Cutting balloon-associated hemodialysis fistula rupture after failed standard balloon angioplasty.
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Biomedical subjects
S Kumita
Publications and source records attributed to S Kumita.
[Assessment of left ventricular function with the solid-state digirad 2020tc Imager].
Multigated equilibrium radionuclide ventriculography from best septal position (LAO view) was performed in 17 patients with cardiac disease with a single detector Anger-type gamma camera (GCA 602A, Toshiba), then immediately imaged with a solid-state, multi-crystal gamma camera (Digirad 2020tc Imager). Acquisition times were the same of 10 minutes. The solid-state gamma camera uses CsI(Tl) as the scintillation material and a Si photodiode. CsI(Tl) has a higher density and higher atomic number than NaI(Tl), so that its efficiency for detecting gamma rays is higher. To confirm this, total acquisition counts in 17 patients obtained from the 2020tc Imager were significantly higher than those obtained from the Anger-type camera (7847 +/- 2061 K vs. 4427 +/- 1162 K counts, p < 0.0001). In comparing left ventricular ejection fractions obtained from the Anger-type camera and the 2020tc Imager data, an excellent correlation was revealed with a correlation coefficient of 0.97 (p < 0.0001). Again, peak ejection rate and peak filling rate obtained from the 2020tc Imager data correlated well with those obtained from the Anger-type camera data (r = 0.93, p < 0.0001 and r = 0.80, p < 0.001, respectively). These data reveal that the 2020tc Imager has an excellent data collection efficiency and a high reliability in assessment of left ventricular function. Thus, the solid-state gamma camera was thought to be a useful hardware in nuclear cardiology.
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[Examination concerning dissociation of left ventricular volume calculation value based on difference of analytical algorithm and perfusion tracer in gated myocardial SPECT].
According to improvement of SPECT system, ECG-gated SPECT with 201TlCl have been applied to the left ventricular volumetry. In this study 24 patients without ischemia demonstrated by stress (99mTc-TF) and rest (201TlCl) dual-isotope ECG-gated myocardial SPECT were enrolled. To evaluate left ventricular volumetry using 201Tl ECG-gated SPECT data, the left ventricular end diastolic volumes (EDV) were compared between Quantitative Gated SPECT (QGS) and Emory Cardiac Toolbox (ECT) as well as between dual-isotopes based on the same ECG-gated data. The EDV values with 99mTc data (EDVTc) using QGS were well correlated with those using ECT (r = 0.96, p < 0.0001). Both QGS and ECT demonstrated well correlation between EDVTc (r = 0.98, p < 0.0001) and the EDV value with 201Tl (EDVTl) (r = 0.93, p < 0.0001). However, QGS processing induced significantly lower EDVTl compared with EDVTc. In contrast, EDVTl were significantly higher than EDVTc in ECT performance. The QGS errors subtracting EDVTl from EDVTc were more evident according to the left ventricular volume increase. On the other hand, ECT error showed no tendency associated with the left ventricular volume. From these results, a careful strategy for selection of tracers and softwares should be necessary to assessment of quantitative values derived from ECG-gated SPECT data because of interaction with softwares, tracers, and subjects.
Adult↗
Comparison of Emory and Cedars-Sinai methods for assessment of left ventricular function from gated myocardial perfusion SPECT in patients with a small heart.
To evaluate the effect of left ventricular (LV) size on the calculation of LV function from gated myocardial SPECT with Emory and Cedars-Sinai programs, we performed 99mTc-tetrofosmin gated SPECT on 49 patients with ischemic heart disease. End-diastolic volume (EDV), end-systolic volume (ESV), and ejection fraction (EF) were semi-automatically calculated by each program. All patients underwent left ventriculography (LVG) within 3 months before and after the SPECT study. We grouped the patients into 22 with a calculated ESV obtained from LVG of over 50 ml (group A) and 27 with an ESV value of 50 ml or below (group B). We then compared the ESV values from gated SPECT with those from LVG in each group. In group A, the ESV from both Emory and Cedars-Sinai programs similarly correlated well with those from LVG (r = 0.92 and r = 0.93, respectively), but in group B, the ESV calculated from the Cedars-Sinai program correlated less with those from LVG (r = 0.53) than those from the Emory program did (r = 0.70). The calculated LV volumes had more errors in the Cedars-Sinai program than in the Emory program, when a patient had a small heart.
Adult↗
Simultaneous assessment of Tc-99m-sestamibi and I-123-BMIPP myocardial distribution in patients with myocardial infarction: evaluation of left ventricular function with ECG-gated myocardial SPECT.
123I-labeled 15-(p-iodophenyl)-3R,S-methyl pentadecanoic acid (BMIPP) is a branched-chain free fatty acid that is used to evaluate various cardiac diseases. The aim of the present study was to investigate the relationship between myocardial perfusion (99mTc-sestamibi) and BMIPP uptake, and to correlate perfusion and metabolic alterations with regional left ventricular dysfunction in patients with myocardial infarction (MI). ECG-gated dual-isotope myocardial SPECT was performed on 130 patients with MI with sestamibi (555 MBq) and BMIPP (148 MBq). The patients were classified into 3 groups according to PTCA therapy and the interval between the onset of infarction and RI injection (OR time). Group A (n = 56) included patients whose OR time was less than one month and who had undergone successful PTCA, Group B (n = 36) had OR times of less than one month and had conservative medical therapy, and Group C (n = 38) had OR times of over one month. The severity scores of the dual-isotope images were calculated from the defect scores in 9 segments. From the ECG-gated SPECT data with sestamibi, the left ventricular ejection fraction (LVEF; %) and regional wall motion were determined automatically using the QGS program LVEF obtained from gated SPECT correlated well with the severity scores for sestamibi and BMIPP (r = -0.68 and -0.76, respectively). The delta severity scores (BMIPP scores - sestamibi scores) of Group A were significantly higher than those of the other two groups (3.6 +/- 3.0 vs. 1.5 +/- 1.7 and 1.0 +/- 1.4, p < 0.001 ). The rate of dysfunctional segments with normal sestamihi distribution was significantly higher in Group A than in Group C (20.7% vs. 6.7%, p < 0.001). ECG-gated dual-isotope SPECT is useful since myocardial perfusion, fatty acid metabolism and left ventricular function can be analyzed during a single examination, so that this procedure has the potential to provide comprehensive information when evaluating patients with ischemic heart disease.
Adult↗
[Quantitative evaluation for scatter and attenuation correction in 99mTc SPECT--multicenter cooperation phantom study].
A multicenter cooperation phantom study was conducted to evaluate the accuracy of a triple energy window scatter correction technique in combination with various attenuation correction methods for 99mTc single photon emission computed tomography (SPECT) imaging. Six centers participated in this research and the data obtained with seven SPECT instruments were analyzed. The phantom used in the experiment was a 20 x 10 cm cylinder filled with homogeneous 99mTc solution, containing two kinds of cold spots (cold rod phantoms). One had a water-filled cylinder 5.5 cm in diameter positioned 2.5 cm from the center. The other contained 6 water-filled cylinders of various sizes. Contrasts of cold regions were in the range from 74% to 120% (true 100%). Another phantom had the shape of a pie-chart divided into six chambers symmetrically positioned in a cylinder 20 cm in diameter and 10 cm in height. Each chamber had volume of 480 ml and contained homogeneous 99mTc solution of different concentrations. This phantom was used to test for linearity between the radio activity concentration and reconstructed count density (linearity phantom). The intercept of the regression line obtained from the linearity phantom was 8.4 kBq ml-1 without scatter correction and -6.8 kBq ml-1 with scatter correction. Contrast was in the range from 78% to 132% (true 100%). The mean relative error for the measured activity concentration was 4.9% +/- 3.5% (mean +/- sd).
Phantoms, Imaging↗
Left ventricular function at rest and during bicycle exercise in normal subjects: assessment by ECG-gated myocardial perfusion SPET with 99Tcm-tetrofosmin.
99Tcm-labelled myocardial perfusion tracers allow simultaneous assessment of myocardial perfusion and left ventricular function using ECG-gated SPET. The aim of this study was to evaluate left ventricular performance during exercise by means of ECG-gated myocardial perfusion SPET. After the administration of 99Tcm-tetrofosmin (555-740 MBq), eight healthy volunteers aged 27-49 years underwent ECG-gated myocardial perfusion SPET at rest and during supine submaximal exercise (75 and 125 W), for 3 min each. Using ECG-gated SPET data, left ventricular end-diastolic volume (LVEDV) demonstrated a biphasic response during exercise (from 106.4 +/- 17.5 to 119.9 +/- 19.9 to 108.1 +/- 19.2 ml). In contrast, left ventricular end-systolic volume decreased gradually and significantly during exercise (from 47.1 +/- 11.9 to 41.5 +/- 8.9 to 36.1 +/- 10.1 ml; P < 0.05), and left ventricular ejection fraction continued to increase at higher workloads (from 56.1 +/- 6.0 to 63.0 +/- 2.7 to 67.0 +/- 4.3; P < 0.01) despite a fall in LVEDV. There was a progressive increase in cardiac output during exercise, which reached a peak of 7.2 +/- 0.9 l.min-1. We conclude that ECG-gated myocardial perfusion SPET can assess left ventricular function during exercise and may provide useful information for the evaluation of patients with ischaemic heart disease.
Adult↗
Crossed cerebellar diaschisis: the role of motor and premotor areas in functional connections.
The authors assessed the relationship between crossed cerebellar diaschisis (CCD) and cortico-pontine cerebellar pathway (CPCP) damage in 29 chronic supratentorial infarct patients to elucidate the role of motor and premotor areas for functional cerebro-cerebellar connections. The CCD rate was calculated from side-to-side cerebellar count differences on 123I-IMP single-photon emission computerized tomography images. Neuronal damage was estimated by the three scores of computed tomography density from equal to normal brain tissue (score 0) to equal to cerebrospinal fluid (score 2) in the 4 major regions on CPCP; frontal association, motor and premotor, sensory and parietal associations, and the posterior limb of the internal capsule. Two-factor factorial ANOVA by the score and the region revealed significant differences of the CCD rate in the score factor (score 0 or 1 vs. score 2, p = < 0.05) and the independency of these two factors. Categories determined by the scores in each region were analyzed by multiple stepwise regression analysis using the theory of quantification I, in which significant correlation only between CCD and the necrotic density (score 2) in motor and premotor areas were demonstrated (r = 0.515, p = < 0.05). The authors conclude that neuronal loss in motor and premotor areas seem to contribute significantly to functional cerebro-cerebellar disconnections.
Adult↗
[Myocardial distribution of iodine-123-iodophenyl-9-methyl-pentadecanoic acid (9MPA) in patients with acute myocardial infarction: comparison with regional wall motion obtained from technetium-99m-sestamibi gated SPECT].
123I-iodophenyl-9-methyl-pentadecanoic acid (9MPA) is a modified long-chain (15 carbons) fatty acid with a methyl branch on its 9 carbon location. Myocardial SPECT images (two sets, 10 min each) were obtained starting 10 min (early phase) and 50 min (delay phase) after the injection of 160 MBq 123I-9MPA at rest in 10 patients with acute myocardial infarction. The segmental myocardial uptake (% uptake) and clearance (% washout) from early to delay image were calculated by the SPECT data. ECG-gated myocardial SPECT with 99mTc-sestamibi was also performed and segmental left ventricular (LV) wall motion was evaluated using QGS (quantitative gated SPECT) program. The % uptake of LV segments with hypokinetic or akinetic wall motion were significantly lower than those with normokinesis (p < 0.01) for both early and delay phases. The % washout of hypokinetic segments were significantly lower than those of normokinetic regions (p < 0.01), while the % washout of akinetic segments were significantly higher than those of severely hypokinetic segments (p < 0.05). Thus, 123I-9MPA myocardial distribution and clearance thought to be associated with left ventricular regional wall motion.
Fatty Acids↗
[Assessment of left ventricular contraction abnormalities with myocardial infarction using gated technetium-99m sestamibi SPECT: comparison of wall thickening and regional ejection fraction analysis for the detection of coronary artery stenosis].
ECG-gated myocardial Technetium-99m sestamibi SPECT is a useful technique to measure myocardial perfusion and function simultaneously. In this study, wall thickening (WT) and regional ejection fraction (rEF) using ECG-gated SPECT have been studied to determine which parameter would be more sensitive to detect coronary artery stenosis in patients with acute myocardial infarction (AMI). Forty-five patients (36 men, 9 women, mean age 63 +/- 9 years old) with AMI were examined. CAG was performed for all patients. ECG-gated SPECT was performed 60 min after the intravenous injection of 555 MBq 99mTc-sestamibi at rest. Commercially available software (QGS) was used to produce WT and rEF polar maps from acquired SPECT data. The WT and rEF polar maps were evaluated visually and quantitatively. WT indicated higher sensitivity (80.3% vs. 59.1%, p < 0.05) and accuracy (86.7% vs. 74.8%, p < 0.05) than rEF for detecting overall coronary artery stenosis on visual interpretation. On quantitative analysis, WT had higher specificity (91.3% vs. 75.4%, p < 0.05) and accuracy (85.9% vs. 72.6%, p < 0.05) than rEF for detecting overall coronary artery stenosis, and showed a higher specificity (93.8% vs. 59.4%, p < 0.01) and accuracy (88.9% vs. 62.2%, p < 0.01) for detecting LCX stenosis. Moreover, sensitivity of WT for detecting coronary artery stenosis without infarction was higher than that of rEF significantly in quantitative analysis (75.0% vs. 31.3%, p < 0.05). These results suggested that WT was superior to rEF for detecting the coronary artery stenosis in patients with and without myocardial infarction. We concluded that WT is more sensitive indicator to determine localization of regional left ventricular dysfunction in AMI than rEF.
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Increased bone mineral turnover without increased glucose utilization in sclerotic and hyperplastic change in fibrous dysplasia.
Fibrous dysplasia is a benign bone disorder. It is diagnosed by distinctive X-ray radiography, CT, and MRI findings. Although bone scintigraphy helps to identify the tumor origin according to accelerated bone turnover, the glucose metabolism in fibrous dysplasia has not yet been investigated. We reported a case of fibrous dysplasia in craniofacial bone which showed signs of the acceleration of bone mineral turnover without elevated glucose utilization by Technetium-99m-HMDP SPECT and Fluorine-18-FDG PET. We concluded that the growth of fibrous dysplasia needed the acceleration of bone mineral turnover without an increase in glucose metabolism.
Bone Density↗
Rapid data acquisition protocol in ECG-gated myocardial perfusion SPECT with Tc-99m-tetrofosmin.
Into 25 patients with heart disorders, 99mTc-tetrofosmin 555-740 MBq was injected intravenously at rest. After 40 minutes, ECG-gated myocardial perfusion SPECT was performed with a two detector gamma camera VERTEX (ADAC), setting up two detectors to form a 90-degree angle. Sixteen frames per R-R interval were acquired during a 180 degree rotation from the RAO 45 degrees to the LPO 45 degrees. A pair of data sets with standard (SDA) and rapid data acquisition (RDA) protocols was collected. In an SDA protocol, SPECT imaging was performed for 50 sec per step in 5 degree angular steps (total acquisition time; 15 minutes). An RDA protocol was conducted with 12 sec per step, 6 degree angular steps (acquisition time, 3 minutes). LVEF (%) and LVEDV (ml) quantitated automatically with a QGS program showed excellent correlations between two protocols with correlation coefficients of 0.980 (p < 0.01) and 0.983 (p < 0.01), respectively. Subsequently visual assessment of regional wall motion based on a four-point grading system was carried out with a 3-D cine LV display. High complete agreement was gained with 158 (90.3%) out of total 175 segments, so that assessment of the global and regional LV function with the RDA protocol demonstrated high reliability and feasibility.
Electrocardiography↗
The discrepancy between 99Tcm-ECD dynamic and static SPET images in patients with ischaemic lesions corresponds to reduced vasoreactivity to acetazolamide.
We evaluated 99Tcm-N,N'-(1,2-ethylenediyl)bis-L-cysteine diethyl ester (99Tcm-ECD) dynamic and static SPET (single photon emission tomographic) images to examine 99Tcm-ECD kinetics under ischaemic cerebrovascular conditions. In 20 patients who showed arterial occlusion on magnetic resonance angiography, dynamic (0-10 min) and static (15-35 min) SPET images were acquired after the intravenous administration of 99Tcm-ECD. Thirteen of the patients had focal perfusion deficits that were more evident on the dynamic than on the static images; the other seven showed no such discrepancy. In those patients with a mismatch between the dynamic and static images, the extent corresponded to reduced vaso-reactivity to acetazolamide. Based on quantitative analysis of the ratio of tracer uptake in affected to that in unaffected areas, the patients with discrepant findings showed significantly different ratios on the dynamic and static images, whereas those with no such mismatch did not. Our results suggest that dynamic 99Tcm-ECD images provide circulatory information and that static images reflect a filling-in phenomenon of ECD metabolites in ischaemic lesions. 99Tcm-ECD dynamic and static SPET images offer an alternative method of detecting mild perfusion deficits without the need for acetazolamide challenge.
Acetazolamide↗
[99mTc-tetrofosmin exercise leg perfusion scintigraphy in arteriosclerosis obliterans (ASO)--assessment of leg ischemia using two phase data acquisition].
Twenty-one patients with arteriosclerosis obliterans (ASO) were studied with 99mTc-tetrofosmin exercise leg perfusion scintigraphy using the delayed administration method. In this method, tracer was injected 4 minutes after termination of symptom-limited repetitive climbing of a stair to validate prolonged vasodilatation in an ischemic lower limb after exercise. Visual and quantitative analyses were performed to evaluate a diseased leg using dynamic and static images. On a posterior whole body image, all cases except one showed decreased foot uptake in the affected side (affected normal ratio; ANR = 0.82 +/- 0.14). On dynamic images, 9 cases showed transient hyper-accumulation (blush phenomenon) only in the thigh of the affected side suggesting that this valuable finding may be a useful diagnostic sign to distinguish a diseased leg. Sensitivity and positive predictive value were 71.4% and 93.8% to detect a diseased leg based on more than one finding of non-visualization of ilio-femoral artery, muscle-soft tissue blush, and early venous return in a dynamic study. Moreover, a low uptake of ANR of below 0.90 in the foot in the static study gave an improved sensitivity of 85.7%. The transit time of the diseased legs (12.0 +/- 3.1 sec.) which was determined as the interval between the time of arterial and venous peak counts was significantly shorter than that of normal legs (17.3 +/- 4.5 sec.; p < 0.0001, paired t-test). The cases with blush phenomenon showed significantly higher thigh ANR (1.04 +/- 0.11) than those without (0.94 +/- 0.08; p < 0.05, unpaired t-test). These results could reflect prolongation of a hypervascular state after exercise in a diseased leg which sometimes induced blush phenomenon at arterial phase and high leg uptake at static phase. This scintigraphy is useful for the detection of a diseased leg as well as for grasping changes of vascular regulation after stress in patients with ASO.
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[The usefulness and the problems of attenuation correction using simultaneous transmission and emission data acquisition method: studies on normal volunteers and phantom].
Attenuation correction using simultaneous transmission data (TCT) and emission data (ECT) acquisition method was applied to 201Tl myocardial SPECT with ten normal adults and the phantom in order to validate the efficacy of attenuation correction using this method. Normal adults study demonstrated improved 201Tl accumulation to the septal wall and the posterior wall of the left ventricle and relative decreased activities in the lateral wall with attenuation correction (p < 0.05: paired t-test). The counts of the posterior wall were however, significantly higher than those of the anterior wall and the lateral wall (p < 0.05: unpaired t-test). Moreover, relative low uptake of the apex was enhanced using attenuation correction. Static phantom studies revealed the self scatter from high 201Tl uptake organs such as the liver and the stomach pushed up the activities in the septal wall and the posterior wall. Cardiac dynamic phantom studies showed partial volume effect due to cardiac motion contributed to under-correction of the apex, which might be overcome using gated SPECT. Although simultaneous TCT and ECT acquisition was conceived of the advantageous method for attenuation correction, miss-correction of the special myocardial segments should be taken into account in assessment of attenuation correction compensated images.
Adult↗
[Assessment of left ventricular systolic function derived from ECG-gated myocardial SPECT with 99mTc-tetrofosmin: automatic determination of LV epi- and endocardial surface].
Non-invasive assessment of ischemic heart disease requires information of both LV function and myocardial perfusion. Recently, ECG-gated myocardial SPECT with technetium-labeled radiopharma-ceuticals can provide both of them. Gated myocardial SPECT were performed in thirty-three patients with cardiac disease using a two-headed rotating gamma camera system (ADAC; VERTEX), 30-60 minutes after resting injection of 555-740 MBq of 99mTc-Tetrofosmin. Then, the SPECT data were used to determine the LV epi- and endocardial surface, and LV volume for measurement of LVEF was calculated automatically. This entire computational process required only 210 seconds per 16 frame study. Interobserver agreement of EF values obtained from gated SPECT was excellent (r = 0.996, n = 10, p < 0.01). LVEFs obtained from gated SPECT showed good correlation to those calculated from radionuclide ventriculography (MUGA) (r = 0.91, p < 0.01). In conclusion, this automatic method using gated myocardial SPECT data was considered to be useful for assessment of LV function with reproducibility.
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[Assessment of cerebral circulation using echo planar imaging--basic analysis in quantitating the mean transit time, cerebral blood flow, and cerebral blood volume].
The mean transit time (MTT), cerebral blood flow (CBF) and cerebral blood volume (CBV) using echo planar imaging (EPI) in 22 aged volunteers were measured based on moment analysis and gamma variate method. The first peak of signal intensity curve (p delta R2.) and the area under the curve after the first peak (AUC) were calculated according to the height over area method, as a convenient quantification. Then, MTT, CBF, and CBV were compared with AUC/p delta R2, p delta R2, and AUC, respectively. There was a good correlation between each other parameter (r = 0.67 - 0.92, every p < 0.001). The slow upward slope and the low peak height, however, caused a larger error between each other parameter.
Blood Flow Velocity↗
[Assessment of regional microcirculatory changes by EPI perfusion studies in patients with multiple lacunar infarction].
The aim of this report is to assess regional cerebral microcirculatory changes by EPI perfusion study in patients with multiple lacunar infarction(MLI). Especially, we focused on the parameter(rCBV, MTT, rCBF) changes in the white matter and on the relationship between these changes in the gray and white matter. Twenty MLI patients(mean age 72 +/- 15 years) and 10 age-similar normal controls (mean age 65 +/- 12 years) were examined. As a result, the MLI patients demonstrated an insignificant rCBF reduction due to the rCBV elevation in the gray matter and a moderate rCBF reduction with less rCBV elevation in the white matter. These results show a difference in the vascular reserve between the gray and white matter, and insufficiency of the vascular reserve in MLI's white matter.
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