Non-rigid motion-compensated 3D whole-heart T2 mapping in a hybrid 3T PET-MR system

PURPOSE

Simultaneous PET-MRI improves inflammatory cardiac disease diagnosis. However, challenges persist in respiratory motion and mis-registration between free-breathing 3D PET and 2D breath-held MR images. We propose a free-breathing non-rigid motion-compensated 3D T2 -mapping sequence enabling whole-heart myocardial tissue characterization in a hybrid 3T PET-MR system and provides non-rigid respiratory motion fields to correct also simultaneously acquired PET data.

METHODS

Free-breathing 3D whole-heart T2 -mapping was implemented on a hybrid 3T PET-MRI system. Three datasets were acquired with different T2 -preparation modules (0, 28, 55 ms) using 3-fold undersampled variable-density Cartesian trajectory. Respiratory motion was estimated via virtual 3D image navigators, enabling multi-contrast non-rigid motion-corrected MR reconstruction. T2 -maps were computed using dictionary-matching. Approach was tested in phantom, 8 healthy subjects, 14 MR only and 2 PET-MR patients with suspected cardiac disease and compared with spin echo reference (phantom) and clinical 2D T2 -mapping (in-vivo).

RESULTS

Phantom results show a high correlation (R2  = 0.996) between proposed approach and gold standard 2D T2 mapping. In-vivo 3D T2 -mapping average values in healthy subjects (39.0 ± 1.4 ms) and patients (healthy tissue) (39.1 ± 1.4 ms) agree with conventional 2D T2 -mapping (healthy = 38.6 ± 1.2 ms, patients = 40.3 ± 1.7 ms). Bland-Altman analysis reveals bias of 1.8 ms and 95% limits of agreement (LOA) of -2.4-6 ms for healthy subjects, and bias of 1.3 ms and 95% LOA of -1.9 to 4.6 ms for patients.

CONCLUSION

Validated efficient 3D whole-heart T2 -mapping at hybrid 3T PET-MRI provides myocardial inflammation characterization and non-rigid respiratory motion fields for simultaneous PET data correction. Comparable T2 values were achieved with both 3D and 2D methods. Improved image quality was observed in the PET images after MR-based motion correction.

Multi-center study of inter-rater reproducibility, image quality, and diagnostic accuracy of CZT versus conventional SPECT myocardial perfusion imaging

BACKGROUND

Cadmium-zinc-telluride (CZT)-based detectors exhibit higher diagnostic sensitivity in myocardial perfusion imaging (MPI) than conventional Anger-MPI for detection of coronary artery disease (CAD); however, reduced specificity and diagnostic accuracy of CZT-MPI were observed. This study aims to compare these different camera systems and to examine the degree of inter-rater reproducibility among readers with varying experience in MPI.

METHODS

83 patients who underwent double stress/rest examinations using both a CZT and conventional SPECT cameras within one visit were included. Anonymized and randomized MPI-images were distributed to 15 international readers using a standardized questionnaire. Subsequent coronary angiography findings of ten patients served as a reference for analysis of sensitivity and specificity.

RESULTS

Image quality was significantly better in CZT-MPI with significantly lower breast attenuation (P < 0.05). CZT-MPI exhibited higher sensitivity than Anger-MPI (87.5% vs. 62.5%) and significantly reduced specificity (40% vs. 100%). Readers experienced with both camera systems had the highest inter-rater agreement indicating higher reproducibility (CZT 0.54 vs. conv. 0.49, P < 0.05).

CONCLUSIONS

Higher diagnostic sensitivity of CZT-MPI offers advantages in detection of CAD yet potentially of at the cost of reduced specificity, therefore it requires special training and a differentiated evaluation approach, especially for non-experienced readers with such camera systems.

Quantitative analysis of myocardial metabolic heterogeneity is superior to visual assessment for the detection of active cardiac sarcoidosis by F-18 FDG PET-CT imaging

Funding Acknowledgements

Type of funding sources: None.

Background

Myocardial inflammation may occur in the context of a multisystem disease such as sarcoidosis, adversely affecting prognosis. A definitive diagnosis of cardiac sarcoidosis (CS) is essential to implementing life-saving treatment but this is complicated by the invasive nature of endomyocardial biopsy (EMB) and its low accuracy. Positron emission tomography (PET) assists in diagnosis, which relies on visual interpretation of myocardial F-18 FDG uptake. The value of quantitative analysis and its application to clinical practice remain uncertain.

Purpose

To investigate the power of quantitative F-18 FDG PET-CT imaging analysis for detecting CS in patients with suspected disease.

Methods

All patients underwent F-18 FDG PET-CT after a 24-hour low-carbohydrate diet and 15-hour fasting as part of their diagnostic work-up for suspected cardiac inflammation. Cardiovascular magnetic resonance acted as gatekeeper to PET-CT in 8 of every 10 scans. Myocardial F-18 FDG uptake was assessed qualitatively and quantitatively using both manually drawn regions of interest and automatic polar maps to measure global and segmental standardised F-18 FDG uptake values (SUV).  The coefficient of variation (CoV) was calculated to determine uptake heterogeneity. To confirm diagnosis, follow-up data regarding disease progression, further testing and treatment were collected. To allow for sufficient follow-up time, the first 40 consecutive patients from a prospective registry (n= 214; Sep 2017-Jun 2020) were included.

Results

A comprehensive clinical picture was obtained successfully in 37 patients (median [IQR], 17 [13.5] months) and a final diagnosis of CS reached in 7 (disease prevalence, 19%). EMB was performed in 2 patients only while 3 underwent PPM/ICD implantation. Significant predictors of CS were fulfilment of Japanese Ministry of Health and Welfare criteria (Wald, 6.44; p = 0.01) and left ventricular dysfunction (Wald 6.72; p = 0.01). Qualitative F-18 FDG PET-CT had a high negative (95%) but low positive (45%) predictive value for CS (sensitivity, 83%; specificity, 77%). F-18 FDG SUV CoV was the strongest imaging predictor (Wald, 6.77; p = 0.009) and was significantly higher in CS than non-CS (CoV median [quartiles], 0.26 [0.21, 0.36] and 0.12 [0.11, 0.14] respectively; p = 0.004). As per ROC curve analysis (AUC, 0.84), a CoV threshold of 0.20 was highly specific (93%) and sensitive (86%) for CS.

Conclusion

In a referring population with a low prevalence of cardiac sarcoidosis, F-18 FDG PET-CT imaging is sensitive for the detection of myocardial inflammation with active disease unlikely in patients with a negative scan. Quantitative evaluation of metabolic heterogeneity within the myocardium provides a strong, independent marker of active disease and should be considered alongside visual assessment.

Initial investigation of free-breathing 3D whole-heart stress myocardial perfusion MRI

Objective: Myocardial first-pass perfusion imaging with MRI is well-established clinically. However, it is potentially weakened by limited myocardial coverage compared to nuclear medicine. Clinical evaluations of whole-heart MRI perfusion by 3D methods, while promising, have to date had the limit of breathhold requirements at stress. This work aims to develop a new free-breathing 3D myocardial perfusion method, and to test its performance in a small patient population.

Methods: This work required tolerance to respiratory motion for stress investigations, and therefore employed a “stack-of-stars” hybrid Cartesian-radial MRI acquisition method. The MRI sequence was highly optimised for rapid acquisition and combined with a compressed sensing reconstruction. Stress and rest datasets were acquired in four healthy volunteers, and in six patients with coronary artery disease (CAD), which were compared against clinical reference information.

Results: This free-breathing method produced datasets that appeared consistent with clinical reference data in detecting moderate-to-strong induced perfusion abnormalities. However, the majority of the mild defects identified clinically were not detected by the method, potentially due to the presence of transient myocardial artefacts present in the images.

Discussion: The feasibility of detecting CAD using this 3D first-pass perfusion sequence during free-breathing is demonstrated. Good agreement on typical moderate-to-strong CAD cases is promising, however, questions still remain on the sensitivity of the technique to milder cases.

Phase analysis, a novel SPECT technique for left ventricular dyssynchrony: Are degrees and milliseconds interchangeable?

BACKGROUND

Phase analysis of gated single photon emission computed tomography (SPECT) myocardial perfusion scintigraphy provides a measure of left ventricular dyssynchrony and may have applications for identifying patients suitable for cardiac resynchronisation therapy. Phase analysis is typically described in degrees of cardiac cycle, less intuitive to cardiologists familiar with ECGs. We assessed the relationship between time and degrees, to determine whether they are interchangeable.

METHODS AND RESULTS

399 patients underwent normal stress-only SPECT myocardial perfusion imaging using Technetium-99m-tetrofosmin. Data analysis used QGS software (Cedars Sinai) calculating bandwidth and standard deviation. Heart rate, age, gender, stress modality, and ejection fraction were analyzed for their relation to phase variables. 13 patients were excluded for conduction abnormalities including right and left bundle branch block and ventricular pacing. Heart rate was strongly correlated to bandwidth and standard deviation measured in time, but unrelated when measured in degrees. Although bandwidth measured by time and degrees were strongly correlated with each other this relationship was not perfect (correlation coefficient 0.87, P < .001). The addition of heart rate to the model explained most of the residual variation between the two. The results for standard deviation were similar.

CONCLUSION

In patients with normal myocardial perfusion and QRS duration bandwidth measured by degrees is not directly interchangeable with time in milliseconds. However most of the variation is explainable by heart rate, which predominantly affects measures of time rather than degrees. We would propose that although the values are less intuitive to cardiologists, normal ranges for phase measured in degrees are potentially more robust.

A bioinspired metal-organic approach to cross-linked functional 3D nanofibrous hydro- and aero-gels with effective mixture separation of nucleobases by molecular recognition

The direct reaction between Cu(CH3COO)2 and uracil-1-acetic acid in water gives rise to the formation of a hydrogel consisting of entangled nanometric ribbons of a crystalline antiferromagnetic 1D Cu(ii) coordination polymer (CP) decorated with biocompatible uracil nucleobases. This hydrogel is the precursor for the preparation of a meso/macroporous ultralight aerogel that shows a remarkable Young's modulus. As a proof-of-concept of the molecular recognition capability of the terminal uracil moieties anchored at Cu(ii) CP chains, this material has been tested as the selective stationary phase for the separation of nucleobase derivatives in HPLC columns.

Salutogénesis de la alimentación en chile: actores involucrados y brechas detectadas

Objetivos: Conocer los principales actores involucrados y las brechas detectadas en el proceso de aprendizaje alimentario de una población adulta urbana en Santiago de Chile. Materiales y métodos: De una muestra de 100 beneficiarios de un CESFAM, se incluyó a quienes tuvieran un alto Índice de Alimentación Saludable (IAS). Se realizaron entrevistas semiestructuradas, las cuales fueron grabadas en audio, transcritas de manera textual y analizadas mediante la Teoría Fundamentada. Resultados: Se entrevistó a 16 personas con IAS alto, en su mayoría mujeres. Los principales actores del proceso de aprendizaje alimentario resultan ser los padres, las experiencias adquiridas en el trabajo y la consulta con el profesional nutricionista. Se detectó una brecha de educación alimentaria entre la población general y el equipo de nutricionistas en contextos de atención primaria de salud. Conclusiones: Los padres, los contextos laborales y la consulta con el nutricionista son las principales influencias en el proceso de aprendizaje alimentario. También fueron identificados tres grupos poblacionales (adolescentes femeninas, madres y niños), como poblaciones carentes de intervención nutricional de carácter educativo-preventivo por nutricionistas en el contexto de la atención primaria de salud en Chile, situación que podría perpetuar y mantener los malos hábitos de alimentación de la población general.

Regadenoson myocardial perfusion scintigraphy for the evaluation of coronary artery disease in patients with lung disease: A series of five cases

Coronary artery disease (CAD) is a leading cause of death and morbidity globally. Myocardial perfusion scintigraphy (MPS) is commonly used for the diagnosis of CAD, necessitating hyperaemia achieved either by physical exertion or by pharmacological stress, most commonly through use of a coronary arteriolar dilator. This is challenging in patients with respiratory conditions because exercise may be submaximal and adenosine is contraindicated because of the risk of bronchoconstriction. Regadenoson is the only selective adenosine A2A receptor agonist approved as a vasodilator in MPS. The risk of bronchospasm with regadenoson has been investigated in large, randomised trials; however, patients with the most severe respiratory conditions were not included. In this case series, we present the use of regadenoson MPS in five patients with moderate-to-severe lung conditions, including patients requiring lung volume reduction surgery and lung transplant. In all cases, regadenoson MPS provided valuable information for risk assessment and treatment optimisation. Although dyspnoea occurred in all patients, regadenoson was well tolerated without serious adverse events or bronchospasm; in no case was intervention required to treat dyspnoea.

Influence of Acculturation on Emotional Learning and Memory in Spanish and English Speakers

Objective

The Emotional Verbal Learning Test-Spanish (EVLT-S) is a novel list learning test similar in structure to traditional verbal memory tests but contains words from 4 discrete emotional categories. Influence of acculturation on emotional learning was examined on EVLT-S learning trials 1 to 5.

Participants and Method

Participants included 50 bilingual healthy individuals in the Spanish-dominant group (Age M = 20.3years; 72% female) and 27 in the English-dominant group (Age M = 23.4years, 51.9% female). They were administered a battery of tests including the EVLT, a non-emotional verbal list learning test (LLT), Vocabulary (VC), Digit Span (DS), and The Short Acculturation Scale for Hispanics (SASH) in their dominant language. To examine learning curves a mixed model ANOVA was conducted with test (EVLT-S/EVLT, LLT-S/LLT) and trial as within-subjects variables and group (Spanish, English) as a between-subjects variable.

Results

There were significant main effects (p &lt; .005) for test, trial, and group. The Spanish-dominant group had the lowest overall performance on the EVLT-S (main effect for group). Post hoc comparisons of the Spanish-dominant group’s LLT-S and EVLT-S performance indicated significant differences at each trail (p &lt; .01), with the EVLT-S scores being lower than the LLT-S scores. The ANOVA was repeated with VC, DS, and SASH included as covariates. When controlling for these variables, the main effect for group was no longer significant. A significant trial by acculturation interaction effect emerged (p&lt;.05), with the English-dominant group generally performing better than the Spanish-dominant group.

Conclusions

Results suggest that Spanish and English language group differences were largely accounted for by word knowledge (VC), working memory (DS), and acculturation differences (SASH) between the groups. The role of these variables is discussed further in the context of acculturation.

Factorial Validity of the Emotional Verbal Learning Test-Spanish (EVLT-S)

Objective

The EVLT-S is the Spanish translation of a novel measure of emotional verbal learning and memory. The current study aimed to preliminarily examine the factorial validity of the EVLT-S to determine if its latent structure was similar to that identified for the EVLT by Strauss and Allen (2013) in a sample of 329 English speakers.

Participants and Method

Two principal component analyses (PCAs) were conducted to examine the latent structure of the EVLT-S. The first PCA examined EVLT/EVLT-S performance in a combined sample of English language-dominant participants (n = 52; Age M = 23.1 years; Education M = 13.4 years; 32.7% White non-Hispanic, 36.5% Hispanic, and 30.8 % other; 55.8% female) and Spanish language-dominant participants (n = 50; Age M = 20.3 years; Education M = 12.8 years; 98% Hispanic and 2% other; 72% female). The second PCA was conducted with the Spanish dominant sample alone (n = 50). PCAs were conducted using comparable scores and procedures reported by Strauss and Allen (2013), including scores for the four emotion categories (happiness, sadness, anger, anxiety), varimax rotation, and Kaiser-Guttman criteria to determine the number of components, allowing for direct comparisons between the current results and those previously reported.

Results

Both PCA’s identified five components that accounted for 68.6 – 70.4 percent of the variance and attained simple structure. Based on factor loadings, these components were labeled Anger, Sadness, Happiness, Anxiety, and Short-Term Memory (STM).

Conclusions

The PCA analyses in this study were exploratory in nature but were remarkably consistent with prior results attained in a much larger sample (n = 329) of English speakers. Results provide preliminary support for a stable and generalizable EVLT latent structure in Spanish and English versions. Future studies with larger samples using confirmatory factor analyses are needed to further establish the factorial validity of the EVLT-S.

References

Strauss, G. P., & Allen, D. N. (2013). Emotional Verbal Learning Test: development and psychometric properties. Archives of clinical neuropsychology, 28(5), 435-451.

Simultaneous 13N-Ammonia and gadolinium first-pass myocardial perfusion with quantitative hybrid PET-MR imaging: a phantom and clinical feasibility study

BACKGROUND

Positron emission tomography (PET) is the non-invasive reference standard for myocardial blood flow (MBF) quantification. Hybrid PET-MR allows simultaneous PET and cardiac magnetic resonance (CMR) acquisition under identical experimental and physiological conditions. This study aimed to determine feasibility of simultaneous 13N-Ammonia PET and dynamic contrast-enhanced CMR MBF quantification in phantoms and healthy volunteers.

METHODS

Images were acquired using a 3T hybrid PET-MR scanner. Phantom study: MBF was simulated at different physiological perfusion rates and a protocol for simultaneous PET-MR perfusion imaging was developed. Volunteer study: five healthy volunteers underwent adenosine stress. 13N-Ammonia and gadolinium were administered simultaneously. PET list mode data was reconstructed using ordered subset expectation maximisation. CMR MBF was quantified using Fermi function-constrained deconvolution of arterial input function and myocardial signal. PET MBF was obtained using a one-tissue compartment model and image-derived input function.

RESULTS

Phantom study: PET and CMR MBF measurements demonstrated high repeatability with intraclass coefficients 0.98 and 0.99, respectively. There was high correlation between PET and CMR MBF (r = 0.98, p < 0.001) and good agreement (bias - 0.85 mL/g/min; 95% limits of agreement 0.29 to - 1.98). Volunteer study: Mean global stress MBF for CMR and PET were 2.58 ± 0.11 and 2.60 ± 0.47 mL/g/min respectively. On a per territory basis, there was moderate correlation (r = 0.63, p = 0.03) and agreement (bias - 0.34 mL/g/min; 95% limits of agreement 0.49 to - 1.18).

CONCLUSION

Simultaneous MBF quantification using hybrid PET-MR imaging is feasible with high test repeatability and good to moderate agreement between PET and CMR. Future studies in coronary artery disease patients may allow cross-validation of techniques.

Guidelines in review: Comparison of ESC and AHA guidance for the diagnosis and management of infective endocarditis in adults

Over recent years, new evidence has led a rethinking of the available guidance on the diagnosis and management of infective endocarditis (IE). This review compares the most recently available guidance provided by the American Heart Association (AHA) IE Writing Committee, and the Task Force for the management of IE of the European Society of Cardiology (ESC). This represents the sixth of a new series of comparative guidelines review published in the Journal.

Hybrid positron emission tomography-magnetic resonance of the heart: current state of the art and future applications

Hybrid positron emission tomography-magnetic resonance (PET-MR) imaging is a novel imaging modality with emerging applications for cardiovascular disease. PET-MR aims to combine the high-spatial resolution morphological and functional assessment afforded by magnetic resonance imaging (MRI) with the ability of positron emission tomography (PET) for quantification of metabolism, perfusion, and inflammation. The fusion of these two modalities into a single imaging platform not only represents an opportunity to acquire complementary information from a single scan, but also allows motion correction for PET with reduction in ionising radiation. This article presents a brief overview of PET-MR technology followed by a review of the published literature on the clinical cardio-vascular applications of PET and MRI performed separately and with hybrid PET-MR.

Guidelines in review: Comparison of the 2014 AHA/ACC guideline for the management of patients with non-ST-elevation acute coronary syndromes and the 2015 ESC guidelines for the management of acute coronary syndromes in patients presenting without persistent ST-segment elevation

In this Guidelines in Review, we review side-by-side the recommendations provided by the 2014 AHA/ACC Guideline for the management of patients with non-ST-elevation acute coronary syndromes and the 2015 ESC Guidelines for the management of acute coronary syndromes in patients presenting without persistent ST-segment elevation. We review the recommendations for imaging in the evaluation of patients with possible ACS followed by the diagnostic evaluation of patients with proven NSTE-ACS, based on their risk for adverse clinical events.

Guidelines in review: Comparison of ESC and ACC/AHA guidelines for the diagnosis and management of patients with stable coronary artery disease

In 2012, the American College of Cardiology Foundation (ACCF) and the American Heart Association (AHA) Task Force on Practice Guidelines jointly with the American College of Physicians, American Association for Thoracic Surgery, Preventive Cardiovascular Nurses Association, Society for Cardiovascular Angiography and Interventions, and Society of Thoracic Surgeons produced a set of recommendations intended to assist physicians in the diagnosis and management of patients with stable ischemic heart disease. Two years later, a focused update on the 2012 guidelines was published. A year before this update, The Task Force on the management of stable coronary artery disease (CAD) of the European Society of Cardiology (ESC) issued a guideline on the management of stable CAD. This document brings together European and American recommendations that include the use of stress testing and non-invasive imaging for the diagnosis and management of patients with known or suspected stable CAD.

CXCR2 Inhibition - a novel approach to treating CoronAry heart DiseAse (CICADA): study protocol for a randomised controlled trial

Background

There is emerging evidence of the central role of neutrophils in both atherosclerotic plaque formation and rupture. Patients with lower neutrophil counts following acute coronary syndromes tend to have a greater coronary flow reserve, which is a strong predictor of long-term cardiovascular health. But so far, no data are available regarding the impact of neutrophil inhibition on cardiovascular clinical or surrogate endpoints. Therefore, the aim of this study is to investigate the effects of AZD5069, a cysteine-X-cysteine chemokine receptor 2 (CXCR2) inhibitor, on coronary flow reserve and coronary structure and function in patients with coronary artery disease.

Methods/Design

Ninety subjects with coronary artery disease undergoing percutaneous coronary intervention will be included in this investigator-driven, randomised, placebo-controlled, double-blind, phase IIa, single-centre study. Participants will be randomised to receive either AZD5069 (40 mg) administered orally twice daily or placebo for 24 weeks. Change in coronary flow reserve as determined by ¹³N-ammonia positron emission tomography-computed tomography will be the primary outcome. Change in the inflammatory component of coronary plaque structure and the backward expansion wave, an invasive coronary physiological measure of diastolic function, will be assessed as secondary outcomes.

Discussion

Cardiovascular surrogate parameters, such as coronary flow reserve, may provide insights into the potential mechanisms of the cardiovascular effects of CXCR2 inhibitors. Currently, ongoing trials do not specifically focus on neutrophil function as a target of intervention, and we therefore believe that our study will contribute to a better understanding of the role of neutrophil-mediated inflammation in coronary artery disease.

Trial registration

EudraCT, 2016-000775-24. Registered on 22 July 2016.

International Standard Randomised Controlled Trial Number, ISRCTN48328178. Registered on 25 February 2016.

Electronic supplementary material

The online version of this article (doi:10.1186/s13063-017-2210-2) contains supplementary material, which is available to authorized users.

Comparison of ESC and ACC/AHA guidelines for myocardial revascularization

In 2014, the Task Force on Myocardial Revascularization of the European Society of Cardiology and the European Association for Cardio-Thoracic Surgery with the special contribution of the European Association of Percutaneous Cardiovascular Interventions published a comprehensive set of recommendations on myocardial revascularization in patients presenting with acute or chronic coronary artery disease. In the United States, pertinent guidance on this topic has been published by the American College of Cardiology, American Heart Association and other relevant societies in multiple guideline documents that have been published in recent years. This document brings together European and American recommendations on myocardial revascularization with a focus on the role of cardiac imaging.

A comparison of 3 on-line nomograms with the detection of primary circulating prostate cells to predict prostate cancer at initial biopsy

INTRODUCTION

The use of nomograms which include the PSA may improve the predictive power of obtaining a prostate biopsy (PB) positive for cancer. We compare the use of three on-line nomagrams with the detection of primary malignant circulating prostate cells (CPCs) to predict the results of an initial PB in men with suspicion of prostate cancer.

METHODS AND PATIENTS

Consecutive men with suspicion of prostate cancer underwent a 12 core TRUS prostate biopsy; age, total serum PSA, percent free PSA, family history, ethnic origin and prostate ultrasound results were used for risk assessment using the online nomograms. Mononuclear cells were obtained by differential gel centrifugation from 8ml of blood and CPCs were identified using double immunomarcation with anti-PSA and anti-P504S. A CPC was defined as a cell expressing PSA and P504S and defined as negative/positive. Biopsies were classified as cancer/no-cancer. Areas under the curve (AUC) for each parameter were calculated and compared and diagnostic yields were calculated.

RESULTS

1,223 men aged>55 years participated, 467 (38.2%) had a biopsy positive for cancer of whom 114/467 (24.4%) complied with the criteria for active observation. Area under the curve analysis showed CPC detection to be superior (p<0.001), avoiding 57% of potential biopsies while missing 4% of clinically significant prostate cancers.

CONCLUSIONS

The CPC detection was superior to the nomograms in predicting the presence of prostate cancer at initial biopsy; its high negative predictive value potentially reduces the number of biopsies while missing few significant cancers, being superior to the nomograms in this aspect. Being a positive/negative test the detection of CPCs avoids defining a cutoff value which may differ between populations.

The role of pharmacological stress testing in women

Pharmacological stress is an alternative method to dynamic exercise that combined with noninvasive imaging allows the detection of flow-limiting coronary artery disease (CAD). It represents the stress procedure of choice in patients who cannot exercise appropriately. In women, pharmacological stress combined with myocardial perfusion scintigraphy (MPS) has demonstrated to be highly accurate for the detection of obstructive CAD and a valuable tool that helps separate patients at low cardiac risk from those with an adverse prognosis. Pharmacological stress with positron emission tomographic (PET) imaging is increasingly used in the investigation of suspected obstructive CAD; available evidence shows that the diagnostic profile and prognostic value of stress PET imaging is similar to that of stress MPS in women.

Caffeine reduces the sensitivity of vasodilator MPI for the detection of myocardial ischaemia: Pro

Caffeine is a non-selective antagonist at the adenosine receptors, which is expected to reverse both the intended (coronary vasodilation) and unintended (hypotension, flushing) effects of exogenously administered adenosine and adenosine-related compounds. In the past, several studies were conducted to characterize the effect of caffeine on vasodilator myocardial perfusion imaging (MPI) with conflicting results. However, new evidence supports earlier observations and shows that recent caffeine intake attenuates vasodilator-induced myocardial hyperaemia and may therefore reduce the sensitivity of radionuclide MPI for the detection of inducible perfusion abnormality in patients with coronary artery disease. Although the magnitude of this effect and hence its clinical significance are dose dependent, the acute response to equivalent doses of caffeine varies largely among individuals, and this might be explained by differences in caffeine exposure and genetically determined variations in caffeine metabolism. Abstinence from caffeinated foods and beverages for a minimum of 12 hours before vasodilator stress is therefore recommended although longer abstention might be required in order to prevent the potentially blocking effect of residual caffeine on vasodilator-mediated actions.

Presymptomatic ALS genetic counseling and testing: Experience and recommendations

Remarkable advances in our understanding of the genetic contributions to amyotrophic lateral sclerosis (ALS) have sparked discussion and debate about whether clinical genetic testing should routinely be offered to patients with ALS. A related, but distinct, question is whether presymptomatic genetic testing should be offered to family members who may be at risk for developing ALS. Existing guidelines for presymptomatic counseling and testing are mostly based on small number of individuals, clinical judgment, and experience from other neurodegenerative disorders. Over the course of the last 8 years, we have provided testing and 317 genetic counseling sessions (including predecision, pretest, posttest, and ad hoc counseling) to 161 first-degree family members participating in the Pre-Symptomatic Familial ALS Study (Pre-fALS), as well as testing and 75 posttest counseling sessions to 63 individuals with familial ALS. Based on this experience, and the real-world challenges we have had to overcome in the process, we recommend an updated set of guidelines for providing presymptomatic genetic counseling and testing to people at high genetic risk for developing ALS. These recommendations are especially timely and relevant given the growing interest in studying presymptomatic ALS.

Multicentre multi-device hybrid imaging study of coronary artery disease: results from the EValuation of INtegrated Cardiac Imaging for the Detection and Characterization of Ischaemic Heart Disease (EVINCI) hybrid imaging population

AIMS

Hybrid imaging provides a non-invasive assessment of coronary anatomy and myocardial perfusion. We sought to evaluate the added clinical value of hybrid imaging in a multi-centre multi-vendor setting.

METHODS AND RESULTS

Fourteen centres enrolled 252 patients with stable angina and intermediate (20-90%) pre-test likelihood of coronary artery disease (CAD) who underwent myocardial perfusion scintigraphy (MPS), CT coronary angiography (CTCA), and quantitative coronary angiography (QCA) with fractional flow reserve (FFR). Hybrid MPS/CTCA images were obtained by 3D image fusion. Blinded core-lab analyses were performed for CTCA, MPS, QCA and hybrid datasets. Hemodynamically significant CAD was ruled-in non-invasively in the presence of a matched finding (myocardial perfusion defect co-localized with stenosed coronary artery) and ruled-out with normal findings (both CTCA and MPS normal). Overall prevalence of significant CAD on QCA (>70% stenosis or 30-70% with FFR≤0.80) was 37%. Of 1004 pathological myocardial segments on MPS, 246 (25%) were reclassified from their standard coronary distribution to another territory by hybrid imaging. In this respect, in 45/252 (18%) patients, hybrid imaging reassigned an entire perfusion defect to another coronary territory, changing the final diagnosis in 42% of the cases. Hybrid imaging allowed non-invasive CAD rule-out in 41%, and rule-in in 24% of patients, with a negative and positive predictive value of 88% and 87%, respectively.

CONCLUSION

In patients at intermediate risk of CAD, hybrid imaging allows non-invasive co-localization of myocardial perfusion defects and subtending coronary arteries, impacting clinical decision-making in almost one every five subjects.

Regadenoson stress for myocardial perfusion imaging

Noninvasive functional imaging plays a major role in the diagnosis of hemodynamically significant coronary artery disease (CAD) by means of the detection of abnormal myocardial perfusion. For this, cardiac stressors are essential as they induce hypoperfusion in the presence of flow-limiting coronary stenosis. Several pharmacological stressors are currently available and it is important that clinicians who are involved in the care and management of patients with CAD become familiar with their indications, contraindications and protocols. Among the primary coronary vasodilator agents, regadenoson is increasingly used as the default stressor or as an alternative to other modalities of stress. This article provides an updated review of regadenoson stress for the assessment of patients with suspected or known CAD and describes its pharmacological properties, stress protocol, efficacy and safety profile.

Cryptomphalus aspersa mollusc eggs extract promotes migration and prevents cutaneous ageing in keratinocytes and dermal fibroblasts in vitro

BACKGROUND

The search of substances that minimize cutaneous ageing has increased in the last few years. Previous studies have described the regenerative properties of the secretion of the mollusc Cryptomphalus aspersa (C. aspersa) when applied topically.

OBJECTIVE

We evaluate the in vitro effects of a new product derived from the eggs of C. aspersa, IFC-CAF, on cell proliferation, migration, distribution of cytoskeletal proteins, production of extracellular components as well as its ability to prevent cutaneous ageing because of intrinsic or extrinsic factors (exposure to UVB) by determination of ageing markers.

METHODS

We have used the human keratinocyte cell line (HaCaT cells), primary dermal fibroblasts (HDF) and senescent dermal fibroblasts (SHDF). The effects of the compound on cell proliferation and on the cell cycle were determined by the MTT colorimetric assay, estimation of total protein and/or trypan blue test and by flow cytometry, respectively. We also studied cell migration using the wound-healing migration assay, whereas ELISA assays, Western Blot and immunofluorescence microscopy were carried out to test the expression of proteins related to cytoskeleton, extracellular matrix and with ageing.

RESULTS

We have found that IFC-CAF does not promote proliferation but induces migration of HaCaT, HDF and SHDF in a time- and dose-dependent manner; a better organization of cytoskeletal proteins (F-actin and vimentin) and promotes the production of extracellular components (fibronectin, collagen 1 and MMPs) and the adhesion to cell-substrate vinculin protein. IFC-CAF also prevents cutaneous ageing. The treatment decreases the expression of the ageing-related markers b-Gal, p53 and p16INK4 in SDDF cells, and improves cell survival after UVB irradiation and nuclear repair in HaCaT cells.

CONCLUSION

IFC-CAF has regenerative properties and protects against ageing factors being, therefore, a potential therapeutic agent for treating or preventing skin ageing.

Particle size distribution and its relationship to black carbon in two urban and one rural site in Santiago de Chile

The size distribution of particles has been studied in three sites in the Metropolitan area of Santiago de Chile in the winter of 2009 and a comparison with black carbon was performed. Two sites are located near busy streets in Santiago and the other site is located in a rural area about 40 km west of Santiago with little influence from vehicles, but large influence from wood burning. The campaign lasted 1 or 2 weeks in each site. We have divided the particle size measurements into four groups (10-39 nm, 40-62 nm, 63-174 nm, and 175-700 nm) in order to compare with the carbon monitor. In the sites near the street, black carbon has a high correlation (R = 0.85) with larger particles (175-700 nm). The correlation decreased when black carbon was compared with smaller particles, having very small correlation with the smallest sizes (10-39 nm). In the rural site, black carbon also has a high correlation (R = 0.86) with larger particles (175-700 nm), but the correlation between black carbon and the finest particles (10-39 nm) decreases to near 0. These measurements are an indication that wood burning does not generate particles smaller than -50 nm. In the urban sites, particle size distribution is peaked toward smaller particles (10-39 nm) only during rush hours, but at other times, particles size distribution is peaked toward larger sizes. When solar radiation was high, evidence of secondary particle formation was seen in the rural site, but not in the urban sites. The correlation between the number of secondary particles and solar radiation was R2 = 0.46, indicating that it there may be other variables that play a role in ultrafine particle formation. Implications: A study of the size distribution of particles and black carbon concentration in two street sites and one rural site shows that in the last site the number of particles ultrafine particles (d < 40 nm) is 10 times lower but the number of larger particles is about 2 times lower. Thus, the rural site has less of the particles that are more dangerous to health. The number ofultrafine particles is mostly associated with traffic, while the number of larger particles is associated with wood burning and other sources. Wood burning does not generate particles smaller than -50 nm.

Ischemic burden by 3-dimensional myocardial perfusion cardiovascular magnetic resonance: comparison with myocardial perfusion scintigraphy

BACKGROUND

The extent and severity of ischemia on myocardial perfusion scintigraphy (MPS) is commonly used to risk-stratify patients with coronary artery disease. Estimation of ischemic burden by cardiovascular magnetic resonance (CMR) with conventional 2-dimensional myocardial perfusion methods is limited by incomplete cardiac coverage. More recently developed 3-dimensional (3D) myocardial perfusion CMR, however, provides whole-heart coverage. The aim of this study was to compare ischemic burden on 3D myocardial perfusion CMR with (99m)Tc-tetrofosmin MPS.

METHODS AND RESULTS

Forty-five patients who had undergone clinically indicated MPS underwent rest and adenosine stress 3D myocardial perfusion and late gadolinium enhancement CMR. Summed stress and rest scores were calculated for MPS and CMR using a 17-segment model and expressed as a percentage of the maximal possible score. Ischemic burden was defined as the difference between stress and rest scores. 3D myocardial perfusion CMR and MPS agreed in 38 of the 45 patients for the detection of any inducible ischemia. The mean ischemic burden for MPS and CMR was similar (7.5±8.9% versus 6.8±9.5%, respectively, P=0.82) with a strong correlation between techniques (rs=0.70, P<0.001). In a subset of 33 patients who underwent clinically indicated invasive coronary angiography, sensitivities and specificities of the 2 techniques to detect angiographic coronary artery disease were similar (McNemar P=0.45).

CONCLUSIONS

3D myocardial perfusion CMR is an alternative to MPS for detecting the presence and rating the severity of ischemia.