Same-Day Yttrium-90 Radioembolization: Feasibility with Resin Microspheres

Purpose

To evaluate the feasibility of a same-day yttrium-90 (⁹⁰Y) radioembolization protocol with resin microspheres (including pretreatment angiography, lung shunt fraction [LSF] determination, and radioembolization) for the treatment of hepatocellular carcinoma (HCC) and liver metastases.

Failure of gated SPECT and echocardiography to detect large apical aneurysm secondary to hyperdynamic left ventricular wall at the aneurysm neck

We present a patient with a history of coronary artery disease and exertional angina after an acute anterior myocardial infarction. Angiography and ventriculography revealed multivessel coronary artery disease and a large apical aneurysm. Echocardiography and gated SPECT studies were performed for further evaluation of ischemia and assessment of left ventricular function. Gated SPECT and echocardiography failed to detect a large apical aneurysm due to a hyperdynamic left ventricular wall at the neck of the aneurysm. This case demonstrates the importance of using multiple imaging modalities in the evaluation of ventricular function in the setting of coronary artery disease.     

Spleen sizing by ultrasound in polycythaemia and thrombocythaemia: comparison with SPECT

Detection of non-palpable early splenic enlargement may aid diagnosis of primary polycythaemia (PP) and primary thrombocythaemia (PT). In this study linear spleen sizing by ultrasound has been compared with spleen volume estimation by single photon emission computerized tomography (SPECT) in 26 patients. Spleen length by ultrasound correlated well with SPECT volume estimation.
Ultrasound spleen length was also measured in 60 normal control subjects where the upper limit of the 95% reference range was 11.6 cm. Changes in spleen length with both age and body weight were substantial and overshadowed the imperfect reproducibility of this method. Therefore, interpretation of an individual's measured spleen length should be in relation to that predicted for adults of the same age and weight, particularly at the extremes of the younger, heavier patients and also the older, lighter patients.
Ultrasound spleen lengths of different patient groups (21 PP, 26 PT, 17 idiopathic erythrocytosis, 12 secondary polycythaemia, nine apparent polycythaemia) were compared both using the measured overall reference range and the differences from the values predicted for their age and weight. The comparison showed that almost all patients with PP whose spleens were not palpable had spleen lengths greater than the upper limit for the normal control group, but separation from the other patient groups was incomplete.
Detection of non-palpable splenomegaly by ultrasound length should remain a 'minor' criterion amongst the 'proposed modified diagnostic criteria' of PP.     

Gated myocardial perfusion single photon emission computed tomography in the clinical outcomes utilizing revascularization and aggressive drug evaluation (COURAGE) trial, Veterans Administration Cooperative study no. 424

Background  Stress gated myocardial perfusion single photon emission computed tomography (gSPECT) is increasingly used before and after intercurrent therapeutic intervention and is the basis for ongoing evaluation in the Department of Veterans Affairs clinical outcomes utilizing revascularization and aggressive drug evaluation (COURAGE) trial. Methods and Results  The COURAGE trial is a North American multicenter randomized clinical trial that enrolled 2287 patients to aggressive medical therapy vs percutaneous coronary intervention plus aggressive medical therapy. Three COURAGE nuclear substudies have been designed. The goals of substudy 0 are to examine the diagnostic accuracy of the extent and severity of inducible ischemia at baseline in COURAGE patients compared with patient symptoms and quantitative coronary angiography and to explore the relationship between inducible ischemia and the benefit from revascularization when added to medical therapy. Substudy 1 will correlate the extent and severity of provocative ischemia with the frequency, quality, and instability of recurrent symptoms in postcatheterization patients. Substudy 2 (n _ 300) will examine the usefulness of sequential gSPECT monitoring 6 to 18 months after therapeutic intervention. Together, these nuclear substudies will evaluate the role of gSPECT to determine the effectiveness of aggressive risk-factor modifications, lifestyle interventions, and anti-ischemic medical therapies with or without revascularization in reducing patients’ ischemic burdens. Conclusions  The unfolding of evidence on the application of gSPECT in trials such as COURAGE defines a new era for nuclear cardiology. We hope the evidence that emerges from the COURAGE trial will further establish the role of nuclear imaging in the evidence-based management of patients with stable coronary disease. The COURAGE trial was supported by the Cooperative Studies Program of the Department of Veterans Affairs Office of Research and Development in collaboration with the Canadian Institutes of Health Research. Unrestricted research grants were obtained from Merck & Co; Pfizer Pharmaceuticals; Bristol-Myers Squibb Medical Imaging; Astellas Pharma; Kos Pharmaceuticals; Data Scope; Astra Zeneca Pharmaceuticals; Astra-Zeneca-Canada; Schering-Plough Coorporation, Ltd; Sanofi-Aventis, Inc; First Horizon; and GE Healthcare. All industrial funding for this trial was directed through the Department of Veterans Affairs. Additional funding for this substudy was provided by grants to the Department of Veterans Affairs and Canadian Institutes of Health Research from Astellas Pharma and Bristol-Myers-Squibb Medical Imaging.     

Dysaccommodation of the stomach: therapeutic nirvana?

Functional dyspepsia (FD) is a highly prevalent gastrointestinal disorder and has a complex pathophysiology. Impaired fundic relaxation in response to a meal is present in 40% of patients with FD. This review focuses on impaired gastric accommodation of the stomach as a pathophysiological mechanism and the possible therapeutic targets that can be derived from the current knowledge of the neuroregulation of the accommodation reflex. First the different means of gastric accommodation assessment are described and the relationship between symptoms and impaired gastric accommodation. The different therapeutic options are subsequently discussed in view of their molecular target, based on the different receptor subtypes involved in the accommodation reflex. Although impaired gastric accommodation is highly prevalent in dyspeptic patients and basic knowledge about the accommodation reflex enables to develop pathophysiologically targeted therapies, it is unlikely that therapies aimed at dysaccommodation of the stomach will lead to symptom relief in all dyspeptic patients. A major challenge is the development of methods that readily identify impaired accommodation in clinical practice.     

Comparison of 180° and 360° acquisition for myocardial perfusion SPECT with compensation for attenuation, detector response, and scatter: Monte Carlo and mathematical observer results

BACKGROUND: The optimal projection data acquisition strategy for myocardial perfusion (MP) single photon emission computed tomography (SPECT) remains controversial. METHODS: We compared MP SPECT using 180 degrees and 360 degrees projection data obtained with the same acquisition time, reconstructed either with filtered back projection (FBP) or the iterative ordered-subsets expectation maximization (OS-EM) algorithm with various combinations of attenuation, detector response, and scatter compensation using mathematical observers and a myocardial defect detection task. We used Monte Carlo-simulated projection data from a population of 3-dimensional nurbs-based cardiac-torso (NCAT) phantoms with ranges of variability in patient anatomy, organ uptake, defect location, defect size, and noise level based on clinical data. Projection data from 180 degrees and 360 degrees acquisitions were generated by assuming the same acquisition time. After iterative or FBP reconstruction, standard postprocessing methods were applied. For each acquisition and reconstruction method, we optimized the number of iterations and cut-off frequency of the Butterworth filter using the Channelized Hotelling Observer methodology. The optimum set of parameters was that which gave the maximum area under the curve. RESULTS: For both acquisition protocols, OS-EM with compensations provided better performance than FBP or OS-EM without compensation. For FBP, the optimized 180 degrees acquisition provided a statistically significant increase in AUC as compared with optimized 360 degrees acquisition. For OS-EM, the AUCs for 180 degrees were slightly larger than for 360 degrees acquisitions when comparing images reconstructed with the same compensations. However, the differences were smaller and not statistically significant. CONCLUSION: With optimized reconstruction and filtering parameters, 180 degrees acquisition provided a statistically significant improvement over 360 degrees acquisition for FBP reconstruction. However, for OS-EM the differences were small and not statistically significant.     

门控心肌显像结合GS Quant软件评价左室功能

目的:评价GS Quant软件结合99mTc-甲氧基异TN(MtBI)门控心肌断层显像(G-SPECT)测定左室射血分数(LVEF)的价值。方法:选择24例于同期2周内完成G-SPECT、门控心血池显像(RNA)和超声心动图检查(UCG)的患者,比较3种方法所测定的LVEF值。结果:99mTc-MIBI G-SPECT所测得的LVEF值与RNA和UCG法所测得的LVEF值均有较好的相关性,相关系数r分别为0.81(P<0.05)和0.76(P<0.05)。结论:99mTc-MIBI G-SPECT所测定的LVEF值有很好的准确性和可重复性,具有较高的临床应用价值,可进一步推广应用门控核素心肌断层显像这一技术。     

应用门控SPECT测量左心室功能的方法学研究

目的：试用门控心肌显像测定左室功能并与心血池显像结果比较。材料和方法：61例受检者进行了Tc-99m—MIBI门控心肌显像及心血池显像．结果：门控断层心肌显像的短轴中间部左室功能结果与平衡法心血池显像有良好的相关性(r=0．82）。结论：门控心肌断层显像测定的左室功能结果方法简便可靠．能同时反映心肌直流及左室功能。