Risk Factors for Postoperative Unfavorable Ambulatory Status After Spinal Surgery for Metastatic Spinal Tumor

STUDY DESIGN

A retrospective comparative study.

OBJECTIVE

This study aimed to investigate factors associated with postoperative unfavorable ambulatory status following surgery for metastatic spinal tumors using a nationwide in-hospital database.

SUMMARY OF BACKGROUND DATA

Surgical treatment for metastatic spinal tumors can improve the ambulatory status and quality of life. However, some patients fail to regain the ability to walk, thereby resulting in poor quality of life. No large-scale study has previously evaluated factors associated with postoperative poor ambulatory status in this clinical context.

MATERIALS AND METHODS

The Diagnosis Procedure Combination database from 2018 to 2019 was used to extract data from patients who underwent surgical procedures for spinal metastasis. Postoperative unfavorable ambulatory status was defined as (1) nonambulatory at discharge or (2) a decreased mobility score of the Barthel Index between admission and discharge. Multivariable logistic regression was used to evaluate factors associated with postoperative unfavorable ambulatory status while adjusting for confounders.

RESULTS

This study analyzed 1786 eligible patients. Of whom, 1061 (59%) patients were ambulatory on admission and 1249 (70%) on discharge. Postoperative unfavorable ambulatory status was observed in 597 (33%) patients, with a significantly lower rate of discharge to home (41%/81%, P <0.001) and a longer postoperative hospital stay (46.2 days/31.4 days, P <0.001). Multivariable regression analysis revealed male sex [odds ratio (OR): 1.43, P =0.002], laminectomy without fusion (OR: 1.55, P =0.034), Charlson Comorbidity Index of ≥7 (OR: 1.37, P =0.014), and preoperative nonambulatory status (OR: 6.61, P <0.001) as factors associated with postoperative unfavorable ambulatory status.

CONCLUSIONS

Our large-scale database analysis revealed that 33% of patients experienced unfavorable ambulatory status following spinal metastasis surgery. Laminectomy without fusion and preoperative nonambulatory status were among several factors influencing the prospect of unfavorable ambulatory status following surgery.

Fractures within 2 years of an obstetric hospitalization: analysis of nationwide administrative data in Japan

INTRODUCTION

Pregnancy- and lactation-associated osteoporosis (PLO) is a condition in which young women develop fractures during pregnancy or breastfeeding. Though PLO is a severely debilitating disease, its pathophysiology and epidemiology have not been clarified and its treatment has not been established. We aimed to identify the incidence and factors associated with fractures occurring within 2 years following an obstetric hospitalization.

MATERIALS AND METHODS

We extracted data on fractures occurring within 2 years of an obstetric hospitalization from the Japanese Diagnosis Procedure Combination database. We analyzed the implementation of bone mineral density and bone metabolism marker tests, prescription status, and factors associated with fractures occurring within 2 years of an obstetric hospitalization.

RESULTS

Among 837,347 patients with a history of obstetric hospitalization from 2010 to 2014, 379 patients had a history of hospitalization due to a fracture occurring within 2 years (4.5/10,000 pregnancies). Among the patients with fractures occurring within 2 years of an obstetric hospitalization, 6.7% underwent bone mineral quantification or a bone metabolism marker test, and 7.5% were prescribed a lactation inhibitor or osteoporosis treatment. Factors associated with fractures occurring within 2 years following an obstetric hospitalization identified included Cushing syndrome, Charlson Comorbidity Index score ≥ 1, age ≥ 40 years old at pregnancy, smoking history, and steroid administration.

CONCLUSION

We investigated fracture cases occurring within 2 years of an obstetrics hospitalization. This finding may be useful in selecting preventative measures for patients at risk of fractures within 2 years after obstetric hospitalization, including PLO.

Trends and safety of robot-assisted partial nephrectomy during the initial 2-year period after government approval in Japan: A nationwide database study from 2016 to 2018

OBJECTIVES

To evaluate the trends and safety of robot-assisted partial nephrectomy during the initial 2-year period after government approval for this type of procedure in April 2016.

METHODS

This nationwide retrospective study included 3722 received robot-assisted partial nephrectomy cases carried out from April 2016 to March 2018 in 124 participating institutions. The institutions were divided into lower- and higher-volume institutions according to the median of 19 robot-assisted partial nephrectomy cases during the study period. Surgical outcomes between 616 cases from lower-volume institutions and 3106 cases from higher-volume institutions were compared using propensity score matching.

RESULTS

During the study period, both the number of robot-assisted partial nephrectomy surgeries and the number of institutions in which the surgery was carried out steadily increased. Overall, the median anesthesia time was 217 min, the median postoperative length of stay was 9 days, and the proportion of blood transfusions, complications and readmissions were 0.8%, 5.1% and 1.0%, respectively. There were no significant differences in anesthesia time, incidence of blood transfusions, and complication rates between the lower-volume and higher-volume institutions. However, a slightly, but significantly, longer postoperative length of stay and a lower incidence of readmission were observed in lower-volume institutions both before and after propensity score matching.

CONCLUSIONS

Robot-assisted partial nephrectomy has become widespread during the initial 2-year period after government approval with an acceptable safety profile, regardless of the institutional caseloads. This technique has become a standard of care for stage 1 renal cancer patients in Japan.

Prevention of surgical site infection via antibiotic administration according to guidelines after gynecological surgery

AIM

We modified the antimicrobial prophylaxis of surgical site infection (SSI) according to the guidelines of the Japanese Society of Chemotherapy and Japan Society of Infectious Diseases (hereinafter referred to as optimization) and measured outcomes.

METHODS

From April 2016 to March 2017, we performed cesarean section and open hysterectomy with optimization, and compared the outcome to that of surgery performed without optimization between April 2014 and March 2016. We measured the rates of antibiotic discontinuation, appropriate antibiotic selection, SSI incidence, resumption of antibiotic therapy and fever incidence, as well as the length of postoperative hospital stay and medical expenses for antibiotics to evaluate the appropriateness and outcomes of antibiotic prophylaxis.

RESULTS

Optimization resulted in a change in the method of selecting antibiotics for cesarean section, but there was no change in SSI incidence rate (0.74% vs 0.0%, P = 0.36). Optimization reduced the use of antibiotics and medical expenses of hysterectomy (median reduction of 50% and 78% for hysterectomy without or with lymphadenectomy, respectively). However, there was no change in outcome regarding SSI incidence (5.7% vs 0.0%, P = 0.11 and 7.8% vs 9.5%, P = 0.77, respectively).

CONCLUSION

Appropriate use of antibiotics according to guidelines reduced antibiotic dose and medical expenses, but there was no change in outcome regarding SSI incidence rate. These findings suggested that implementation of dosing regimens according to the guidelines would be useful to reduce antibiotic medicine costs and prevent resistant bacteria and complications associated with antibiotics.

Morphological features of papillary muscles in the right ventricle

Our study was performed by dissecting formalinized cord, aiming at:the number of bodies of each papillary muscle in the right ventricle, the shape of the muscular body, also the morphological characteristics of the tendon chordaes. The anterior papillary muscles of the right ventricle, were studied on 54 cords, finding a total of 82 papillary muscles. Unique anterior papillary was found in 59.26% of case, representing 38.10% of total anterior papillary muscles.

In 29.63% of cases, the anterior papillary muscle was double and in 11.11% of cases was threefold. The conical shape we found in 57.32% of the anterior papillary muscles, and the cylindrical shape encountered in 29.27% of cases.

In case of double papilaery muscles, sometimes beeing joined at various levels between them, they realized particular aspects in each 2.44 % of cases, presenting the „N” and „H” letter appearance and in 1.22% of cases one of the two papilary presented an arcuate shape. At the unique papillary in one case (1.22%) we have found pyramidal forms and reversed „V” letter.

The valvular tendinous chordae of the anterior papillaries, we have pursued on a number of 78 papillary muscles and we found that most frequently they broke loose from the superior side, in 41.03% of cases detaching from the tip of conical unique papillaries romthe superior si of those cylindrical. The posterior papillar muscles of the rght ventricle we studied on 42 cords, presenting 69 papillary muscles. Single posterior papillary muscle we found in 52.38% of cases, in 33.33% of cases was double, triple in 11.90% of cases and in one case (2.38%) the posterior papillry was quadruple. Most commonly, the posterior papillary muscle presents a conical shape, aspect found in 65.22% of cases, in 27.54% of cases was cylindric, in 2.90% of cases we found a papillary muscle in reversed „Y” shape (at double papillary), and in one single case (1.54%) we found one arcuated papillary (in one double paillary), one irregular papillary (at unique papillaries) and one papillary in reversed „N” letter (between two muscular bodies of one triple papillary).

Valvular chordaes of the posterior papillary muscles, most frequently broke loose from the tip or superior edge of the papillary, aspect found in 35.48% of cases. Septal papillary muscles that we studied on 43 cords, were represented either by a number of 3-5 beams, or 5-9 simpe chordae tendons, both tipes could present or not at their origin on the septomarginal strip, a muscular cone. Rarely can present 1-3 large muscular cones that sometimes can be considered true papillary muscles.

We found the arterial muscle cone, present in all cases, beeing represented by chordae bundles arising from a muscular cone and rarely not showing muscular cone at his origin or can be represented by two beams of valvular chordae. We encountered one case where septal papillaries were represented by 3 conical muscular bodies, well represented, comparable in size with the anterior and posterior papillary muscles, especially the superior and inferior muscular bodies, the middle beeing shorter. We found in 13.95% of cases the existence of the posterior’s angle papillary muscle of the right ventricle, conical and cylindrical papillary muscle, that sent tendon chordae only to the septal leaflet.

Diagnostic possibility of diffusion tensor imaging for the evaluation of myometrial invasion in endometrial cancer: an ex vivo study

PURPOSE

To investigate the feasibility of magnetic resonance imaging (MRI) diffusion tensor imaging (DTI) for evaluating the myometrial invasion of uterine endometrial cancer.

MATERIALS AND METHODS

Twelve specimens of uterine endometrial cancer were obtained. The depth of myometrial invasion was classified as stage E (limited to the endometrium; n = 4), stage S (superficial invasion of less than 50% of the myometrium; n = 5), or stage D (deep invasion of greater than 50% of the myometrium; n = 3). The specimens were fixed in 10% formalin and stored at 4°C before imaging. At 15 hours after fixation, MRI was performed using a 4.7-T experimental imager/spectrometer system.

RESULTS

We found a high fractional anisotropy (FA) value zone (anisotropic zone) at the myometrium adjacent to the tumor on FA maps of histopathological stage S and stage D cancers, whereas the anisotropic zone did not exist in stage E cancers. Histopathological analysis showed that compared to the other regions, the anisotropic zone had tightly packed stromal tissue. The disruption of the anisotropic zone was consistent with myometrial invasion.

CONCLUSION

Our ex vivo study suggests that DTI might be a useful tool for the diagnosis of myometrial invasion of uterine endometrial cancer ex vivo.

Lactobacillus pentosus strain b240 suppresses pneumonia induced by Streptococcus pneumoniae in mice

AIMS

Oral administration of probiotics has been known to improve inflammatory responses against infectious diseases. Here, we describe the inhibitory effect of oral intake of heat-killed Lactobacillus pentosus strain b240 (b240) on pneumococcal pneumonia in a murine experimental model.

METHOD AND RESULTS

 The mice treated with oral b240 for 21 days before Streptococcus pneumoniae infection exhibited prolonged survival time and less body weight loss, compared with saline-treated control mice. Mild pneumonia with significantly reduced secretion of inflammatory cytokines/chemokines according to related mitogen-activated protein kinase signalling molecules (phosphorylated c-Jun N-terminal kinase) was found in b240-treated mice, whereas severe pneumonia with hypercytokinemia was evident in control mice. Prominent reduction in the number of pneumococci and elevated expression of Toll-like receptor 2 and 4 in the lung tissues was concomitantly noted in b240-treated mice.

CONCLUSIONS

These findings indicate that b240 has inhibitory effects on pneumococcal pneumonia induced by Strep. pneumoniae infection and improves inflammatory tissue responses, resulting in reduced damages to the respiratory tissues.

SIGNIFICANCE AND IMPACT OF THE STUDY

These results demonstrate that oral administration of b240 might protect host animals from Strep. pneumoniae infection by augmentation of innate immune response.

Involvement of Rho kinase in the pathogenesis of acute pulmonary embolism-induced polystyrene microspheres in rats

Acute pulmonary embolism (PE) is a life-threatening disease, and several vasoconstrictors, including endothelin-1 (ET-1), play a key role in vasoconstriction and hypoxemia during the development of PE. Rho kinase is activated by various vasoconstrictors resulting in vascular contraction and remodeling. Recent evidence has revealed an important role of Rho kinase in the pathogenesis of systemic and pulmonary vascular diseases. However, contribution of Rho kinase in PE remains unclear. We thus investigated the role of Rho kinase in the PE rat model induced by intrajugular administration of polystyrene microspheres (mean diameter, 26 microm). At 6 h following the administration of microspheres (1.5 ml/kg), right ventricular systolic pressure (RVSP) was higher in the PE than in the control rats (15.8 +/- 1.6 vs. 32.9 +/- 7.5 mmHg). Arterial oxygen tension was lower (92.3 +/- 12.5 vs. 66.0 +/- 17.7 Torr), and alveolar-arterial difference in oxygen partial pressure was higher (3.9 +/- 3.8 vs. 36.5 +/- 26.9 Torr) in the PE rats. Western blotting analysis revealed upregulation and downregulation in expression of vascular cell adhesion molecule-1 and endothelial nitric oxide synthase in lungs from the PE rats, respectively, and radioimmunoassay demonstrated an increase in plasma ET-1 levels. Lung Rho kinase alpha expression was greater in the PE rats. At 5 h following administration of microspheres (0.75 ml/kg), intravenous Rho kinase inhibitors HA1077 and Y27632 (3 mg/kg each) attenuated elevation of RVSP (22.0 +/- 3.7, 17.1 +/- 3.2, 14.3 +/- 2.6 mmHg, PE, PE+HA1077, PE+Y27632) and the severity of hypoxemia (66.3 +/- 16.2, 94.9 +/- 23.0, 89.1 +/- 8.5 Torr, PE, PE+HA1077, PE+Y27632) in the PE rats. These results suggest that pulmonary endothelial dysfunction and activation of Rho kinase may contribute to the potentiation of vasoconstriction and hypoxemia in the PE rats.

Chondroblastoma of the temporal bone

A rare case of chondroblastoma arising from the temporal bone that occurred in a 60-year-old woman is reported. The tumor appeared well demarcated and osteolytic on the radiographs. CT scan clearly depicted marginal and central calcification in the tumor. MR imaging demonstrated two components in the tumor: a solid component with predominantly low signal intensities on both T1- and T2-weighted sequences, and a multilocular cystic component with T1- and T2-elongation and fluid-fluid levels on the T2-weighted images. Postcontrast MR imaging revealed marked enhancement in the solid component and the septa of the cystic component.

[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.

Assessment of left ventricular diastolic function with electrocardiography-gated myocardial perfusion SPECT: comparison with multigated equilibrium radionuclide angiography

BACKGROUND

Technetium-labeled myocardial perfusion tracers allow the simultaneous assessment of myocardial perfusion and left ventricular function by electrocardiography (ECG)-gated myocardial perfusion single photon emission computed tomography (SPECT). This study evaluates left ventricular systolic and diastolic function by ECG-gated SPECT with the use of higher framing (32 frames per cardiac cycle) data acquisition.

METHODS AND RESULTS

After receiving an injection of technetium 99m tetrofosmin, 48 patients with cardiac diseases were examined by ECG-gated myocardial perfusion SPECT with a 3-headed gamma camera. During gated data collection, 32 frames per cardiac cycle were acquired over 360 degrees in 60 steps, each of which consisted of 60 beats. Immediately thereafter, the 32 frames taken at each projection angle were combined into 16-frame and 8-frame data sets. Left ventricular end-diastolic volume (LVEDV, in milliliters), left ventricular end-systolic volume (LVESV, in milliliters), and left ventricular ejection fraction (LVEF, percentage) were automatically calculated from the 32-frame, 16-frame, and 8-frame gated data sets. Left ventricular time-volume curves from the 3 data sets were generated by Fourier curve fitting analysis with the use of 3 harmonics, and then peak filling rate (PFR, per second) was measured. Twenty-nine patients also underwent multigated equilibrium radionuclide angiography (ERNA) to determine the LVEF and PFR. Combining the 32-frame data into 16-frame and 8-frame data sets from the 48 patients generated a smaller LVEDV and a larger LVESV, and LVEF was significantly lower in accordance with the decreasing number of frames. Compared with ERNA studies (n = 29), the Bland-Altman method showed underestimated LVEFs and larger 95% limits of agreement in lower framing gated SPECT.

CONCLUSIONS

Left ventricular functional parameters obtained from 32-frame gated SPECT correlated closely with those determined by ERNA studies. ECG-gated SPECT with 32-frame data can provide comprehensive information with which to evaluate many types of cardiac diseases.

[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.

Serial assessment of left ventricular function during dobutamine stress by means of electrocardiography-gated myocardial SPECT: combination with dual-isotope myocardial perfusion SPECT for detection of ischemic heart disease

BACKGROUND

Technetium-labeled myocardial perfusion tracers allow simultaneous assessment of myocardial perfusion and left ventricular function by electrocardiography (ECG)-gated myocardial single photon emission computed tomography (SPECT). The purpose of this study was to evaluate left ventricular performance during dobutamine stress by means of ECG-gated myocardial perfusion SPECT with short-time data collection.

METHODS AND RESULTS

After administration of Tc-99m sestamibi or tetrofosmin (600-740 MBq), 67 patients with ischemic heart disease, including 35 with prior myocardial infarction, were examined by ECG-gated myocardial perfusion SPECT at rest and during dobutamine stress (at dosages of 4, 8, 12, 16, and 20 microg/kg/min, with increments every 8 minutes). The ECG-gated data collection time was 5 minutes for each dobutamine dosage. After acquisition of gated SPECT data at the highest dose, thallium 201 chloride (111 MBq) was injected, and dual-isotope SPECT was also performed to assess the myocardial ischemia. In 32 patients without prior myocardial infarction, the sensitivity of individual stenosed-vessel detection with dual-isotope perfusion SPECT, with wall motion abnormality obtained from gated SPECT, and with the combined method was 55.9%, 52.9%, and 73.5%, respectively, based on coronary angiography. ECG-gated SPECT during dobutamine infusion revealed regional wall motion abnormalities (worsening or biphasic response) in 19 (57.6%) of 33 infarcted areas with culprit coronary arterial stenosis. The prevalence of reversible perfusion defects on dual-isotope SPECT was higher in segments with wall motion abnormalities than in segments with normal wall motion response (89.5% vs 42.9%, P <.02).

CONCLUSIONS

Myocardial perfusion and left ventricular function during dobutamine infusion were analyzed in a single examination by means of the combined method. This procedure has the potential to provide comprehensive information with which to evaluate patients with ischemic heart disease.

Introduction of DT40 cells into chick embryos

AIM

To examine the transfection of exogenous genes into chick embryos, applying the characteristics of avian leukosis virus (ALV)-induced chicken B cell line DT40 to the production of chimeric birds.

METHODS

The DT40 cells incorporated with exogenous gene ( lacZ constructs encoding Escherichia coli beta-galactosidase: beta-gal) were introduced into chick embryos by the injection of cells into stage X blastoderm. Manipulated eggs were incubated for 3 (trial 1) or 6 (trial 2) days, and the expression of lacZ DNA was detected by a histochemical staining method of beta-galactosidase and polymerase chain reaction (PCR) analysis.

RESULTS

The survival rates of the manipulated embryos incubated for 3 days (stage 18-20: trial 1) and 6 days (stage 28, 30: trial 2) were about 42% and 38%, respectively. The expression rates of the lacZ gene in the embryos in the trials 1 and 2 were about 60% and 23%, respectively, for the survived embryos.

CONCLUSION

The rate of embryonic viability and expression rate of introduced genes were not so high, but it suggested the possibility of utilizing the DT40 cells as a vector for carrying exogenous genes into chick embryos.

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.

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.

Estimation of myocardial perfusion and viability using simultaneous 99mTc-tetrofosmin--FDG collimated SPECT

This study was designed to elucidate the usefulness of crosstalk correction for dual-isotope simultaneous acquisition (DISA) with 99mTc-tetrofosmin and FDG in estimating myocardial perfusion and viability.

METHODS

Eighteen patients with coronary artery disease were studied. First, SPECT was performed with a low-energy high-resolution collimator after a single injection of 99mTc-tetrofosmin (single 99mTc-tetrofosmin). Second, PET and DISA with an ultra-high-energy collimator were performed after glucose loading and an injection of FDG. DISA was designed to operate with simultaneous 3-channel acquisition, and weighted scatter correction of crosstalk from the 18F photopeak to the 99mTc photopeak was performed by modification of an existing dual-window technique. The FDG SPECT images were compared with the images obtained by PET. Both crosstalk-corrected and uncorrected 99mTc-tetrofosmin images were generated and compared with the single 99mTc-tetrofosmin images.

RESULTS

Regional percentage uptake of FDG agreed well between DISA and PET. However, regional percentage uptake of 99mTc-tetrofosmin was generally higher on the uncorrected 99mTc-tetrofosmin images than on the single 99mTc-tetrofosmin images, especially in areas of low flow (percentage count of 99mTc-tetrofosmin > or = 50%). The crosstalk correction contributed to improving the agreement between regional percentage uptakes and significantly improved the detectability of myocardial perfusion-metabolism mismatching.

CONCLUSION

With 3-channel acquisition and weighted-scatter correction of crosstalk from the 18F photopeak to the 99mTc photopeak, DISA with 99mTc-tetrofosmin and FDG is feasible for assessing regional myocardial perfusion and viability.

Attenuation correction for cardiac dual-head gamma camera coincidence imaging using segmented myocardial perfusion SPECT

The diagnostic accuracy of cardiac FDG imaging obtained with the dual-head coincidence gamma camera (DHC) is impaired by artifacts induced by nonuniform attenuation. This study proposed a new method (registration and segmentation method for attenuation correction [AC-RS]) to correct these attenuations in the chest region without the need for additional hardware or expensive transmission scanning equipment.

METHODS

Before DHC imaging, 99mTc-tetrofosmin SPECT was performed using dual-energy acquisition from both the photopeak and Compton scatter windows. The scatter window images of the 99mTc-tetrofosmin were then registered 3-dimensionally with the cardiac DHC images and segmented into anatomic regions to obtain body and lung contours by applying the optimal threshold method on localized histograms. Theoretic attenuation coefficient values were assigned to the corresponding anatomic regions, and the DHC emission images were reconstructed using these attenuation correction factors. The results were quantitatively evaluated by imaging a cardiac phantom filled with a uniform solution and placed in a chest phantom. Eight nondiabetic subjects were also examined using this technique, and the results were compared with those of measured attenuation-corrected PET images.

RESULTS

Use of this technique in phantom and clinical studies decreased the degree of artifacts seen in the inferior wall activity and corrected the emission images. When the results were compared with those of PET scans, the regional relative counts of the uncorrected DHC scan did not correlate with the results of the PET scan. However, the regional relative counts of the AC-RS-corrected DHC scan exhibited a linear correlation with the results of the PET scan (r = 0.73; P < 0.001).

CONCLUSION

Reasonably accurate attenuation-corrected cardiac DHC images can be obtained using AC-RS without the need for transmission scanning.

Long-term results of modified distal splenorenal shunts for the treatment of esophageal varices

BACKGROUND/AIMS

Long-term results were compared for 3 types of distal splenorenal shunt for the treatment of esophageal varices.

METHODOLOGY

Between July 1983 and December 1997, 45 patients with esophageal varices underwent distal splenorenal shunt. Group 1 underwent standard distal splenorenal shunt (n = 11). Group 2 underwent distal splenorenal shunt with splenopancreatic disconnection (n = 11). Group 3 underwent distal splenorenal shunt with splenopancreatic disconnection and gastric transection (n = 23).

RESULTS

Additional treatment for recurrent varices was required in group 1, (n = 1, 9.1%), group 2 (n = 2, 18.2%), and group 3 (n = 1, 4.3%). All of the patients with recurrent varices developed a shunt stenosis within the 1st year after distal splenorenal shunt. The prevalence of hyperammonemia in group 1 was 40.0% at 1, 5, and 10 years. In group 2, the prevalence was 14.3% at 1 year, 31.4% at 5 years, and 54.3% at 10 years. In group 3, the prevalence was 0% at 1 year, and 9.1% at 5 and 10 years. The differences between group 3 and groups 1 and 2 were significant (P < 0.01). The cumulative survival rates at 1 year were 90.9%, 63.6%, and 95.7% for groups 1, 2, and 3, respectively. At 10 years, the cumulative survivals rates were 70.7%, 63.6%, and 69.4% for groups 1, 2, and 3, respectively. There were no significant differences in survival between the 3 groups.

CONCLUSIONS

Distal splenorenal shunt with splenopancreatic disconnection and gastric transection may reduce the incidence of postoperative hyperammonemia.

Use of ECG-gated SPET to assess the evolution of perfusion after acute myocardial infarction

Serial improvement in myocardial perfusion images from the acute or subacute to the chronic stage of acute myocardial infarction (AMI) has been attributed to improved coronary microcirculation or cell function after acute ischaemia and reperfusion. However, conventionally used non-gated imaging cannot eliminate the effect of improved regional contraction. We studied the possibility that such scintigraphic improvement reflects the functional recovery by using ECG-gated myocardial perfusion imaging with technetium-99m sestamibi. Nineteen AMI patients who received acute reperfusion therapy underwent ECG-gated myocardial single-photon emission tomography (SPET) in the subacute and chronic stages. Serial changes in regional image count distributions were analysed on the non-gated, end-diastolic (ED) and end-systolic (ES) images by using segmental mean percent peak activity (MPA) and AMPA (MPA in chronic stage - MPA in subacute stage) on bull's-eye polar maps. These changes were compared with those in regional wall motion on biplane left ventriculography (LVG) from the acute (just after reperfusion) to the chronic stage. During the follow-up, regional wall motion remained the same in 42 (group A) but improved in 17 (group B) of the 59 ischaemically compromised segments. MPA showed no improvement in group A but significant improvement in group B on the non-gated and ES images (P<0.0001 and P<0.001, respectively). However, MPA on the ED images showed no improvement in either group. In the follow-up study of AMI, the scintigraphic improvement documented on the non-gated myocardial images appears to be mainly related to the recovery of wall thickening and not to a real improvement in myocardial perfusion. Therefore, ECG-gated myocardial imaging, which enables simultaneous assessment of changes in perfusion and contraction, is preferable to conventional non-gated imaging for follow-up of AMI.

Endoscopic variceal ligation (EVL) combined with partial splenic embolization (PSE)

BACKGROUND/AIMS

The effectiveness of reducing the recurrence rate of esophageal varices by combining partial splenic embolization (PSE) with endoscopic variceal ligation (EVL) was investigated.

METHODOLOGY

Patients with complete eradication of esophageal varices were collected as study cases with the following results: 31 cases with PSE and EVL (PSE+EVL group), 25 cases with EVL alone (EVL group), and 33 cases with EIS alone (EIS group). The cumulative recurrence rates were obtained by observing new varices.

RESULTS

The cumulative recurrence rates at 6 months were 21.1% in the PSE+EVL group, 58.1% in the EVL group and 32.5% in the EIS group. Those at 1 year were 37.0%, 70.7% and 50.2%, respectively, and those at 2 years were 58.1%, 80.4% and 73.0%, respectively. For all 3 time periods, recurrence rates of the PSE+EVL group were significantly lower than those of the EVL group (p=0.042). Cumulative rates in the PSE+EVL group tended to be lower than those in the EIS group. Further analysis was made on the comparative recurrence rates of the 3 groups, according to Child's classification. The cumulative recurrence rates in Child A cases did not significantly differ between the 3 groups. Cumulative rates in Child B cases were significantly lower in the PSE+EVL group than in the EVL group (p=0.032), and those in the PSE+EVL group tended to be lower than those in the EIS group. These trends were observed between the PSE+EVL group and the EVL group in Child C cases, while cumulative rates did not show differences between the PSE+EVL group and the EIS group.

CONCLUSIONS

It was inferred that PSE-combined EVL therapy is a very effective therapy for achieving long-term complete eradication of esophageal varices.

Sclerotherapy plus ligation versus ligation for the treatment of esophageal varices: a prospective randomized study

BACKGROUND

We devised a new combined method of endoscopic variceal ligation and injection sclerotherapy, namely, endoscopic scleroligation, for the treatment of esophageal varices. The aim of this prospective randomized trial was to compare endoscopic scleroligation with endoscopic variceal ligation alone with regard to efficacy, complications, variceal recurrence, and survival.

METHODS

Fifty-one patients with cirrhosis and esophageal varices were randomly assigned to be treated by endoscopic scleroligation (n = 25) or endoscopic variceal ligation (n = 26). In the initial session in the endoscopic scleroligation group, endoscopic injection sclerotherapy was performed with injection of 5% ethanolamine oleate around the lower esophagus to obliterate the feeding veins. This was followed by endoscopic variceal ligation from the injection site to the most orad varix. In subsequent sessions, endoscopic injection sclerotherapy was performed with 1% polidocanol. In the endoscopic variceal ligation group, that procedure was performed in all treatment sessions.

RESULTS

Both methods were equally effective in achieving complete eradication of esophageal varices. Among the cases in which complete eradication was achieved, the 1- and 3-year cumulative recurrence rates in the endoscopic scleroligation group (9.5%, 22.1%) were significantly lower than those in the endoscopic variceal ligation group (61.9%, 72.2%) (p < 0.01). The survival rates and incidences of treatment-related complications have been similar among patients treated by both methods.

CONCLUSIONS

Endoscopic scleroligation is superior to endoscopic variceal ligation in preventing variceal recurrence.

Dietary soybeans intake and bone mineral density among 995 middle-aged women in Yokohama

To investigate relationship of dietary factors, especially source of calcium intake, to bone mineral density (BMD) among Japanese middle-aged women, a total of 995 healthy women age of 40 to 49 (mean +/- SD, 45 +/- 3), who lives in Yokohama-city, were recruited through convenience sampling by the municipal information paper and health announcement at each 18 public health center in 18 wards for the three-day course on prevention of osteoporosis from October 1996 to March 1998. The BMD of the 2nd metacarpal bone was measured using Computed X-ray Densitometry (CXD) method, by a trained radiologist. Dietary intake of calcium was assessed by self-reporting food frequency questionnaire on calcium dietary sources such as milk, dairy products, small fish, vegetables, and soybeans and carefully checked by trained dietician. An independent gradient of non-adjusted and adjusted BMD for age and weekly calcium intake, through soybeans intake frequency (p = 0.03) was noted. This study suggest soybeans, through possible beneficial effects of vitamin-K, soyprotein, and isoflavonoid, may affect BMD of middle aged women.

[Assessment of left ventricular function by 201Tl ECG-gated myocardial SPECT]

We applied the QGS program for LV function analysis (described by Germano, 1995) to a 201Tl SPECT study at rest, and estimated its accuracy. We performed 201Tl ECG-gated myocardial SPECT in 25 patients with ischemic heart disease under an acquisition time used in the routine 99mTc ECG-gated SPECT study. The quality of the gated images was visually assessed with a 4-point grading system. LVEDV, LVESV, LVEF determined by the QGS program were compared with those by Simpson's method on biplane LVG in 25 patients. Regional wall motion scores in 7 myocardial segments were assessed on the three-dimensional display created by the QGS program and the cine display of biplane LVG with a 5-point grading system. Wall motion scores obtained by the QGS program were compared with those by LVG. Although 72.0% of 201Tl ECG-gated SPECT images were fair or poor in image quality, there were good correlations between the values obtained by the QGS program and LVG (LVEDV: r = 0.82, LVESV: r = 0.88, LVEF: r = 0.89). In addition, wall motion scores by the QGS program were correspondent to those by LVG in 77.1% of all 175 myocardial segments. We conclude that the QGS program provides high accuracy in evaluating left ventricular function even from 201Tl ECG-gated myocardial SPECT data.

Fluorine-18-fluorodeoxyglucose PET identification of cardiac metastasis arising from uterine cervical carcinoma

Cardiac metastasis of uterine cervical carcinoma is rare. We describe a patient with a past history of uterine cervical carcinoma who presented with metastasis to the heart, lungs and distant lymph nodes 3 yr after surgery and chemotherapy. Since the patient complained of chest pain and demonstrated electrocardiogram abnormalities, we performed echocardiography, electron beam CT and MRI, which revealed a tumor in the right ventricular wall. The tumor was assessed by 67Ga scintigraphy and 18F-fluorodeoxyglucose (FDG) PET scanning. The mean differential 18F-FDG uptake ratio of the tumor was 7.9, suggesting malignancy, which was later confirmed by myocardial biopsy. Information about the extent of the tumor and partial necrosis within it was provided by 18F-FDG PET. Although both radionuclide imaging techniques also detected metastatic lesions in the lungs and lymph nodes, 18F-FDG PET scanning detected small lesions more sensitively than 67Ga scintigraphy.

Sympathetic reinnervation demonstrated on serial iodine-123-metaiodobenzylguanidine SPECT images after cardiac transplantation

The transplanted heart is without autonomic nervous control in the early postsurgical period. We present here a case of cardiac transplantation in which 123I-metaiodobenzylguanidine (MIBG) SPECT and an exercise-loading test were used to monitor the sympathetic reinnervation. The distribution of myocardial 123I-MIBG uptake extended with time from 1 to 2 yr after surgery. However, functional improvement, estimated by the heart rate response to exercise, was not discernable during this period. The findings in this case suggest the feasibility of 123I-MIBG SPECT imaging in the serial monitoring of sympathetic reinnervation after transplantation and that scintigraphic evidence of reinnervation precedes functional recovery.

Baumkuchen map analysis to detect postural cerebral hypoperfusion with upright 99Tcm-HMPAO brain SPET

We have evaluated a polar cortical flow Baumkuchen map (BK map), constructed from projection data by inwardly layering cortical flow stripes from the base to the apex, to detect postural cerebral hypoperfusion using 99Tcm-HMPAO brain SPET. A circular cortical perfusion outline was constructed from sinogram data at a 20% threshold; a ring was then formed by constructing an inner line with a radius equal to half that of the outer line. This ring on the transaxial image was superimposed onto the cortical image, then divided into 60 portions at 6 degrees intervals from the centre. The maximal number of counts per pixel within each sector was determined, translated into polar coordinate profiles and displayed as a polar map. We studied 11 patients with unilateral stenosis of the internal carotid artery or middle cerebral artery (MCA) and 7 patients without stenosis, using upright and supine (rest) 99Tcm-HMPAO brain SPET Cerebral perfusion was visibly altered on the BK maps of all 11 patients with arterial stenosis and on the transaxial images of 8 of them. A semi-quantitative analysis of the BK maps using a ratio of the counts in the regions of interest over the right and left MCA areas, showed that the mean of the ratios was significantly lower in the upright images than in the upright + rest and rest images (P = 0.0044 and 0.0033, respectively). Although the difference in the means of the ratios between the upright and upright + rest images was significant for both the BK map and transaxial image data (P = 0.0044 and 0.0051, respectively), the BK map was accurate in detecting changes in perfusion in the upright position. We conclude that BK map analysis is useful for detecting changes in patients examined using upright brain SPET.

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.

[Usefulness of ECG-gated 99mTc-MIBI myocardial SPECT in the follow-up study of patients with acute myocardial infarction]

To clarify the background of the scintigraphic improvement in non-gated myocardial perfusion imaging for patients with acute myocardial infarction, we performed serial ECG-gated 99mTc-MIBI myocardial SPECT in 17 patients with acute myocardial infarction (AMI) receiving successful reperfusion therapy. ECG-gated myocardial SPECT and left ventriculography were performed at 1 week (acute phase) and 1 month (subacute phase) after the onset of AMI. Regional %uptake (regional count x 100/maximal count) was determined for each of 8 myocardial segments of the Bull's eye map. We analyzed the data in 53 AMI segments out of total 136 myocardial segments, on the non-gated (NG), end-diastolic (ED), and end-systolic (ES) images. In addition, the delta %uptake (%uptake in subacute phase--%uptake in acute phase) was also determined as an index representing the improvement of myocardial tracer uptake on each image. In 17 segments (group A) with wall motion recovery assessed by serial left ventriculography, the %uptake on the NG image was significantly improved (61.6 +/- 10.0 to 75.7 +/- 10.1, p < 0.0001). However, in 36 segments (group B) without wall motion recovery, the change of %uptake on the NG image was small. There was no significant change in the %uptake on the ED image in groups A and B. On the contrary, the %uptake on the ES image showed a significant increase in group A (58.4 +/- 11.8 to 68.9 +/- 11.8, p < 0.001), but did not in group B. Thus, this change on the ES image reflects the wall motion recovery. Furthermore, in group A, there was a significant correlation between the delta %uptake on the NG image and those on the ES image (p < 0.02), but was not between those on the NG and the ED images. Thus, the change in the %uptake on the NG image was more related to those on the ES image which is more affected by the change in regional wall motion than those on the ED image which reflects improved myocardial perfusion. These results suggest that ECG-gated myocardial 99mTc-MIBI SPECT is more useful to assess the serial change in myocardial perfusion and contraction than the conventional non-gated SPECT in the follow-up study of patients with AMI.

Epidemiological study of a food-borne outbreak of enterotoxigenic Escherichia coli O25:NM by pulsed-field gel electrophoresis and randomly amplified polymorphic DNA analysis

This study investigated the applicability of molecular epidemiological techniques to the identification of the causal agent of an outbreak of diarrhea caused by ingestion of food contaminated with enterotoxigenic Escherichia coli (ETEC). The outbreak occurred at four elementary schools in July 1996 and affected more than 800 people. Illness was most strongly associated with eating tuna paste (relative risk, 1.79; 95% confidence interval = 1.16 to 2.79; P = 0.0001). To evaluate the epidemiological characteristics of the pathogen, the DNAs from numerous isolated ETEC strains were subjected to randomly amplified polymorphic DNA analysis, pulsed-field gel electrophoresis of nuclease S1-treated plasmid DNA, and analysis of genomic DNA restriction fragment length polymorphisms. All ETEC isolates were of the O25:NM (nonmotile) serotype, which carries a heat-stable enterotoxin Ib gene. Genotypic analysis demonstrated that the strains isolated from the patients at all four schools were identical. The isolates of ETEC O25:NM obtained from the tuna paste that had been served for lunch at these schools were genetically indistinguishable from those isolated from the patients. Results suggest that this outbreak was food borne. The molecular biology-based epidemiological techniques used in this study were useful in characterizing the causal agent in this food-borne epidemic.

The role of annexin II tetramer in the activation of plasminogen

Annexin II tetramer (AIIt) is a major Ca2+-binding protein of endothelial cells which has been shown to exist on both the intracellular and extracellular surfaces of the plasma membrane. In this report, we demonstrate that AIIt stimulates the activation of plasminogen by facilitating the tissue plasminogen activator (t-PA)-dependent conversion of plasminogen to plasmin. Fluid-phase AIIt stimulated the rate of activation of [Glu]plasminogen about 341-fold compared with an approximate 6-fold stimulation by annexin II. AIIt bound to [Glu]plasminogen(S741C-fluorescein) with a Kd of 1. 26 +/- 0.04 microM (mean +/- S.D., n = 3) and this interaction resulted in a large conformational change in [Glu]plasminogen. Kinetic analysis established that AIIt produces a large increase of about 190-fold in the kcat, app and a small increase in the Km,app which resulted in a 90-fold increase in the catalytic efficiency (kcat/Km) of t-PA for [Glu]plasminogen. AIIt also stimulated the t-PA-dependent activation of [Lys]plasminogen about 28-fold. Furthermore, other annexins such as annexin I, V, or VI did not produce comparable activation of t-PA-dependent conversion of [Glu]plasminogen to plasmin. The stimulation of the activation of [Glu]plasminogen by AIIt was Ca2+-independent and inhibited by epsilon-aminocaproic acid. AIIt bound to human 293 cells potentiated t-PA-dependent plasminogen activation. AIIt that was bound to phospholipid vesicles or heparin also stimulated the activation of [Glu]plasminogen 5- or 11-fold, respectively. Furthermore, immunofluorescence labeling of nonpermeabilized HUVEC revealed a punctated distribution of AIIt subunits on the cell surface. These results therefore identify AIIt as a potent in vitro activator of plasminogen.

[Prediction of the myocardial contractility improvement on early stage after the revascularization using low-dose dobutamine stress 99mTc-MIBI gated SPECT]

For prediction of recovery of LV contractility, 99mTc-MIBI gated SPECT at rest and that with dobutamine (DOB) loading were performed in 15 patients with myocardial infarction (MI). Regional % uptake (regionalx100/maximal count), % wall thickening [%WT; (ES-ED)x100/ED maximal count], and delta %WT (%WT at DOB stress-%WT at rest) were calculated for each of 8 segments (seg.), including 34 MI out of total 120 seg., which derived from short axis LV count profile. These 34 seg. were divided into two groups, recontractile (18 seg.) and non-recontractile (16 seg.), whether improvement of the wall motion following the intervention (3-5 months) was observed by echocardiography. In the result, there were 7 recontractile seg. in 8 seg. with mildly reduced perfusion (> or = normal mean % uptake-2 S.D.), and there were 11 recontractile seg. in 26 seg. with severe reduced perfusion (< normal mean % uptake-2 S.D.). Moreover, in segments with severely reduced perfusion, there was no significant % uptake difference between recontractile and non-recontractile seg. However, delta %WT of recontractile group (11.1 +/- 4.8%) was significantly higher than that of non-recontractile group (5.7 +/- 2.9%) (p < 0.01). In conclusion, although the improvement of contractility on early stage after the revascularization was sometimes underestimated with only perfusion (% uptake), myocardial DOB response of %WT which were obtained by gated SPECT with MIBI would avoid the underestimation.

[The HIV/AIDS Epidemic in Cambodia]

In December 1995 and March 1996, we visited institutes which were conducting epidemiological studied of HIV/AIDS in Cambodia, and obtained data for further collaborative study between Japan and Cambodia. Data included information on AIDS patients and HIV infected persons, and behavioral epidemiology of CSWs (Commercial Sex Workers). The cumulative reported number of AIDS patients and HIV infected persons in Cambodia was 86 and 2,536 cases respectively in 1995. The cause of infection was mostly heterosexual contact with very few cases from injecting drug use (IDU) and other causes. The seroprevalence rate of HIV antibody among donated blood rapidly increased from 0.08% in 1991 to 4.47% in 1995, and those among CSWs and pregnant women were 37.9% and 2.6%, respectively, in 1995. The average rate of condom use among CSWs was 66%, but the rate of usual usage was only 14%. These results indicate that the HIV/AIDS epidemic had spread rapidly through CSWs, that it had been spread among peoples in communities, and that usage of condoms among CSWs was insufficient in Cambodia. Without strong countermeasures against HIV/AIDS in this country, HIV/AIDS epidemic may spread significantly to not only peoples in this country but also those in neighbouring countries in the future.

[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.

[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.

[ECG-gated dual-isotope myocardial SPECT with 201Tl and 99mTc-tetrofosmin: simultaneous assessment of stress/rest myocardial perfusion and left ventricular function]

ECG-gated dual-isotope acquisition protocol involving rest imaging with 201Tl and stress 99mTc-tetrofosmin (TF) SPECT was designed for the simultaneous assessment of rest/stress myocardial perfusion and rest ventricular systolic function. This study assessed the feasibility and diagnostic accuracy of this protocol. Forty-five patients underwent the dual-isotope SPECT protocol. Twenty minutes after resting injection of 111 MBq of 201Tl, 370 MBq of 99mTc-TF was administered at a peak exercise. The dual-isotope gated SPECT acquisition was performed 1 hour later. Then, the regional count increase rate (%WT) of 99mTc-TF from end-diastole end-systole was calculated using an automated method which was developed for quantification of regional wall thickening based on circumferential profile analysis in our laboratory. Myocardial perfusion and contractility analysis was carried out using 8 segments of left ventricle with comparison of coronary angiographical findings. The sensitivity and specificity for the detection of diseased coronary vessels (> = or 75% stenosis) were 76% and 94%, respectively. Infarcted regions showing reversible defect had significantly greater %WT as compared with those with fixed defects (63 seg; 12.7 +/- 6.1% vs. 36 seg; 8.9 +/- 7.2%, p < 0.01). In conclusion, this dual-isotope protocol has some advantages; i.e., shortening an examination time, having the exact registration of stress/rest perfusion, and simultaneous evaluation of resting regional wall thickening.