Analysis of ventricular function by CT

Multimodality imaging in arrhythmogenic cardiomyopathy - From diagnosis to management

Arrhythmogenic Cardiomyopathy (AC), an inherited cardiac disorder characterized by myocardial fibrofatty replacement, carries a significant risk of sudden cardiac death (SCD) due to ventricular arrhythmias. A comprehensive multimodality imaging approach, including echocardiography, cardiac magnetic resonance imaging (CMR), and cardiac computed tomography (CCT), allows for accurate diagnosis, effective risk stratification, vigilant monitoring, and appropriate intervention, leading to improved patient outcomes and the prevention of SCD. Echocardiography is primary tool ventricular morphology and function assessment, CMR provides detailed visualization, CCT is essential in early stages for excluding congenital anomalies and coronary artery disease. Echocardiography is preferred for follow-up, with CMR capturing changes over time. The strategic use of these imaging methods aids in confirming AC, differentiating it from other conditions, tracking its progression, managing complications, and addressing end-stage scenarios.

Computed tomography imaging in preprocedural planning of transcatheter valvular heart interventions

Cardiac Computed Tomography (CCT) has become a reliable imaging modality in cardiology providing robust information on the morphology and structure of the heart with high temporal and isotropic spatial resolution. For the past decade, there has been a paradigm shift in the management of valvular heart disease since previously unfavorable candidates for surgery are now provided with less-invasive interventions. Transcatheter heart valve interventions provide a real alternative to medical and surgical management and are often the only treatment option for valvular heart disease patients. Successful transcatheter valve interventions rely on comprehensive multimodality imaging assessment. CCT is the mainstay imaging technique for preprocedural planning of these interventions. CCT is critical in guiding patient selection, choice of procedural access, device selection, procedural guidance, as well as allowing postprocedural follow-up of complications. This article aims to review the current evidence of the role of CCT in the preprocedural planning of patients undergoing transcatheter valvular interventions.

Pulmonary Vascular Resistance to Predict Right Heart Failure in Patients Undergoing Left Ventricular Assist Device Implantation

Right heart failure (RHF) is associated with poor outcomes, especially in patients undergoing left ventricular assist device (LVAD) implantation. The aim of this study was to identify predictors of RHF after LVAD implantation. Of 129 consecutive patients (mean age 56 ± 11 years, 89% male) undergoing LVAD implantation, 34 developed RHF. Compared to patients without RHF, those with RHF required longer invasive mechanical ventilation and had longer intensive care unit and hospital stays (p < 0.01). One-year all-cause mortality was significantly higher in patients with versus without RHF after LVAD implantation (29.4% vs. 1.2%; hazard ratio 35.4; 95% confidence interval 4.5-277; p < 0.001). Mortality was highest in patients with delayed RHF after initial LVAD-only implantation (66.7%). Patients who did versus did not develop RHF had significantly higher baseline pulmonary vascular resistance (PVR; 404 ± 375 vs. 234 ± 162 dyn/s/cm5; p = 0.01). PVR > 250 dyn/s/cm5 was a significant predictor of survival in patients with RHF after LVAD implantation. These data confirm the negative impact of RHF on morbidity and mortality after LVAD implantation. Preoperative PVR > 250 dyn/s/cm5 determined using invasive right heart catheterization was an independent predictor of developing RHF after LVAD implantation, and of subsequent mortality, and could be used for risk stratification in the setting for deciding between single or biventricular support strategy.

Three-Tesla magnetic resonance imaging of left ventricular volume and function in comparison with computed tomography and echocardiography

This study investigated the correlation between 3-Tesla magnetic resonance imaging (MRI) and 256 multiple-slice computed tomography (MSCT) or 2-dimensional echocardiography (ECHO) in evaluating left ventricle. Forty patients were retrospectively enrolled to undergo cardiac MSCT, 3-Tesla MRI and 2-dimensional ECHO within 1 week. The end-diastolic (EDV) and end-systolic volume (ESV), stroke volume (SV) and ejection fraction (EF) were analyzed and compared. MSCT was highly significantly correlated with MRI. Compared with MRI, MSCT slightly overestimated ESV for about 8.7 mL, but slightly underestimated EF and SV for about 6.8% and 5.8 mL, respectively. A high consistency existed between MSCT and MRI, with the 95% limit of agreement (-19.6, 25.4) mL for EDV, (-2.6,20.1) mL for ESV, (-28.3,16.6) mL for SV, and (-18.8%,5.1) % for EF. ECHO was also significantly correlated with MRI. The ECHO slightly underestimated the left ventricular function compared with MRI, with an underestimation of 9.4 mL for EDV, 3.5 mL for ESV, 5.8 mL for SV and 1.0% for EF. A wider agreement limit existed between MRI and ECHO. MSCT has a better correlation and agreement relationship with MRI parameters than 2-dimensional ECHO in assessing the left ventricle and may serve as a possible alternative to MRI.

Left atrial strain assessment using cardiac computed tomography in patients with hypertrophic cardiomyopathy

PURPOSE

To evaluate left atrial (LA) function in patients with hypertrophic cardiomyopathy (HCM) by LA strain assessment using cardiac computed tomography (CT-derived LA strain).

MATERIALS AND METHODS

This was a retrospective study of 34 patients with HCM and 31 non-HCM patients who underwent cardiac computed tomography (CT) using retrospective electrocardiogram-gated mode. CT images were reconstructed every 5% (0-95%) of the RR intervals. CT-derived LA strain (reservoir [LASr], conduit [LASc], and booster pump strain [LASp]) were semi-automatically analyzed using a dedicated workstation. We also measured the left atrial volume index (LAVI) and left ventricular longitudinal strain (LVLS) for the left atrial and ventricular functional parameters to assess the relationship with CT-derived LA strain.

RESULTS

CT-derived LA strain significantly correlated with LAVI: r = - 0.69, p < 0.001 for LASr; r = - 0.70, p < 0.001 for LASp; and r = - 0.35, p = 0.004 for LASc. CT-derived LA strain also significantly correlated with LVLS: r = - 0.62, p < 0.001 for LASr; r = - 0.67, p < 0.001 for LASc; and r = - 0.42, p = 0.013 for LASp. CT-derived LA strain in patients with HCM was significantly lower than that in non-HCM patients: LASr (20.8 ± 7.6 vs. 31.7 ± 6.1%, p < 0.001); LASc (7.9 ± 3.4 vs. 14.2 ± 5.3%, p < 0.001); and LASp (12.8 ± 5.7 vs. 17.6 ± 4.3%, p < 0.001). Additionally, CT-derived LA strain showed high reproducibility; inter-observer correlation coefficients were 0.94, 0.90, and 0.89 for LASr, LASc, and LASp, respectively.

CONCLUSION

CT-derived LA strain is feasible for quantitative assessment of left atrial function in patients with HCM.

Role of CT in the Pre- and Postoperative Assessment of Conotruncal Anomalies

Conotruncal anomalies, also referred to as outflow tract anomalies, are congenital heart defects that result from abnormal septation of the great vessels' outflow tracts. The major conotruncal anomalies include tetralogy of Fallot, double-outlet right ventricle, transposition of the great arteries, truncus arteriosus, and interrupted aortic arch. Other defects, which are often components of the major anomalies, include pulmonary atresia with ventricular septal defect, pulmonary valve agenesis, aortopulmonary window, and double-outlet left ventricle. CT has emerged as a robust diagnostic tool in preoperative and postoperative assessment of various congenital heart diseases, including conotruncal anomalies. The data provided with multidetector CT imaging are useful for treatment planning and follow-up monitoring after surgery or intervention. Unlike echocardiography and MRI, CT is not limited by a small acoustic window, metallic devices, and need for sedation or anesthesia. Major advances in CT equipment, including dual-source scanners, wide-detector scanners, high-efficiency detectors, higher x-ray tube power, automatic tube current modulation, and advanced three-dimensional postprocessing, provide a low-risk, high-quality alternative to diagnostic cardiac catheterization and MRI. This review explores the various conotruncal anomalies and elucidates the role of CT imaging in their pre- and postoperative assessment. Keywords: CT, CT Angiography, Stents, Pediatrics © RSNA, 2022.

Cardiac radioablation in the treatment of ventricular tachycardia

Cardiac radioablation with SBRT is a very promising non-invasive modality for the treatment of refractory VT and potentially other cardiac arrhythmias. Initial reports indicate that it is relatively safe and associated with excellent responses, particularly in reduction of ICD-related events, need for anti-arrhythmic medications, and resulting in significantly improved quality of life for patients. Establishment of objective criteria for candidates for cardiac radioablation will accelerate the adoption of this important radiation therapy modality in the treatment of refractory VT and other cardiac arrhythmias in the coming years. In addition, in order to develop more prospective safety and efficacy data, treatment of patients should ideally be performed in the context of clinical trials or prospective registries at, or in collaboration with, experienced centers. Taken together, the future of cardiac radioablation is rich and worthy of further investigation to become a standard treatment in the armamentarium against refractory VT.

Patient selection for LIVE therapy: From clinical indications to multimodality imaging individual case planning

BACKGROUND

Less Invasive Ventricular Enhancement (LIVE) with Revivent TC is an innovative therapy for symptomatic ischemic heart failure (HF). It is designed to reconstruct a negatively remodeled left ventricle (LV) after an anterior myocardial infarction (MI) by plication of the scar tissue. Its indications are specific, and as with any other structural heart intervention, the success of the procedure starts with appropriate patient selection. We aim to present the indications of the technique, crucial aspects in patient selection, and individual case planning approach.

METHODS AND RESULTS

After clinical evaluation, transthoracic echocardiography is the first imaging modality to be performed in a potential candidate for the therapy. However, definitive indication and detailed case planning rely on late gadolinium-enhanced cardiac magnetic resonance imaging or multiphasic contrast-enhanced cardiac computed tomography. These imaging modalities also assist with relative or absolute contra-indications for the procedure. Individual assessment is done to tailor the procedure to the specifics of the LV anatomy and location of the myocardial scar.

CONCLUSION

LIVE procedure is a unique intervention to treat symptomatic HF and ischemic cardiomyopathy after anterior MI. It is a highly customizable intervention that allows a patient-tailored approach, based on multimodality imaging assessment and planification.

Method and Atlas to Enable Targeting for Cardiac Radioablation Employing the American Heart Association Segmented Model

PURPOSE

Cardiac radioablation using stereotactic body radiation therapy is gaining popularity as a noninvasive treatment for otherwise refractory ventricular arrhythmias. As radiation oncologists might be unaccustomed to the lexicon used by cardiologists to describe the location of arrhythmogenic foci, a preliminary guide to cardiac-specific anatomy and orientation is needed to foster effective communication between the radiation oncologist and cardiology team.

METHODS AND MATERIALS

Electrocardiogram-gated and respiratory-gated computed tomography imaging was acquired per institutional protocol. Additional relevant imaging modalities are described. The American Heart Association 17-segment model is described in detail because this framework is used frequently by cardiologists to describe the location left ventricular abnormalities.

RESULTS

A step-by-step guide is provided for properly rotating the heart from standard orthogonal views obtained during radiation simulation to the cardiac-specific orientation needed to appreciate the 17-segment model. Once the proper configuration is achieved, the location of each segment is defined in detail.

CONCLUSIONS

This atlas serves as an introduction to the relevant anatomy and principles, and it provides a suggested approach to help delineate cardiac radioablation targets using the established American Heart Association 17-segment model.

Roles of Cardiac Computed Tomography in Guiding Transcatheter Tricuspid Valve Interventions

PURPOSE OF REVIEW

The field of transcatheter tricuspid valve interventions (TTVI) is rapidly evolving to meet a well-defined but unmet clinical need. Severe tricuspid regurgitation is common and is associated with significant morbidity and mortality. Surgical options are limited and of high risk. The success of TTVI depends on careful procedural planning, and cardiac computed tomography (CCT) plays an emerging key role.

RECENT FINDINGS

TTVI technologies have various targets, including the leaflets, annulus, and venae cavae, along with valve replacement. Based on the planned procedure, CCT allows for device sizing, careful assessment of the access route, and comprehensive analysis of relevant adjacent anatomic structures to enhance procedural safety. It can also evaluate right-sided heart function, and its data can be for fusion imaging and 3D printing. Procedural planning is key to TTVI's success and is highly dependent on high-quality CCT data. This review details the comprehensive roles of CCT, specifics of the dedicated TTVI protocol, and its limitations.

Machine learning and network medicine: a novel approach for precision medicine and personalized therapy in cardiomyopathies

The early identification of pathogenic mechanisms is essential to predict the incidence and progression of cardiomyopathies and to plan appropriate preventive interventions. Noninvasive cardiac imaging such as cardiac computed tomography, cardiac magnetic resonance, and nuclear imaging plays an important role in diagnosis and management of cardiomyopathies and provides useful prognostic information. Most molecular factors exert their functions by interacting with other cellular components, thus many diseases reflect perturbations of intracellular networks. Indeed, complex diseases and traits such as cardiomyopathies are caused by perturbations of biological networks. The network medicine approach, by integrating systems biology, aims to identify pathological interacting genes and proteins, revolutionizing the way to know cardiomyopathies and shifting the understanding of their pathogenic phenomena from a reductionist to a holistic approach. In addition, artificial intelligence tools, applied to morphological and functional imaging, could allow imaging scans to be automatically analyzed to extract new parameters and features for cardiomyopathy evaluation. The aim of this review is to discuss the tools of network medicine in cardiomyopathies that could reveal new candidate genes and artificial intelligence imaging-based features with the aim to translate into clinical practice as diagnostic, prognostic, and predictive biomarkers and shed new light on the clinical setting of cardiomyopathies. The integration and elaboration of clinical habits, molecular big data, and imaging into machine learning models could provide better disease phenotyping, outcome prediction, and novel drug targets, thus opening a new scenario for the implementation of precision medicine for cardiomyopathies.

Incremental role of CT coronary angiography in the assessment of left ventricular diastolic function

OBJECTIVE

To determine whether Computed Tomography (CT) coronary angiography (CTCA) has clinical value for the assessment of left ventricular (LV) diastolic dysfunction (DD) beyond traditional information on coronary artery anatomy.

METHOD

In this retrospective study, a consecutive group of 72 patients (mean age 59±13 years)-who met the eligibility criteria of sinus rhythm, no significant valvular abnormalities, and who had transthoracic echocardiogram (TTE)-were analysed. The CTCA was prospectively triggered during diastole. Outcomes of interest were CTCA derived LV and left atrial (LA) volumes, diastolic expansion (DE) index: LV volume÷LA volume and DE fraction (DEF): [(LV volume-LA volume)÷LV volume]×100. TTE-LA volume was measured as maximum, minimum and pre-A. Studied patients were divided according to the current classification of LVDD as a reference standard. A small subgroup of nine patients underwent further invasive cardiac catheterisation.

RESULTS

CTCA-LV and LA volumes were larger compared with TTE, 37%±20% and 11%±21%, respectively. CTCA-LA volume correlated well with all TTE-LA volumes (maximum: R2=0.58; pre-A wave: R2=0.39; minimum: R2=0.26; p<0.0001) with the smallest differences in maximum LA volume (9±32 mL; mean±2 SD). The DE and DEF correlated with both LA function and LVDD. DE >1.65 and DE <1.40 have good specificity (85% and 88%, respectively), and positive predictive value to differentiate LVDD. DE and DEF were dependent on the patients' age but independent of other variables.

CONCLUSIONS

CTCA derived diastasis volume indices can provide additional quantifiable information on LVDD.

Radiation dose, contrast enhancement, image noise and heart rate variability of ECG-gated CT volumetry using 3D threshold-based segmentation: Comparison between conventional single scan and dual focused scan methods

OBJECTIVE

To compare radiation dose, contrast enhancement, image noise and heart rate variability in electrocardiography (ECG)-gated computed tomography (CT) ventricular volumetry using a three-dimensional (3D) threshold-based segmentation between the conventional single scan and dual focused scan methods in patients with congenital heart disease.

METHODS

After matching for age, sex, heart rate during the CT examination, and tube voltage, 96 patients (age range, 7 - 36 years; male:female = 63:33) who underwent ECG-gated CT volumetry using a 3D threshold-based segmentation, were divided into 32 patients who underwent a conventional single scan (group 1) and 64 who underwent dual focused scans (group 2). CT radiation dose, contrast enhancement, image noise, and heart rate variability were compared between the two groups.

RESULTS

Volume CT dose index, dose-length product, and effective dose estimates, in group 1 were significantly higher than those in group 2 (28.4 ± 24.6 mGy vs. 9.7 ± 4.5 mGy, 636.5 ± 572.9 mGy cm vs. 379.5 ± 192.4 mGy cm, 8.9 ± 8.0 mSv vs. 5.3 ± 2.7 mSv, 8.2 ± 6.4 mSv vs. 5.0 ± 2.2 mSv, respectively; p values < 0.019). No significant differences in right and left ventricular contrast enhancement were found between the two groups (470.2 ± 152.4 HU vs. 481.0 ± 139.2 HU and 428.6 ± 97.8 HU vs. 429.3 ± 106.7 HU, respectively; p values > 0.05). Image noise measured in the air showed no significant differences between groups 1 and 2 (5.6 ± 1.9 HU vs. 5.5 ± 1.1 HU; p >  0.05). The proportion of heart rate variability ≥ 20 beats per minute in group 1 (15.6 %, 5/32) was significantly higher than that in group 2 (3.1 %, 2/64; p <  0.040).

CONCLUSION

Compared with the conventional single scan method, the dual focused scan method can provide a lower radiation dose with comparable contrast enhancement and image noise for ECG-gated CT ventricular volumetry using a 3D threshold-based segmentation in patients with congenital heart disease.

Right Ventricular Mass Quantification Using Cardiac CT and a Semiautomatic Three-Dimensional Hybrid Segmentation Approach: A Pilot Study

Objective

To evaluate the technical applicability of a semiautomatic three-dimensional (3D) hybrid CT segmentation method for the quantification of right ventricular mass in patients with cardiovascular disease.

Materials and Methods

Cardiac CT (270 cardiac phases) was used to quantify right ventricular mass using a semiautomatic 3D hybrid segmentation method in 195 patients with cardiovascular disease. Data from 270 cardiac phases were divided into subgroups based on the extent of the segmentation error (no error; ≤ 10% error; > 10% error [technical failure]), defined as discontinuous areas in the right ventricular myocardium. The reproducibility of the right ventricular mass quantification was assessed. In patients with no error or < 10% error, the right ventricular mass was compared and correlated between paired end-systolic and end-diastolic data. The error rate and right ventricular mass were compared based on right ventricular hypertrophy groups.

Results

The quantification of right ventricular mass was technically applicable in 96.3% (260/270) of CT data, with no error in 54.4% (147/270) and ≤ 10% error in 41.9% (113/270) of cases. Technical failure was observed in 3.7% (10/270) of cases. The reproducibility of the quantification was high (intraclass correlation coefficient = 0.999, p < 0.001). The indexed mass was significantly greater at end-systole than at end-diastole (45.9 ± 22.1 g/m² vs. 39.7 ± 20.2 g/m², p < 0.001), and paired values were highly correlated (r = 0.96, p < 0.001). Fewer errors were observed in severe right ventricular hypertrophy and at the end-systolic phase. The indexed right ventricular mass was significantly higher in severe right ventricular hypertrophy (p < 0.02), except in the comparison of the end-diastolic data between no hypertrophy and mild hypertrophy groups (p > 0.1).

Conclusion

CT quantification of right ventricular mass using a semiautomatic 3D hybrid segmentation is technically applicable with high reproducibility in most patients with cardiovascular disease.

2020 SCCT Guideline for Training Cardiology and Radiology Trainees as Independent Practitioners (Level II) and Advanced Practitioners (Level III) in Cardiovascular Computed Tomography: A Statement from the Society of Cardiovascular Computed Tomography

Cardiovascular computed tomography (CCT) is a well-validated noninvasive imaging tool with an ever-expanding array of applications beyond the assessment of coronary artery disease. These include the evaluation of structural heart diseases, congenital heart diseases, peri-procedural electrophysiology applications, and the functional evaluation of ischemia. This breadth requires a robust and diverse training curriculum to ensure graduates of CCT training programs meet minimum competency standards for independent CCT interpretation. This statement from the Society of Cardiovascular Computed Tomography aims to supplement existing societal training guidelines by providing a curriculum and competency framework to inform the development of a comprehensive, integrated training experience for cardiology and radiology trainees in CCT. This article is being published synchronously in Radiology: Cardiothoracic Imaging, Journal of Cardiovascular Computed Tomography, and JACC: Cardiovascular Imaging. © 2020 Society of Cardiovascular Computed Tomography. Published by RSNA with permission.

2020 SCCT Guideline for Training Cardiology and Radiology Trainees as Independent Practitioners (Level II) and Advanced Practitioners (Level III) in Cardiovascular Computed Tomography: A Statement from the Society of Cardiovascular Computed Tomography

Cardiovascular computed tomography (CCT) is a well-validated non-invasive imaging tool with an ever-expanding array of applications beyond the assessment of coronary artery disease. These include the evaluation of structural heart diseases, congenital heart diseases, peri-procedural electrophysiology applications, and the functional evaluation of ischemia. This breadth requires a robust and diverse training curriculum to ensure graduates of CCT training programs meet minimum competency standards for independent CCT interpretation. This statement from the Society of Cardiovascular Computed Tomography aims to supplement existing societal training guidelines by providing a curriculum and competency framework to inform the development of a comprehensive, integrated training experience for cardiology and radiology trainees in CCT.

2020 SCCT Guideline for Training Cardiology and Radiology Trainees as Independent Practitioners (Level II) and Advanced Practitioners (Level III) in Cardiovascular Computed Tomography: A Statement from the Society of Cardiovascular Computed Tomography

Cardiovascular computed tomography (CCT) is a well-validated non-invasive imaging tool with an ever-expanding array of applications beyond the assessment of coronary artery disease. These include the evaluation of structural heart diseases, congenital heart diseases, peri-procedural electrophysiology applications, and the functional evaluation of ischemia. This breadth requires a robust and diverse training curriculum to ensure graduates of CCT training programs meet minimum competency standards for independent CCT interpretation. This statement from the Society of Cardiovascular Computed Tomography aims to supplement existing societal training guidelines by providing a curriculum and competency framework to inform the development of a comprehensive, integrated training experience for cardiology and radiology trainees in CCT.

Cardiac CT angiography: normal and pathological anatomical features-a narrative review

The normal and pathological anatomy of the heart and coronary arteries are nowadays widely developed topics and constitute a fundamental part of the cultural background of the radiologist. The introduction of cardiac ECG-gated synchronized CT scanners with an ever-increasing number of detectors and with increasingly high structural characteristics (increase in temporal resolution, increase in contrast resolution with dual-source, dual energy scanners) allows the virtual measurement of anatomical in vivo structures complying with heart rate with submillimetric precision permitting to clearly depict the normal anatomy and follow the pathologic temporal evolution. Accordingly to these considerations, cardiac computed tomography angiography (CCTA) asserts itself as a gold standard method for the anatomical evaluation of the heart and permits to evaluate, verify, measure and characterize structural pathological alterations of both congenital and acquired degenerative diseases. Accordingly, CCTA is increasingly used as a prognostic model capable of modifying the outcome of diseased patients in planning interventions and in the post-surgical/interventional follow-up. The profound knowledge of cardiac anatomy and function through highly detailed CCTA analysis is required to perform an efficient and optimal use in real-world clinical practice.

Advanced imaging of right ventricular anatomy and function

Right ventricular (RV) size and function are important predictors of cardiovascular morbidity and mortality in patients with various conditions. However, non-invasive assessment of the RV is a challenging task due to its complex anatomy and location in the chest. Although conventional echocardiography is widely used, its limitations in RV assessment are well recognised. New techniques such as three-dimensional and speckle tracking echocardiography have overcome the limitations of conventional echocardiography allowing a comprehensive, quantitative assessment of RV geometry and function without geometric assumptions. Cardiac magnetic resonance (CMR) and CT provide accurate assessment of RV geometry and function, too. In addition, tissue characterisation imaging for myocardial scar and fat using CMR and CT provides important information regarding the RV that has clinical applications for diagnosis and prognosis in a broad range of cardiac conditions. Limitations also exist for these two advanced modalities including availability and patient suitability for CMR and need for contrast and radiation exposure for CT. Hybrid imaging, which is able to integrate anatomical information (usually obtained by CT or CMR) with physiological and molecular data (usually obtained with positron emission tomography), can provide optimal in vivo evaluation of Rv functional impairment. This review summarises the clinically useful applications of advanced echocardiography techniques, CMR and CT for comprehensive assessment of RV size, function and mechanics.

Comparison Between 3D Echocardiography and Cardiac Magnetic Resonance Imaging (CMRI) in the Measurement of Left Ventricular Volumes and Ejection Fraction

BACKGROUND

Echocardiography and Cardiac Magnetic Resonance Imaging (CMRI) are two noninvasive techniques for the evaluation of cardiac function for patients with coronary artery diseases. Although echocardiography is the commonly used technique in clinical practice for the assessment of cardiac function, the measurement of LV volumes and left ventricular ejection fraction (LVEF) by the use of this technique is still influenced by several factors inherent to the protocol acquisition, which may affect the accuracy of echocardiography in the measurement of global LV parameters.

OBJECTIVE

The aim of this study is to compare the end systolic volume (ESV), the end diastolic volume (EDV), and the LVEF values obtained with three dimensional echocardiography (3D echo) with those obtained by CMRI (3 Tesla) in order to estimate the accuracy of 3D echo in the assessment of cardiac function.

METHODS

20 subjects, (9 controls, 6 with myocardial infarction, and 5 with myocarditis) with age varying from 18 to 58, underwent 3D echo and CMRI. LV volumes and LVEF were computed from CMRI using a stack of cine MRI images in a short axis view. The same parameters were calculated using the 3D echo. A linear regression analysis and Bland Altman diagrams were performed to evaluate the correlation and the degree of agreement between the measurements obtained by the two methods.

RESULTS

The obtained results show a strong correlation between the 3D echo and CMR in the measurement of functional parameters (r = 0.96 for LVEF values, r = 0.99 for ESV and r= 0.98 for EDV, p < 0.01 for all) with a little lower values of LV volumes and higher values of LVEF by 3D echo compared to CMRI. According to statistical analysis, there is a slight discrepancy between the measurements obtained by the two methods.

CONCLUSION

3D echo represents an accurate noninvasive tool for the assessment of cardiac function. However, other studies should be conducted on a larger population including some complicated diagnostic cases.

Simultaneous Assessment of Left Ventricular Function and Coronary Artery Anatomy by Third-generation Dual-source Computed Tomography Using a Low Radiation Dose

BACKGROUND

To assess left ventricular function and coronary artery simultaneously by third-generation dual-source computed tomography (CT) using a low radiation dose.

METHODS

A total of 48 patients (36 men, 12 women; mean age 57.0 ± 9.5 years) who underwent both electrocardiography-gated cardiac CT angiography (CCTA) using 70–90 kVp and echocardiography were included in this retrospective study. The correlation between left ventricular end-diastolic volume (LVEDV), left ventricular end-systolic volume (LVESV), and left ventricular ejection fraction (LVEF) measured using CCTA and echocardiography was determined. The quality of coronary artery images was analyzed using a 4-point scale (1, excellent; 4, poor). The effective radiation dose of CCTA was calculated.

RESULTS

Mean heart rate during the CT examination was 59.9 ± 9.9 bpm (range 38–79) and the body mass index of 48 patients was 24.5 ± 2.6 kg/m² (range 17.0–29.4). LVEDV, LVESV, and LVEF measured using CCTA and echocardiography demonstrated a fair to moderate correlation (Pearson correlation coefficient: r = 0.395, p = 0.005 for LVEDV; r = 0.509. p < 0.001 for LVESV; r = 0.551, p < 0.001 for LVEF). Average image quality score of coronary arteries was 1.0 ± 0.1 (range 1–2). A total of 99.0% (783 of 791) of segments had an excellent image quality score, and 1.0% (8 of 791) of segments had a good score. Mean effective radiation dose was 2.2 ± 0.7 mSv.

CONCLUSIONS

Third-generation dual-source CT using a low tube voltage simultaneously provides information regarding LV function and coronary artery disease at a low radiation dose. It can serve as an alternative option for functional assessment, particularly when other imaging modalities are inadequate.

Cardiothoracic Morphology Measures in Heart Failure Patients to Inform Device Designs

PURPOSE

Approximately 5.7 million people in the US are affected by congestive heart failure. This study aimed to quantitatively evaluate cardiothoracic morphology and variability within a cohort of heart failure patients for the purpose of optimally engineering cardiac devices for a variety of heart failure patients.

METHODS

Co-registered cardiac-gated and non-gated chest computed tomography (CT) scans were analyzed from 20 heart failure patients (12 males; 8 females) who were primarily older adults (79.5 ± 8.8 years). Twelve cardiothoracic measurements were collected and compared to study sex and left ventricular (LV) ejection fraction (EF) type differences in cardiothoracic morphology.

RESULTS

Four measures were significantly greater in males compared to females: LV long-axis length, LV end diastolic diameter (LVEDD) at 50% length of the LV long-axis, the minimal distance between the sternum and heart, and the angle between the LV long-axis and coronal plane. Four measures were significantly greater in patients with reduced EF compared to preserved LV: LV long-axis length, LVEDD at 50% length of the LV long-axis, left ventricular volume normalized by body surface area, and the angle between the mitral valve plane and LV long-axis.

CONCLUSIONS

These cardiothoracic morphology measurements are important to consider in the design of cardiac devices for heart failure management (e.g. cardiac pacemakers, ventricular assist devices, and implantable defibrillators), since morphology differs by sex and ejection fraction.

EDUCATIONAL SERIES IN CONGENITAL HEART DISEASE: Cardiovascular MRI and CT in congenital heart disease

Cardiovascular MRI and CT are useful imaging modalities complimentary to echocardiography. This review article describes the common indications and consideration for the use of MRI and CT in the management of congenital heart disease.

Assessment of Left Ventricular Ejection Fraction by Thallium-201 Myocardial SPECT-CT in Patients with Angina Pectoris: Comparison with 2D Echocardiography

Purpose

Left ventricular (LV) ejection fraction (EF) is an important parameter for assessing cardiac systolic function and predicting prognosis in patients with cardiovascular disease. The aim of this study was to evaluate the feasibility of assessing LVEF by Tl-201 hybrid myocardial single-photon emission computed tomography (SPECT)/CT using two attenuation correction methods in patients with angina pectoris.

Methods

A total of 339 patients with angina pectoris (62.8 ± 12.9 years, male:female = 206:133) were analyzed. All patients underwent Tl-201 myocardial SPECT/CT and transthoracic two-dimensional (2D) echocardiograph. We compared LVEF assessed by SPECT/CT using two attenuation correction methods: CT-based attenuation correction (CTAC) and non-attenuation correction (non-AC) methods and 2D echocardiography.

Results

LVEF assessed by either of the two attenuation correction techniques and 2D echocardiography showed moderate correlation in all patients with angina pectoris (r = 0.487 for CTAC and r = 0.473 for non-AC, p < 0.001). Results were similar in the subgroup of patients with perfusion abnormalities on myocardial SPECT/CT images. Overall diagnostic performances were similar for the CTAC and non-AC methods for evaluating normal and decreased LVEF by myocardial SPECT/CT.

Conclusion

LVEF measured by the CTAC method of Tl-201-gated myocardial SPECT/CT was comparable with the conventional non-AC method in patients with angina pectoris and in the subgroup of patients with perfusion abnormality. Tl-201-gated myocardial hybrid SPECT/CT can be a reliable tool in the assessment of LVEF in clinic.

Reproducibility of Semi-automated Three-dimensional Volumetric Analysis using Cardiac Computed Tomography in Patients With Left Ventricular Assist Device

BACKGROUND

Multi-detector gated cardiac computed tomography (CCT) allows three-dimensional (3D) quantification of cardiac chambers and is clinically indicated to assess left ventricular assist device (LVAD) malfunction and complications. Automated volumetric analysis is, however, disrupted by inflow cannula artifact in patients with LVAD. With this study, we evaluated intra-observer variability in semi-automated 3D cardiac volumetric analysis using CCT in patients with LVADs.

METHODS

Ten clinically indicated CCTs were studied retrospectively from 9 patients with LVADs. 3D chamber quantification included left and right ventricles end-systolic and end-diastolic volumes (ESV, EDV); and left and right atrial ESV. Derived measurements included cardiac output (CO), ejection fraction (EF), and stroke volume (SV). Automated volumetric analysis was performed, and manual corrections were added when necessary. Absolute and relative differences, Bland-Altman plots, and interclass correlation coefficients (ICCs) were used to assess intra-observer reproducibility for these measurements.

RESULTS

Intra-observer reproducibility was excellent for volumetric (ICC >0.99) and derived data (ICC >0.91). Comparing right vs left heart volumetric assessments, the former had a higher relative difference (atria 2.8% vs 1.6%, ESV 3.0% vs 1.9%, EDV 2.7% vs 1.3%), which also translated to a greater relative difference in right-side derived data (CO 11.1% vs. 8.8%, EF 10.5% vs. 9.9%, SV 10.9% vs. 9.0%). The mean difference in left ventricular ejection fraction was 0.4% (limits of agreement [LOA]: -2 and 3.2) and right ventricular ejection fraction was 1.2% (LOA: -4.7 and 7.1).

CONCLUSIONS

Our results for semi-automated 3D volumetric analysis showed excellent reproducibility for both volumetric and derived data.

SUMMARY

Electrocardiography-gated cardiac computed tomography with semi-automated volumetric analysis has excellent reproducibility in patients with left ventricular assist device making it imaging modality of choice for functional assessment in this patient population, where cardiac magnetic resonance imaging is contraindicated and transthoracic echocardiography may be limited by poor acoustic windows.

Regional myocardial strain measurements from 4DCT in patients with normal LV function

BACKGROUND

CT SQUEEZ is a new automated technique to evaluate regional endocardial strain by tracking features on the endocardium from 4D cine CT data. The objective of this study was to measure the range of endocardial regional strain (RS_CT) values obtained with CT SQUEEZ in the normal human left ventricle (LV) from standard clinical 4D coronary CTA exams.

METHODS

RS_CT was measured over the heart cycle in 25 humans with normal LV function using cine CT from three vendors. Mean and standard deviation of RS_CT values were computed in 16 AHA LV segments to estimate the range of values expected in the normal LV.

RESULTS

Curves describing RS_CT vs. time were consistent between subjects. There was a slight gradient of decreasing minimum RS_CT value (increased shortening) from the base to the apex of the heart. Mean RS_CT values at end-systole were: base = -32% ± 1%, mid = -33% ± 1%, apex = -36% ± 1%. The standard deviation of the minimum systolic RS_CT in each segment over all subjects was 5%. The average time to reach maximum shortening was 34% of the RR interval.

CONCLUSIONS

Regional strain (RS_CT) can be rapidly obtained from standard gated coronary CCTA protocols using 4DCT SQUEEZ processing. We estimate that 95% of normal LV end-systolic RS_CT values will fall between -23% and -43%; therefore, we hypothesize that an RS_CT value higher than -23% will indicate a hypokinetic segment in the human heart.

Comparison of Echocardiography, Cardiac Magnetic Resonance, and Computed Tomographic Imaging for the Evaluation of Left Ventricular Myocardial Function: Part 2 (Diastolic and Regional Assessment)

Assessing left ventricular diastolic and regional function is a crucial part of the cardiovascular evaluation. Diastolic function is as important as systolic function for left ventricular performance because it is the determinant of the ability of the left atrium and ventricle to fill at relatively low pressures. Additionally, diastolic function plays an important role in the management and prognosis of patients with symptoms and signs of heart failure. Technical advances in the imaging modalities have allowed a comprehensive noninvasive assessment of global and regional cardiac mechanics and precise estimation of cardiovascular hemodynamics. In this review, we will discuss and compare clinically available techniques and novel approaches using echocardiography, cardiac magnetic resonance, and computed tomography for the assessment of diastolic and regional left ventricular function.

Computed tomography of cardiomyopathies

Cardiac computed tomography (CT) is increasingly used in the evaluation of cardiomyopathies, particularly in patients who are not able to undergo other non-invasive imaging tests such as magnetic resonance imaging (MRI) due to the presence of MRI-incompatible pacemakers/defibrillators or other contraindications or due to extensive artifacts from indwelling metallic devices. Advances in scanner technology enable acquisition of CT images with high spatial resolution, good temporal resolution, wide field of view and multi-planar reconstruction capabilities. CT is useful in cardiomyopathies in several ways, particularly in the evaluation of coronary arteries, characterization of cardiomyopathy phenotype, quantification of cardiac volumes and function, treatment-planning, and post-treatment evaluation. In this article, we review the imaging techniques and specific applications of CT in the evaluation of cardiomyopathies.

Diagnosing and Managing Carcinoid Heart Disease in Patients With Neuroendocrine Tumors: An Expert Statement

Carcinoid heart disease is a frequent occurrence in patients with carcinoid syndrome and is responsible for substantial morbidity and mortality. The pathophysiology of carcinoid heart disease is poorly understood; however, chronic exposure to excessive circulating serotonin is considered one of the most important contributing factors. Despite recognition, international consensus guidelines specifically addressing the diagnosis and management of carcinoid heart disease are lacking. Furthermore, there is considerable variation in multiple aspects of screening and management of the disease. The aim of these guidelines was to provide succinct, practical advice on the diagnosis and management of carcinoid heart disease as well as its surveillance. Recommendations and proposed algorithms for the investigation, screening, and management have been developed based on an evidence-based review of the published data and on the expert opinion of a multidisciplinary consensus panel consisting of neuroendocrine tumor experts, including oncologists, gastroenterologists, and endocrinologists, in conjunction with cardiologists and cardiothoracic surgeons.

Comprehensive Modeling and Visualization of Cardiac Anatomy and Physiology from CT Imaging and Computer Simulations

In clinical cardiology, both anatomy and physiology are needed to diagnose cardiac pathologies. CT imaging and computer simulations provide valuable and complementary data for this purpose. However, it remains challenging to gain useful information from the large amount of high-dimensional diverse data. The current tools are not adequately integrated to visualize anatomic and physiologic data from a complete yet focused perspective. We introduce a new computer-aided diagnosis framework, which allows for comprehensive modeling and visualization of cardiac anatomy and physiology from CT imaging data and computer simulations, with a primary focus on ischemic heart disease. The following visual information is presented: (1) Anatomy from CT imaging: geometric modeling and visualization of cardiac anatomy, including four heart chambers, left and right ventricular outflow tracts, and coronary arteries; (2) Function from CT imaging: motion modeling, strain calculation, and visualization of four heart chambers; (3) Physiology from CT imaging: quantification and visualization of myocardial perfusion and contextual integration with coronary artery anatomy; (4) Physiology from computer simulation: computation and visualization of hemodynamics (e.g., coronary blood velocity, pressure, shear stress, and fluid forces on the vessel wall). Substantially, feedback from cardiologists have confirmed the practical utility of integrating these features for the purpose of computer-aided diagnosis of ischemic heart disease.

Radiation dose and image quality of 70 kVp functional cardiovascular computed tomography imaging in congenital heart disease

BACKGROUND

The use of cardiac computed tomography (CT) for quantification of ventricular function is limited by relatively high radiation dose.

OBJECTIVES

The goal of this study was to describe the radiation exposure and image quality of 70 kVp functional cardiac CT in patients with congenital heart disease (CHD).

METHODS

A retrospective review of 70 kVp ECG gated functional CT scans using tube current modulation was performed in CHD patients at a single institution. Quantitative and qualitative (assessed by myocardial segment, 1-4; 1 = optimal) image quality was determined. Per segment image quality was compared between thin (1.5 mm) and thick (8 mm) reconstructions and by patient age and size. Scan DLP was used to estimate radiation dose.

RESULTS

72 scans were performed during the time of review (7/2013-6/2015). Median patient age was 19.5 years (8.0, 27.1) and BMI was 20.1 (16.6, 24.5) kg/m(2). Median functional scan DLP was 78.8 (45.5, 98) and unadjusted and adjusted procedural mSv were 1.10 (0.64, 1.37) and 1.13 (0.90, 1.37). Image quality of 1 was achieved in all myocardial segments in >75% of scans. Patients with a weight ≥75 kg were more likely to have a scan achieve optimal image when using thick reconstructions compared to thin (81.3% vs. 43.8%; p = 0.028).

CONCLUSIONS

Imaging of ventricular function with 70 kVp in CHD patients can be done with low radiation doses and provides diagnostic image quality, particularly for patients <75 kg. In larger patients, thicker slice reconstruction improved image quality.