):93-99. · 1.50 Impact Factor
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Yohei Yamakawa, Nobukazu Takahashi,
Toshiyuki Iswkawa,
Kazuaki Uchino,
Yasuyuki Mochida,
Toshiaki Ebina,
Tsukasa Kobayashi,
Kohei Matsushita,
Katsumi Matsumoto,
Noriko Kawasaki,
Mie Shimura,
Yasuo Ohkusu,
Shinichi Sumita,
Kazuo Kimura,
Tomio Inoue,
Satoshi Umemura
[show abstract]
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ABSTRACT: ObjectivesThis study sought to evaluate an imaging approach using gated99mTc-MIBI (MIBI) SPECT and gated18F-FDG (FDG) PET for assessment of myocardial viability and cardiac function.
MethodsForty-eight patients (38 men, mean age 68.1 ± 9.6 years) underwent ECG-gated FDG PET and MIBI SPECT within a week. The baseline
diagnoses were coronary artery disease (31), mitral regurgitation (1), paroxysmal arrhythmia (10), and dilated cardiomyopathy
(6). The gated FDG PET data were analyzed using pFAST software, and the gated MIBI SPECT data were analyzed using QGS software.
Fifteen patients were diagnosed with myocardial infarction, and follow-up study was performed to assess the functional outcome
four months later. An improvement in LVEF of >5% was defined as significant. The LV myocardium was divided into 17 segments,
and regional defect scores were visually assessed using a 4-point scale for each segment (0 = normal, 1 = mildly reduced,
2 = moderately reduced, 3 = absent). A segment with a greater defect score on MIBI SPECT than on FDG PET was defined as a
mismatch. The patients were divided into two groups: those with at least two mismatched segments (MM-group), and those with
none or one (M-group).
ResultsLVEF, EDV and ESV measured by gated FDG PET were highly correlated with those obtained by gated MIBI SPECT (r = 0.848, 0.855
and 0.911, p < 0.0001, respectively). The mean values of LVEF did not differ significantly, but EDV and ESV obtained by gated
FDG PET were significantly grater than those obtained by gated MIBI SPECT (p < 0.0001). In 15 patients diagnosed with myocardial
infarction, a significant association (p < 0.05) was found between the relative uptake of FDG PET and MIBI SPECT and the functional
outcome 4 months later. Global LV function improved in 6 of the 8 patients showing mismatch but in only 1 of the 7 patients
with matched defects, resulting in a sensitivity of 86% and specificity of 75%. The overall accuracy to predict global functional
outcome was high (80%).
ConclusionThis imaging approach allows accurate evaluation of myocardial viability. Furthermore, the high correlations of gated FDG
PET and gated MIBI SPECT measurements hold promise for the assessment of left ventricular function using gated FDG PET.
Annals of Nuclear Medicine 04/2012; 18(5):375-383. · 1.50 Impact Factor
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ABSTRACT: Certain small-molecule inhibitors that target epidermal growth factor receptor (EGFR), such as Gefitinib, Erlotinib, and Lapatinib, provide a new approach for cancer treatment. In accordance with the pharmacophore model for inhibitor competition at EGFR-binding site, this study proposes a rationalized design for a novel 4-anilinoquinoline EGFR tyrosine kinase inhibitor, [6,7-dimethoxyethoxy]-quinolin-4-yl]-(3-ethynylphenyl)-amine (YCU07). This is the first study to apply ring-closing metathesis toward synthesis of the quinoline nucleus for this 4-anilinoquinoline EGFR inhibitor. YCU07 expressed significant inhibitory activity for EGFR tyrosine kinase in A431 cells, as confirmed by an ABTS microwell peroxidase substrate system read colorimetrically at 405 nm. Injection of (68)Ga-labeled glutamic acid polypeptide (GAP)-YCU07 conjugate in nude mice implanted with A431 was imaged by animal PET camera (LabPET8; Gamma Medica-Ideas) and computed tomography (eXplore Locus; GE Healthcare), to evaluate its biodistribution. (68)Ga-GAP-YCU accumulated in the receptor-positive tumors, with uptake values of 1.50% +/- 0.09% and 2.36% +/- 0.36% of injected activity per gram tissue at 30 and 90 minutes, respectively.
Cancer Biotherapy & Radiopharmaceuticals 08/2010; 25(4):479-85. · 1.44 Impact Factor
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ABSTRACT: Chronic kidney disease is a noteworthy pathophysiology as a risk factor of cardiovascular disease. We investigated the usefulness of combining glomerular filtration rate and 201thallium(201TI)/123iodine-beta-methyliodophenyl pentadecanoic acid (123I-BMIPP) dual myocardial scintigraphic findings for predicting cardiac events.
Seventy-five patients suspected of coronary artery disease underwent 201TI/123I-BMIPP dual myocardial scintigraphy. Clinical and nuclear variables were included in the multivariate analysis for predicting hard events (cardiac death and nonfatal myocardial infarction) and soft events (unstable angina, heart failure, and coronary revascularization). Glomerular filtration rate was estimated by the modification of diet in renal disease formula. Kaplan-Meier analysis was performed to investigate the incremental prognostic value of glomerular filtration rate.
During the mean follow-up period of 425 days, eight patients had hard events and 20 patients had soft events. Multivariate analysis revealed that glomerular filtration rate and the sum of total defect score in 123I-BMIPP image were independent predictors of total cardiac events, whereas sex, diabetes, glomerular filtration rate, and the number of abnormal segments in 201TI image were those of hard events. Kaplan-Meier analysis revealed that greater risk stratification was achieved by adding a glomerular filtration rate of lesser than 60 ml/min/1.73 m2 to the sum of the total defect score > or = 5 in the 123I-BMIPP image. Greater risk stratification for hard events was also achieved by adding a glomerular filtration rate of lesser than 30 ml/min/1.73 m2 to the number of abnormal segments > or = 2 in 201TI image.
Better risk stratification can be achieved by adding glomerular filtration rate to 201TI/123I-BMIPP dual myocardial scintigraphic findings.
Nuclear Medicine Communications 02/2009; 30(1):54-61. · 1.40 Impact Factor
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ABSTRACT: The Mini-Mental State Examination (MMSE) is considered a useful supplementary method to diagnose dementia and evaluate the severity of cognitive disturbance. However, the region of the cerebrum that correlates with the MMSE score is not clear. Recently, a new method was developed to analyze regional cerebral blood flow (rCBF) using a Z score imaging system (eZIS). This system shows changes of rCBF when compared with a normal database. In addition, a three-dimensional stereotaxic region of interest (ROI) template (3DSRT), fully automated ROI analysis software was developed. The objective of this study was to investigate the correlation between rCBF changes and total MMSE score using these new methods.
The association between total MMSE score and rCBF changes was investigated in 24 patients (mean age +/- SD 71.5 +/- 9.2 years; 6 men and 18 women) with memory impairment using eZIS and 3DSRT. Step-wise multiple regression analysis was used for multivariate analysis, with the total MMSE score as the dependent variable and rCBF change in 24 areas as the independent variable.
Total MMSE score was significantly correlated only with the reduction of left hippocampal perfusion but not with right (P < 0.01).
Total MMSE score is an important indicator of left hippocampal function.
Annals of Nuclear Medicine 07/2008; 22(6):539-42. · 1.50 Impact Factor
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ABSTRACT: [(18)F]-2-fluoro-2-deoxy-D-glucose ([(18)F]-FDG) is a useful radiotracer to detect malignant tumors. However, inflammatory processes are likely to be mistaken as malignant tumors owing to strong accumulation of [(18)F]-FDG. The fluorinated nucleoside base 5-fluorouracil has remained an important antimetabolite agent in the treatment of a variety of cancers. The objective of this study was to evaluate the possibility of discriminating between malignant tumors and inflammation by [(18)F]-5-fluorouracil ([(18)F]-5-FU).
[(18)F]-5-FU was made with >95% radiochemical purity in our laboratory. BALB/cAJcl-nu/nu mice were subcutaneously inoculated with colon carcinoma cell line, colon 26, into the left side of the back and turpentine oil into the right side of the back to cause chemical inflammation. We examined the biodistribution of [(18)F]-5-FU in control mice and tumor-inflammation mice. We also examined the biodistribution of [(18)F]-FDG as a baseline study. Approximately 1 MBq of either [(18)F]-5-FU or [(18)F]-FDG was injected into the tail vein of each mouse. The biodistribution study was performed at 1 and 2 h after injection. The radioactivity of each organ was measured by a gamma counter.
[(18)F]-5-FU uptakes in the liver and the kidney were especially high. Tumor-to-blood ratios were significantly higher at 2 h than at 1 h (3.69 +/- 0.40 vs. 1.81 +/- 0.37, P < 0.001). Tumor-to-inflammation ratios at 2 h following injection were significantly higher than those at 1 h (1.94 +/- 0.44 vs. 1.26 +/- 0.20, P < 0.001). At 2 h after radiotracer injection, the tumor-to-inflammation ratio of [(18)F]-5-FU was significantly higher than that of [(18)F]-FDG (1.94 +/- 0.44 vs. 1.03 +/- 0.23, P = 0.001).
Our data suggest that [(18)F]-5-FU has a diagnostic potential as a positron emission tomography ligand for differentiating malignant tumors from inflammatory lesions.
Annals of Nuclear Medicine 01/2008; 22(1):65-72. · 1.50 Impact Factor
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ABSTRACT: Many studies have documented the clinical usefulness of standardized uptake values (SUV) for diagnosis. However, in the event of injection error, accurate measurements cannot be obtained if the radioactivity of fluorodeoxyglucose (FDG) leakage is not subtracted from the administered dosage. Here, a correction formula for radioactivity estimation that takes into account the radioactivity of FDG leakage was derived on the basis of a phantom experiment. Furthermore, to determine whether SUV could be accurately calculated by the correction formula, we performed a volunteer study.
Images were displayed by altering the conversion constant from 1.0, 0.1 to 0.01, and the range of correctable counts was verified on the basis of image inversion. To estimate the radioactivity of FDG leakage by imaging, the count of the leakage was measured, converted into a radioactivity concentration using a cross-calibration factor (CCF), and multiplied by volume, as measured by imaging. Three factors that markedly affect count, i.e., count rate performance, partial volume effect and crosstalk, were assessed in phantom studies in order to derive a correction formula. In addition, to clarify the accuracy of the correction formula, we attached to the right elbow.
With a conversion constant of 0.1, there was no image inversion at <or=1.565 MBq/ml. At concentrations below this, the average detection rate was 90%. This suggests that count rate performance can be corrected at <or=1.0 MBq/ml. Crosstalk investigations clarified that the effects of adjacent radioactivity concentrations on FDG leakage were not marked. On the basis of investigations on partial volume effect and count rate performance, the following formulas were derived: For leakages of >or=28 mm Leakage radioactivity (MBq)=positron emission tomography (PET) radioactivity (MBq)x0.9. For leakages of >or=15 mm but <28 mm Leakage radioactivity (MBq)=PET radioactivity (MBq)x0.9x(0.0517xleakage size (mm)-0.4029). In a volunteer study with 10 MBq leakage, SUV recalculated using the formula achieved 99.97% correction, whereas with 100 MBq leakage, SUV achieved 67.5% resulting in poor correction.
The present correction technique can accurately calculate SUV and could be useful for the clinical diagnosis of malignant tumors.
Annals of Nuclear Medicine 12/2007; 21(10):607-13. · 1.50 Impact Factor
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Akiko Suzuki,
Yuji Nakamoto,
Takashi Terauchi,
Masami Kawamoto,
Yoshihiro Okumura,
Yutaka Suzuki,
Toshihiko Sato, Nobukazu Takahashi,
Jin Lee,
Michio Senda,
Kimiichi Uno,
Tomio Inoue
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ABSTRACT: Diagnostic guidelines for the use of 2-(fluorine 18) fluoro-2 deoxy-D-glucose (FDG)-positron emission tomography (PET) in cancer screening have yet to be established. We assessed inter-observer variability in screening FDG-PET.
Subjects comprised 40 individuals who underwent FDG-PET and computed tomography (CT) for cancer screening. To assess various patterns of FDG uptakes, three subsets of the cases were selected: 'Cancer', 15 cases with cancer; 'Not malignant', 15 cases with suspected cancer by FDG-PET who were confirmed as cancer-free; and 'Normal', 10 cases without remarkable FDG uptake who were confirmed as cancer-free. A total of 68 lesions made up of malignancy (n = 18), benign (n = 21), and physiological FDG uptake (n = 29) were interpreted by six physicians. Each observer reviewed each case three times. Step 1 involved interpretation of PET images alone, Step 2 involved side-by-side reading of PET and CT images, and Step 3 involved re-evaluation of findings with the results of other screening tests. We assessed inter-observer agreement for each step.
Inter-observer agreement for all lesions at each step was moderate, compared to fair agreement for 'Normal' subjects. Inter-observer agreement of 'Cancer' and 'Not malignant' subjects in Step 1 were better than those in Step 2 and 3; however, the differences were not statistically significant.
The interpretation of FDG-PET is adequately reproducible, while that of 'Normal' subjects is less reproducible. Improvement of inter-observer variability in assessing physiological FDG uptakes requires universal reporting criteria in FDG-PET. Correlative interpretation of PET, CT and other information may require standardization in subjects with suspected cancer by FDG-PET.
Japanese Journal of Clinical Oncology 09/2007; 37(8):615-22. · 1.78 Impact Factor
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ABSTRACT: This study aims to clarify the effect of renal function on 2-[(18)F] fluoro-2-deoxy-D-glucose positron emission tomography (FDG-PET) imaging and determine the clinical significance of renal function in this setting. We compared FDG distribution between normal volunteers and patients with suspected renal failure.
Twenty healthy volunteers and 20 patients with suspected renal failure who underwent FDG-PET between November 2002 and May 2005 were selected for this study. We define "patients with suspected renal failure" as having a blood serum creatinine level in excess of 1.1 mg/dl. The serum creatinine level was examined once in 2 weeks of the FDG-PET study. Regions of interest were placed over 15 regions for semi-quantitative analysis: the white matter, cortex, both upper lung fields, both middle lung fields, both lower lung fields, mediastinum, myocardium of the left ventricle, the left atrium as a cardiac blood pool, central region of the right lobe of the liver, left kidney, and both femoris muscles.
The mean standardized uptake values (SUVs) of brain cortex and white matter were higher in healthy volunteers than in renal patients. The mean SUVs of the mediastinum at the level of the aortic arch and left atrium as a cardiac blood pool were lower in healthy volunteers than in patients with suspected renal failure. These regions differed between healthy volunteers and patients with suspected renal failure (P < 0.05).
We found decreasing brain accumulation and increasing blood pool accumulation of FDG in patients with high plasma creatinine. Although the difference is small, this phenomenon will not have a huge effect on the assessment of FDG-PET imaging in patients with suspected renal failure.
Annals of Nuclear Medicine 07/2007; 21(4):217-22. · 1.50 Impact Factor
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ABSTRACT: Electrochemical transfer of (18)F(-) from enriched [(18)O]-water to pure acetonitrile was investigated to develop a simple and effective synthesis of (18)F-radiopharmaceuticals. The transfer of (18)F is composed of two steps: first step is electro-deposition on a graphite anode and the next step is electro-emission into pure acetonitrile by inversing the polarity of the electric tension. A sufficiently high fraction of the electro-emission, 73%, was achieved. The electrochemical transfer of (18)F to aprotic polar solvents without any additives, such as phase transfer catalysis, will make the synthesis of diverse (18)F-radiopharamceuticals simple and easy.
Applied Radiation and Isotopes 06/2007; 65(5):524-7. · 1.17 Impact Factor
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Noriko Inoue, Nobukazu Takahashi,
Toshiyuki Ishikawa,
Shinichi Sumita,
Tsukasa Kobayashi,
Kohei Matsushita,
Katsumi Matsumoto,
Minoru Taima,
Miei Shimura,
Kazuaki Uchino,
Kazuo Kimura,
Tomio Inoue,
Satoshi Umemura
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[hide abstract]
ABSTRACT: Cardiac resynchronization therapy (CRT) improves glucose metabolism in the septum of patients with heart failure, so in the present study the predictive value of combined fluorodeoxyglucose (FDG)-positron emission tomography (PET) and metoxy-isobutyl isonitrile (MIBI)-single photon emission computed tomography (SPECT) for the prognosis of patients undergoing CRT was investigated.
Fourteen patients (70.3+/-8.2 years) who underwent FDG-PET and MIBI-SPECT before implantation of a biventricular pacemaker were enrolled. The total number of matches, mismatches, reverse mismatches, summed difference score (SDS: sum total of FDG - MIBI scores) and SDS per segment (%SDS) in each of 5 areas of myocardium (septum, anterior, lateral, inferior area, apex) was calculated and compared between the survival groups (all survival: survival group; survival without ischemic heart disease (IHD): non-IHD survival group) and non-survival group. Both the number of reverse mismatch segments and the %SDS in the septum in the non-IHD survival group were significantly greater than in the non-survival group (3.2+/-1.6 vs 0.5+/-0.6, p<0.05; 0.62+/-0.61 vs -0.11+/-0.19, p<0.05). The receiver-operating characteristics curves for prognosis showed that the area under the curve for the number of reverse mismatch segments in the septum (0.93; confidence interval 0.61-0.98) was significantly greater.
A reverse mismatch pattern in the septum can predict a good prognosis for patients treated with CRT.
Circulation Journal 02/2007; 71(1):126-31. · 3.77 Impact Factor
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ABSTRACT: 2-(18)F-fluoro-2-deoxy-D-glucose (FDG)-positron emission tomography (PET) imaging in prostate cancer is challenging because glucose utilization in well-differentiated prostate cancer is often lower than in other tumor types. Nonetheless, FDG-PET has a high positive predictive value for untreated metastases in viscera, but not lymph nodes. A positive FDG-PET can provide useful information to aid the clinician's decision on future management in selected patients who have low prostate-specific antigen levels and visceral changes as a result of metastases. On the other hand, FDG-PET is limited in the identification of prostate tumors, as normal urinary excretion of radioisotope can mask pathological uptake. Moreover, there is an overlap in the degree of uptake between prostate cancer, benign prostatic hyperplasia and inflammation. The tracer choice is also important. (11)C-choline has the advantage of reduced urinary excretion, and thus (11)C-choline PET may provide more accurate information on the localization of main primary prostate cancer lesions than MRI or MR spectroscopy. (11)C-choline PET is sensitive and accurate in the preoperative staging of pelvic lymph nodes in prostate cancer. A few studies are available but there were no PET or PET/CT studies with a large number of patients for tissue confirmation of prostate cancer; further investigations are required.
Oncology 02/2007; 72(3-4):226-33. · 2.27 Impact Factor
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ABSTRACT: The purpose of this study is to evaluate effect of attenuation correction technique on 18F-fluoride positron emission tomography (PET).
We performed PET scans after the injection of 185 MBq 18F-fluoride on 32 patients from October 20th, 2004 to April 13th, 2005. We calculated bone-to-muscle ratios for the images with and without attenuation correction. We placed regions of interest (ROIs) on normal bone accumulation in 22 patients. The exclusion criteria were bone metastasis, Paget's disease, and rheumatoid arthritis. Several regions were chosen for ROI placement: skull, cervical vertebra, mandible, scapula, thoracic vertebra, rib, humerus, lumbar vertebra, radius, ulna, pelvis, femoral head, femoral shaft, tibia, and fibula. The count ratios of normal bones to gluteus muscle were calculated as bone-to-muscle ratios. The count ratios of abnormal skeletal lesions to gluteus muscles were calculated as bone-to-muscle ratios, while the count ratios of abnormal skeletal lesions to normal bones were calculated as bone-to-bone ratios.
PET images without attenuation correction showed significantly higher mean bone-to-muscle ratios than those with attenuation correction (p < 0.05) for all normal bones except the femoral head and lumbar vertebrae. For abnormal bones, bone-to-muscle ratios without attenuation correction were significantly higher than those with attenuation correction (p < 0.005). The same statistical significance was found for bone-to-bone ratios (p < 0.005).
The attenuation correction technique is not necessary to conduct the visual interpretation of 18F-fluoride PET images. The bone-to-muscle ratio analysis without attenuation correction may be of use to differentiate malignant from benign disease processes.
Annals of Nuclear Medicine 02/2007; 21(2):93-9. · 1.50 Impact Factor
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Noriko Inoue, Nobukazu Takahashi,
Kazuo Kimura,
Toshiyuki Ishikawa,
Shinichi Toyama,
Yuzuru Yoshii,
Kazuaki Uchino,
Yohei Yamakawa,
Katsumi Matsumoto,
Tomio Inoue,
Satoshi Umemura
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[hide abstract]
ABSTRACT: The plasma brain natriuretic peptide (BNP) concentration at rest correlates with left ventricular end-diastolic pressure (LVEDP), left ventricular ejection fraction (LVEF), and pulmonary capillary wedge pressure (PCWP). High lung thallium-201 uptake has been reported to be associated with hemodynamic variables such as LVEDP, LVEF, and PCWP. However, there is no study that has investigated the correlation of plasma BNP concentration with lung thallium-201 uptake. We examined whether the plasma BNP concentration was related to lung thallium-201 uptake. Before exercise, venous blood samples were obtained from 39 patients with old myocardial infarction. We investigated the correlations between plasma BNP concentration and lung thallium-201 uptake, and whether they were related to LVEF, extent of nonviable myocardium, and ischemic myocardium, respectively, with thallium-201 exercise stress testing. The plasma BNP concentration significantly correlated with lung thallium-201 uptake (P < 0.05), nonviable segments (P < 0.01), and LVEF (P < 0.01). Lung thallium-201 uptake correlated with nonviable segments (P < 0.01). Our results suggest that increased secretion of BNP is related to increased lung thallium-201 uptake, and they are related to the extent of nonviable myocardium and decreased left ventricular function. Plasma BNP concentration and lung thalium-201 uptake may reflect the extent of myocardial fibrosis causing myocyte stretch.
Heart and Vessels 03/2006; 21(2):78-83. · 2.05 Impact Factor
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Katsumi Matsumoto, Nobukazu Takahashi,
Toshiyuki Ishikawa,
Shinichi Sumita,
Kohei Matsushita,
Noriko Inoue,
Tsukasa Kobayashi,
Kazuaki Uchino,
Kazuo Kimura,
Tomio Inoue,
Satoshi Umemura
[show abstract]
[hide abstract]
ABSTRACT: We assessed left ventricular (LV) function and myocardial glucose metabolism by fluoro-18-deoxyglucose (18F-FDG) positron emission tomography (PET) in patients with tachycardia-induced cardiomyopathy (TC).
The subjects were 42 patients with heart disease, consisting of 7 patients with TC (61.4 +/- 19.0 years, LVEF 34.1%+/- 10.6%) and 35 with ischemic heart disease (IHD) (63.1 +/- 10.8 years, LVEF 49.9%+/- 13.5%). Five volunteers with normal ECG were the control group. All of the patients underwent 18F-FDG PET and echocardiography, and all of the patients with TC underwent 18F-FDG PET and echocardiography before and 6 months after antitachycardia therapy. Six patients underwent radiofrequency catheter ablation (RFCA) and 1 patient was medically treated with antitachycardia therapy. Myocardial glucose metabolism was assessed semiquantitatively by using the % dose uptake of 60 kg of BW (% dose uptake).
Mean % dose uptake of the control group was 5.52 +/- 0.54%. After antitachycardia therapy, LVEF significantly improved (34.1 +/- 10.6% vs 54.3 +/- 13.6%, P < 0.01), and % dose uptake also significantly improved (1.26 +/- 0.55% vs 1.49 +/- 0.62%, P < 0.05). Patients with IHD showed higher % dose uptake than those with TC before antitachycardia therapy (3.18 +/- 1.36 vs 1.26 +/- 0.55%, P < 0.01), controls showed higher value of % dose uptake than TC before antitachycardia therapy (5.52 +/- 0.54% vs 1.26 +/- 0.55%, P < 0.01).
Semiquantitative analysis of 18F-FDG PET showed that antitachycardia therapy improved myocardial glucose metabolism in patients with TC.
Pacing and Clinical Electrophysiology 02/2006; 29(2):175-80. · 1.35 Impact Factor
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ABSTRACT: Prostate cancer is difficult to visualise in its early stages using current imaging technology. The present study aimed to clarify the utility of 11C-choline PET for localising and evaluating cancer lesions in patients with prostate cancer by conducting a prospective comparison with magnetic resonance (MR) imaging combined with proton MR spectroscopy.
PET and MR imaging combined with proton MR spectroscopy were performed in 20 patients with prostate cancer. Correlations among the metabolite ratio of choline + creatine to citrate (Cho+Cr/Ci) on MR spectroscopy, serum PSA and maximum standardised uptake value (SUVmax) of (11)C-choline were assessed. The location of the primary lesion was assessed by the site of SUVmax and the laterality of the highest Cho+Cr/Ci ratio and confirmed by examination of surgical pathology specimens (n=16).
PET exhibited a diagnostic sensitivity of 100% (20/20) for primary lesions, while the sensitivities of MR imaging and MR spectroscopy were 60% (12/20) and 65% (13/20), respectively. Weak linear correlations were observed between SUVmax and serum PSA (r=0.52, p<0.05), and between SUVmax and Cho+Cr/Ci ratio (r=0.49, p<0.05). Regarding the localisation of main primary lesions, PET results agreed with pathological findings in 13 patients (81%) (kappa=0.59), while MR spectroscopy results were in accordance with pathological findings in eight patients (50%) (kappa=0.11).
This preliminary study suggests that 11C-choline PET may provide more accurate information regarding the localisation of main primary prostate cancer lesions than MR imaging/MR spectroscopy. A further clinical study of 11C-choline PET in a large number of patients suspected of prostate cancer will be necessary to determine the clinical utility of 11C-choline PET in patients who clinically require biopsy.
European journal of nuclear medicine and molecular imaging 08/2005; 32(7):742-8. · 4.99 Impact Factor
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Nobukazu Takahashi,
Tomio Inoue,
Tadasi Oka,
Akiko Suzuki,
Tuyosi Kawano,
Kazuaki Uchino,
Yasuyuki Mochida,
Tosiaki Ebina,
Katumi Matumoto,
Youhei Yamakawa,
Satosi Umemura
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[hide abstract]
ABSTRACT: The incidence of missed diagnoses of acute cardiac ischemia in the emergency department could be reduced by a new imaging modality. In the present study, the clinical significance of (99m)Tc-pyrophosphate (PYP), (123)I-beta-methyl-p-iodephenyl-pentadecanoic acid (BMIPP), (201)TlCl scintigraphy (imaging) and T2-weighted inversion-recovery magnetic resonance imaging (MRI) for the detection of culprit lesion in patients with acute coronary syndromes (ACS) was compared.
The study group comprised 18 patients with ACS: 12 patients with acute myocardial infarction (AMI) (11 males; mean age, 63+/-11 years) and 6 patients with unstable angina (UA) (3 males, mean age, 67+/-5 years). Of the 12 patients with AMI, 10 underwent (201)TlCl and PYP single photon emission computed tomography (SPECT) studies as a dual-energy acquisition ((201)TlCl/PYP) and 8 underwent (201)TlCl SPECT within 1 week of the BMIPP study. All 18 patients underwent BMIPP SPECT and MRI. The MRI pulse sequence was black blood turbo short-inversion-time inversion recovery (STIR) (breath-hold T2-weighted studies). The T2-weighted inversion-recovery MRI showed higher sensitivity and negative predictive value than PYP and (201)TlCl, and higher specificity and positive predictive value than BMIPP and (201)TlCl. The area under the receiver-operating characteristic curve for PYP, BMIPP, (201)TlCl and MRI was 0.787, 0.725, 0.731 and 0.878, respectively. The difference between the areas of MRI and BMIPP was significant (p<0.05).
Accurate detection of culprit lesion is improved by using MRI rather than BMIPP, particularly for patients with ACS.
Circulation Journal 12/2004; 68(11):1023-9. · 3.77 Impact Factor
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ABSTRACT: Peritoneal carcinomatosis can be difficult to diagnose using computed tomography (CT). The purpose of this study was to evaluate the role of 2-(fluorine 18) fluoro-2-deoxy-D-glucose (FDG) positron emission tomography (PET) in the detection of peritoneal carcinomatosis.
We reviewed the CT and FDG PET radiological reports and clinical charts of 18 patients with peritoneal carcinomatosis and 17 cancer patients without peritoneal carcinomatosis. We also assessed FDG PET scans from 20 healthy volunteers as a baseline study. The maximum standardised uptake values (SUVmax) over peritoneal lesions in cancer patients and over the area of most intense intestinal uptake in healthy volunteers and cancer patients without peritoneal carcinomatosis were measured.
The sensitivity and positive predictive value (PPV) of combined FDG PET and CT were superior to those of CT alone for the detection of peritoneal lesions (sensitivity: 66.7% vs 22.2%, p<0.025; PPV: 92.3% vs 50.0%, p<0.05). The most frequent pattern of FDG uptake in patients with peritoneal carcinomatosis was abnormally intense focal uptake near the abdominal wall. An SUVmax threshold of 5.1 produced a diagnostic accuracy of combined FDG PET and CT of 78%. The additional information provided by FDG PET allowed a more accurate diagnosis in 14 patients (40.0%), and led to alteration of the therapeutic strategy in five (14.3%) of the enrolled cancer patients.
We found that use of an intra-abdominal FDG uptake cut-off value for SUVmax of >5.1 assists in the diagnosis of peritoneal carcinomatosis. FDG PET may play an important role in the clinical management of patients with suspected peritoneal carcinomatosis.
European journal of nuclear medicine and molecular imaging 10/2004; 31(10):1413-20. · 4.99 Impact Factor
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Yohei Yamakawa, Nobukazu Takahashi,
Toshiyuki Ishikawa,
Kazuaki Uchino,
Yasuyuki Mochida,
Toshiaki Ebina,
Tsukasa Kobayashi,
Kohei Matsushita,
Katsumi Matsumoto,
Noriko Kawasaki,
Mie Shimura,
Yasuo Ohkusu,
Shinichi Sumita,
Kazuo Kimura,
Tomio Inoue,
Satoshi Umemura
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ABSTRACT: This study sought to evaluate an imaging approach using gated 99mTc-MIBI (MIBI) SPECT and gated 18F-FDG (FDG) PET for assessment of myocardial viability and cardiac function.
Forty-eight patients (38 men, mean age 68.1 +/- 9.6 years) underwent ECG-gated FDG PET and MIBI SPECT within a week. The baseline diagnoses were coronary artery disease (31), mitral regurgitation (1), paroxysmal arrhythmia (10), and dilated cardiomyopathy (6). The gated FDG PET data were analyzed using pFAST software, and the gated MIBI SPECT data were analyzed using QGS software. Fifteen patients were diagnosed with myocardial infarction, and follow-up study was performed to assess the functional outcome four months later. An improvement in LVEF of >5% was defined as significant. The LV myocardium was divided into 17 segments, and regional defect scores were visually assessed using a 4-point scale for each segment (0 = normal, 1 = mildly reduced, 2 = moderately reduced, 3 = absent). A segment with a greater defect score on MIBI SPECT than on FDG PET was defined as a mismatch. The patients were divided into two groups: those with at least two mismatched segments (MM-group), and those with none or one (M-group).
LVEF, EDV and ESV measured by gated FDG PET were highly correlated with those obtained by gated MIBI SPECT (r = 0.848, 0.855 and 0.911, p < 0.0001, respectively). The mean values of LVEF did not differ significantly, but EDV and ESV obtained by gated FDG PET were significantly grater than those obtained by gated MIBI SPECT (p < 0.0001). In 15 patients diagnosed with myocardial infarction, a significant association (p < 0.05) was found between the relative uptake of FDG PET and MIBI SPECT and the functional outcome 4 months later. Global LV function improved in 6 of the 8 patients showing mismatch but in only 1 of the 7 patients with matched defects, resulting in a sensitivity of 86% and specificity of 75%. The overall accuracy to predict global functional outcome was high (80%).
This imaging approach allows accurate evaluation of myocardial viability. Furthermore, the high correlations of gated FDG PET and gated MIBI SPECT measurements hold promise for the assessment of left ventricular function using gated FDG PET.
Annals of Nuclear Medicine 08/2004; 18(5):375-83. · 1.50 Impact Factor
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ABSTRACT: The purpose of this study was to clarify the clinical implications of thymic fluorodeoxyglucose (FDG) uptake after chemotherapy in pediatric patients with malignant disease. Twenty-two pediatric patients, aged 0-17 years (mean 7.0 years), who had undergone FDG positron emission tomography (PET) were examined retrospectively. A total of 48 FDG-PET scans of the 22 patients were reviewed. Seven PET scans were recorded before the initial chemotherapy, and the remaining 41 scans were conducted during and after chemotherapy. Thymic FDG uptake was evaluated using standardized uptake value (SUV) analysis. The effect of chemotherapy on thymic FDG uptake was assessed by comparing SUV before, during, and after chemotherapy. The change in thymic FDG uptake with increasing time after the completion of chemotherapy was also assessed. Clinical laboratory data including number of white blood cells (WBCs), erythrocytes (RBCs), platelets, plasma glucose level and differential white blood count were analyzed for their association with thymic FDG uptake. Thymic FDG uptake in patients during chemotherapy was significantly lower than that in patients before chemotherapy (mean+/-SD 1.71+/-0.48 vs 2.27+/-0.32, respectively, P<0.01). Thymic FDG uptake in patients after chemotherapy was significantly higher than that in patients during chemotherapy (mean+/-SD 2.74+/-0.70 vs 1.71+/-0.48, respectively, P<0.01). A significant relationship between thymic FDG uptake and interval after completion of chemotherapy (r=0.74, P<0.0001) was observed. Significant relationships between blood counts (WBCs, RBCs, and platelets) and thymic FDG uptake were also observed. Comparison of the differential white blood count and thymic FDG uptake revealed a significant relationship only with lymphocyte count. Thymic FDG uptake in pediatric patients after completion of chemotherapy should not be mistaken as recurrent or metastatic thymic malignancy. Thymic FDG uptake appears to be associated with thymic function or hematopoietic function in bone marrow. Interpretation of FDG-PET must be made with this consideration in mind.
European journal of nuclear medicine and molecular imaging 06/2004; 31(6):831-6. · 4.99 Impact Factor
