Spatio-temporal PET imaging reconstruction with learned diffeomorphism

openLa Tomografia ad Emissione di Positroni (PET) è una modalità di imaging medico per ricostruire la distribuzione dell’attività metabolica, che viene utilizzata per rilevare lesioni tumorali grazie alle loro peculiari impronte metaboliche. Tuttavia, poiché richiede un lungo tempo di acquisizione, è soggetta ad artefatti da movimento e ciò porta ad una difficile individuazione dei tumori di piccole dimensioni, che sono i più importanti per una diagnosi precoce. L’algoritmo Morphed Maximum Likelihood Activity and Attenuation (M-MLAA) è stato sviluppato per affrontare il problema degli artefatti da movimento sfruttando i dati suddivisi in gate e la rete neurale SynthMorph per la registrazione di immagini, al fine di ricostruire un’immagine corretta dagli artefatti di movimento. L’obiettivo di questo progetto è l’implementazione su dati clinici dell’algoritmo M-MLAA e la valutazione delle sue prestazioni; purtroppo, ciò non è stato possibile a causa di problemi nell’implementazione dell’algoritmo Maximum Likelihood Activity and Attenuation (MLAA) sulla libreria Python Synergistic Image Reconstruction Framework (SIRF). I risultati mostrano che tali problemi potrebbero essere causati da una definizione errata della trasformata di Radon nella libreria. Nonostante ciò, l’algoritmo M-MLAA mostra buone prestazioni quando testato su dati sintetici, suggerendo che potrebbe rappresentare un promettente metodo di correzione dagli artefatti di movimento nella ricostruzione di immagini PET, consentendo di individuare lesioni tumorali in fase precoce.Positron Emission Tomography (PET) is a medical imaging modality to reconstruct the distribution of metabolic activity that is used to detect cancer lesions thanks to their peculiar metabolic fingerprints. However, since it requires long acquisition time, it is affected by motion artifacts and this leads to a difficult detection of small size tumours, that are the most important for early-stage diagnosis. The Morphed Maximum Likelihood Activity and Attenuation (M-MLAA) algorithm has been developed to assess the motion artifact problem by gaining advantage of gated data and SynthMorph image registration network to reconstruct a motion corrected image. This project’s goal is to implement the M-MLAA algorithm on clinical data and to evaluate its performance; unfortunately, this was not achieved due to problems in the implementation of the Maximum Likelihood Activity and Attenuation (MLAA) algorithm on Synergistic Image Reconstruction Framework (SIRF) Python library. The results show that those problems might be caused by an incorrect definition of the Radon transform in the library. Despite that, M-MLAA algorithm shows good performances when tested on synthetic data, suggesting that it could be a promising motion correction reconstruction method for PET images, capable of detecting early-stage cancer lesions

Limits on anomalous top quark gauge couplings from Tevatron and LHC data

AbstractWe review and update current limits on possible anomalous couplings of the top quark to W gauge bosons. We consider data from top quark decay (as encoded in the W-boson helicity fractions) and single-top production (in the t-, s- and Wt-channels). We find improved limits with respect to previous results (in most cases of almost one order of magnitude) and extend the analysis to include four-quark operators. We find that new physics is constrained to live above an energy scale between 430 GeV and 3.2 TeV, depending on the form of its contribution

Dilated Cardiomyopathy. From Genetics to Clinical Management

The current definition of dilated cardiomyopathy (DCM) is relatively simple: it is a heart muscle disease characterized by left ventricular (LV) or biventricular dilation and systolic dysfunction in the absence of either pressure or volume overload or coronary artery disease sufficient enough to explain the dysfunction. In the last 30 years, prognosis of patients with DCM has dramatically been improved with few similarities in the history of cardiology and medicine. Typically, in the 1980s, the average survival rate was approximately 50% in a 5-year follow-up. Nowadays, at 10 years of follow-up, the survival/free from heart transplant rate is far beyond 85%, and the projection of this improvement is significantly better for those who have had DCM diagnosed in the late 2010s. This improvement in outcomes is fundamentally due to a better characterization of etiological factors, medical management for heart failure, and device treatment, like the implantable cardioverter defibrillator (ICD), for sudden cardiac death prevention. However, other milestones should be recognized for the improvement in the survival rate, namely, the early diagnosis due to familial and sport-related screening, which allow detection of DCM at a less severe stage, and the uninterrupted, active, and individualized long-term follow-up with continuous reevaluation of the disease and re-stratification of the risk

Index numbers of retail sales monthly data 7-1982.

We establish two new characterizations of magnetic Sobolev spaces for Lipschitz magnetic fields in terms of nonlocal functionals. The first one is related to the BBM formula, due to Bourgain, Brezis and Mironescu. The second one is related to the work of the first author on the classical Sobolev spaces. We also study the convergence almost everywhere and the convergence in L1 appearing naturally in these contexts

Persistent recovery of normal left ventricular function and dimension in idiopathic dilated cardiomyopathy during long\u2010term follow\u2010up: does real healing exist?

BACKGROUND: An important number of patients with idiopathic dilated cardiomyopathy have dramatically improved left ventricular function with optimal treatment; however, little is known about the evolution and long-term outcome of this subgroup, which shows apparent healing. This study assesses whether real healing actually exists in dilated cardiomyopathy. METHODS AND RESULTS: Persistent apparent healing was evaluated among 408 patients with dilated cardiomyopathy receiving tailored medical treatment and followed over the very long-term. Persistent apparent healing was defined as left ventricular ejection fraction 6550% and indexed left ventricular end-diastolic diameter 6433 mm/m(2) at both mid-term (19\ub14 months) and long-term (103\ub19 months) follow-up. At mid-term, 63 of 408 patients (15%) were apparently healed; 38 (60%; 9%of the whole population) showed persistent apparent healing at long-term evaluation. No predictors of persistent apparent healing were found. Patients with persistent apparent healing showed better heart transplant\u2013free survival at very long-term follow-up (95% versus 71%; P=0.014) compared with nonpersistently normalized patients. Nevertheless, in the very longterm, 37% of this subgroup experienced deterioration of left ventricular systolic function, and 5% died or had heart transplantation. CONCLUSIONS: Persistent long-term apparent healing was evident in a remarkable proportion of dilated cardiomyopathy patients receiving optimal medical treatment and was associated with stable normalization of main clinical and laboratory features. This condition can be characterized by a decline of left ventricular function over the very long term, highlighting the relevance of serial nd individualized follow-up in all patients with dilated cardiomyopathy, especially considering the absence of predictors for longterm apparent healing

Long-Term Evolution and Prognostic Stratification of Biopsy-Proven Active Myocarditis

Background— Active myocarditis is characterized by large heterogeneity of clinical presentation and evolution. This study describes the characteristics and the long-term evolution of a large sample of patients with biopsy-proven active myocarditis, looking for accessible and valid early predictors of long-term prognosis. Methods and Results— From 1981 to 2009, 82 patients with biopsy-proven active myocarditis were consecutively enrolled and followed-up for 147±107 months. All patients underwent clinical and echocardiographic evaluation at baseline and at 6 months. At this time, improvement/normality of left ventricular ejection fraction (LVEF), defined as a LVEF increase > 20 percentage points or presence of LVEF≥50%, was assessed. At baseline, left ventricular dysfunction (LVEF<50%) and left atrium enlargement were independently associated with long-term heart transplantation–free survival, regardless of the clinical pattern of disease onset. At 6 months, improvement/normality of LVEF was observed in 53% of patients. Persistence of New York Heart Association III to IV classes, left atrium enlargement, and improvement/normality of LVEF at 6 months emerged as independent predictors of long-term outcome. Notably, the short-term reevaluation showed a significant incremental prognostic value in comparison with the baseline evaluation (baseline model versus 6 months model: area under the curve 0.79 versus 0.90, P =0.03). Conclusions— Baseline left ventricular function is a marker for prognosis regardless of the clinical pattern of disease onset, and its reassessment at 6 months appears useful for assessing longer-term outcome

Conflicting gender-related differences in the natural history of patients with Idiopathic Dilated Cardiomyopathy

Objective. To evaluated possible clinical and instrumental, natural history and prognostic divergences in women and men with idiopathic dilated cardiomyopathy (IDCM). Patients and Methods. From 1988 to 2012, we evaluated 803 consecutive patients with IDCM recorded in the Heart Muscle Disease Registry of Trieste (Italy). All patients had serial follow-up evaluations at 6, 12, and 24 months, and subsequently every two years, or more frequently if clinically indicated. Results. Two hundred and twenty-seven patients (28%) were female. At first evaluation women were significantly older (48 vs. 45 years old, p = 0.008); presented more frequently left bundle branch block at ECG (38% vs. 28%, p = 0.01), smaller left ventricular end-diastolic indexed volume at echocardiography (85 vs. 93 ml/m2, p &lt;0.002) and more frequently moderate to severe mitral regurgitation at Doppler (43% vs. 33%, p = 0.015). No differences in NYHA class, medical treatment and device implantation rates were found. During a median of 108 months follow-up, women showed a significantly lower ten-year total mortality/heart transplantation (20% vs. 32% respectively, p = 0.001) and cardiovascular mortality rates (9% vs. 15%, p = 0.024) despite a less marked clinical and echocardiographic improvement. Conclusions. In our population of patients with IDCM, women showed a better long-term prognosis notwithstanding a presentation with a more advanced disease and a lower clinical-instrumental improvement on optimal medical therapy compared to men.&nbsp

Conflicting gender-related differences in the natural history of patients with idiopathic dilated cardiomyopathy

Objective: To evaluated possible clinical and instrumental, natural history and prognostic divergences in women and men with idiopathic dilated cardiomyopathy (IDCM). Patients and Methods: From 1988 to 2012, we evaluated 803 consecutive patients with IDCM recorded in the Heart Muscle Disease Registry of Trieste (Italy). All patients had serial follow-up evaluations at 6, 12, and 24 months, and subsequently every two years, or more frequently if clinically indicated. Results: Two hundred and twenty-seven patients (28%) were female. At first evaluation women were significantly older (48 vs. 45 years old, p = 0.008); presented more frequently left bundle branch block at ECG (38% vs. 28%, p = 0.01), smaller left ventricular end-diastolic indexed volume at echocardiography (85 vs. 93 ml/m2, p <0.002) and more frequently moderate to severe mitral regurgitation at Doppler (43% vs. 33%, p = 0.015). No differences in NYHA class, medical treatment and device implantation rates were found. During a median of 108 months follow-up, women showed a significantly lower ten-year total mortality/heart transplantation (20% vs. 32% respectively, p = 0.001) and cardiovascular mortality rates (9% vs. 15%, p = 0.024) despite a less marked clinical and echocardiographic improvement. Conclusion: In our population of patients with IDCM, women showed a better long-term prognosis notwithstanding a presentation with a more advanced disease and a lower clinical-instrumental improvement on optimal medical therapy compared to men