An assessment of radiation use, knowledge and concerns in trainee cardiologists in Ireland.

OBJECTIVE: To evaluate knowledge, routine use and concerns of trainee cardiologists in the Republic of Ireland regarding radiation use in the cardiac catheterization laboratory. METHODS: We handed out a Radiation Questionnaire to cardiology trainees in February 2020 at the Irish Cardiac Society "Spring Meeting". The questionnaire assessed radiation protection use amongst trainees and tested knowledge of X-ray basics. RESULTS: Many trainees report inadequate access to properly sized lead protection, and infrequent dosimeter usage. Over one-third of trainees report musculoskeletal issues from wearing leads, the majority of whom use correct size lead <60% of the time.33.3% report radiation concerns will affect their decision making regarding subspeciality training, but notably 83.3% of females and only 19% of males surveyed report this, showing this is a bigger issue for females in cardiology. Less than half of trainees feel adequately educated about radiation. CONCLUSION: Our assessment show deficiencies in the provision and use of personal protective equipment to trainees, highlights extra radiation concerns of female cardiology trainees, and notes gaps in knowledge in radiation use. ADVANCES IN KNOWLEDGE: Our assessment highlights deficiencies in the education of cardiology trainees regarding ionizing radiation, and suggests this area needs to be improved upon.

Modified Ventricular Global Function Index Correlates With Exercise Capacity in Repaired Tetralogy of Fallot.

Background Cardiac MRI (CMR) derived ventricular global function index (GFI), a ratio of stroke volume to the sum of mean ventricular cavity and myocardial volumes, has demonstrated improved prediction of clinical outcomes in adults with atherosclerotic disease over ejection fraction. We sought to assess CMR derived GFI and a novel modification that accounts for unique loading conditions in patients with repaired tetralogy of Fallot (rTOF) and determine its correlation with exercise performance. Methods and Results Seventy-five patients with rTOF who underwent CMR were identified. Clinical variables were recorded and biventricular GFI calculated. A right ventricular (RV) effective GFI (eGFI) was derived by incorporating effective stroke volume. Thirty-five pediatric patients were matched with 29 age-matched healthy controls. Twenty-five patients completed cardiopulmonary exercise tests within 6 months of CMR. Stepwise regression models were used to determine univariate and multivariable predictors of indexed and percent predicted peak VO2. Median age at CMR was 20 years (interquartile range, 13-28). Pediatric rTOF patients had lower RV eGFI (P < 0.001), RV ejection fraction (P=0.002), but higher indexed RV end-diastolic and end-systolic volumes (P < 0.001, P < 0.001) compared with controls. Univariate analysis demonstrated a correlation between indexed peak VO2 with RV eGFI (R2=0.32, P=0.004), but with neither RVGFI, RV ejection fraction, indexed RV volumes nor RV mass. RV eGFI remained significantly associated with indexed peak VO2 during multivariable modeling. Conclusions Reduced RV eGFI was associated with reduced exercise capacity in rTOF patients, while RV GFI, RV ejection fraction, indexed RV volumes and mass were not. Our modification of the GFI, RV eGFI, may be a valuable non-invasive marker of cardiac function in rTOF.

The Yield of Routine Cardiac Imaging in Breast Cancer Patients Receiving Trastuzumab-Based Treatment: A Retrospective Cohort Study.

BACKGROUND: There are limited data on the yield of routine cardiac imaging for trastuzumab-treated patients with breast cancer. METHODS: We conducted a retrospective cohort study of patients with breast cancer treated with adjuvant trastuzumab between 2007 and 2012 at Princess Margaret Cancer Centre (Toronto, Canada). We classified imaging tests as clinically prompted or routinely ordered and determined whether each test led to changes in patient care. A generalized estimating equation model was used to determine if patient characteristics predicted routine studies more likely to change care. We analysed routine tests that were exclusively preceded by consecutive tests that did not change care to determine if their yield differed by time since trastuzumab start and the number of prior tests that did not change care. RESULTS: We identified 448 patients who received 1735 cardiac imaging studies after trastuzumab initiation. Of 1555 routine tests, 44 led to changes in care (2.8%) for 43 patients, whereas 50 of 180 clinically prompted tests (27.8%) altered care in 29 patients (P-value < 0.001). Earlier stage cancer, diabetes, prior anthracyclines, and prior cardiovascular disease were associated with a higher likelihood of changes in care following routine tests (P-value < 0.05). Among routine tests that were exclusively preceded by consecutive tests that did not change care, tests ordered outside months 3-9 and those that followed ≥ 3 tests were even less likely to change care. CONCLUSIONS: Routine cardiac imaging tests rarely changed care for trastuzumab-treated patients with breast cancer, particularly among lower risk anthracycline-naïve women who had multiple prior tests that did not change care.

The role of cardiovascular imaging for myocardial injury in hospitalized COVID-19 patients.

Recent EACVI recommendations described the importance of limiting cardiovascular imaging during the COVID-19 pandemic in order to reduce virus transmission, protect healthcare professionals from contamination, and reduce consumption of personal protective equipment. However, an elevated troponin remains a frequent request for cardiac imaging in COVID-19 patients, partly because it signifies cardiac injury due to a variety of causes and partly because it is known to convey a worse prognosis. The present paper aims to provide guidance to clinicians regarding the appropriateness of cardiac imaging in the context of troponin elevation and myocardial injury, how best to decipher the mechanism of myocardial injury, and how to guide patient management.

Trends in the Use of Cardiac Imaging for Patients With Heart Failure in Canada.

Importance: Cardiac imaging is a component of the provision of medical care for patients with heart failure that has experienced a broad expansion in past decades. However, there is a paucity of studies examining the patterns of use of cardiac imaging modalities in real-world clinical practice. Objectives: To investigate temporal trends in the use and costs of cardiac imaging for the examination of patients with heart failure in Canada and to examine the association between the institution of an accreditation program and the use of echocardiography. Design, Setting, and Participants: A repeated cross-sectional study based on population-based administrative databases in Ontario, Canada, of individuals with heart failure identified using a validated algorithm based on hospital admissions and ambulatory physician claims was conducted between April 1, 2002, and March 31, 2017. Main Outcomes and Measures: The incidence and prevalence of heart failure and the age- and sex-adjusted rate of use and costs of cardiac imaging, including resting and stress echocardiography, myocardial perfusion scintigraphy, invasive coronary angiography, computed tomography, magnetic resonance imaging, and positron emission tomography. Results: A total of 882 355 adults (50.1% women; median age, 76 years [interquartile range, 66-83 years]) with prevalent heart failure were identified. The age- and sex-standardized prevalence of heart failure remained stable during the study (2.4% [95% CI, 2.4%-2.4%] in 2002 and 2.0% [95% CI, 2.0%-2.0%] in 2016). There was an increase in the rate of use of resting echocardiography, from 386 tests (95% CI, 373-398) per 1000 patients with heart failure in 2002 to 533 (95% CI, 519-547) per 1000 patients in 2011. Coinciding with the initiation of an accreditation program for echocardiography in 2012, there was an immediate reduction in the rate of use (-59.5 tests per 1000 patients with heart failure; P < .001), which was followed by a plateau in subsequent years. At the same time, there was a 10.8% relative reduction in the use of myocardial perfusion scintigraphy and an 11.2% relative reduction in the use of invasive coronary angiography from 2011 to 2016 and the incorporation of newer modalities after they became publicly insured health services. Conclusions and Relevance: These findings suggest that resting echocardiography remains the most used imaging technique for patients with heart failure, exceeding the use of and the cost spent on other modalities. Stabilization in the use of traditional imaging modalities coincided temporally with the emergence of advanced techniques and provincewide quality improvement policy initiatives.

Measuring the frequency and variation of unnecessary care across Canada.

BACKGROUND: Through the Choosing Wisely Canada (CWC) campaign, national medical specialty societies have released hundreds of recommendations against health care services that are unnecessary, i.e. present little to no benefit or cause avoidable harm. Despite growing interest in unnecessary care both within Canada and internationally, prior research has typically avoided taking a national or even multi-jurisdictional approach in measuring the extent of the issue. This study estimates use of three unnecessary services identified by CWC recommendations across multiple Canadian jurisdictions. METHODS: Two retrospective cohort studies were conducted using administrative health care data collected between fiscal years 2011/12 and 2012/13 to respectively quantify use of 1) diagnostic imaging (spinal X-ray, CT or MRI) among Albertan patients following a visit for lower back pain and 2) cardiac tests (electrocardiogram, chest X-ray, stress test, or transthoracic echocardiogram) prior to low-risk surgical procedures in Alberta, Saskatchewan, and Ontario. A cross-sectional study of the 2012 Canadian Community Health Survey was also conducted to estimate 3) the proportion of females aged 40-49 that reported having a routine mammogram in the past two years. RESULTS: Use of unnecessary care was relatively frequent across all three services and jurisdiction measured: 30.7% of Albertan patients had diagnostic imaging within six months of their initial visit for lower back pain; a cardiac test preceded 17.9 to 35.5% of low-risk surgical procedures across Alberta, Saskatchewan, and Ontario; and 22.2% of Canadian women aged 40-49 at average-risk for breast cancer reported having a routine screening mammogram in the past two years. CONCLUSIONS: The use of potentially unnecessary care appears to be common in Canada. This investigation provides methodology to facilitate future measurement efforts that may incorporate additional jurisdictions and/or unnecessary services.

Registro Español de Imagen Cardiaca. I Informe Oficial de la Sección de Imagen Cardiaca de la Sociedad Española de Cardiología (2017) / Spanish Cardiovascular Imaging Registry. First Official Report of the Spanish Society of Cardiology Working Group on Cardiovascular Imaging (2017)

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Surveillance of Congenital Heart Defects among Adolescents at Three U.S. Sites.

The prevalence, co-morbidities, and healthcare utilization in adolescents with congenital heart defects (CHDs) is not well understood. Adolescents (11 to 19 years old) with a healthcare encounter between January 1, 2008 (January 1, 2009 for MA) and December 31, 2010 with a CHD diagnosis code were identified from multiple administrative data sources compiled at 3 US sites: Emory University, Atlanta, Georgia (EU); Massachusetts Department of Public Health (MA); and New York State Department of Health (NY). The estimated prevalence for any CHD was 4.77 (EU), 17.29 (MA), and 4.22 (NY) and for severe CHDs was 1.34 (EU), 3.04 (MA), and 0.88 (NY) per 1,000 adolescents. Private or commercial insurance was the most common insurance type for EU and NY, and Medicaid for MA. Inpatient encounters were more frequent in severe CHDs. Cardiac co-morbidities included rhythm and conduction disorders at 20% (EU), 46% (MA), and 9% (NY) as well as heart failure at 3% (EU), 15% (MA), and 2% (NY). Leading noncardiac co-morbidities were respiratory/pulmonary (22% EU, 34% MA, 16% NY), infectious disease (17% EU, 22% MA, 20% NY), non-CHD birth defects (12% EU, 23% MA, 14% NY), gastrointestinal (10% EU, 28% MA, 13% NY), musculoskeletal (10% EU, 32% MA, 11% NY), and mental health (9% EU, 30% MA, 11% NY). In conclusion, this study used a novel approach of uniform CHD definition and variable selection across administrative data sources in 3 sites for the first population-based CHD surveillance of adolescents in the United States. High resource utilization and co-morbidities illustrate ongoing significant burden of disease in this vulnerable population.

Primera hospitalización por insuficiencia cardiaca: mortalidad hospitalaria y perfil del paciente / First hospital admission due to heart failure: In-hospital mortality and patient profile

Objetivos: Evaluamos el perfil de paciente y los resultados del primer ingreso hospitalario asociado a un acontecimiento de insuficiencia cardiaca (IC) en el período de tiempo comprendido entre 2010-2014. Diseño: Estudio de cohorte retrospectivo de centro único. Contexto: Utilizamos los datos de un hospital de atención terciaria (Hospital Universitari de Bellvitge, Barcelona, España). Participantes: Se incluyeron todos los pacientes con diagnóstico primario de IC registrados en la base de datos de altas hospitalarias entre los años 2010 y 2014, excluyendo los casos en los que la IC se presentó 10 años antes del episodio objeto de estudio. Intervención: El diagnóstico de IC en atención primaria fue evaluado para diferenciar entre pacientes con IC de inicio y aquellos sin ella. Principales medidas: Los análisis descriptivo, bivariado y multivariado se realizaron usando como variables de agrupamiento la edad, el diagnóstico previo de IC en atención primaria y la muerte hospitalaria. Se ajustaron variables significativas en un modelo de regresión logística lineal para cada resultado. Resultados: Seleccionamos 3.868 primeros ingresos por IC (56,8% de todos los episodios de IC). En 1.220 pacientes (31,7%) el diagnóstico de IC fue realizado por el médico de atención primaria. El modelo principal fue el de una mujer (OR=2,4), con alta prevalencia de hipertensión (OR=1,7), fibrilación auricular (OR=1,3), enfermedad renal crónica (OR=1,6) y tasa de mortalidad del 9,8%. La tasa de muerte intrahospitalaria fue del 5,8%; los principales factores contribuyentes fueron la edad (mayor de 85 años; OR=5,57), la presencia de enfermedad renal crónica (OR=1,44) y la duración del ingreso (7 días; OR=1,90). Conclusiones: Los casos de primer ingreso asociado a IC representan el 56,7% de todos los casos de IC. Aproximadamente un tercio de los pacientes fueron diagnosticados en el momento de su primera hospitalización. El mayor número de casos se dio en el grupo de mujeres ancianas, aunque no solo en ellas. Los principales contribuyentes de muerte intrahospitalaria fueron la edad, la duración del ingreso y la presencia de enfermedad renal crónica

Objectives: We evaluated the patient profile and outcomes of first heart failure (HF) related hospital admission patients in the 2010-2014 period. Design: Retrospective, single-centre, cohort study. Setting: We used administrative data from a tertiary care hospital (Hospital Universitari de Bellvitge, Barcelona, Spain). Participants: All patients with primary diagnosis of HF registered at the hospital discharge database from 2010 to 2014 were included, ruling out that HF was present 10 years prior to the current episode. Intervention: Primary care HF diagnosis status was assessed in order to distinguish new onset from no-new onset patients. Main measures: Descriptive, bivariate and multivariate analysis were performed using age, previous primary care HF diagnosis and in-hospital death as grouping variables. Significant variables were fitted into a Linear logistic regression model for each outcome. Results: We selected 3,868 first HF-related admissions (56.8% of all HF episodes). In 1,220 patients (31.7%) HF was diagnosed by their primary care physician. Main pattern was a woman (OR=2.4), with higher prevalence of hypertension (OR=1.7), atrial fibrillation (OR=1.3), chronic kidney disease (OR=1.6) and mortality rate (9.8%). In-hospital death rate was 5.8%, age over 85 (OR=5.57), chronic kidney disease (OR=1.44) and length of stay over 7 days (OR=1.90) being the main contributors. Conclusions: First HF related admissions account for 56.7% of all HF episodes. Roughly one third of patients were already diagnosed by the time of their first hospital admission. Elderly women were the most frequent, but not the only, group of patients. Age, hospital stay and chronic kidney disease were the main contributors for in-hospital death

Evaluation of atrial septal defects with 4D flow MRI-multilevel and inter-reader reproducibility for quantification of shunt severity.

PURPOSE: With the hypothesis that 4D flow can be used in evaluation of cardiac shunts, we seek to evaluate the multilevel and interreader reproducibility of measurements of the blood flow, shunt fraction and shunt volume in patients with atrial septum defect (ASD) in practice at multiple clinical sites. MATERIALS AND METHODS: Four-dimensional flow MRI examinations were performed at four institutions across Europe and the US. Twenty-nine patients (mean age, 43 years; 11 male) were included in the study. Flow measurements were performed at three levels (valve, main artery and periphery) in both the pulmonary and systemic circulation by two independent readers and compared against stroke volumes from 4D flow anatomic data. Further, the shunt ratio (Qp/Qs) was calculated. Additionally, shunt volume was quantified at the atrial level by tracking the atrial septum. RESULTS: Measurements of the pulmonary blood flow at multiple levels correlate well whether measuring at the valve, main pulmonary artery or branch pulmonary arteries (r = 0.885-0.886). Measurements of the systemic blood flow show excellent correlation, whether measuring at the valve, ascending aorta or sum of flow from the superior vena cava (SVC) and descending aorta (r = 0.974-0.991). Intraclass agreement between the two observers for the flow measurements varies between 0.96 and 0.99. Compared with stroke volume, pulmonic flow is underestimated with 0.26 l/min at the main pulmonary artery level, and systemic flow is overestimated with 0.16 l/min at the ascending aorta level. Direct measurements of ASD flow are feasible in 20 of 29 (69%) patients. CONCLUSION: Blood flow and shunt quantification measured at multiple levels and performed by different readers are reproducible and consistent with 4D flow MRI.

3D SASHA myocardial T1 mapping with high accuracy and improved precision.

PURPOSE: To improve the precision of a free-breathing 3D saturation-recovery-based myocardial T1 mapping sequence using a post-processing 3D denoising technique. METHODS: A T1 phantom and 15 healthy subjects were scanned on a 1.5 T MRI scanner using 3D saturation-recovery single-shot acquisition (SASHA) for myocardial T1 mapping. A 3D denoising technique was applied to the native T1-weighted images before pixel-wise T1 fitting. The denoising technique imposes edge-preserving regularity and exploits the co-occurrence of 3D spatial gradients in the native T1-weighted images by incorporating a multi-contrast Beltrami regularization. Additionally, 2D modified Look-Locker inversion recovery (MOLLI) acquisitions were performed for comparison purposes. Accuracy and precision were measured in the myocardial septum of 2D MOLLI and 3D SASHA T1 maps and then compared. Furthermore, the accuracy and precision of the proposed approach were evaluated in a standardized phantom in comparison to an inversion-recovery spin-echo sequence (IRSE). RESULTS: For the phantom study, Bland-Altman plots showed good agreement in terms of accuracy between IRSE and 3D SASHA, both on non-denoised and denoised T1 maps (mean difference -1.4 ± 18.9 ms and -4.4 ± 21.2 ms, respectively), while 2D MOLLI generally underestimated the T1 values (69.4 ± 48.4 ms). For the in vivo study, there was a statistical difference between the precision measured on 2D MOLLI and on non-denoised 3D SASHA T1 maps (P = 0.005), while there was no statistical difference after denoising (P = 0.95). CONCLUSION: The precision of 3D SASHA myocardial T1 mapping was substantially improved using a 3D Beltrami regularization based denoising technique and was similar to that of 2D MOLLI T1 mapping, while preserving the higher accuracy and whole-heart coverage of 3D SASHA.

Cardiac computed tomography previous to atrial fibrillation ablation - effects of technological improvements and protocol optimization. / Tomografia computorizada cardíaca prévia a ablação de fibrilhação auricular ­ efeitos da evolução tecnológica e otimização de protocolos.

BACKGROUND: Cardiac computed tomography (CT) can provide a precise tridimentional anatomic map and exclude intra-cardiac thrombus. We aimed to access the impact of CT protocol optimization and technological evolution on the contrast and radiation dose as well as on image quality previous to atrial fibrillation (AF) ablation. METHODS: From a prospective registry of consecutive patients who underwent cardiac CT in a single center, we selected 270 patients in whom the CT was done for evaluation prior to AF ablation and they were distributed in 3 groups: Group1: the first 150 patients included; Group2: the last 60 patients performed with the same CT scanner; Group3: the first 60 exams performed with the new CT scanner. Quality of the protocol was access based on radiation dose, contrast volume used, the use of a second (delayed) acquisition, and on quantitative image quality analisis (signal to noise and contrast to noise ratios; density homogeneity racio between LA and LAA). RESULTS: We found a significant radiation dose as well as contrast dose reduction between the first and last subgroups (G1: 5,6mSv and 100ml; G2: 1,3mSv and 90ml; G3: 0,6mSv and 65ml). Even though group 3 had less radiation and contrast used it still had better quantitative image quality (signal/noise of 13,5; contrast/noise 14,8; density homogeneity racio of 0,92). CONCLUSION: Protocol optimization and technology both contributed to significant lower radiation dose and contrast volume used on cardiac CTs prior to AF ablation, without compromising image quality.

Criteria for the Management of Technological Assets in Cardiovascular Imaging.

Adequate, updated and functional technology is essential in cardiology. In Spain, the economic scenario has strongly impacted technology renewal programs and obsolescence is a growing problem. The current report attempts to describe the current situation and the conditions that must concur to update, replace or adopt new technologies in the field of cardiology.

The HEART score is useful to predict cardiovascular risks and reduces unnecessary cardiac imaging in low-risk patients with acute chest pain.

The present study was to investigate whether the HEART score can be used to evaluate cardiovascular risks and reduce unnecessary cardiac imaging in China.Acute coronary syndrome patients with the thrombosis in myocardial infarction risk score < 2 were enrolled in the emergency department. Baseline data were collected and a HEART score was determined in each participant during the indexed emergency visit. Participants were follow-up for 30 days after discharge and the studied endpoints included acute myocardial infarction, cardiovascular mortality and all-cause mortality.A total of 244 patients were enrolled and 2 was loss of follow-up. The mean age was 50.4 years old and male patients accounted for 64.5%. Substernal pain and featured as pressure of the pain accounted for 34.3% and 39.3%, respectively. After 30 days' follow-up, no patient in the low-risk HEART score group and 2 patients (1.5%) in the high risk HEART score group had cardiovascular events. The sensitivity of HEART score to predict cardiovascular events was 100% and the specificity was 46.7%. The potential unnecessary cardiac testing was 46.3%. Cox proportional hazards regression analysis showed that per one category increase of the HEART score was associated with nearly 1.3-fold risk of cardiovascular events.In the low-risk acute chest pain patients, the HEART score is useful to physicians in evaluating the risk of cardiovascular events within the first 30 days. In addition, the HEART score is also useful in reducing the unnecessary cardiac imaging.

3D true-phase polarity recovery with independent phase estimation using three-tier stacks based region growing (3D-TRIPS).

OBJECTIVES: A postprocessing technique termed 3D true-phase polarity recovery with independent phase estimation using three-tier stacks based region growing (3D-TRIPS) was developed, which directly reconstructs phase-sensitive inversion-recovery images without acquisition of phase-reference images. The utility of this technique is demonstrated in myocardial late gadolinium enhancement (LGE) imaging. MATERIALS AND METHODS: A data structure with three tiers of stacks was used for 3D-TRIPS to directly achieve reliable region growing for successful background-phase estimation. Fifteen patients undergoing postgadolinium 3D phase-sensitive inversion recovery (PSIR) cardiac LGE magnetic resonance imaging (MRI) were recruited, and 3D-TRIPS LGE reconstructions were compared with standard PSIR. Objective voxel-by-voxel comparison was performed. Additionally, blinded review by two radiologists compared scar visibility, clinical acceptability, voxel polarity error, or groups and blurring. RESULTS: 3D-TRIPS efficiently reconstructed postcontrast phase-sensitive myocardial LGE images. Objective analysis showed an average 95% voxel-by-voxel agreement between 3D-TRIPS and PSIR images. Blinded radiologist review demonstrated similar image quality between 3D-TRIPS and PSIR reconstruction. CONCLUSION: 3D-TRIPS provided similar image quality to PSIR for phase-sensitive myocardial LGE MRI reconstruction. 3D-TRIPS does not require acquisition of a reference image and can therefore be used to accelerate phase-sensitive LGE imaging.

An 8-channel Tx/Rx dipole array combined with 16 Rx loops for high-resolution functional cardiac imaging at 7 T.

OBJECTIVE: To demonstrate imaging performance for cardiac MR imaging at 7 T using a coil array of 8 transmit/receive dipole antennas and 16 receive loops. MATERIALS AND METHODS: An 8-channel dipole array was extended by adding 16 receive-only loops. Average power constraints were determined by electromagnetic simulations. Cine imaging was performed on eight healthy subjects. Geometrical factor (g-factor) maps were calculated to assess acceleration performance. Signal-to-noise ratio (SNR)-scaled images were reconstructed for different combinations of receive channels, to demonstrate the SNR benefits of combining loops and dipoles. RESULTS: The overall image quality of the cardiac functional images was rated a 2.6 on a 4-point scale by two experienced radiologists. Imaging results at different acceleration factors demonstrate that acceleration factors up to 6 could be obtained while keeping the average g-factor below 1.27. SNR maps demonstrate that combining loops and dipoles provides a more than 50% enhancement of the SNR in the heart, compared to a situation where only loops or dipoles are used. CONCLUSION: This work demonstrates the performance of a combined loop/dipole array for cardiac imaging at 7 T. With this array, acceleration factors of 6 are possible without increasing the average g-factor in the heart beyond 1.27. Combining loops and dipoles in receive mode enhances the SNR compared to receiving with loops or dipoles only.

Segmental biventricular analysis of myocardial function using high temporal and spatial resolution tissue phase mapping.

OBJECTIVE: Myocardial dysfunction of the right ventricle (RV) is an important indicator of RV diseases, e.g. RV infarction or pulmonary hypertension. Tissue phase mapping (TPM) has been widely used to determine function of the left ventricle (LV) by analyzing myocardial velocities. The analysis of RV motion is more complicated due to the different geometry and smaller wall thickness. The aim of this work was to adapt and optimize TPM to the demands of the RV. MATERIALS AND METHODS: TPM measurements were acquired in 25 healthy volunteers using a velocity-encoded phase-contrast sequence and kt-accelerated parallel imaging in combination with optimized navigator strategy and blood saturation. Post processing was extended by a 10-segment RV model and a detailed biventricular analysis of myocardial velocities was performed. RESULTS: High spatio-temporal resolution (1.0 × 1.0 × 6 mm3, 21.3 ms) and the optimized blood saturation enabled good delineation of the RV and its velocities. Global and segmental velocities, as well as time to peak velocities showed significant differences between the LV and RV. Furthermore, complex timing of the RV could be demonstrated by segmental time to peak analysis. CONCLUSION: High spatio-temporal resolution TPM enables a detailed biventricular analysis of myocardial motion and might provide a reliable tool for description and detection of diseases affecting left and right ventricular function.

Cardiac magnetic resonance T1 and extracellular volume mapping with motion correction and co-registration based on fast elastic image registration.

OBJECTIVE: Our aim was to investigate the technical feasibility of a novel motion compensation method for cardiac magntic resonance (MR) T1 and extracellular volume fraction (ECV) mapping. MATERIALS AND METHODS: Native and post-contrast T1 maps were obtained using modified look-locker inversion recovery (MOLLI) pulse sequences with acquisition scheme defined in seconds. A nonrigid, nonparametric, fast elastic registration method was applied to generate motion-corrected T1 maps and subsequently ECV maps. Qualitative rating was performed based on T1 fitting-error maps and overlay images. Local deformation vector fields were produced for quantitative assessment. Intra- and inter-observer reproducibility were compared with and without motion compensation. RESULTS: Eighty-two T1 and 39 ECV maps were obtained in 21 patients with diverse myocardial diseases. Approximately 60% demonstrated clear quality improvement after motion correction for T1 mapping, particularly for the poor-rating cases (23% before vs 2% after). Approximately 67% showed further improvement with co-registration in ECV mapping. Although T1 and ECV values were not clinically significantly different before and after motion compensation, there was improved intra- and inter-observer reproducibility after motion compensation. CONCLUSIONS: Automated motion correction and co-registration improved the qualitative assessment and reproducibility of cardiac MR T1 and ECV measurements, allowing for more reliable ECV mapping.