Ernest Garcia

Iodofiltic acid I 123 (BMIPP) fatty acid imaging improves initial diagnosis in emergency department patients with suspected acute coronary syndromes: A multicenter trial

OBJECTIVESnThe aim of this study was to assess the performance of beta-methyl-p-[123I]-iodophenyl-pentadecanoic acid (BMIPP) single-photon emission computed tomography (SPECT) to detect acute coronary syndromes (ACS) in emergency department patients with chest pain.nnnBACKGROUNDnEmergency department diagnosis of chest pain is problematic, often requiring prolonged observation and stress testing. BMIPP SPECT detects abnormalities in fatty acid metabolism resulting from myocardial ischemia, even many hours after symptom cessation.nnnMETHODSnEmergency department patients with suspected ACS were enrolled at 50 centers. Patients received 5 mCi BMIPP within 30 h of symptom cessation. BMIPP SPECT images were interpreted semiquantitatively by 3 blinded readers. Initial clinical diagnosis was based on symptoms, initial electrocardiograms, and troponin, whereas the final diagnosis was based on all available data (including angiography and stress SPECT) but not BMIPP SPECT. Final diagnoses were adjudicated by a blinded committee as ACS, intermediate likelihood of ACS, or negative for ACS.nnnRESULTSnA total of 507 patients were studied and efficacy was evaluated in 448 patients with sufficient data. The sensitivity of BMIPP by 3 blinded readers for a final diagnosis of ACS and intermediate likelihood of ACS was 71% (95% confidence interval [CI]: 64% to 79%), 74% (95% CI: 68% to 81%), and 69% (95% CI: 62% to 77%); the corresponding specificity of BMIPP was 67% (95% CI: 61% to 73%), 54% (95% CI: 48% to 60%), and 70% (95% CI: 64% to 76%). Compared with the initial diagnosis alone, BMIPP+initial diagnosis increased sensitivity from 43% to 81% (p<0.001), negative predictive value from 62% to 83% (p<0.001), and positive predictive value from 41% to 58% (p<0.001), whereas specificity was unchanged (61% to 62%, p=NS).nnnCONCLUSIONSnThe addition of BMIPP data to the initially available clinical information adds incremental value toward the early diagnosis of an ACS, potentially allowing determination of the presence or absence of ACS to be made earlier in the evaluation process. (Safety and Efficacy Iodofiltic Acid I 123 in the Treatment of Acute Coronary Syndrome [Zeus-ACS]; NCT00514501).

Omalizumab in children with inadequately controlled severe allergic (IgE-mediated) asthma

Abstract Background: Many children with severe persistent allergic (IgE-mediated) asthma remain inadequately controlled despite treatment with high-dose inhaled corticosteroids (ICS) plus a long-acting β2-agonist (LABA). Research and design methods: This pre-specified analysis of a randomized, double-blind, placebo-controlled trial evaluated the efficacy and safety of omalizumab in children (6–<12 years) with perennial allergen sensitivity, and history of asthma exacerbations and symptoms despite treatment with ICS (fluticasone ≥500u2009µgu2009·u2009day−1 or equivalent) plus a LABA. Patients received omalizumab (75–375u2009mg once or twice a month by subcutaneous injection, as determined from dosing tables) or placebo over 52 weeks (24-week fixed-steroid then 28-week adjustable-steroid phases). Results: Out of 246 randomized patients (omalizumab, nu2009=u2009166; placebo, nu2009=u200980), efficacy was analysed in 235 (omalizumab, nu2009=u2009159; placebo, nu2009=u200976). Over the 24-week fixed-steroid phase, omalizumab reduced the rate of clinically significant asthma exacerbations (worsening symptoms requiring doubling of baseline ICS dose and/or systemic steroids) by 34% versus placebo (0.42 vs 0.63, rate ratio 0.662; Pu2009=u20090.047). Over 52 weeks, the exacerbation rate was reduced by 50% (Pu2009<u20090.001). Omalizumab had an acceptable safety profile, with no statistically significant (Pu2009<u20090.05) differences in adverse events observed between omalizumab and placebo. Conclusion: Add-on omalizumab is well-tolerated and reduces exacerbations in children (6–<12 years) with severe persistent allergic asthma, inadequately controlled despite high-dose ICS plus a LABA. It should be noted that the sample size was not based on providing statistical power in the severe subgroup, and no corrections were made for multiple comparisons; however, outcomes consistently favoured omalizumab. Trial registration: ClinicalTrials.gov identifier: NCT00079937.

Quantitative myocardial perfusion single-photon emission computed tomographic imaging: Quo vadis? (where do we go from here?)

Quantitative myocardial perfusion single-photon emission computed tomography can be improved further by technical advancements that are imminent in the clinical setting. These improvements are directed toward two main goals: (1) increasing the accuracy that the myocardial count distribution from tomographic slices represents the true tracer concentration and (2) increasing the accuracy of extracting this myocardial count distribution for quantitative analysis. Once these advancements are fully validated and implemented clinically, the clinical value of these cardiac diagnostic tests will be enhanced by increased accuracy of detecting and characterizing myocardial hypoperfusion and coronary artery disease.

Visualization of cardiovascular nuclear medicine tomographic perfusion studies

Several methodologies and tools for enhancing the clinicians ability to visualize and characterize perfusion defects are presented. The tools include an improved method for sampling the myocardium which reduces the partial volume effects often encountered when sampling the apex, volume-weighted and distance-weighted polar maps that enhance the information extracted from the new sampling technique, a method for visualizing perfusion information in three dimensions which decreases the distortions inherent in 2-D polar maps and also allows for unifying the perfusion information with the anatomic information obtained from 3-D coronary trees, and a method for visualizing 3-D gated perfusion information that allows a clinician to assess both perfusion and wall thickening.<<ETX>>

Quantitative Nuclear Cardiology: We are almost there!

It’s a great honor and privilege to have the opportunity to present the 10th annual lecture in memory of my friend and our colleague Dr Mario S. Verani. I join all the previous Verani lecturers in the admiration that we had for him as a clinician, researcher and human being. Mario’s legacy and accomplishments as a physician researcher are well documented as to his contribution to myocardial perfusion imaging (MPI), particularly in the use of adenosine as a pharmacological stress agent and in establishing the nuclear cardiology lab at Baylor as one of the top clinical and research facilities in the World. But his legacy as a human being and as one of our leaders overshadows the rest of his accomplishments. Those of us who knew him remember the constant smile on his face. We particularly appreciated how Mario combined his accomplishments with a humble sense of humor. It’s no wonder that Mario’s illness and passing challenged our expectation of our own future. Inspired by Mario’s optimism about life in general and our field of nuclear cardiology in particular, the message that I bring is that nuclear cardiology, which by its nature is quantitative, is almost there, scientifically, technically, and clinically. Moreover, at a time of so much uncertainty in healthcare, we should not worry about tomorrow or fear what is coming, but rather we should pour our energy in what is here to stay. This article is to remind us why our nuclear cardiology field is here to stay.

Advances in Software for Faster Procedure and Lower Radiotracer Dose Myocardial Perfusion Imaging

The American Society of Nuclear Cardiology has recently published documents that encourage laboratories to take all the appropriate steps to greatly decrease patient radiation dose and has set the goal of 50% of all myocardial perfusion studies performed with an associated radiation exposure of 9mSv by 2014. In the present work, a description of the major software techniques readily available to shorten procedure time and decrease injected activity is presented. Particularly new reconstruction methods and their ability to include means for resolution recovery and noise regularization are described. The use of these improved reconstruction algorithms results in a consistent reduction in acquisition time, injected activity and consequently in the radiation dose absorbed by the patient. The clinical implications to the use of these techniques are also described in terms of maintained and even improved study quality, accuracy and sensitivity for the detection of heart disease.

Principles of Nuclear Cardiology Imaging

Nuclear cardiology imaging is solidly based on many branches of science and engineering, including nuclear, optical, and mathematical physics; electrical and mechanical engineering; chemistry; and biology. This chapter uses principles from these scientific fields to provide an understanding of both the signals used and the imaging system that captures these signals. These principles have been simplified to fit the scope of this atlas.

Myocardial ischemia detection by expert system interpretation of thallium-201 tomograms

The accuracy of interpreting tomographic nuclear medicine images of the heart varies depending on the expertise of the diagnostician. This variability is a problem at some community hospitals or private imaging centers where expertise is limited due to the small number of studies performed. In order to standardize image interpretation at an expert’s level, we developed a totally automated rule-based expert system for interpreting three-dimensional myocardial perfusion distributions obtained from stress and delayed thallium-201 perfusion tomograms. The rules of the expert system determine the presence, location, and certainty of each fixed or reversible coronary lesion, combining certainty factors according to the MYCIN algorithm. Computer consultations were compared with interpretations of a human expert for a pilot group of 20 patients. The expert system interpreted myocardial perfusion distributions with artifacts, coronary territory overlap and multiple defects at a level approaching that of the human expert.

Coronary vasculature visualization from limited angiographic views

An approach for reconstructing the three-dimensional geometry of the coronary arteries from a limited number of two-dimensional angiographic views and producing a computer model which can be used to quantify and visualize the coronary vasculature is presented. The approach incorporates a hierarchical database that organizes geometric information from arbitrary arterial structures in a natural fashion. Detecting and locating vascular structure from angiographic images are partially automated through entropy edge detection techniques. The back projection algorithm accurately models the nonparallel geometry inherent in X-ray biplane angiography and produces a quantitative description of vascular structure, including estimates of vessel diameters aid lengths. The approach has been applied in phantom studies, in which quantitative comparisons were made, and patient studies, in which qualitative evaluations were made.<<ETX>>

Advances in cardiac imaging: taking a closer look at PET perfusion imaging : American Society of Nuclear Cardiology, Philadelphia, PA, 24 September 2010.

Question 1. Dr. Elizabeth Branscomb, Birmingham, AL, USA My first question regards comparing a SPECT perfusion study with a PET perfusion study. Specifically, Dr. Heller mentioned an algorithm in which patients with intermediate to high pretest probability of coronary artery disease are first stressed with PET instead of SPECT. What is it going to take, other than quality indicators, to get the payers onboard with using PET as a first test in that subgroup?