A rare case of giant left circumflex coronary artery fistula to coronary sinus in patient with persistent left superior vena cava and bicuspid aortic valve.

A 61-year-old male presented with symptoms of decompensated heart failure and cardiogenic shock. Transthoracic and transesophageal echocardiography showed severely impaired left ventricular (LV) systolic function (LVEF of 20-25%), bicuspid aortic valve with moderate aortic insufficiency and no significant stenosis, dilated coronary sinus and a tortuous vascular structure in the left-sided atrioventricular groove. Cardiac computed tomography confirmed the diagnosis of persistent left superior vena cava and a giant coronary artery fistula to the coronary sinus. Cardiac magnetic resonance illustrated non-specific late gadolinium enhancement in the mid-wall of the septum. The patient was treated medically and with cardiac re-synchronization therapy.

Surgical management of patient with left ventricular aneurysm and ventricular tachycardia.

The management of patients with dilated cardiomyopathy and large anterior ventricular aneurysm presenting with ventricular tachycardia is not well-described. We report the case of 45-year-old male who presented with recurrent episodes of prolonged polymorphic ventricular tachycardia and previously failed medical management and endocardial and epicardial transcatheter ablation. We performed a Dor procedure to exclude the left ventricular aneurysm in conjunction with cryoablation to terminate his ventricular tachycardia. This surgical approach was found to be successful with conversion of the patient into normal sinus rhythm and restoration of the patient's left ventricular morphology and function. We also propose a methodology for the surgical management of patients with left ventricular aneurysm and intractable ventricular tachycardia focused on a discussion with the patient and the cardiac team about the options for treatment, including surgery or continuing pharmacological and electrical cardioversion therapy, choosing the surgical technique that would exclude the most diseased and akinetic myocardial segment, and being more liberal with the use of cryoablation.

MB-FSGAN: Joint segmentation and quantification of kidney tumor on CT by the multi-branch feature sharing generative adversarial network.

The segmentation of the kidney tumor and the quantification of its tumor indices (i.e., the center point coordinates, diameter, circumference, and cross-sectional area of the tumor) are important steps in tumor therapy. These quantifies the tumor morphometrical details to monitor disease progression and accurately compare decisions regarding the kidney tumor treatment. However, manual segmentation and quantification is a challenging and time-consuming process in practice and exhibit a high degree of variability within and between operators. In this paper, MB-FSGAN (multi-branch feature sharing generative adversarial network) is proposed for simultaneous segmentation and quantification of kidney tumor on CT. MB-FSGAN consists of multi-scale feature extractor (MSFE), locator of the area of interest (LROI), and feature sharing generative adversarial network (FSGAN). MSFE makes strong semantic information on different scale feature maps, which is particularly effective in detecting small tumor targets. The LROI extracts the region of interest of the tumor, greatly reducing the time complexity of the network. FSGAN correctly segments and quantifies kidney tumors through joint learning and adversarial learning, which effectively exploited the commonalities and differences between the two related tasks. Experiments are performed on CT of 113 kidney tumor patients. For segmentation, MB-FSGAN achieves a pixel accuracy of 95.7%. For the quantification of five tumor indices, the R2 coefficient of tumor circumference is 0.9465. The results show that the network has reliable performance and shows its effectiveness and potential as a clinical tool.

3D Motion Estimation of Left Ventricular Dynamics Using MRI and Track-to-Track Fusion.

OBJECTIVE: This study investigates the estimation of three dimensional (3D) left ventricular (LV) motion using the fusion of different two dimensional (2D) cine magnetic resonance (CMR) sequences acquired during routine imaging sessions. Although standard clinical cine CMR data is inherently 2D, the actual underlying LV dynamics lies in 3D space and cannot be captured entirely using single 2D CMR image sequences. By utilizing the image information from various short-axis and long-axis image sequences, the proposed method intends to estimate the dynamic state vectors consisting of the position and velocity information of the myocardial borders in 3D space. METHOD: The proposed method comprises two main components: tracking myocardial points in 2D CMR sequences and fusion of multiple trajectories correspond to the tracked points. The tracking which yields the set of corresponding temporal points representing the myocardial points is performed using a diffeomorphic nonrigid image registration approach. The trajectories obtained from each cine CMR sequence is then fused with the corresponding trajectories from other CMR views using an unscented Kalman smoother (UKS) and a track-to-track fusion algorithm. RESULTS: We evaluated the proposed method by comparing the results against CMR imaging with myocardial tagging. We report a quantitative performance analysis by projecting the state vector estimates we obtained onto 2D tagged CMR images acquired from the same subjects and comparing them against harmonic phase estimates. The proposed algorithm yielded a competitive performance with a mean root mean square error of 1.3±0.5 pixels (1.8±0.6 mm) evaluated over 118 image sequences acquired from 30 subjects. CONCLUSION: This study demonstrates that fusing the information from short and long-axis views of CMR improves the accuracy of cardiac tissue motion estimation. Clinical Impact: The proposed method demonstrates that the fusion of tissue tracking information from long and short-axis views improves the binary classification of the automated regional function assessment.

Is Fractional Flow Reserve Useful in Assessing Coronary Artery Fistula: A Case-Based Discussion and Review.

We present two cases where fractional flow reserve (FFR) was utilised to guide management of coronary artery fistula (CAF), an approach advocated in recent case studies. CAF is a coronary anomaly that may present with a variety of syndromes though is frequently asymptomatic. When to exclude the fistula (surgically or percutaneously) is not always clear. A way to quantify if the fistula is physiologically meaningful would be advantageous. Our findings suggest FFR may only be assessing the concomitant epicardial coronary artery disease (CAD) rather than the degree of coronary steal and its routine use in this setting is not supported.

Detecting left ventricular impaired relaxation in cardiac MRI using moving mesh correspondences.

UNLABELLED: Anatomical cine cardiovascular magnetic resonance (CMR) imaging is widely used to assess the systolic cardiac function because of its high soft tissue contrast. Assessment of diastolic LV function has not regularly been performed due the complex and time consuming procedures. This study presents a semi-automated assessment of the left ventricular (LV) diastolic function using anatomical short-axis cine CMR images. The proposed method is based on three main steps: (1) non-rigid registration, which yields a sequence of endocardial boundary points over the cardiac cycle based on a user-provided contour on the first frame; (2) LV volume and filling rate computations over the cardiac cycle; and (3) automated detection of the peak values of early (E) and late ventricular (A) filling waves. In 47 patients cine CMR imaging and Doppler-echocardiographic imaging were performed. CMR measurements of peak values of the E and A waves as well as the deceleration time were compared with the corresponding values obtained in Doppler-Echocardiography. For the E/A ratio the proposed algorithm for CMR yielded a Cohen's kappa measure of 0.70 and a Gwet's AC1 coefficient of 0.70. CONCLUSION: Semi-automated assessment of the left ventricular (LV) diastolic function using anatomical short-axis cine CMR images provides mitral inflow measurements comparable to Doppler-Echocardiography.

Transcatheter ACURATE-TA Aortic Valve Implantation in a Patient With a Previous Mechanical Mitral Valve.

Transcatheter aortic valve implantation (TAVI) in the presence of a mechanical mitral valve (MMV) prosthesis is still challenging because of the rigid mitral frame within the aortomitral curtain. Moreover, low-lying coronary ostia represent a hazardous problem of coronary obstruction, especially in narrow or porcelain aortic roots. The present case demonstrates the successful management of 2 challenging anatomical issues, the rigid cage of the MMV and the low-lying left main coronary ostium (LMCO), with the implantation of the ACURATE-TA bioprosthesis (Symetis SA, Ecublens, Switzerland). It also highlights the importance of having multiple TAVI devices in order to choose the ideal transcatheter aortic bioprosthesis to fit the unique anatomical presentation of the patient.

Symetis valve implantation in failing freestyle with close proximity between coronary Ostia and annulus.

Transcatheter treatment of patients with degenerated aortic valve stentless prosthesis and low proximal coronary ostia to the aortic annulus remain a challenge because of the elevated risk for coronary obstruction. Newer generation transcatheter aortic valve devices that engage and pull the aortic valve calcium towards the aortic annulus may be beneficial in these patients. We present a case of successful treatment of a degenerated tubular stentless prosthesis with low coronary ostia with a Symetis Acurate TA prosthesis.

Multimodality imaging for assessment of coronary embolus.

Caseous mitral annulus calcification involving aortomitral curtain is a rare occurrence. We report a case of a 64-year-old woman with end-stage renal failure and a candidate for renal transplant who presented with late ST-elevation myocardial infarction. Intracoronary imaging, computed tomography cardiac imaging, and histopathology confirmed coronary embolus into the left main stem artery from an extensive caseous mitral annulus calcification.

Ultrasound guidance for beating heart mitral valve repair augmented by synthetic dynamic CT.

Minimally invasive valvular intervention commonly requires intra-procedural navigation to provide spatial and temporal information of relevant cardiac structures and device components. Recently intra-procedural trans-esophageal echocardiography (TEE) has been exploited for this purpose due to its accessibility, low cost, ease of use, and real-time imaging capacity. However, the position and orientation of tissue targets relative to surgical tools can be challenging to perceive, particularly using 2D imaging planes. In this paper, we propose the use of CT images to provide a high-quality 3D context to enhance ultrasound images through image registration, providing an augmented guidance system with minimal impact on standard clinical workflow. We also describe an approach to generate synthetic 4D CT images through non-rigid registration of available ultrasound. This can be employed to avoid a requirement for higher radiation. Synthetic CT images were validated through direct comparison of synthetic and real multi-phase CT images. Validation of CT and ultrasound image registration was performed for both dynamic and synthetic CT image datasets. Our results demonstrated that the synthetically generated dynamic CT images provide similar anatomical representation for relevant cardiac anatomy relative to real dynamic CT images, and similar high registration accuracy that can be achieved for intra-procedural TEE to this versus real dynamic CT images.

Model-based navigation of left and right ventricular leads to optimal targets for cardiac resynchronization therapy: a single-center feasibility study.

BACKGROUND: Left ventricular (LV) and right ventricular pacing site characteristics have been shown to influence response to cardiac resynchronization therapy (CRT). This study aimed to determine the clinical feasibility of image-guided lead delivery using a 3-dimensional navigational model displaying both LV and right ventricular (RV) pacing targets. Serial echocardiographic measures of clinical response and procedural metrics were evaluated. METHODS AND RESULTS: Thirty-one consecutive patients underwent preimplant cardiac MRI with the generation of a 3-dimensional navigational model depicting optimal segmental targets for LV and RV leads. Lead delivery was guided by the model in matched views to intraprocedural fluoroscopy. Blinded assessment of final lead tip location was performed from postprocedural cardiac computed tomography. Clinical and LV remodeling response criteria were assessed at baseline, 3 months, and 6 months using a 6-minute hall walk, quality of life questionnaire, and echocardiography. Mean age and LV ejection fraction was 66 ± 8 years and 26 ± 8%, respectively. LV leads were successfully delivered to a target or adjacent segment in 30 of 31 patients (97%), 68% being nonposterolateral. RV leads were delivered to a target or adjacent segment in 30 of 31 patients (97%), 26% being nonapical. Twenty-three patients (74%) met standard criteria for response (LV end-systolic volume reduction ≥ 15%), 18 patients (58%) for super-response (LV end-systolic volume reduction ≥ 30%). LV ejection fraction improved at 6 months (31 ± 8 versus 26 ± 8%, P=0.04). CONCLUSIONS: This study demonstrates clinical feasibility of dual cardiac resynchronization therapy lead delivery to optimal targets using a 3-dimensional navigational model. High procedural success, acceptable procedural times, and a low rate of early procedural complications were observed. CLINICAL TRIAL REGISTRATION URL: http://www.clinicaltrials.gov. Unique identifier: NCT01640769.

Anatomy-based eligibility measure for robotic-assisted bypass surgery.

OBJECTIVE: Robotic-assisted endoscopic single-vessel small thoracotomy allows clinicians to perform coronary artery bypass grafting surgery in a minimally invasive manner using the da Vinci Surgical System. Not all patients are suitable for this technique, and the lack of an appropriate method for patient eligibility avoids completion of the procedure robotically. The objective of this study was to develop a patient eligibility method based on the anatomy of the chest of the patient. METHODS: Preoperative computed tomography thorax scans of 110 patients were analyzed. Two-dimensional measurements taken on the axial images were used with the goal of finding a relation between the anatomy of the patient and the completion of the procedure robotically. RESULTS: Patients with a distance from the left anterior descending coronary artery to the anterior chest wall of smaller than 15 mm have a 20% probability of requiring conversion of the procedure to open surgery. This probability increases if the chest of the patient is very elliptical, having an anterior-posterior dimension of less than 45% of the transverse dimension. CONCLUSIONS: The smaller the distance is from the left anterior descending artery to the anterior chest wall, the lower the chances are of completing the procedure robotically.

A three-dimensional measurement approach for the morphology of the femoral head.

The hip joint is one of the most frequent sites of osteoarthritis. Advances in diagnosis and clinical treatment have progressed dramatically in the last few decades; however, there are limitations associated with the lack of reliable measures for quantifying hip joint morphology. Current diagnostic measures of the hip are performed with pre-determined measures, typically lengths and angles, on 2D radiographic planes. The current measurement techniques do not utilize the inherent 3D nature of CT and MR imaging and do not necessarily quantify the relevant clinical pathologies. A valid and reliable measurement modality that measures the surface geometry of the femoral head is necessary for early diagnosis and treatment of hip disease. The purpose of this study was to establish a method to quantify femoral head morphology using a three-dimensional model. A novel measurement approach was applied to 45 cadaveric femurs (23 right; 22 left; nine female, 17 male) and their digitally reconstructed 3D CT models. The mean difference between the cadaveric and digital measures was -2.04 mm with 95% confidence limits (CI) of 13.67 mm and -17.75 mm, respectively. The digital measurement approach was found to have excellent intraobserver reliability (ICC = 0.99, CI 0.98-0.99) and interobserver reliability (ICC = 0.98, CI 0.93-0.99). This valid and reliable novel digital measurement approach enables quantification of the 3D surface geometry of the femoral head and is able to measure individual variations and potentially detect abnormalities. This method may be used to assist future studies to establish valid diagnostic measurements for femoral head and head-neck junction pathologies.

Direct estimation of cardiac biventricular volumes with an adapted Bayesian formulation.

Accurate estimation of the ventricular volumes is essential to the assessment of global cardiac functions. The existing estimation methods are mostly restricted to the left ventricle (LV), and often require segmentation which is challenging and computationally expensive. This paper proposes to estimate the volumes of both LV and right ventricle (RV) jointly with an efficient segmentation-free method. The proposed method employs an adapted Bayesian formulation. It introduces a novel likelihood function to exploit multiple appearance features, and a novel prior probability model to incorporate the area correlation between LV and RV cavities. The method is validated on a comprehensive dataset containing 56 clinical subjects (3360 images in total). The experimental results demonstrate that the estimated biventricular volumes are highly correlated to their independent ground truth. As a result, the proposed method enables a direct, efficient, and accurate assessment of global cardiac functions.

Regional assessment of cardiac left ventricular myocardial function via MRI statistical features.

Automating the detection and localization of segmental (regional) left ventricle (LV) abnormalities in magnetic resonance imaging (MRI) has recently sparked an impressive research effort, with promising performances and a breadth of techniques. However, despite such an effort, the problem is still acknowledged to be challenging, with much room for improvements in regard to accuracy. Furthermore, most of the existing techniques are labor intensive, requiring delineations of the endo- and/or epi-cardial boundaries in all frames of a cardiac sequence. The purpose of this study is to investigate a real-time machine-learning approach which uses some image features that can be easily computed, but that nevertheless correlate well with the segmental cardiac function. Starting from a minimum user input in only one frame in a subject dataset, we build for all the regional segments and all subsequent frames a set of statistical MRI features based on a measure of similarity between distributions. We demonstrate that, over a cardiac cycle, the statistical features are related to the proportion of blood within each segment. Therefore, they can characterize segmental contraction without the need for delineating the LV boundaries in all the frames. We first seek the optimal direction along which the proposed image features are most descriptive via a linear discriminant analysis. Then, using the results as inputs to a linear support vector machine classifier, we obtain an abnormality assessment of each of the standard cardiac segments in real-time. We report a comprehensive experimental evaluation of the proposed algorithm over 928 cardiac segments obtained from 58 subjects. Compared against ground-truth evaluations by experienced radiologists, the proposed algorithm performed competitively, with an overall classification accuracy of 86.09% and a kappa measure of 0.73.