<p>This dissertation aims to demonstrate the feasibility of direct infarct visualization using 3D medical ultrasound. The dissertation proceeds by providing the first ever demonstration of fully-sampled 3D ultrasonic speckle tracking using raw B-Mode data of the heart. The initial demonstration uses a Cramer-Rao lower bound limited displacement estimator. The dissertation then proceeds to develop an implementable method for biased time-delay estimation. Biased time-delay estimation is shown to surpass the traditional limits described by the Cramer-Rao lower bound in a mean square error sense. Additional characterization of this new class of estimator is performed to demonstrate that with easily obtainable levels of prior information it is possible to estimate displacements that do surpass the Cramer-Rao lower bound. Finally, using 2D and 3D realizations of biased displacement estimation (Bayesian speckle tracking) the passive strain induced in the ventricle walls during atrial systole is shown to be sufficient to distinguish healthy and chronically infarcted myocardium.</p> / Dissertation

To increase medical service quality for medical ecology is necessary nowadays, it provides not only customers satisfaction and ensure patent s¡¦ willing for next visit, but also have the requirements of the hospital accreditation. Furthermore, medical service quality has become the main purchasing direction for hospital administrators. This survey is based on ¡§5Q model for different dimensions¡¨ by Zineldin (2006), including quality of object, quality of processes, quality of infrastructure, quality of interaction, quality of atmosphere. However, it evaluates which medical service quality that may affect patient¡¦s satisfaction and loyalty for having examination check in radiological department. The result of this research can be used by the hospital to provide the medial service quality, hospital competitiveness, sustainable development, and to supply more effective strategies in future direction. This survey investigated the patients for the examination of medical imaging from the biggest military hospital in southern, which was assessed as a regional Teaching Hospital by department of Health, the executive Yuan. A total of 600 questionnaires were sent out to patients, with 586 valid samples, and with 14 uncompleted invalid samples. The effective response rate is about 97.9%. In this study, the quality of medical service is based on five dimensions analysis, respectively patient satisfaction and patient loyalty. In addition, the patient satisfaction provided analysis and discussion for patient loyalty. The research was the participants with medical treatment from military hospital and was carried the analysis in order to further understand the significant difference in the causes for medical treatment, medical service quality, patient satisfaction and royalty. The research is summarized as follows: 1.The medical service quality ¡§quality of object, quality of processes, quality of infrastructure, quality of interaction, quality of atmosphere. ¡§ were all positive and significant influence on patient satisfaction, particularly quality of atmosphere and quality of interaction. 2. The quality of object, quality of interaction, quality of atmosphere had also strong and positive impact on the loyalty of the patients, but the quality of process, and the quality of infrastructure hadn¡¦t affect the patients¡¦ loyalty remarkably. 3. In addition, patient satisfaction appeared a relevant and significant impact on patient loyalty. 4. For treatment reasons, people who were military and military dependents were significant higher than the patients who live closely to hospital for quality of object, quality of infrastructure, quality of interaction, quality of atmosphere and patient satisfaction.

We have designed and demonstrated a new class of medical navigation methods that use the fingerprint-like biometrically distinct ultrasound echo patterns produced by different locations in tissue. As an example of this new biometric navigation approach, we have constructed and tested a system that uses ultrasound data to achieve prospective motion compensation in MRI, especially for respiratory motion during interventional MRI procedures in moving organs such as the liver. The ultrasound measurements are collated with geometrical information from MRI during a training stage to form a mapping table that relates ultrasound measurements to positions. During prospective correction, the system makes frequent ultrasound measurements and uses the map to determine the corresponding position. Results in motorized linear motion phantoms and freely breathing animals indicate that the system performs well. Apparent motion is reduced by up to 97.8%, and motion artifacts are reduced or eliminated in 2D Spoiled Gradient-Echo images. The motion compensation is sufficient to permit MRI thermometry of focused ultrasound heating during respiratory-like motion, with results similar to those obtained in the absence of motion. This new technique may have applications for MRI thermometry and other dynamic imaging in the abdomen during free breathing. We have also extended this technique to situations in which external position information during training is unavailable or incomplete, by extending the concept of Simultaneous Localization and Mapping to include determining the topology of a dense motion path through a gaussian random field. In the course of these investigations, we have also developed modified forms of referenceless MRI thermometry and Kalman filtering, specially adapted to optimize accuracy under our experimental conditions.

Fluorescence diffuse optical tomography provides non-invasive, in vivo imaging of molecular targets in small animals. While standard fluorescence microscopy is limited to shallow depths and small fields of view, tomographic methods allows recovery of the distribution of fluorescent probes throughout the small animal body. In this thesis, we present novel reconstruction algorithms for the tomographic separation of optical parameters using time-domain (TD) measurements. These technique are validated using simulations and with experimental phantom and mouse imaging studies. We outline the contributions of each chapter of the thesis below. First, we explore the TD fluorescence tomography reconstruction problem for single and multiple fluorophores with discrete lifetimes. We focus on late arriving photons and compare a direct inversion approach with a two-step, asymptotic approach operating on the same TD data. We show that for lifetime multiplexing, the two methods produce fundamentally different kinds of solutions. The direct inversion is computationally inefficient and results in poor separation but has overall higher resolution while the asymptotic approach provides better separation, relative quantitation of lifetime components and localization but has overall lower resolution. We verify these results with simulation and experimental phantoms. Second, we introduce novel high resolution lifetime multiplexing algorithms which combine asymptotic methods for separation of fluorophores with the high resolving power of early photon tomography. We show the effectiveness of such methods to achieve high resolution reconstructions of multiple fluorophores in simulations with complex-shaped phantoms, a digital mouse atlas and also experimentally in fluorescent tube phantoms. Third, we compare the performance of tomographic spectral and lifetime multiplexing. We show that both of these techniques involve a two-step procedure, consisting of a diffuse propagation step and a basis-function mixing step. However, in these two techniques, the order of the two steps is switched, which leads to a fundamental difference in imaging performance. As an illustration of this difference, we show that the relative concentrations of three colocalized fluorophores in a diffuse medium can accurately be retrieved with lifetime methods but cannot be retrieved with spectral methods. Fourth, we address the long standing challenge in diffuse optical tomography (DOT) of cross-talk between absorption and scattering. We extend the ideas developed from lifetime multiplexing algorithms by using a constrained optimization approach for separation of absorption and scattering in DOT. Using custom designed phantoms, we demonstrate a novel technique allows better separation of absorption and scattering inclusions compared to existing algorithms for CW and TD diffuse optical tomography. Finally, we show experimental validation of the lifetime multiplexing algorithms developed in this thesis using three experimental models. First, we show the reconstruction of overlapping complex shapes in a dish phantom. Second, we demonstrate the localization accuracy of lifetime based methods using fluorescent pellets embedded in a sacrificed mouse. Third, we show using planar imaging and tomography, the in vivo recovery of multiple anatomically targeted near-infrared fluorophores. In summary, we have presented novel reconstruction algorithms and experimental methods that extend the capability of time-domain fluorescence diffuse optical tomography systems. The methods developed in this thesis should also have applicability for general multi-parameter image reconstruction problems. / Engineering and Applied Sciences

As new therapeutic targets and drugs are discovered for B-cell lymphoma and other cancers, companion diagnostics are also needed to determine target engagement, therapeutic efficacy, and patient segmentation for clinical trials. We first employed synthetic chemistry to build a platform for modifying small molecule drugs into imaging probes, using the poly(ADP-ribose) polymerase 1 (PARP1) inhibitor AZD2281 (Olaparib) as a model for technology development. Our results showed that small-molecule companion imaging drugs can be used for fluorescence imaging in cells, as well as for pharmacokinetic studies and positron emission tomography (PET) imaging in vivo, without significantly perturbing their target binding properties or cellular uptake. To apply this approach to B-cell lymphoma drugs currently in clinical trials, we modified an irreversible inhibitor of Bruton's Tyrosine Kinase (BTK), PCI-32765 (Ibrutinib), with the fluorophore Bodipy FL (BFL), and used it for imaging in cells and in a mouse window-chamber xenograft model. The excellent co-localization of our probe (Ibrutinib-BFL) with BTK demonstrated its utility for studying additional BTK inhibitors and as a companion imaging probe. In parallel, we hypothesized that central nervous system (CNS) lymphoma diagnosis from paucicellular cerebrospinal fluid (CSF) samples could be improved with molecular profiling of putative lymphoma cells trapped in a customized microfluidic chip. Following fabrication and characterization of a polydimethylsiloxane (PDMS) diagnostic device containing an array of affinity-free single-cell capture sites, we were able to efficiently recover >90% of lymphocytes, perform immunostaining on chip, and apply an image-processing algorithm to group cells based on their molecular marker expression, such as kappa/lambda light chain restriction. Additionally, in combination with Ibrutinib-BFL or other imaging drugs, we demonstrated the potential for on-chip drug imaging for use in conjunction with drug development. Finally, we applied bioorthogonal conjugation chemistries on cellulose paper for potential applications in lowering the cost of drug screening. We anticipate that these approaches will enable direct, molecular information for personalized treatment decisions in B-cell lymphomas, as well as provide a roadmap for the development of companion diagnostic probes and devices for additional indications.

Asmens sveikatos priežiūros įstaigose dirbančių medicinos darbuotojų profesinė sveikata priklauso nuo atliekamo darbo apimties ir darbų specifikos. Šiuo metu visuotinai pripažįstama radiologinio tyrimo reikšmė, atliekamų tyrimų vis daugėja. Platus jonizuojančios spinduliuotės šaltinių ir cheminių medžiagų panaudojimas susijęs su tiesiogine juos aptarnaujančių darbuotojų sveikatos rizika sąlygoja profesinių ligų atsiradimą Tyrimo tikslas - Įvertinti Kauno miesto ASPĮ radiologijos skyrių darbuotojų (gydytojų – radiologų, laborantų) nusiskundimų sveikata sąsajas su darbo aplinkos veiksniais. Tyrimo metodika. Tyrimas atliktas 2008 metų sausio - vasario mėnesiais. Buvo apklausiami 8 Kauno miesto VŠĮ ASPĮ radiologijos skyrių medicinos darbuotojai. Vienmomentinės anoniminės anketinės apklausos būdu ištirta 188 darbuotojai. Atsako dažnis – 77,47 proc. Klausimynas sudarytas remiantis literatūros analize bei kitų Lietuvoje atliktų tyrimų rezultatais. Apklausa buvo siekta išsiaiškinti, kaip radiologijos skyriaus darbuotojai vertina savo sveikatą ir darbo aplinką. Statistiniams ryšiams įvertinti buvo naudojamas SPSS 13 statistinis paketas. Rezultatai. 87,8 proc. darbuotojų dirba jonizuojančios spinduliuotės sąlygomis ir 47,9 proc. – užterštoje cheminėmis medžiagomis darbo aplinkoje. Darbo vietoje visada darbų saugos reikalavimų laikosi daugiau nei pusė (62,2 proc.) respondentų. Kas antras (56,9 proc.) respondentas savo sveikatos pakitimus sieja su darbo aplinkos sąlygomis. Dažniau... [toliau žr. visą tekstą] / Professional health of workers in health care system depends on volume and specifics of work. Nowadays, the significance of radiology tests is relatively high, and the number of tests is increasing. Wide application of sources of ionization and chemical substances is directly related with the risk of occupational diseases for health care staff working under such conditions. Aim of the study: to evaluate the health complaints and its relationship with work conditions of radiology departments' staff (radiologists and laboratory workers) at Kaunas health care settings. Material and methods. The study was conducted in January–February 2008. The sample included radiology staff of 8 health care settings in Kaunas. Anonymous questionnaire was received from 188 subjects (response rate 77,5%). The questionnaire was constructed for evaluation of health and work conditions. Statistical data analysis was performed using statistical package „SPSS for Windows 13.0“. Results. Altogether, 87,8% of staff works in ionized environment and 47,9% in chemically polluted conditions. The requirements of security at work are fulfilled by 62,2% of responders. More than half of responders (56,9%) relate their subjective health changes with work environment. Among laboratory workers this relationship is stronger than among radiologists (p<0,05). Conclusions. Current health status is estimated as good among one third of responders (more by radiologists than laboratory workers). Most common health... [to full text]

Darbo tikslas - nustatyti ir įvertinti asmens svaikatos priežiūros įstaigų medicinos personalo (gydytojų radiologų ir radiologijos laborantų) informuotumą apie pacientų gaunamą apšvitą ir radiacinę saugą Vilniaus mieste. Tyrimo objektas – gydytojai radiologai ir radiologijos laborantai. Tyrimo metu buvo apklausti 140 respondentų iš 15 asmens sveikatos priežiūros įstaigų. Viso buvo apklausta 35 gydytojai radiologai (iš jų 15 vyrų ir 20 moterų) ir 105 radiologijos laborantai (iš jų 4 vyrai ir 101 moteris), o tai atitinkamai sudarė 25,0% ir 75,0%. Apklaustųjų amžius svyruoja nuo 23 iki 71 metų (vidurkis 47,43). Tyrimo tikslui ir uždaviniams pasiekti panaudotas aprašomasis tyrimo tipas bei anketinės apklausos metodas. Statistinė duomenų analizė atlikta naudojant SPSS 13 programos versiją. Pateikiamas rodiklių pasiskirstymas absoliučiais skaičiais ir procentais, apskaičiuotas chi kvadratas (Chi-kv.). Sirtumas statistiškai reikšmingas kai pasikliovimo lygmuo p<0,05. Atlikta mokslinių straipsnių, sveikatos sistemos teisinės ir normatyvinės medžiagos ir t.t., analizė. Gautos šios išvados: įvertinus bendrą žinių lygį tarp apklaustų respondentų, galima teigti, kad gydytojai radiologai ir radiologijos laborantai pakankamai gerai žino radiacinės saugos principus bei apšvitos keliamą pavojų. Tačiau atliktas tyrimas taip pat parodė, kad jiems vis dar trūksta žinių kai kuriais specifiniais klausimais, pavyzdžiui tokiais kaip tipinės efektinės dozės gaunamos atliekant įvairias procedūras... [toliau žr. visą tekstą] / Main task – to estimate and evaluate medical personnel’s of health care (doctors of radiology and radiology assistants) informativeness about receivable irradiance towards patients and radiational safety in city of Vilnius. Object of research - doctors of radiology and radiology assistants. During this research 140 respondents were questioned from 15 health care institutions. Overall 35 radiologists were questioned (15 men and 20 women), 105 radiology assistants (4 men and 101 women) and that’s accordingly 20, 0% and 75, 0%. Age variance of the respondents is from 23 up to 71 years old (average of 47.43 years old). Descriptive research type and survey was used in order to achieve the goals of this research. Statistical data analysis was performed by using SPSS program, version 13. The given distribution of index is in natural numbers and in percentage, Chi-square is counted (Chi-sq). Statistically the difference is meaningful when the level of probability is p<0,05. The analysis of science articles, law normative materials, health care systems, etc. was accomplished. The conclusion: after the evaluation of knowledge of the respondents it is clear that, doctors of radiology and radiology assistants have enough knowledge about radiational safety and dangers of irradiance. The research also revealed that they do not have enough knowledge concerning the specific topics, for example the doses that are received during variable procedures, the dependence of the dose, the observation... [to full text]

Platinum complexes (cisplatin, carboplatin and oxaliplatin) are effective anticancer agents. However the major drawbacks of platinum chemotherapy are toxic side effects and resistance. The affinity of platinum complexes to sulfur donor ligands of side chains of methionine and cysteine amino acids was assumed to be responsible for toxicity and resistance. Recently, it was found that the reaction of platinum complex with proteins containing sulfur donor ligands could actually favor its anticancer activity. Copper transporter 1 (Ctr 1), a protein involved in the transport of copper into the cell, also helps in the influx of cisplatin by binding to N-terminal domain of Ctr 1 which is rich in methionine and histidine residues. A better understanding of how the size and shape of amine ligand, and leaving groups affect the reaction of platinum (II) complexes with methionine could give new ways to optimize its anticancer activity. This preliminary research focuses to answer this by HPLC-UV-VIS analysis of bulky platinum complexes including [Pt(dien)Cl]Cl, Pt(Me4en)(NO3)2 and Pt(en)(NO3)2 with two methionine containing small peptides that serve as models for protein interactions.

Stereotactic radiosurgery with several static conformal beams shaped by a micro multileaf collimator (muMLC) is used for treating small irregularly shaped brain lesions. Specific requirements for this technique are a precise localization and positioning of the target (1mm) and a precise (1mm) and numerically accurate (+/-5%) dose delivery. In this work, a pencil beam algorithm based treatment planning software BrainScan 5.2 (Brainlab, Germany) is validated against measurements (diode, radiographic films) and Monte Carlo simulations (BEAMnrc and XVMC codes). The latter is required because of difficulties in obtaining precise and accurate dose measurements for small fields. A dedicated muMLC component module for the BEAMnrc code was developed as part of this project. Results show that Monte Carlo calculations agree with measured dose distributions to within 2% and/or 1 mm except for field sizes smaller than 1.2 cm where agreement is within 5% due to uncertainties in measured output factors. Comparison with the pencil beam algorithm calculations were performed for square and irregularly shaped fields at different incidence angles on rectangular and humanoid homogeneous phantoms. Results show that the pencil beam algorithm is suitable for radiosurgery although some differences were found in the comparison of interleaf leakage and beam profile penumbras.

Les maladies cardio-vasculaires demeurent une cause majeure de mortalité et morbidité dans les sociétés développées. La recherche de déterminants prédictifs d’évènements vasculaires représente toujours un enjeu d’actualité face aux coûts croissants des dépenses reliées aux soins médicaux et à l’élargissement des populations concernées, notamment face à l’occidentalisation des pays émergeants comme l’Inde, le Brésil et la Chine. La cardiologie nucléaire occupe depuis trente ans, une place essentielle dans l’arsenal des méthodes diagnostiques et pronostiques des cardiopathies. De plus, de nouvelles percées permettront de dépister d’une façon plus précoce et précise, la maladie athérosclérotique cardiaque et périphérique chez les populations atteintes ainsi qu’en prévention primaire. Nous présenterons dans cette thèse, deux approches nouvelles de la cardiologie nucléaire. La dysfonction endothéliale est considérée comme le signal pathologique le plus précoce de l’athérosclérose. Les facteurs de risques cardiovasculaires traditionnels atteignent la fonction endothéliale et peuvent initier le processus d’athérosclérose même en l’absence de lésion endothéliale physique. La quantification de la fonction endothéliale coronarienne comporte donc un intérêt certain comme biomarqueur précoce de la maladie coronarienne. La pléthysmographie isotopique, méthodologie développée lors de ce cycle d’étude, permet de quantifier la fonction endothéliale périphérique, cette dernière étant corrélée à la fonction endothéliale coronarienne. Cette méthodologie est démontrée dans le premier manuscrit (Harel et. al., Physiol Meas., 2007). L’utilisation d’un radiomarquage des érythrocytes permet la mesure du flot artériel au niveau du membre supérieur pendant la réalisation d’une hyperémie réactive locale. Cette nouvelle procédure a été validée en comparaison à la pléthysmographie par jauge de contrainte sur une cohorte de 26 patients. Elle a démontré une excellente reproductibilité (coefficient de corrélation intra-classe = 0.89). De plus, la mesure du flot artérielle pendant la réaction hyperémique corrélait avec les mesure réalisées par la méthode de référence (r=0.87). Le deuxième manuscrit expose les bases de la spectroscopie infrarouge comme méthodologie de mesure du flot artériel et quantification de la réaction hyperémique (Harel et. al., Physiol Meas., 2008). Cette étude utilisa un protocole de triples mesures simultanées à l’aide de la pléthysmographie par jauge de contrainte, radio-isotopique et par spectroscopie infrarouge. La technique par spectroscopie fut démontrée précise et reproductible quant à la mesure des flots artériels au niveau de l’avant-bras. Cette nouvelle procédure a présenté des avantages indéniables quant à la diminution d’artéfact et à sa facilité d’utilisation. Le second volet de ma thèse porte sur l’analyse du synchronisme de contraction cardiaque. En effet, plus de 30% des patients recevant une thérapie de resynchronisation ne démontre pas d’amélioration clinique. De plus, ce taux de non-réponse est encore plus élevé lors de l’utilisation de critères morphologiques de réponse à la resynchronisation (réduction du volume télésystolique). Il existe donc un besoin urgent de développer une méthodologie de mesure fiable et précise de la dynamique cardiaque. Le troisième manuscrit expose les bases d’une nouvelle technique radio-isotopique permettant la quantification de la fraction d’éjection du ventricule gauche (Harel et. al. J Nucl Cardiol., 2007). L’étude portant sur 202 patients a démontré une excellente corrélation (r=0.84) avec la méthode de référence (ventriculographie planaire). La comparaison avec le logiciel QBS (Cedar-Sinai) démontrait un écart type du biais inférieur (7.44% vs 9.36%). De plus, le biais dans la mesure ne démontrait pas de corrélation avec la magnitude du paramètre pour notre méthodologie, contrairement au logiciel alterne. Le quatrième manuscrit portait sur la quantification de l’asynchronisme intra-ventriculaire gauche (Harel et. al. J Nucl Cardiol, 2008). Un nouveau paramètre tridimensionnel (CHI: contraction homogeneity index) (médiane 73.8% ; IQ 58.7% - 84.9%) permis d’intégrer les composantes d’amplitude et du synchronisme de la contraction ventriculaire. La validation de ce paramètre fut effectuée par comparaison avec la déviation standard de l’histogramme de phase (SDΦ) (médiane 28.2º ; IQ 17.5º - 46.8º) obtenu par la ventriculographie planaire lors d’une étude portant sur 235 patients. Ces quatre manuscrits, déjà publiés dans la littérature scientifique spécialisée, résument une fraction des travaux de recherche que nous avons effectués durant les trois dernières années. Ces travaux s’inscrivent dans deux axes majeurs de développement de la cardiologie du 21ième siècle. / Cardiovascular diseases remain a major cause of mortality and morbidity in developed countries. The search for predictive determinants of vascular events represents a relevant and timely goal, considering the increasing costs of medical care and the progress in developing countries such as India, Brazil and China. Nuclear cardiology has, for 30 years, played an essential role in the diagnosis and prognosis of various cardiac and vascular diseases. Moreover, new developments will allow earlier and more specific detection of cardiac and peripheral atherosclerosis disease in affected individuals and in primary prevention. In this thesis, we will focus on advances in two major themes of nuclear cardiology. Endothelial dysfunction is regarded as the earliest pathological markers of atherosclerosis. Traditional cardiovascular risks factors impair endothelial function and can initiate the atherosclerosis process, even in the absence of overt endothelial disruption. Quantification of coronary endothelial function is, therefore, of considerable interest as an early biomarker for coronary disease. The radionuclide plethysmography methodology developed during the course of my doctoral studies allows the quantification of peripheral endothelial function, which has been correlated with coronary endothelial function. This methodology is detailed in the first manuscript (Harel et. al., Physiol Meas., 2007). The use of red blood cell radio-labeling permits arterial flow to be measured in the upper limb during local reactive hyperemia. This new procedure was validated against strain gauge plethysmography in a cohort of 26 patients with excellent reproducibility (intraclass coefficient of correlation = 0.89). Moreover, the arterial measurements of flow during the hyperemic reaction correlated well with the reference method (r=0.87). The second manuscript exposes the basis of infrared spectroscopy as a method for measuring arterial flow and quantifying the hyperemic reaction (Harel et. al., Physiol Meas., 2008). The study protocol consisted of simultaneous measurements by strain gauge, radionuclide and infrared spectroscopy plethysmography. The spectroscopy technique was shown to be precise and reproducible for forearm measurement of arterial blood flow. This novel procedure came major advantages in reducing artifacts and in its ease of use. The second axis of my thesis relates to the analysis of cardiac contraction synchrony. Indeed, more than 30% of patients receiving resynchronization therapy do not show clinical improvement. Moreover, this non-response rate is even higher if we consider morphological criteria of resynchronization (end-systolic volume reduction). There is therefore, an urgent need to improve a methodology to reliably and precisely measure cardiac dynamics so as to identify and monitor potential responders. The third manuscript exposes the basis of a new radionuclide technique to quantify left ventricle ejection fraction (Harel et. al. J Nucl Cardiol., 2007). The study of 202 patients showed an excellent correlation (r=0.84) with the reference method (planar ventriculography). The comparison with QBS software (Cedar-Sinai), showed a lower standard deviation of bias (7.44% vs 9.36%). Moreover, unlike the alternative software, the bias did not correlate with the magnitude of the ejection fraction. The fourth manuscript relates to the quantification of the left intra-ventricular synchronism (Harel et. al. J Nucl Cardiol, 2008). A new three-dimensional parameter (CHI: contraction homogeneity index) (median 73.8%; IQ 58.7% - 84.9%) was defined to allow the integration of amplitude and synchrony components of ventricular contraction. Validation of this parameter was undertaken out by comparing the standard deviation of the histogram of phase (SDΦ) (median 28.2º; IQ 17.5º- 46.8º) obtained by planar ventriculography in a study of 235 patients. These four manuscripts, already published in the specialized scientific literature, summarize a fraction of the research tasks that we have carried out during the three last years, representing two major axes of nuclear cardiology advancement in the 21st century.