Background: Non-uniformity in signal intensity occurs commonly in magnetic resonance (MR) imaging, which may pose substantial problems when using a 3T scanner. Therefore, image non-uniformity correction is usually app...Background: Non-uniformity in signal intensity occurs commonly in magnetic resonance (MR) imaging, which may pose substantial problems when using a 3T scanner. Therefore, image non-uniformity correction is usually applied. Purpose: To compare the correction effects of the phased-array uniformity enhancement (PURE), a calibration-based image non-uniformity correction method, among three different software versions in 3T Gd-EOB-DTPA-enhanced MR imaging. Material and Methods: Hepatobiliary-phase images of a total of 120 patients who underwent Gd-EOB-DTPA-enhanced MR imaging on the same 3T scanner were analyzed retrospectively. Forty patients each were examined using three software versions (DV25, DV25.1, and DV26). The effects of PURE were compared by visual assessment, histogram analysis of liver signal intensity, evaluation of the spatial distribution of correction effects, and evaluation of quantitative indices of liver parenchymal enhancement. Results: The visual assessment indicated the highest uniformity of PURE-corrected images for DV26, followed by DV25 and DV25.1. Histogram analysis of corrected images demonstrated significantly larger variations in liver signal for DV25.1 than for the other two versions. Although PURE caused a relative increase in pixel values for central and lateral regions, such effects were weaker for DV25.1 than for the other two versions. In the evaluation of quantitative indices of liver parenchymal enhancement, the liver-to-muscle ratio (LMR) was significantly higher for the corrected images than for the uncorrected images, but the liver-to-spleen ratio (LSR) showed no significant differences. For corrected images, the LMR was significantly higher for DV25 and DV26 than for DV25.1, but the LSR showed no significant differences among the three versions. Conclusion: There were differences in the effects of PURE among the three software versions in 3T Gd-EOB-DTPA-enhanced MR imaging. Even if the non-uniformity correction method has the same brand name, correction effects may differ depending on the software version, and these differences may affect visual and quantitative evaluations.展开更多
AIM:To analyze the lipid distribution in gastric mucosae.METHODS:Imaging mass spectrometry(MS)is a useful tool to survey the distribution of biomolecules in surgical specimens.Here we used the imaging MS apparatus nam...AIM:To analyze the lipid distribution in gastric mucosae.METHODS:Imaging mass spectrometry(MS)is a useful tool to survey the distribution of biomolecules in surgical specimens.Here we used the imaging MS apparatus named i MScope to identify the dominant molecules present in the human gastric mucosa near the fundic glands.Five gastric specimens were subjected to iM Scope analysis.These specimens were also analyzed by immunohistochemistry using MUC5 AC,H(+)-K(+)-ATPaseβ Claudin18 antibodies.RESULTS:Three major molecules with m/z 725.5,780.5,and 782.5 detected in the gastric mucosa were identified as sphingomyelin(SM)(d18:1/16:0),phosphatidylcholine(PC)(16:0/18:2),and PC(16:0/18:1),respectively,through MS/MS analyses.Using immunohistological staining,SM(d18:1/16:0)signals were mainly colocalized with the foveolar epithelium marker MUC5 AC.In contrast,PC(16:0/18:2)signals were observed in the region testing positive for the fundic gland marker H(+)-K(+)-ATPaseβ.PC(16:0/18:1)signals were uniformly distributed throughout the mucosa.CONCLUSION:Our basic data will contribute to the studies of lipid species in physical and pathological conditions of the human stomach.展开更多
Heart and skeletal muscle insulin resistance and abnormal myocardial flow reserve (MFR) occurs in patients with type-II diabetes. Improvement of heart and skeletal muscle insulin resistance with rosiglitazone use over...Heart and skeletal muscle insulin resistance and abnormal myocardial flow reserve (MFR) occurs in patients with type-II diabetes. Improvement of heart and skeletal muscle insulin resistance with rosiglitazone use over 16 weeks have been reported. However, it is not clear whether chronic use of troglitazone can improve heart and skeletal muscle insulin resistance and MFR. Materials and Methods: To test the hypothesis whether effects of troglitazone on heart and skeletal muscle insulin resistance and MFR in patients with type-II diabetes, rest and dipyridamole stress perfusion positron emission tomography (PET) with 13N-ammonia and heart and skeletal muscle 18FDG PET scans under insulin clamping were undertaken before and 12 month after the initiation of troglitazone therapy (400 mg/day) in 23 patients with type-II diabetes. Twenty patients with type-II diabetes without CAD and without medications were served as controls. In controls, any medications were not added from the first PET study and 12 months after the second PET study. Results: Baseline myocardial blood flow (MBF) was comparable before and after the troglitazone group as was the controls. MBF during dipyridamole administration (0.56 mg/min/kg) was not significantly improved in troglitazone group and controls. MFR was not improved in troglitazone group and controls. In troglitazone group, whole body glucose disposal rate (GDR;μmole/min/kg) significantly improved (pre;19.0 ± 9.55, post;28.7 ± 15.3, p as did the skeletal muscle glucose utilization rate (SMGU (μmole/min/kg);pre;20.3 ± 12.0, post;34.8 ± 10.6, p insulin resistance is implicated in patients with type-II diabetes and impaired MFR is uncoupled with insulin resistance in the whole body and heart and skeletal muscle in patients with type-II diabetes.展开更多
Insulin resistance is associated with several coronary risk factors and is thought to play a critical role for the development of coronary artery disease. Insulin resistance has several causes, including an impaired s...Insulin resistance is associated with several coronary risk factors and is thought to play a critical role for the development of coronary artery disease. Insulin resistance has several causes, including an impaired skeletal muscle glucose utilization rate (SMGU), reduced peripheral blood flow, and altered fatty tissue metabolism, with SMGU being considered the most important. Nonetheless, insulin resistance has only been estimated by the glucose disposal rate (GDR) in previous studies. Methods: Skeletal muscle metabolic imaging with 18FDG and positron emission tomography (PET) was undertaken to measure SMGU during hyperinsulinemiceuglycemic clamping in 22 normotensive type-2 diabetics under no medications (T2- DM), 17 normotensive non-diabetic hypertriglyceridemics, 22 patients with hypertension, and 12 agematched controls. Whole body insulin resistance was assessed by the GDR during hyperinsulinemiceuglycemic insulin clamping. Results: The SMGU and GDR were significantly reduced in T2DM (32.1 ± 16.6 μmol/min/kg and 24.3 ± 13.0 μmol/min/kg, respectively), hypertriglyceridemics (36.5 ± 13.5 μmol/min/ kg and 22.7 ± 8.07 μmol/min/kg respectively) and patients with hypertension (35.4 ± 26.6 μmol/min/kg and 29.0 ± 9.90 μmol/min/kg, respectively) compared with controls (72.2 ± 44.1 μmol/min/kg and 43.0 ± 22.9 μmol/min/kg, p < 0.01, respectively). In all groups studied, SMGU was significantly correlated with GDR (r = 0.76, p < 0.01) and GDR (F = 13.9) was independently related to SMGU (r = 0.81, p < 0.01). Conclusion: Insulin resistance is significantly associated with SMGU to a similar degree among patients with T2DM, essential hypertension and hypertriglyceridemia. 18FDG PET functional imaging allows insulin resistance to be assessed.展开更多
Stimulus-preceding negativity (SPN), readiness potential (RP), and contingent negative variation (CNV) were recorded to verify the hypothesis that the CNV late wave is the sum of the RP and the SPN. SPN and RP were el...Stimulus-preceding negativity (SPN), readiness potential (RP), and contingent negative variation (CNV) were recorded to verify the hypothesis that the CNV late wave is the sum of the RP and the SPN. SPN and RP were elicited using a time-estimation task, and the CNV was recorded using a warned reaction-time task. A “virtual CNV” was calculated by superimposing the SPN on the RP. Then the real and virtual CNVs were compared to evaluate the hypothesis. Although an amplitude difference between the real and virtual CNV late waves was observed at the frontal site, the amplitudes at the central and parietal sites were not different between the two. These results suggest that the CNV late wave and the SPN might have a common underlying physiological mechanism in the parietal area, and that these potentials might be related to attentional systems.展开更多
Background: Skeletal muscle glucose utilization (SMGU) can be accessed by positron emission tomography (PET) and18F-FDG to characterize insulin resistance. The quantity of skeletal muscle in the lumbar is sufficient t...Background: Skeletal muscle glucose utilization (SMGU) can be accessed by positron emission tomography (PET) and18F-FDG to characterize insulin resistance. The quantity of skeletal muscle in the lumbar is sufficient to indicate that SMGU in the lumbar (SMGU- lumbar) can be measured with18F-FDG PET of the chest instead of obtaining thigh muscle SMGU (SMGU-thigh). This would reduce PET scan time to avoid thigh muscle PET scan. This study was aimed to compare SMGU-lumbar and thigh muscle SMGU under insulin clamping to identify the validity of measurements of SMGU in the lumbar for studies of insulin resistance. Methods: Thirty-three patients underwent sequential dynamic18F-FDG PET of both the thoracic (37 min) and thigh region (22 min) during hyperinsulinemic euglycemic insulin clamping. Both SMGU-lumbar and SMGU-thigh were calculated by Patlak graphical analysis. Whole body insulin resistance was assessed by a whole body glucose disposal rate during hyperinsulinemic euglycemic insulin clamping. Input function was obtained from the time activity curve of the descending aorta and venous blood sampling as previously validated. Results: SMGU-thigh (0.0506 ± 0.0334 μmol/min/g) was comparable to SMGU-lumbar (0.0497 ± 0.0255 μmol/min/g). The Bland-Altman method of difference plot analysis showed a significant correlationship between SMGU- thigh and SMGU-lumbar (r = 0.506, p = 0.0028). There were seen very good significant correlationship between whole body glucose utilization rate in both thigh (r = 0.737, p = 0.0001) and lumbar (r = 0.772, p = 0.0001). Conclusion: These results support the validity of measuring SMGU-lumbar to estimate insulin resistance during PET imaging of the chest.展开更多
Background: Existence of myocardial insulin resistance (IR) has been reported in type II diabetics (T2- DM) and coronary artery disease (CAD). Improvement in heart and skeletal muscle IR after thiazolidinedione’s the...Background: Existence of myocardial insulin resistance (IR) has been reported in type II diabetics (T2- DM) and coronary artery disease (CAD). Improvement in heart and skeletal muscle IR after thiazolidinedione’s therapy was reported in T2DM and CAD. However effects of troglitazone therapy (TRO) on myocardial IR remain uncertain. To clarify heart and skeletal muscle and whole body IR in T2DM without CAD by TRO to clarify whether TRO would provide different results. Methods: We analyzed data on 15 T2DM patients who underwent dynamic PET with 18F-FDG under insulin clamping before and during TRO (200 mg/day) and 17 controls. Results: Whole body glucose disposal rate (WBGR mg/min/kg) in T2DM before TRO (3.41 ± 1.72) was significantly lower than in controls (9.76 ± 2.97, p < 0.01) as was the skeletal muscle glucose utilization rate (SMGU mg/min/kg);T2DM (0.367 ± 0.217) vs. controls (1.34 ± 0.613, p < 0.01) and myocardial glucose utilization rate (MGU mg/min/kg;T2DM 5.86 ± 2.03 vs. controls 7.34 ± 1.80, p < 0.05). WBGR in T2DM during TRO (5.17 ± 2.75, p < 0.05) was significantly higher than that before TRO, as was the SMGU (0.782 ± 0.20, p < 0.05). The MGU in T2DM during TRO (6.59 ± 0.72) was comparable with that before TRO. Conclusion: Myocardial IR response to TRO differed from that in skeletal muscle and the whole body in T2DM without CAD.展开更多
Objective: The width of the photopeak energy window influences the image quality and quantitative accuracy of gamma camera imaging. We compared 20% and 15% energy windows in renal scintigraphy with 99mTc-mercaptoacety...Objective: The width of the photopeak energy window influences the image quality and quantitative accuracy of gamma camera imaging. We compared 20% and 15% energy windows in renal scintigraphy with 99mTc-mercaptoacetyltriglycine (MAG3), especially in terms of camera-based quantitative estimation of renal function. Materials and Methods: Forty patients who underwent dynamic renal scintigraphy with 99mTc-MAG3 were enrolled in this study. Images were acquired simultaneously using two energy windows centered at 140 keV and with widths of 20% and 15%. Fractional renal uptake was calculated as the ratio of initial renal uptake estimated by patient imaging to injected dose estimated by syringe imaging, and was converted to MAG3 clearance using an empirical equation determined previously from data obtained with a 20% energy window. Relative function of the right kidney was also assessed. Visual evaluation was performed to compare image quality between the 20% and 15% energy windows. Results: Both total kidney MAG3 clearance and relative function of the right kidney were identical between the 20% and 15% energy windows. Image quality was also similar irrespective of the energy window width. Conclusions: The camera-based method established using a 20% energy window is applicable for the estimation of renal function using a 15% energy window, and data obtained using 20% and 15% windows are interchangeable.展开更多
Lymphoscintigraphy readily provides confirmation of chylothorax but not detailed localization of the leakage site. A 77-year-old woman developed traumatic chylothorax and underwent lymphoscintigraphy with radiolabeled...Lymphoscintigraphy readily provides confirmation of chylothorax but not detailed localization of the leakage site. A 77-year-old woman developed traumatic chylothorax and underwent lymphoscintigraphy with radiolabeled albumin to identify the site of lymph leakage. Dynamic imaging demonstrated appearance of focal activity presumably in the upper mediastinum, followed by spread to the left hemithorax. Subsequently, SPECT/CT showed that the leakage site was located in the left side of the upper mediastinum, and this location was confirmed during video-assisted thoracoscopic surgery. Dynamic imaging demonstrated the site of first appearance of abnormal activity, and SPECT/CT enabled detailed localization of the abnormal activity with anatomic correlation. The combination of dynamic imaging with SPECT/CT appears to be recommendable for lymphoscintigraphic assessment of chylothorax.展开更多
We compared the contrast effect of high and medium iodine-concentration contrast materials for preoperative CT eva- luation of breast cancer patients. Female breast cancer patients who underwent enhanced CT of the che...We compared the contrast effect of high and medium iodine-concentration contrast materials for preoperative CT eva- luation of breast cancer patients. Female breast cancer patients who underwent enhanced CT of the chest and upper abdomen before surgery were analyzed retrospectively. High (370 mg I/mL, 100 mL) or medium (300 mg I/mL, 125 mL) concentrations of contrast material were injected for 60 sec, followed by saline flush, and postcontrast CT images were obtained 90 sec after contrast injection. CT values were assessed for the breast tumor, normal breast parenchyma, liver, aorta, and muscle. For the high and medium concentration agents, 45 and 49 patients were analyzed, respectively. No significant differences between the two contrast agents were found in terms of CT values of the breast tumor, normal breast parenchyma, liver, aorta, or muscle. The tumor-background differences in CT values did not differ significantly between the two agents. A comparable contrast effect was indicated in single-phase CT of breast cancer patients between high and medium iodine-concentration contrast material when the total iodine dose and injection duration were identical.展开更多
文摘Background: Non-uniformity in signal intensity occurs commonly in magnetic resonance (MR) imaging, which may pose substantial problems when using a 3T scanner. Therefore, image non-uniformity correction is usually applied. Purpose: To compare the correction effects of the phased-array uniformity enhancement (PURE), a calibration-based image non-uniformity correction method, among three different software versions in 3T Gd-EOB-DTPA-enhanced MR imaging. Material and Methods: Hepatobiliary-phase images of a total of 120 patients who underwent Gd-EOB-DTPA-enhanced MR imaging on the same 3T scanner were analyzed retrospectively. Forty patients each were examined using three software versions (DV25, DV25.1, and DV26). The effects of PURE were compared by visual assessment, histogram analysis of liver signal intensity, evaluation of the spatial distribution of correction effects, and evaluation of quantitative indices of liver parenchymal enhancement. Results: The visual assessment indicated the highest uniformity of PURE-corrected images for DV26, followed by DV25 and DV25.1. Histogram analysis of corrected images demonstrated significantly larger variations in liver signal for DV25.1 than for the other two versions. Although PURE caused a relative increase in pixel values for central and lateral regions, such effects were weaker for DV25.1 than for the other two versions. In the evaluation of quantitative indices of liver parenchymal enhancement, the liver-to-muscle ratio (LMR) was significantly higher for the corrected images than for the uncorrected images, but the liver-to-spleen ratio (LSR) showed no significant differences. For corrected images, the LMR was significantly higher for DV25 and DV26 than for DV25.1, but the LSR showed no significant differences among the three versions. Conclusion: There were differences in the effects of PURE among the three software versions in 3T Gd-EOB-DTPA-enhanced MR imaging. Even if the non-uniformity correction method has the same brand name, correction effects may differ depending on the software version, and these differences may affect visual and quantitative evaluations.
文摘AIM:To analyze the lipid distribution in gastric mucosae.METHODS:Imaging mass spectrometry(MS)is a useful tool to survey the distribution of biomolecules in surgical specimens.Here we used the imaging MS apparatus named i MScope to identify the dominant molecules present in the human gastric mucosa near the fundic glands.Five gastric specimens were subjected to iM Scope analysis.These specimens were also analyzed by immunohistochemistry using MUC5 AC,H(+)-K(+)-ATPaseβ Claudin18 antibodies.RESULTS:Three major molecules with m/z 725.5,780.5,and 782.5 detected in the gastric mucosa were identified as sphingomyelin(SM)(d18:1/16:0),phosphatidylcholine(PC)(16:0/18:2),and PC(16:0/18:1),respectively,through MS/MS analyses.Using immunohistological staining,SM(d18:1/16:0)signals were mainly colocalized with the foveolar epithelium marker MUC5 AC.In contrast,PC(16:0/18:2)signals were observed in the region testing positive for the fundic gland marker H(+)-K(+)-ATPaseβ.PC(16:0/18:1)signals were uniformly distributed throughout the mucosa.CONCLUSION:Our basic data will contribute to the studies of lipid species in physical and pathological conditions of the human stomach.
文摘Heart and skeletal muscle insulin resistance and abnormal myocardial flow reserve (MFR) occurs in patients with type-II diabetes. Improvement of heart and skeletal muscle insulin resistance with rosiglitazone use over 16 weeks have been reported. However, it is not clear whether chronic use of troglitazone can improve heart and skeletal muscle insulin resistance and MFR. Materials and Methods: To test the hypothesis whether effects of troglitazone on heart and skeletal muscle insulin resistance and MFR in patients with type-II diabetes, rest and dipyridamole stress perfusion positron emission tomography (PET) with 13N-ammonia and heart and skeletal muscle 18FDG PET scans under insulin clamping were undertaken before and 12 month after the initiation of troglitazone therapy (400 mg/day) in 23 patients with type-II diabetes. Twenty patients with type-II diabetes without CAD and without medications were served as controls. In controls, any medications were not added from the first PET study and 12 months after the second PET study. Results: Baseline myocardial blood flow (MBF) was comparable before and after the troglitazone group as was the controls. MBF during dipyridamole administration (0.56 mg/min/kg) was not significantly improved in troglitazone group and controls. MFR was not improved in troglitazone group and controls. In troglitazone group, whole body glucose disposal rate (GDR;μmole/min/kg) significantly improved (pre;19.0 ± 9.55, post;28.7 ± 15.3, p as did the skeletal muscle glucose utilization rate (SMGU (μmole/min/kg);pre;20.3 ± 12.0, post;34.8 ± 10.6, p insulin resistance is implicated in patients with type-II diabetes and impaired MFR is uncoupled with insulin resistance in the whole body and heart and skeletal muscle in patients with type-II diabetes.
文摘Insulin resistance is associated with several coronary risk factors and is thought to play a critical role for the development of coronary artery disease. Insulin resistance has several causes, including an impaired skeletal muscle glucose utilization rate (SMGU), reduced peripheral blood flow, and altered fatty tissue metabolism, with SMGU being considered the most important. Nonetheless, insulin resistance has only been estimated by the glucose disposal rate (GDR) in previous studies. Methods: Skeletal muscle metabolic imaging with 18FDG and positron emission tomography (PET) was undertaken to measure SMGU during hyperinsulinemiceuglycemic clamping in 22 normotensive type-2 diabetics under no medications (T2- DM), 17 normotensive non-diabetic hypertriglyceridemics, 22 patients with hypertension, and 12 agematched controls. Whole body insulin resistance was assessed by the GDR during hyperinsulinemiceuglycemic insulin clamping. Results: The SMGU and GDR were significantly reduced in T2DM (32.1 ± 16.6 μmol/min/kg and 24.3 ± 13.0 μmol/min/kg, respectively), hypertriglyceridemics (36.5 ± 13.5 μmol/min/ kg and 22.7 ± 8.07 μmol/min/kg respectively) and patients with hypertension (35.4 ± 26.6 μmol/min/kg and 29.0 ± 9.90 μmol/min/kg, respectively) compared with controls (72.2 ± 44.1 μmol/min/kg and 43.0 ± 22.9 μmol/min/kg, p < 0.01, respectively). In all groups studied, SMGU was significantly correlated with GDR (r = 0.76, p < 0.01) and GDR (F = 13.9) was independently related to SMGU (r = 0.81, p < 0.01). Conclusion: Insulin resistance is significantly associated with SMGU to a similar degree among patients with T2DM, essential hypertension and hypertriglyceridemia. 18FDG PET functional imaging allows insulin resistance to be assessed.
文摘Stimulus-preceding negativity (SPN), readiness potential (RP), and contingent negative variation (CNV) were recorded to verify the hypothesis that the CNV late wave is the sum of the RP and the SPN. SPN and RP were elicited using a time-estimation task, and the CNV was recorded using a warned reaction-time task. A “virtual CNV” was calculated by superimposing the SPN on the RP. Then the real and virtual CNVs were compared to evaluate the hypothesis. Although an amplitude difference between the real and virtual CNV late waves was observed at the frontal site, the amplitudes at the central and parietal sites were not different between the two. These results suggest that the CNV late wave and the SPN might have a common underlying physiological mechanism in the parietal area, and that these potentials might be related to attentional systems.
文摘Background: Skeletal muscle glucose utilization (SMGU) can be accessed by positron emission tomography (PET) and18F-FDG to characterize insulin resistance. The quantity of skeletal muscle in the lumbar is sufficient to indicate that SMGU in the lumbar (SMGU- lumbar) can be measured with18F-FDG PET of the chest instead of obtaining thigh muscle SMGU (SMGU-thigh). This would reduce PET scan time to avoid thigh muscle PET scan. This study was aimed to compare SMGU-lumbar and thigh muscle SMGU under insulin clamping to identify the validity of measurements of SMGU in the lumbar for studies of insulin resistance. Methods: Thirty-three patients underwent sequential dynamic18F-FDG PET of both the thoracic (37 min) and thigh region (22 min) during hyperinsulinemic euglycemic insulin clamping. Both SMGU-lumbar and SMGU-thigh were calculated by Patlak graphical analysis. Whole body insulin resistance was assessed by a whole body glucose disposal rate during hyperinsulinemic euglycemic insulin clamping. Input function was obtained from the time activity curve of the descending aorta and venous blood sampling as previously validated. Results: SMGU-thigh (0.0506 ± 0.0334 μmol/min/g) was comparable to SMGU-lumbar (0.0497 ± 0.0255 μmol/min/g). The Bland-Altman method of difference plot analysis showed a significant correlationship between SMGU- thigh and SMGU-lumbar (r = 0.506, p = 0.0028). There were seen very good significant correlationship between whole body glucose utilization rate in both thigh (r = 0.737, p = 0.0001) and lumbar (r = 0.772, p = 0.0001). Conclusion: These results support the validity of measuring SMGU-lumbar to estimate insulin resistance during PET imaging of the chest.
文摘Background: Existence of myocardial insulin resistance (IR) has been reported in type II diabetics (T2- DM) and coronary artery disease (CAD). Improvement in heart and skeletal muscle IR after thiazolidinedione’s therapy was reported in T2DM and CAD. However effects of troglitazone therapy (TRO) on myocardial IR remain uncertain. To clarify heart and skeletal muscle and whole body IR in T2DM without CAD by TRO to clarify whether TRO would provide different results. Methods: We analyzed data on 15 T2DM patients who underwent dynamic PET with 18F-FDG under insulin clamping before and during TRO (200 mg/day) and 17 controls. Results: Whole body glucose disposal rate (WBGR mg/min/kg) in T2DM before TRO (3.41 ± 1.72) was significantly lower than in controls (9.76 ± 2.97, p < 0.01) as was the skeletal muscle glucose utilization rate (SMGU mg/min/kg);T2DM (0.367 ± 0.217) vs. controls (1.34 ± 0.613, p < 0.01) and myocardial glucose utilization rate (MGU mg/min/kg;T2DM 5.86 ± 2.03 vs. controls 7.34 ± 1.80, p < 0.05). WBGR in T2DM during TRO (5.17 ± 2.75, p < 0.05) was significantly higher than that before TRO, as was the SMGU (0.782 ± 0.20, p < 0.05). The MGU in T2DM during TRO (6.59 ± 0.72) was comparable with that before TRO. Conclusion: Myocardial IR response to TRO differed from that in skeletal muscle and the whole body in T2DM without CAD.
文摘Objective: The width of the photopeak energy window influences the image quality and quantitative accuracy of gamma camera imaging. We compared 20% and 15% energy windows in renal scintigraphy with 99mTc-mercaptoacetyltriglycine (MAG3), especially in terms of camera-based quantitative estimation of renal function. Materials and Methods: Forty patients who underwent dynamic renal scintigraphy with 99mTc-MAG3 were enrolled in this study. Images were acquired simultaneously using two energy windows centered at 140 keV and with widths of 20% and 15%. Fractional renal uptake was calculated as the ratio of initial renal uptake estimated by patient imaging to injected dose estimated by syringe imaging, and was converted to MAG3 clearance using an empirical equation determined previously from data obtained with a 20% energy window. Relative function of the right kidney was also assessed. Visual evaluation was performed to compare image quality between the 20% and 15% energy windows. Results: Both total kidney MAG3 clearance and relative function of the right kidney were identical between the 20% and 15% energy windows. Image quality was also similar irrespective of the energy window width. Conclusions: The camera-based method established using a 20% energy window is applicable for the estimation of renal function using a 15% energy window, and data obtained using 20% and 15% windows are interchangeable.
文摘Lymphoscintigraphy readily provides confirmation of chylothorax but not detailed localization of the leakage site. A 77-year-old woman developed traumatic chylothorax and underwent lymphoscintigraphy with radiolabeled albumin to identify the site of lymph leakage. Dynamic imaging demonstrated appearance of focal activity presumably in the upper mediastinum, followed by spread to the left hemithorax. Subsequently, SPECT/CT showed that the leakage site was located in the left side of the upper mediastinum, and this location was confirmed during video-assisted thoracoscopic surgery. Dynamic imaging demonstrated the site of first appearance of abnormal activity, and SPECT/CT enabled detailed localization of the abnormal activity with anatomic correlation. The combination of dynamic imaging with SPECT/CT appears to be recommendable for lymphoscintigraphic assessment of chylothorax.
文摘We compared the contrast effect of high and medium iodine-concentration contrast materials for preoperative CT eva- luation of breast cancer patients. Female breast cancer patients who underwent enhanced CT of the chest and upper abdomen before surgery were analyzed retrospectively. High (370 mg I/mL, 100 mL) or medium (300 mg I/mL, 125 mL) concentrations of contrast material were injected for 60 sec, followed by saline flush, and postcontrast CT images were obtained 90 sec after contrast injection. CT values were assessed for the breast tumor, normal breast parenchyma, liver, aorta, and muscle. For the high and medium concentration agents, 45 and 49 patients were analyzed, respectively. No significant differences between the two contrast agents were found in terms of CT values of the breast tumor, normal breast parenchyma, liver, aorta, or muscle. The tumor-background differences in CT values did not differ significantly between the two agents. A comparable contrast effect was indicated in single-phase CT of breast cancer patients between high and medium iodine-concentration contrast material when the total iodine dose and injection duration were identical.
