Catheter probe endoscopic ultrasonography by using cold lubricating jelly-filled method for esophageal subepithelial tumors.

Catheter probe endoscopic ultrasonography (C-EUS) by ultrasonographic jelly-filled method has been used to evaluate esophageal subepithelial tumors (SETs). Ultrasonographic jelly is safe on the skin, but its internal safety has not been demonstrated. The jelly stored at room temperature is easily injected into the esophagus through the instrument channel of the endoscope. However, using jelly stored at room temperature remains problematic because the jelly is drained rapidly. We used cold lubricating jelly and an intravenous extension tube to resolve these problems. In this study, we evaluated the safety and efficacy of cold lubricating jelly-filled method. The medical records of patients who underwent C-EUS by using water or cold lubricating jelly-filled method for esophageal SETs from March 2013 to September 2016 in Gangneung Asan hospital were reviewed. Clinical characteristics and EUS findings were evaluated retrospectively. Image quality and procedure time between water and cold lubricating jelly-filled method were compared retrospectively. This study included 138 patients (74 males, 64 females) with esophageal SET with a mean age of 57.1 ± 11.1 years. Thirty-four patients had lesions in the upper esophagus, 58 patients had lesions in the middle esophagus, and 46 patients had lesions in the lower esophagus. The EUS diagnoses were leiomyoma (82.6%), hemangioma (4.3%), extrinsic compressive lesion (3.6%), granulosa cell tumor (2.9%), ectopic calcification (1.4%), cyst (1.4%), lipoma (0.7%), varix (0.7%), and inconclusive lesion (2.2%). The mean image score in the cold lubricating jelly filled-method group was higher than that in the water-filled method group (3.2 ± 0.7 vs. 2.8 ± 0.7, P = 0.002). The procedure time in the cold lubricating jelly filled-method group was shorter than that in the water-filled method group (10 minutes 27 seconds ± 4 minutes 22 seconds versus 13 minutes 20 seconds ± 6 minutes 20 seconds, P = 0.045). No procedure-related complication was observed. C-EUS using the cold lubricating jelly-filled method seems to provide better image quality and shorter procedure time compared with C-EUS using the water-filled method.

Correlation of Asymmetry Indices Measured by Arterial Spin-Labeling MR Imaging and SPECT in Patients with Crossed Cerebellar Diaschisis.

BACKGROUND AND PURPOSE: Crossed cerebellar diaschisis, not only a secondary result of supratentorial infarction but also an indicator of clinical outcomes, has frequently been reported on PET and SPECT but has been rarely described with arterial spin-labeling MR imaging. The purpose of this study was to determine the ability of arterial spin-labeling MR imaging to evaluate crossed cerebellar diaschisis compared with that of SPECT. To our knowledge, this is the first study to validate arterial spin-labeling in crossed cerebellar diaschisis by using SPECT as a reference standard. MATERIALS AND METHODS: This study included 16 patients in whom crossed cerebellar diaschisis was shown on SPECT and 10 control subjects in whom crossed cerebellar diaschisis was not shown on SPECT. During the qualitative analysis, asymmetric cerebellar perfusion on arterial spin-labeling was divided into 1 of the following 3 grades by 2 blinded observers: the affected cerebellum was isointense compared with the unaffected cerebellum (grade I), it was slightly hypointense (grade II), or it was markedly hypointense (grade III). In the quantitative analysis, asymmetry indices were calculated by using SPECT and arterial spin-labeling images. For statistical analysis, κ statistics, the interobserver correlation coefficient, the independent t test, Pearson correlation, and linear regression analysis were used. RESULTS: Almost all the diagnoses of crossed cerebellar diaschisis on SPECT were noted on arterial spin-labeling in both qualitative and quantitative analyses with good interobserver agreement (κ = 0.961; interobserver correlation coefficient, 0.806). The mean asymmetry index of arterial spin-labeling (26.06 ± 9.00) was significantly larger than that for SPECT (15.28 ± 5.34; P < .001). There was a significant positive correlation between the asymmetry indices obtained for SPECT and those for arterial spin-labeling (r = 0.77 [95% CI, 0.443-0.916]; P < .001). The relationship of asymmetry indices between SPECT and arterial spin-labeling (x, y) was calculated as y = 6.2131 + 1.2986x (R(2) = 0.592; P < .001). CONCLUSIONS: Arterial spin-labeling can be a noninvasive alternative to SPECT for evaluating crossed cerebellar diaschisis.

Monitoring differentiated thyroid cancer patients with negative serum thyroglobulin. Diagnostic implication of TSH-stimulated antithyroglobulin antibody.

AIM: Serum antithyroglobulin antibody (TgAb) has been reported as a surrogate marker for differentiated thyroid cancer (DTC) in some conditions. We investigated changes in serum TgAb levels after stimulation with thyroid-stimulating hormone (TSH) and the clinical implications for monitoring DTC. PATIENTS, METHODS: We retrospectively enrolled 53 DTC patients who had undergone total thyroidectomy and were negative for serum Tg and positive for TgAb. Patients underwent high-dose radioactive iodine treatment, and serum TgAb was measured before (TgAbBAS) and after TSH stimulation (TgAbSTIM). TgAb was followed up 6 to 12 months later (TgAbF/U). The change in TgAb after TSH stimulation (∆TgAbSTIM) was calculated as a percentage of the baseline level. Patient disease status was classified into no residual disease (ND) and residual or recurred disease (RD) by follow-up imaging studies and pathologic data. The characteristics and diagnostic value of serum TgAb levels and ∆ TgAbSTIM were investigated with respect to disease status. RESULTS: 38 patients were in the ND group and 15 were in the RD group. TgAbBAS, TgAbSTIM and TgAbF/U were significantly higher in the RD compared to the ND group (p = 0.0008, 0.0002, and < 0.0001, respectively). ∆TgAbSTIM was also significantly higher in the RD group (p = 0.0009). In the patients who presented with obviously high (≥ 50%) or low (< -50%) ∆ TgAbSTIM, the proportions in the RD group were markedly different at 100% and 7%, respectively. ∆ TgAbSTIM had significant diagnostic value for RD (p < 0.001). CONCLUSION: The change in serum TgAb level after TSH stimulation is different between the RD and ND groups, and thus, it may be used as a surrogate diagnostic marker for DTC when the serum Tg is negative and TgAb is positive.

Significance of smoking history and FDG uptake for pathological N2 staging in clinical N2-negative non-small-cell lung cancer.

BACKGROUND: This study was conducted to evaluate whether smoking history and the standardized uptake value (SUV) of 2-[fluorine-18]fluoro-2-deoxy-D-glucose (FDG) uptake are associated with unexpected pathological N2 status (pN2) in non-small-cell lung cancer (NSCLC). PATIENTS AND METHODS: We analyzed the data of 220 patients who underwent surgical resection with clinical N2-negative status on computed tomography (CT) and positron emission tomography (PET)-CT. The maximum SUV of primary tumor was chosen for logistic analysis. RESULTS: Seventy-two patients (33%) had never smoked. The SUV ranged from 1.0 to 29.0 (median 9.1). In univariate analysis, adenocarcinomas (P = 0.019), female gender (P = 0.010), N1 on CT (P = 0.025), and N1 PET-CT (P = 0.001) were associated with a high probability of pN2. The proportion of pN2 in never smokers was higher than in ever smokers (26% versus 10% respectively; P = 0.002). The SUV remained on a multivariate logistic model (odds ratio 1.1; 95% confidence interval 1.0-1.2; P = 0.010) and it had a better predictive value in never smokers than in ever smokers (P = 0.017). CONCLUSIONS: This study indicates an association between smoking history and pN2 in clinically negative N2 NSCLC. The different roles of FDG uptake were also suggested based on smoking history.

A potential role for skeletal muscle caveolin-1 as an insulin sensitivity modulator in ageing-dependent non-obese type 2 diabetes: studies in a new mouse model.

AIMS/HYPOTHESIS: Type 2 diabetes mellitus is a common age-dependent disease. We discovered that male offspring of non-diabetic C57BL/6 and DBA/2 mice, called JYD mice, develop type 2 diabetes when they grow old. JYD mice show characteristics of insulin resistance, hyperglycaemia and hyperinsulinaemia in old age without obesity. We postulated that the mechanism of age-dependent type 2 diabetes in this model relates to caveolin-1 status in skeletal muscle, which appears to regulate insulin sensitivity in the mice. METHODS: We compared insulin sensitivity in aged C57BL/6 and JYD mice using glucose and insulin tolerance tests and (18)F-fluorodeoxyglucose positron emission tomography. We also determined insulin signalling molecules and caveolin proteins using western blotting, and altered caveolin-1 levels in skeletal muscle of C57BL/6 and JYD mice using viral vector systems, to examine the effect of this on insulin sensitivity. RESULTS: In 30-week-old C57BL/6 and JYD mice, the basal levels of IRS-1, Akt and peroxisome proliferator-activated receptor-gamma decreased, as did insulin-stimulated phosphorylation of Akt and insulin receptor beta. However, caveolin-1 was only increased about twofold in 30-week-old JYD mice as compared with 3-week-old mice, whereas an eightfold increase was seen in C57BL/6 mice. Downregulation of caveolin-1 production in C57BL/6 mice caused severe impairment of glucose and insulin tolerance. Upregulation of caveolin-1 in aged diabetic JYD mice significantly improved insulin sensitivity with a concomitant increase of glucose uptake in the skeletal muscle. CONCLUSIONS/INTERPRETATION: The level of skeletal muscle caveolin-1 is correlated with the progression of age-dependent type 2 diabetes in JYD mice.

Usefulness of (18)F-fluorodeoxyglucose PET for radiosurgery planning and response monitoring in patients with recurrent spinal metastasis.

INTRODUCTION: With the advancement and successful treatment of metastatic spinal cord disease, newer treatments are needed for the long-term survivors of recurrent disease. The lack of a standardized re-treatment regimen and the difficulty in delineating the tumor margins among patients who have received the treatment with metallic spinal fixation and conventional radiation are two of the challenges to be faced in recurrent metastatic spinal cord disease. In these patients, we applied hypofractionated stereotactic radiosurgery by defining the tumor margin with (18)F-fluorodeoxyglucose (FDG) positron emission tomography (PET). PATIENTS AND METHODS: Three consecutive recurrent spinal metastasis patients underwent the CyberKnife treatment (Accuray, Inc., Sunnyvale, CA) from March 2004 to July 2004. A three-fraction schedule was applied at approximately 24 hour intervals. One patient had sarcoma and the other two patients had breast cancer. All patients had received previous conventional radiotherapy after operation ranging from 30 Gy to 45 Gy. CT-based planning was corrected by the FDG-PET hyperuptake area with the help of nuclear medicine. The mass responses were followed not only by MRI but also by FDG-PET, which was taken prior to treatment, and at one and six months after the treatment. The changes in standard uptake value (SUV) of serial PET were taken as a measure of response. To evaluate the relative SUV changes from different pretreatment values, we set a reduction index (RI), which represents the ratio of SUV change to pretreatment SUV. RESULTS: No significant complications were noted during treatment with a mean follow-up of 13.3 months. The tumor volume on CT-based planning was 2.2 times larger than that of the CT-PET combined planning in case 1 of paraspinal muscle invasion. But the tumor volumes showed minimal changes in the other cases, in which the metastatic tumors were confined to the vertebral bodies. The SUV one month after treatment showed variable decreases and the RI ranged from 0.07 to 0.7. However, the SUVs at 6 months were well correlated with the clinical results. One patient showed marginal failure and the other two patients showed local control of the tumor, as their RI values were 0.65 and 0.87, respectively. CONCLUSION: To our knowledge, this is the first report using FDG-PET with radiosurgery in patients with recurrent spinal metastases hidden under metallic artifacts. The mass responses measured by SUV changes in FDG-PET correlated with the clinical results.

Parametric image of myocardial blood flow generated from dynamic H2(15)O PET using factor analysis and cluster analysis.

Algorithm-based parametric imaging of myocardial blood flow (MBF), as measured by H2(15)O PET, has been the goal of many research efforts. A method for generating parametric images of regional MBF by factor and cluster analysis on H2(15)O dynamic myocardial PET was validated by its comparison with gold-standard MBF values determined invasively using radiolabelled microspheres. Right and left ventricular blood pool activities and their factor images were obtained by the application of factor analysis to dynamic frames. By subtraction of the factor images multiplied by their corresponding values on the factors from the original dynamic images for each frame, pure tissue dynamic images were obtained, from which arterial blood activities were excluded. Cluster analysis that averaged pixels having time-activity curves with the same shape was applied to pure tissue images to generate parametric MBF images. The usefulness of this method for quantifying regional MBF was evaluated using canine experiment data. H2(15)O PET scans and microsphere studies were performed on seven dogs at rest and after pharmacological stress. The image qualities and the contrast of parametric images obtained using the proposed method were significantly improved over either the tissue factor images or the parametric images obtained using a conventional method. Regional MBFs obtained using the proposed method correlated well with those obtained by the region of interest method (r = 0.94) and by the microsphere technique (r = 0.90). A non-invasive method is presented for generating parametric images of MBF from H2(15)O PET, using factor and cluster analysis.

188Re-tin-colloid as a new therapeutic agent for rheumatoid arthritis.

Radiation synovectomy is a useful treatment modality in patients with refractory synovitis. We have developed a 188Re-tin-colloid as a new radiopharmaceutical agent and investigated its efficacy and safety in patients with rheumatoid arthritis. Radiation synovectomy was performed using 188Re-tin-colloid in 22 knees from 21 rheumatoid arthritis patients refractory to intra-articular corticosteroid injection. The efficacy and safety of administration of 370-1110 MBq of 188Re-tin-colloid were evaluated after 1, 3, 6, 9 and 12 months. Pain intensity on a visual analogue scale decreased significantly 12 months after therapy (mean+/-SD: 68.0+/-26.1 mm vs. 25.1+/-23.4 mm; P=0.0001 by the paired t-test). Pain decreased in 19 cases (86.3%), joint tenderness improved in 14 cases (63.6%) and joint swelling was reduced in all cases (100%). 188Re-tin-colloid was safe. The residual activity of 188Re in the blood was 0.077%+/-0.25% of the injected dose. The radioactivity of 188Re in the urine was 0.14%+/-0.13% of the injected dose. Transient reactive synovitis was observed in 18 cases (81.8%). No clinical side-effects or abnormalities in leucocyte count, platelet count, liver function tests or urine analysis were observed in any patient. In conclusion, in this first study of radiation synovectomy using 188Re-tin-colloid for patients with rheumatoid arthritis, the treatment resulted in the improvement of arthritis and was well tolerated.

Blind separation of cardiac components and extraction of input function from H(2)(15)O dynamic myocardial PET using independent component analysis.

UNLABELLED: The independent component analysis (ICA) method is suggested to be useful for separation of the ventricles and the myocardium and for extraction of the left ventricular input function from the dynamic H(2)(15)O myocardial PET. The ICA-generated input function was validated with the sampling method, and the myocardial blood flow (MBF) calculated with this input function was compared with the microsphere results. METHODS: We assumed that the elementary activities of the ventricular pools and the myocardium were spatially independent and that the mixture of them composed dynamic PET image frames. The independent components were estimated by recursively minimizing the mutual information (measure of dependence) between the components. The ICA-generated input functions were compared with invasively derived arterial blood samples. Moreover, the regional MBF calculated using the ICA-generated input functions and single-compartment model was correlated with the results obtained from the radiolabeled microspheres. RESULTS: The ventricles and the myocardium were successfully separated in all cases within a short computation time (<15 s). The ICA-generated input functions displayed shapes similar to those obtained by arterial sampling except that they had a smoother tail than those obtained by sampling, which meant that ICA removed the statistical noise from the time--activity curves. The ICA-generated input function showed a longer time delay of peaks than those obtained by arterial sampling. MBFs estimated using the ICA-generated input functions ranged from 1.10 to approximately 2.52 mL/min/g at rest and from 1.69 to approximately 8.00 mL/min/g after stress and correlated well with those calculated with microspheres (y = 0.45 + 0.98x; r = 0.95, P < 0.000). CONCLUSION: ICA, a rapid and reliable method for extraction of the pure physiologic components, was a valid and useful method for quantification of the regional MBF using H(2)(15)O PET.

Reproducibility of an automatic quantitation of regional myocardial wall motion and systolic thickening on gated 99mTc-sestamibi myocardial SPECT.

UNLABELLED: We investigated the reproducibility of an automatic quantitative algorithm for measuring regional myocardial wall motion and systolic thickening. METHODS: 99mTc-sestamibi gated myocardial SPECT with dipyridamole stress was performed twice consecutively on 31 patients with known or suspected coronary artery disease, with the patients in the same position for each scan. With AutoQUANT software, segmental wall motion and systolic thickening were quantified automatically and expressed in millimeters and percentage increase, respectively, for 20 segments. Afterward, the correlation and agreement between repeated measurements were investigated, and the influences of wall location, perfusion grade, and partitioning of the myocardium on reproducibility were evaluated by ANOVA and t testing. RESULTS: High correlations (r = 0.95 for wall motion and 0.88 for systolic thickening) and good agreements (weighted kappa = 0.81 and 0.71, respectively) were obtained from repeated measurements on consecutive gated SPECT. Changes in wall location and perfusion grade did not cause significant differences between repeated measurements (P > 0.05 in ANOVA and t testing), but a change in partitioning did. On Bland-Altman analysis, 2 SDs for repeated wall motion and for systolic thickening were 2.0 mm and 20%, respectively. CONCLUSION: The automatic quantitative algorithm for myocardial SPECT provided by AutoQUANT software has good reproducibility under diverse conditions. A change of motion > 2.0 mm or a change of systolic thickening > 20% can be regarded as significant during a follow-up study using this software.

Quantification of regional myocardial blood flow using dynamic H2(15)O PET and factor analysis.

UNLABELLED: Because the use of factor analysis has been proposed for extracting pure physiologic temporal or spatial information from dynamic nuclear medicine images, factor analysis should be capable of robustly estimating regional myocardial blood flow (rMBF) using H2(15)O PET without additional C15O PET, which is a cumbersome procedure for patients. Therefore, we measured rMBF using time-activity curves (TACs) obtained from factor analysis of dynamic myocardial H2(15)O PET images without the aid of C15O PET. METHODS: H2(15)O PET of six healthy dogs at rest and during stress was performed simultaneously with microsphere studies using 85Sr, 46Sc, and 113SN: We performed factor analysis in two steps after reorienting and masking the images to include only the cardiac region. The first step discriminated each factor in the spatial distribution and acquired the input functions, and the second step extracted regional-tissue TACS: Image-derived input functions obtained by factor analysis were compared with those obtained by the sampling method. rMBF calculated using a compartmental model with tissue TACs from the second step of the factor analysis was compared with rMBF measured by microsphere studies. RESULTS: Factor analysis was successful for all the dynamic H2(15)O PET images. The input functions obtained by factor analysis were nearly equal to those obtained by arterial blood sampling, except for the expected delay. The correlation between rMBF obtained by factor analysis and rMBF obtained by microsphere studies was good (r = 0.95). The correlation between rMBF obtained by the region-of-interest method and rMBF obtained by microsphere studies was also good (r = 0.93). CONCLUSION: rMBF can be measured robustly by factor analysis using dynamic myocardial H2(15)O PET images without additional C15O blood-pool PET.

Limited incremental diagnostic values of attenuation-noncorrected gating and ungated attenuation correction to rest/stress myocardial perfusion SPECT in patients with an intermediate likelihood of coronary artery disease.

UNLABELLED: Either gated myocardial perfusion SPECT or attenuation-corrected SPECT can be used to improve specificity in the diagnosis of coronary artery disease (CAD). We investigated whether attenuation-noncorrected gating and ungated attenuation correction could improve the diagnostic performance of rest/stress perfusion SPECT in patients having an intermediate pretest likelihood of CAD. METHODS: Sixty-eight patients (29 men, 39 women; mean age, 59 +/- 12 y) with coronary artery stenosis > or =70% (1 vessel, n = 13; 2 vessels, n = 18; 3 vessels, n = 8; normal, n = 29) underwent rest attenuation-corrected 201TI SPECT and dipyridamole stress gated attenuation-corrected 99mTc-methoxyisobutyl isonitrile SPECT with an ADAC vertex camera. Three physicians graded the post-test likelihood of CAD for each arterial territory using a 5-point scale (1, normal; 2, possibly normal; 3, equivocal; 4, possibly abnormal; 5, abnormal). The sensitivity, specificity, and areas under receiver-operating-characteristic curves were compared for each operator by 3 methods: attenuation-noncorrected rest/stress SPECT, gated poststress SPECT plus attenuation-noncorrected rest/stress SPECT, and attenuation-corrected rest/stress SPECT plus gated poststress SPECT plus attenuation-noncorrected rest/stress SPECT. RESULTS: When higher than grade 3 was used as the criterion for CAD, no differences in sensitivity and specificity were found among the 3 methods for each operator. Areas under receiver-operating-characteristic curves for the diagnosis of CAD and stenosis revealed no differences for each modality (P > 0.05 for each comparison). CONCLUSION: In patients with an intermediate risk of CAD, viewing attenuation-noncorrected gated poststress SPECT and ungated attenuation-corrected rest/stress SPECT images did not improve the diagnostic performance for CAD and stenosis.

Dosimetry of rhenium-188 diethylene triamine penta-acetic acid for endovascular intra-balloon brachytherapy after coronary angioplasty.

To examine the possibility of using rhenium-188 diethylene triamine penta-acetic acid (DTPA) for endovascular intra-balloon brachytherapy after angioplasty, dose distribution around the balloon was calculated and validated by film dosimetry. Medical internal radiation dosimetry (MIRD) was calculated assuming that the balloon had ruptured and that the contents had been released into the systemic circulation. 188Re-perrhenate eluate from the 188W/188Re generator was concentrated using an ion column and used to label DTPA. The dose distribution around the angioplasty balloon (20 mm length, 3 mm diameter cylinder) was estimated by Monte Carlo simulation using the EGS4 code. The time required for 17.6 Gy to be absorbed at 1 mm from the balloon's surface following application of 3700 MBq/ml of 188Re was found to be 278 s. Fifty percent of the energy was deposited in the first millimetre of the vessel wall from the balloon's surface. The calculated radiation absorbed dose agreed with that measured by film dosimetry, which was performed using a water phantom, with errors ranging from 9.4% to 17%. Upon balloon rupture the total amount of 188Re-DTPA was presumed to enter the systemic circulation. The resulting radiation absorbed dose was calculated using the MIRDOSE3 program and residence times obtained from dogs and amounted to 0.0056 mGy/MBq to the whole body and 4.56 mGy/MBq to the urinary bladder. The absorbed dose of 188Re-DTPA to the whole body was one-tenth of that of 188Re-perrhenate. A window-based program was developed to calculate the exposure time and the radiation dose absorbed as a function of the 188Re concentration and the arbitrary distance from the balloon to the surrounding tissues. We conclude that 188Re-DTPA is easy to prepare, safe to use and suitable for intra-balloon brachytherapy after coronary angioplasty.

Reproducibility of assessment of myocardial function using gated 99Tc(m)-MIBI SPECT and quantitative software.

PURPOSE: We investigated the reproducibility of the quantification of left ventricular volumes and ejection fraction, and grading of myocardial wall motion and systolic thickening with gated myocardial single-photon emission computed tomography (SPECT) and Cedars quantification software. PATIENTS, MATERIALS AND METHODS: We performed post-stress gated myocardial SPECT in 33 consecutive patients twice sequentially in situ. Sixteen frames per cycle were used for gating. Using Cedars quantitative gated SPECT software ventricular volumes and ejection fraction (EF) were calculated. Wall motion and thickening was graded using 5- and 4-point scores, respectively. Coefficients of variation for re-examination of volumes and EF were calculated. Kappa values for assessing reproducibility of wall motion or wall thickening were calculated. RESULTS: Root mean square of errors was 5.0 ml for end-diastolic volume, 3.9 ml for end-systolic volume and 1.9% for EF. No bias or difference was found between the first and second acquisition by Bland-Altman analysis. Kappa values for wall motion and thickening of repeated acquisition was 0.76 and 0.87, respectively. The value of 2 SD from Bland-Altman analysis was 14.4 ml for EDV, 11.2 ml for ESV and 5.3% for EF. CONCLUSION: We conclude that quantification of functional indices and assessment of wall motion or thickening using gated 99Tc(m)-sestamibi (MIBI) SPECT was reproducible and we found that their ranges of physiological fluctuation were narrow enough.

Development of a method for measuring myocardial contractility with gated myocardial SPECT and arterial tonometry.

BACKGROUND: Gated myocardial single photon emission computed tomography (SPECT) and radial artery applanation tonometry were used, respectively, to quantify the time-volume curve of the left ventricle and to estimate ventricular pressure wave. We developed ways of determining end-systolic elastance (Ees) with the normalized-single-beat method and tested the reproducibility of these measurements. METHODS AND RESULTS: In patients with coronary artery disease (male/female = 33:2, age 66 +/- 10 years, ejection fraction 22% to 77%), rest thallium-201 gated/poststress technetium-99m sestamibi gated SPECT/24-hour rest Tc-99m sestamibi gated SPECT and arterial tonometry were performed. Quantitative gated SPECT software yielded a systolic time-volume curve, and tonometrically measured radial artery pressure wave yielded central aortic pressure wave. With systolic half of pressure-volume curve, void volume (Vo) was estimated and Ees was calculated. Over 71 measurements Ees ranged from 1.7 to 5.3 and Vo from -4 to 200 mL. Ejection duration, other indexes of central pressure waveform, end-diastolic volume, end-systolic volume, and ejection fraction were reproducible. The reproducibility of Vo was excellent (r = 0.97). Ees at rest (n = 15) showed fair reproducibility between Tc-99m-sestamibi and TI-201 SPECT (r = 0.51). CONCLUSION: With gated myocardial SPECT, a noninvasive method of quantifying myocardial global contractility was developed. Reproducibility of this measurement was sufficient for use in clinical routine. Ees measured by this method warrants validation by invasively measured Ees.

Idiopathic granulomatous hepatitis manifested with fever of unknown origin.

Idiopathic granulomatous hepatitis is a rare disease of unknown cause that is characterized by recurrent fevers and granuloma in the liver. Attempts to define an exact etiology of the fever of granulomatous hepatitis frequently do not yield a precise diagnosis. Idiopathic granulomatous hepatitis was confirmed after a thorough work up and negative cultures and serologies were obtained, and in the absence of another condition that could lead to granulomas in the liver. We have experienced a 67-year-old female patient who presented with prolonged fever for 2 months and revealed granuloma in liver biopsy. She was treated with glucocorticosteroid and defervescence resulted.

Transient behavior analysis of a mechanical monoleaflet heart valve prosthesis in the closing phase.

In this paper, an analysis of the dynamics in the closing phase of the occluder of a mechanical monoleaflet heart valve prosthesis is presented. The dynamic analysis of the fluid in the vicinity of the occluder was based on the control volume approach. The backflow velocity of the fluid was computed by applying the continuity and momentum equations in the unsteady state. By considering the fluid pressure and gravity as external forces acting on the occluder, the moment equilibrium on the occluder was employed to analyze the motion of the occluder during closing and the force of impact between the occluder and the guiding struts. The computed magnitudes of the occluder tip velocities, as well as the backflow of the fluid during the closing phase using this model, were in agreement with previously reported experimental measurements. The maximum impact force between the occluder and guiding struts of 140-280 N was determined to occur during the initial impact for a duration of 35-45 microseconds. The results of such model studies may be extended for the analysis of the endurance limit of the valve prostheses as well as to determine the mechanical stresses on the formed elements and the incipience of cavitation bubbles during the closing phase of the valve function.

Dynamic behavior analysis of mechanical monoleaflet heart valve prostheses in the opening phase.

In this paper, fluttering behavior of a mechanical monoleaflet tilting disk heart valve prostheses during the opening phase was analyzed. The impact between the occluder and the guiding strut at the fully open position was included in the analysis with a Bjork-Shiley monoleaflet aortic valve. The motion of the valve occluder was modeled as a rotating system, and equations were derived by employing the moment equilibrium principle. Forces due to lift, drag, gravity, and buoyancy were considered as external forces acting on the occluder. The 4th-order Runge-Kutta method was used to solve the governing equations. The results demonstrated that the occluder reaches the steady equilibrium position only after damped vibration. Fluttering frequency varies as a function of time after opening and is in the range of 8-84 Hz. Valve opening appears to be affected by the orientation of the valve relative to gravitational force. The opening velocities are in the range of 0.56-1.37 m/sec and the dynamic loads by impact of the occluder and the strut are in the range of 60-190 N.