Ultra-high-resolution photon-counting detector computed tomography of the lungs: Phantom and clinical assessment of radiation dose and image quality.

PURPOSE: Photon-counting-detector computed tomography (PCD-CT) offers enhanced noise reduction, spatial resolution, and image quality in comparison to energy-integrated-detectors CT (EID-CT). These hypothesized improvements were compared using PCD-CT ultra-high (UHR) and standard-resolution (SR) scan-modes. METHODS: Phantom scans were obtained with both EID-CT and PCD-CT (UHR, SR) on an adult body-phantom. Radiation dose was measured and noise levels were compared at a minimum achievable slice thickness of 0.5 mm for EID-CT, 0.2 mm for PCD-CT-UHR and 0.4 mm for PCD-CT-SR. Signal-to-noise ratios (SNR) and contrast-to-noise ratios (CNR) were calculated for five tissue densities. Additionally, data from 25 patients who had PCD-CT of chest were reconstructed at 1 mm and 0.2 mm (UHR) slice-thickness and compared quantitatively (SNR) and qualitatively (noise, quality, sharpness, bone details). RESULTS: Phantom PCD-CT-UHR and PCD-CT-SR scans had similar measured radiation dose (16.0mGy vs 15.8 mGy). Phantom PCD-CT-SR (0.4 mm) had lower noise level in comparison to EID-CT (0.5 mm) (9.0HU vs 9.6HU). PCD-CT-UHR (0.2 mm) had slightly higher noise level (11.1HU). Phantom PCD-CT-SR (0.4 mm) had higher SNR in comparison to EID-CT (0.5 mm) while achieving higher resolution (Bone 115 vs 96, Acrylic 14 vs 14, Polyethylene 11 vs 10). SNR was slightly lower across all densities for PCD-CT UHR (0.2 mm). Interestingly, CNR was highest in the 0.2 mm PCD-CT group; PCD-CT CNR was 2.45 and 2.88 times the CNR for 0.5 mm EID-CT for acrylic and poly densities. Clinical comparison of SNR showed predictably higher SNR for 1 mm (30.3 ± 10.7 vs 14.2 ± 7, p = 0.02). Median subjective ratings were higher for 0.2 mm UHR vs 1 mm PCD-CT for nodule contour (4.6 ± 0.3 vs 3.6 ± 0.1, p = 0.02), bone detail (5 ± 0 vs 4 ± 0.1, p = 0.001), image quality (5 ± 0.1 vs 4.6 ± 0.4, p = 0.001), and sharpness (5 ± 0.1 vs 4 ± 0.2). CONCLUSION: Both UHR and SR PCD-CT result in similar radiation dose levels. PCD-CT can achieve higher resolution with lower noise level in comparison to EID-CT.

Quantum iterative reconstruction on a photon-counting detector CT improves the quality of hepatocellular carcinoma imaging.

BACKGROUND: Excellent image quality is crucial for workup of hepatocellular carcinoma (HCC) in patients with liver cirrhosis because a signature tumor signal allows for non-invasive diagnosis without histologic proof. Photon-counting detector computed tomography (PCD-CT) can enhance abdominal image quality, especially in combination with a novel iterative reconstruction algorithm, quantum iterative reconstruction (QIR). The purpose of this study was to analyze the impact of different QIR levels on PCD-CT imaging of HCC in both phantom and patient scans. METHODS: Virtual monoenergetic images at 50 keV were reconstructed using filtered back projection and all available QIR levels (QIR 1-4). Objective image quality properties were investigated in phantom experiments. The study also included 44 patients with triple-phase liver PCD-CT scans of viable HCC lesions. Quantitative image analysis involved assessing the noise, contrast, and contrast-to-noise ratio of the lesions. Qualitative image analysis was performed by three raters evaluating noise, artifacts, lesion conspicuity, and overall image quality using a 5-point Likert scale. RESULTS: Noise power spectra in the phantom experiments showed increasing noise suppression with higher QIR levels without affecting the modulation transfer function. This pattern was confirmed in the in vivo scans, in which the lowest noise levels were found in QIR-4 reconstructions, with around a 50% reduction in median noise level compared with the filtered back projection images. As contrast does not change with QIR, QIR-4 also yielded the highest contrast-to-noise ratios. With increasing QIR levels, rater scores were significantly better for all qualitative image criteria (all p < .05). CONCLUSIONS: Without compromising image sharpness, the best image quality of iodine contrast optimized low-keV virtual monoenergetic images can be achieved using the highest QIR level to suppress noise. Using these settings as standard reconstruction for HCC in PCD-CT imaging might improve diagnostic accuracy and confidence.

Emerging concepts in the detection of liver fibrosis in non-alcoholic fatty liver disease.

INTRODUCTION: The non-invasive identification of liver fibrosis related to Non-Alcoholic Fatty Liver Disease is crucial for risk-stratification of patients. Currently, the reference standard to stage hepatic fibrosis relies on liver biopsy, but multiple approaches are developed to allow for non-invasive diagnosis and risk stratification. Non-invasive tests, including blood-based scores and vibration-controlled transient elastography, have been widely validated and represent a good surrogate for risk stratification according to recent European and American guidelines. AREAS COVERED: Novel approaches are based on 'liquid' biomarkers of liver fibrogenesis, including collagen-derived markers (PRO-C3 or PRO-C6), or 'multi-omics' technologies (e.g. proteomic-based molecules or miRNA testing), bearing the advantage of tailoring the intrahepatic disease activity. Alternative approaches are based on 'dry' biomarkers, including magnetic resonance-based tools (including proton density fat fraction, magnetic resonance elastography, or corrected T1), which reach similar accuracy of liver histology and will potentially help identify the best candidates for pharmacological treatment of fibrosing non-alcoholic steatohepatitis. EXPERT OPINION: In the near future, the sequential use of non-invasive tests, as well as the complimentary use of liquid and dry biomarkers according to the clinical need (diagnosis, risk stratification, and prognosis, or treatment response) will guide and improve the management of this liver disease.

Radiation Dose Reduction for Coronary Artery Calcium Scoring Using a Virtual Noniodine Algorithm on Photon-Counting Detector Computed-Tomography Phantom Data.

Background: On the basis of the hypothesis that virtual noniodine (VNI)-based coronary artery calcium scoring (CACS) is feasible at reduced radiation doses, this study assesses the impact of radiation dose reduction on the accuracy of this VNI algorithm on a photon-counting detector (PCD)-CT. Methods: In a systematic in vitro setting, a phantom for CACS simulating three chest sizes was scanned on a clinical PCD-CT. The standard radiation dose was chosen at volumetric CT dose indices (CTDIVol) of 1.5, 3.3, 7.0 mGy for small, medium-sized, and large phantoms, and was gradually reduced by adjusting the tube current resulting in 100, 75, 50, and 25%, respectively. VNI images were reconstructed at 55 keV, quantum iterative reconstruction (QIR)1, and at 60 keV/QIR4, and evaluated regarding image quality (image noise (IN), contrast-to-noise ratio (CNR)), and CACS. All VNI results were compared to true noncontrast (TNC)-based CACS at 70 keV and standard radiation dose (reference). Results: INTNC was significantly higher than INVNI, and INVNI at 55 keV/QIR1 higher than at 60 keV/QIR4 (100% dose: 16.7 ± 1.9 vs. 12.8 ± 1.7 vs. 7.7 ± 0.9; p < 0.001 for every radiation dose). CNRTNC was higher than CNRVNI, but it was better to use 60 keV/QIR4 (p < 0.001). CACSVNI showed strong correlation and agreement at every radiation dose (p < 0.001, r > 0.9, intraclass correlation coefficient > 0.9). The coefficients of the variation in root-mean squared error were less than 10% and thus clinically nonrelevant for the CACSVNI of every radiation dose. Conclusion: This phantom study suggests that CACSVNI is feasible on PCD-CT, even at reduced radiation dose while maintaining image quality and CACS accuracy.

Left atrial strain correlates with severity of cardiac involvement in Anderson-Fabry disease.

OBJECTIVES: Cardiac involvement in Anderson-Fabry disease (AFD) results in myocardial lipid depositions. An early diagnosis can maximize therapeutic benefit. Thus, this study aims to investigate the potential of cardiac MRI (CMR) based parameters of left atrial (LA) function and strain to detect early stages of AFD. METHODS: Patients (n = 58, age 40 (29-51) years, 31 female) with genetically proven AFD had undergone CMR including left ventricular (LV) volumetry, mass index (LVMi), T1, and late gadolinium enhancement, complemented by LA and LV strain measurements and atrial emptying fractions. Patients were stratified into three disease phases and compared to age and sex-matched healthy controls (HC, n = 58, age 41 [26-56] years, 31 female). RESULTS: A total of 19 early-, 20 intermediate-, and 19 advanced-phase patients were included. LV and LA reservoir strain was significantly impaired in all AFD phases, including early disease (both p < 0.001). In contrast, LA volumetry, T1, and LVMi showed no significant differences between the early phase and HC (p > 0.05). In the intermediate phase, LVMi and T1 demonstrated significant differences. In advanced phase, all parameters except active emptying fractions differed significantly from HC. ROC curve analyses of early disease phases revealed superior diagnostic confidence for the LA reservoir strain (AUC 0.88, sensitivity 89%, specificity 75%) over the LV strain (AUC 0.82). CONCLUSIONS: LA reservoir strain showed impairment in early AFD and significantly correlated with disease severity. The novel approach performed better in identifying early disease than the established approach using LVMi and T1. Further studies are needed to evaluate whether these results justify earlier initiation of therapy and help minimize cardiac complications. KEY POINTS: • Parameters of left atrial function and deformation showed impairments in the early stages of Anderson-Fabry disease and correlated significantly with the severity of Anderson-Fabry disease. • Left atrial reservoir strain performed superior to ventricular strain in detecting early myocardial involvement in Anderson-Fabry disease and improved diagnostic accuracies of approaches already using ventricular strain. • Further studies are needed to evaluate whether earlier initiation of enzyme replacement therapy based on these results can help minimize cardiac complications from Anderson-Fabry disease.

Biventricular strain assessment indicates progressive impairment of myocardial contractility in phenotypically negative patients with Fabry's disease.

PURPOSE: The accumulation of sphingolipids in Fabry's disease (FD) leads to left ventricular (LV) hypertrophy and shortened T1 in cardiac magnetic resonance (CMR). Early detection of myocardial involvement is essential for the timely initiation and efficacy of enzyme replacement therapy. However, there is a diagnostic gap between the onset of accumulation and detectable myocardial changes. This study aimed to evaluate the diagnostic value of biventricular strain assessment in early FD. METHODS: Genetically proven FD patients (n = 58) and healthy volunteers (HV, n = 62) who had undergone 3 T CMR were retrospectively identified and stratified into 3 groups according to disease severity. Biventricular volumetry, global longitudinal strains (GLS), indexed biventricular masses (RVMi/LVMi), and T1 were evaluated. Group comparisons were performed by ANOVA and diagnostic accuracy was evaluated by ROC-analysis. RESULTS: The study population included 19 group I, 20 group II and 19 group III patients. LV volumetry and T1 showed no significant difference between early FD patients and HV (all p > 0.760). However, RVMi was increased, while RV-GLS and LV-GLS were significantly impaired (p = 0.024 and < 0.001, respectively). Biventricular strains accurately discriminated early FD patients and HV with RV-GLS being non-inferior to LV-GLS (AUC for both 0.83, p > 0.05). Adding strains to the established approach using T1 and LVMi further increased diagnostic accuracy (AUC 0.99, p < 0.05). CONCLUSIONS: Biventricular strains may help detect altered myocardial deformation patterns in phenotypically negative FD patients. These findings may lead to an earlier initiation of therapy, which in turn may slow hypertrophy and the associated long-term risks.

Baseline Splenic Volume Outweighs Immuno-Modulated Size Changes with Regard to Survival Outcome in Patients with Hepatocellular Carcinoma under Immunotherapy.

Background: An association between immunotherapy and an increase in splenic volume (SV) has been described for various types of cancer. SV is also highly predictive of overall survival (OS) in patients with hepatocellular carcinoma (HCC). We evaluated SV and its changes with regard to their prognostic influence in patients with HCC undergoing immunotherapy. Methods: All patients with HCC who received immunotherapy in first or subsequent lines at our tertiary care center between 2016 and 2021 were screened for eligibility. SV was assessed at baseline and follow-up using an AI-based tool for spleen segmentation. Patients were dichotomized into high and low SV based on the median value. Results: Fifty patients were included in the analysis. The median SV prior to treatment was 532 mL. The median OS of patients with high and low SV was 5.1 months and 18.1 months, respectively (p = 0.01). An increase in SV between treatment initiation and the first follow-up was observed in 28/37 (75.7%) patients with follow-up imaging available. This increase in itself was not prognostic for median OS (7.0 vs. 8.5 months, p = 0.73). However, patients with high absolute SV at the first follow-up continued to have impaired survival (4.0 months vs. 30.7 months, p = 0.004). Conclusion: High SV prior to and during treatment was a significant prognostic factor for impaired outcome. Although a large proportion of patients showed an SV increase after the initiation of immunotherapy, this additional immuno-modulated SV change was negligible compared to long-standing changes in the splanchnic circulation in patients with HCC.

Role of CTA Surveillance for Management of Endovascular Repair of Aortic Dissection.

OBJECTIVES: The aim of this study was to evaluate the effect of timing for post-interventional CT imaging on the rate of re-intervention and all-cause mortality in patients with endovascular treatment of type B aortic dissections (TBAD). MATERIAL AND METHODS: Data on 70 patients with endovascular repair of aortic dissection during a three-year period from a single institution retrospectively were collected. Study participants were stratified based on those who had a postoperative CTA in the first 30 days after index intervention (early) vs. those who did not (late). The re-intervention and all-cause mortality rates between the two groups were investigated using Kaplan-Meier and Cox regression analysis. RESULTS: During a median follow-up time of 230 days, the primary endpoint (additional operation) was reached in 24/70 patients (34.3%) with no statistically significant difference between the early and late CTA group (log-rank-test: P = 0.886). All-cause mortality was present in 14/70 (20%) patients, with no statistically significant difference between both groups (log-rank-test: P = 0.440). Additionally, both groups had no significant differences in time to additional operation and death. Cox regression analysis revealed the presence of a chronic TBAD and underlying connective tissue disease as relevant risk factors for the need for an additional operation and obesity as a protective and renal failure as a negative factor for all-cause mortality. CONCLUSION: CTA surveillance within 30 days of the index operation did not significantly modify mortality or rate of re-intervention after endovascular treatment for TBAD. Surveillance recommendations should be tailored to individualized factors.

Deep learning model to quantify left atrium volume on routine non-contrast chest CT and predict adverse outcomes.

BACKGROUND: Low-dose computed tomography (LDCT) are performed routinely for lung cancer screening. However, a large amount of nonpulmonary data from these scans remains unassessed. We aimed to validate a deep learning model to automatically segment and measure left atrial (LA) volumes from routine NCCT and evaluate prediction of cardiovascular outcomes. METHODS: We retrospectively evaluated 273 patients (median age 69 years, 55.5% male) who underwent LDCT for lung cancer screening. LA volumes were quantified by three expert cardiothoracic radiologists and a prototype AI algorithm. LA volumes were then indexed to the body surface area (BSA). Expert and AI LA volume index (LAVi) were compared and used to predict cardiovascular outcomes within five years. Logistic regression with appropriate univariate statistics were used for modelling outcomes. RESULTS: There was excellent correlation between AI and expert results with an LAV intraclass correlation of 0.950 (0.936-0.960). Bland-Altman plot demonstrated the AI underestimated LAVi by a mean 5.86 â€‹mL/m2. AI-LAVi was associated with new-onset atrial fibrillation (AUC 0.86; OR 1.12, 95% CI 1.08-1.18, p â€‹< â€‹0.001), HF hospitalization (AUC 0.90; OR 1.07, 95% CI 1.04-1.13, p â€‹< â€‹0.001), and MACCE (AUC 0.68; OR 1.04, 95% CI 1.01-1.07, p â€‹= â€‹0.01). CONCLUSION: This novel deep learning algorithm for automated measurement of LA volume on lung cancer screening scans had excellent agreement with manual quantification. AI-LAVi is significantly associated with increased risk of new-onset atrial fibrillation, HF hospitalization, and major adverse cardiac and cerebrovascular events within 5 years.

Compressed sensing acceleration of cardiac cine imaging allows reliable and reproducible assessment of volumetric and functional parameters of the left and right atrium.

OBJECTIVES: To compare volumetric and functional parameters of the atria derived from highly accelerated compressed sensing (CS)-based cine sequences in comparison to conventional (Conv) cine imaging. METHODS: CS and Conv cine sequences were acquired in 101 subjects (82 healthy volunteers (HV) and 19 patients with heart failure with reduced ejection fraction (HFrEF)) using a 3T MR scanner in this single-center study. Time-volume analysis of the left (LA) and right atria (RA) were performed in both sequences to evaluate atrial volumes and function (total, passive, and active emptying fraction). Inter-sequence and inter- and intra-reader agreement were analyzed using correlation, intraclass correlation (ICC), and Bland-Altman analysis. RESULTS: CS-based cine imaging led to a 69% reduction of acquisition time. There was significant difference in atrial parameters between CS and Conv cine, e.g., LA minimal volume (LAVmin) (Conv 24.0 ml (16.7-32.7), CS 25.7 ml (19.2-35.2), p < 0.0001) or passive emptying fraction (PEF) (Conv 53.9% (46.7-58.4), CS 49.0% (42.0-54.1), p < 0.0001). However, there was high correlation between the techniques, yielding good to excellent ICC (0.76-0.99) and small mean of differences in Bland-Altman analysis (e.g. LAVmin - 2.0 ml, PEF 3.3%). Measurements showed high inter- (ICC > 0.958) and intra-rater (ICC > 0.934) agreement for both techniques. CS-based parameters (PEF AUC = 0.965, LAVmin AUC = 0.864) showed equivalent diagnostic ability compared to Conv cine imaging (PEF AUC = 0.989, LAVmin AUC = 0.859) to differentiate between HV and HFrEF. CONCLUSION: Atrial volumetric and functional evaluation using CS cine imaging is feasible with relevant reduction of acquisition time, therefore strengthening the role of CS in clinical CMR for atrial imaging. KEY POINTS: • Reliable assessment of atrial volumes and function based on compressed sensing cine imaging is feasible. • Compressed sensing reduces scan time and has the potential to overcome obstacles of conventional cine imaging. • No significant differences for subjective image quality, inter- and intra-rater agreement, and ability to differentiate healthy volunteers and heart failure patients were detected between conventional and compressed sensing cine imaging.

Safety of transradial and transfemoral left ventricular compared with transfemoral right ventricular endomyocardial biopsy.

AIMS: With the present study, we sought to determine the safety of three different endomyocardial biopsy (EMB) access routes in 514 patients admitted for diagnostic workup of heart failure of unknown aetiology. METHODS AND RESULTS: In this retrospective monocentric cohort study, we analysed 514 consecutive patients with heart failure without evidence of significant coronary artery disease or valvular disease undergoing EMB between November 2013 and December 2018, stratified in three access route groups: transradial arterial left ventricular (LV-)EMB (323 patients), transfemoral LV-EMB (138 patients), and transfemoral right ventricular (RV-)EMB (53 patients). Patients undergoing selective transradial LV-EMB were older compared with patients undergoing selective transfemoral LV-EMB or RV-EMB [transradial LV-EMB: 56.0 (45.0/64.0) vs. transfemoral LV-EMB: 53 (42.5/64.5), P = 0.455; transradial LV-EMB: 56 (45.0/64.0) vs. RV-EMB: 53 (42.5/64), P = 0.695] and presented more often in New York Heart Association-functional class III and IV. A total of eight major complications including permanent atrioventricular block requiring pacemaker implantation, pericardial tamponade necessitating pericardiocentesis, stroke and transient cerebral ischaemic attack as well as severe valvular damage, vascular access site complications, and ventricular fibrillation were documented with no significant differences between the groups (8/514, 1.5%). Minor complications such as transient chest pain, non-sustained electrocardiogram abnormalities, and transient atrioventricular block were rare and equally distributed between groups. CONCLUSIONS: Transradial LV-EMB is a safe procedure for experienced radial operators and non-inferior compared with transfemoral LV-EMB and RV-EMB. An accurate peri-procedural and post-procedural monitoring and follow-up care should be recommended for all patients undergoing this procedure in order to identify potential complications.

T1 and T2 mapping to detect chronic inflammation in cardiac magnetic resonance imaging in heart failure with reduced ejection fraction.

AIMS: The purpose of this retrospective single-centre study was to evaluate the non-invasive detection of endomyocardial biopsy (EMB)-established chronic myocardial inflammation in patients with heart failure with reduced ejection fraction (HFrEF) using T1 and T2 mapping. METHODS AND RESULTS: The study population consisted of 52 retrospectively identified HFrEF patients who underwent EMB and cardiac magnetic resonance imaging at 3 Tesla. EMB was defined according to the position statement of the European Society of Cardiology and served as reference to identify inflammation in all patients. A control group of healthy volunteers with prior cardiac magnetic resonance imaging studies (n = 58) was also identified. Global and segmental T1 and T2 values as well as septal measurements and tissue heterogeneity parameters were calculated. Out of the 52 patients with HFrEF, 33 patients had myocardial inflammation detected by EMB, while 19 patients were EMB negative for inflammation. Mean left ventricular ejection fraction was 31% in both groups (P = 0.97). Global T1 and T2 values in HFrEF patients were significantly higher compared with healthy controls (T1 1275 ± 69 ms vs. 1,175 ± 44 ms, P < 0.001; T2 40.0 ± 3.4 ms vs. 37.9 ± 1.6 ms, P < 0.001). The distribution of T1 and T2 values between patients with and without EMB-proven chronic myocardial inflammation was not statistically different when regarding global (T1 1292 ± 71 ms vs. 1266 ± 67 ms, P = 0.26; T2 40.0 ± 2.6 ms vs. 40.0 ± 3.9 ms, P = 1.0), septal (T1 1299 ± 63 ms vs. 1289 ± 76 ms, P = 0.76; T2 40.1 ± 3.5 ms vs 40.0 ± 6.4 ms, P = 0.49) or maximum segmental values (T1 1414 ± 111 ms vs. 1363 ± 88 ms, P = 0.15; T2 47.3 ± 5.2 ms vs. 48.8 ± 11.8 ms, P = 0.53). Mean absolute deviation of segmental T1 and T2 values and log-transformed pixel-wise standard deviation as parameters of tissue heterogeneity did not reveal statistical significant differences between inflammation-positive and inflammation-negative HFrEF patients (all P > 0.4). CONCLUSIONS: Conventionally performed quantitative T1 and T2 mapping values significantly correlated with prevalence of HFrEF but did not discriminate HFrEF patients with or without chronic myocardial inflammation in our cohort. This suggests that EMB is the preferred method to detect chronic myocardial inflammation in HFrEF.

Feasibility of a MPR-based 3DTEE guidance protocol for transcatheter direct mitral valve annuloplasty.

OBJECTIVES: Several interventional approaches have been established for the treatment of severe mitral regurgitation (MR) in patients at elevated risk for surgery. Direct annuloplasty is a relatively novel option in transcatheter mitral valve repair dedicated to reverse pathology in specific subsets of MR. With regard to echocardiographic guidance, this procedure presents with higher efforts in comparison with edge-to-edge therapy to enable safe and exact positioning of the device's anchors; evidence on optimal peri-interventional imaging is sparse. We tested a specific 3D-echo-guidance protocol implementing single-beat multiplanar reconstruction (MPR) and evaluated its feasibility. METHODS: Overall, 16 patients consecutively treated with transcatheter direct annuloplasty for severe MR (87.5% functional/6.3% degenerative/6.3% mixed pathology) were entered in this monocentric analysis. Of these, two patients received a combined procedure including edge-to-edge repair. For all implantations, a 3D-echo-guidance protocol inheriting MPR was employed. RESULTS: Periprocedural device time decreased continuously (overall mean 140 ± 55.1 minutes, 213 ± 38 minutes in the first 4 vs 108 ± 33 minutes in the last 4 procedures, P = .018) using the MPR-based echo protocol, going along with reduced fluoroscopy times and doses. Technical success rate was high (93.8%) without any serious cardiac-related adverse events. MR could be relevantly improved. CONCLUSION: Echocardiographic guidance of transcatheter direct annuloplasty using a real time MPR-based protocol is feasible and safe. Optimized imaging might enable reduced implantation times and potentially increases safety.

Advanced Protocol for Three-Dimensional Transesophageal Echocardiography Guidance Implementing Real-Time Multiplanar Reconstruction for Transcatheter Mitral Valve Repair by Direct Annuloplasty.

Transcatheter direct annuloplasty has been introduced as a novel interventional treatment option for severe mitral valve regurgitation. Until now, only one direct annuloplasty device (Edwards Cardioband) has been commercially available, being implanted in more than 250 patients worldwide. Yet this procedure poses greater challenges regarding optimal fluoroscopic and echocardiographic guidance compared with edge-to-edge repair: correct localization and orientation of the anchors upon penetration into the fibrous mitral annulus tissue and the basal left ventricular myocardium are preconditions for an optimal result and essential to avoid damage of the neighboring structures (atrioventricular node, circumflex artery, coronary sinus). Real-time single-beat multiplanar reconstruction has become available as an additional imaging tool for three-dimensional transesophageal echocardiography in most recent echo machines. In this review, we introduce a three-dimensional transesophageal echocardiography-based imaging protocol implementing real-time multiplanar reconstruction for transcatheter direct annuloplasty procedures, which optimizes and also simplifies echocardiographic guidance during the implantation. The advanced echocardiographic protocol might also help to expedite implantation times and potentially increase the safety of the procedure. In this "how-to" article, we describe in detail this novel approach for optimized guidance and compare its advantages and challenges to "conventional" echocardiographic imaging for transcatheter mitral valve repair.

Progression of transthyretin (TTR) amyloidosis in donors and recipients after domino liver transplantation-a prospective single-center cohort study.

Liver transplantation (LT) is the first-line therapy in patients with transthyretin (TTR) amyloidosis and progressive familial amyloid polyneuropathy (FAP). Explanted organs from these patients can be used for domino liver transplantation (DLT). After DLT, de novo amyloidosis may develop in domino recipients (DR). Data were collected prospectively in a transplant database. Electroneurography by nerve conduction velocity (NCV), quantitative sensory testing, heart rate variability (HRV), sympathetic skin response, orthostatic reaction (tilt table test), transthoracic echocardiography, cardiac MRI and organ biopsy results were evaluated. The cohort included 24 FAP- (11 Val30Met, 13 nonVal30Met) and 23 DR-patients. DR symptoms referred to post-DLT only, while those of FAP patients were both pre- and post-transplantation. Symptoms of TTR-amyloidosis in Val30Met and Non-Val30Met patients pre- and post-LT were similarly distributed. Biopsy-proven de novo amyloidosis occurred in 4/23 DR after a mean observation of 10 years. Analysis for manifestations of amyloidosis only included patients with available 5-year follow-up data (n = 13 FAP, n = 12 DR). Compared to Val30Met FAP patients pre-LT, Val30Met DR patients had better NCV (P = 0.04) and HRV (P = 0.015). In the Non-Val30Met group no differences were found between DR and FAP patients pre-LT. TTR-amyloidosis symptoms showed no differences in FAP patients pre- and 5 years post-LT, irrespective of Val30Met status. In DR patients, de novo amyloidosis occurred earlier than expected. Therefore, recipients for DLT need to be carefully selected and followed.

Therapeutic implications of a combined diagnostic workup including endomyocardial biopsy in an all-comer population of patients with heart failure: a retrospective analysis.

BACKGROUND: Aetiology of heart failure (HF) often remains obscure. We therefore evaluated the usefulness of a combined diagnostic approach including cardiac magnetic resonance imaging (CMRI) and endomyocardial biopsy (EMB) to assess the cause of unexplained cardiomyopathy underlying HF. METHODS AND RESULTS: We retrospectively investigated 100 consecutive patients (36% women, mean age 53.6 ± 18.8 years) presenting with unexplained cardiomyopathy (HF with reduced ejection fraction or left ventricular hypertrophy; excluding ischaemic and valvular heart disease; left ventricular ejection fraction 31.6 ± 13.9%, Left ventricular end-diastolic pressure 18.2 ± 9.3 mmHg, heart rate 89 ± 26.6 b.p.m.; mean ± SEM) at the University Medical Center Mainz. We performed electrocardiography, echocardiography, CMRI, and cardiac catheterization with EMB analysed at a Food and Drug Administration-approved reference centre in 100%, 94%, 69%, and 100% of patients, respectively. On the basis of CMRI findings, electrocardiography, echocardiography, and medical history, the exact cause of cardiomyopathy remained uncertain in 37 of 69 cases (53.6%). In EMB, 25% of patients had viral replication, 23% had inflammation defined as lymphocytic infiltrations without active virus replication, 1% had giant cell myocarditis, and 1% had eosinophilic myocarditis. After diagnostic workup including EMB findings, the cause of cardiomyopathy remained unidentified in 14% of the cases, classified as idiopathic dilated cardiomyopathy or hypertrophic cardiomyopathy in 10% or 4%, respectively. EMB helped to discuss a causal treatment strategy of HF involving immunosuppression or antiviral treatment in 53% of patients, which was opted for in 12% of the patients. CONCLUSIONS: A comprehensive workup including imaging and EMB in an all-comer population of patients with HF may help physicians to improve diagnostics of unexplained cardiomyopathy in the majority of cases.

Multidetector Computed Tomography Angiography (MD-CTA) of Coronary Artery Bypass Grafts - Update 2017.

BACKGROUND: Coronary artery bypass grafting (CABG) is still an important therapeutic approach in the treatment especially of advanced coronary artery disease. In this study, we elucidate the current role of multidetector computed tomography angiography (MD-CTA) in imaging patients after CABG surgery. METHOD: This study is based on recent reports in the literature (2007 - 2016) on imaging of CABG using 64-slice MD-CT scanners and beyond. We included 13 reports that compared ECG-gated MD-CTA with conventional invasive coronary angiography (ICA) as the reference standard for the assessment of graft patency and for the detection of > 50 % stenoses. These studies had to provide absolute values for true-positive, true-negative, false-positive and false-negative results or at least allow calculation of these numbers. In total, 1002 patients with 2521 bypass grafts were the basis for this review. RESULTS AND CONCLUSION: The sensitivity and specificity for the assessment of graft patency or the detection of > 50 % graft stenosis were 97.2 % and 97.5 %, respectively. The negative and positive predictive values were 93.6 % and 99 %, respectively. By using prospective ECG-gating and an increasing pitch factor, the radiation dose exposure declined to 2.4 mSv in the latest reports. ECG-gated MD-CTA provides a fast and reliable, noninvasive method for assessing patients after CABG. The most substantial benefit of the newest CT scanner generations is a remarkable reduction of radiation dose exposure while maintaining a still excellent diagnostic accuracy during recent years. KEY POINTS: · MD-CTA using 64-slice MDCT scanners and beyond is a reliable, noninvasive method for evaluating CABGs.. · Technical advances such as prospective ECG-gating, iterative reconstruction algorithms and high-pitch scanning lead to a remarkable drop-down in radiation dose exposures as low as 2.4 mSv.. · Despite significant dose reductions, MD-CTA could maintain a high diagnostic accuracy in evaluating CABGs in recent years.. CITATION FORMAT: · Jungmann F, Emrich T, Mildenberger P et al. Multidetector Computed Tomography Angiography (MD-CTA) of Coronary Artery Bypass Grafts - Update 2017. Fortschr Röntgenstr 2018; 190: 237 - 249.

Development of multiple focal nodular hyperplasia lesions after portocaval shunting. A case report.

It has been postulated that altered hepatic blood flow, particularly reduced portal flow, is responsible for the induction of hyperplasia of liver cells and nodule formation. This report describes the case of a 31-year old female patient developing multiple focal nodular hyperplasia (FNH) lesions two years after portocaval shunting and extended right hemihepatectomy due to the suspicion of a malignant liver tumor. Portocaval shunting became necessary due to iatrogenic thrombosis of the entire portal vein after preoperative embolization of the right portal vein. This observation provides for the first time direct evidence for the pathogenesis of FNH in humans.