Pulsed field ablation selectively spares the oesophagus during pulmonary vein isolation for atrial fibrillation.

AIMS: Extra-atrial injury can cause complications after catheter ablation for atrial fibrillation (AF). Pulsed field ablation (PFA) has generated preclinical data suggesting that it selectively targets the myocardium. We sought to characterize extra-atrial injuries after pulmonary vein isolation (PVI) between PFA and thermal ablation methods. METHODS AND RESULTS: Cardiac magnetic resonance (CMR) imaging was performed before, acutely (<3 h) and 3 months post-ablation in 41 paroxysmal AF patients undergoing PVI with PFA (N = 18, Farapulse) or thermal methods (N = 23, 16 radiofrequency, 7 cryoballoon). Oesophageal and aortic injuries were assessed by using late gadolinium-enhanced (LGE) imaging. Phrenic nerve injuries were assessed from diaphragmatic motion on intra-procedural fluoroscopy. Baseline CMR showed no abnormality on the oesophagus or aorta. During ablation procedures, no patient showed phrenic palsy. Acutely, thermal methods induced high rates of oesophageal lesions (43%), all observed in patients showing direct contact between the oesophagus and the ablation sites. In contrast, oesophageal lesions were observed in no patient ablated with PFA (0%, P < 0.001 vs. thermal methods), despite similar rates of direct contact between the oesophagus and the ablation sites (P = 0.41). Acute lesions were detected on CMR on the descending aorta in 10/23 (43%) after thermal ablation, and in 6/18 (33%) after PFA (P = 0.52). CMR at 3 months showed a complete resolution of oesophageal and aortic LGE in all patients. No patient showed clinical complications. CONCLUSION: PFA does not induce any signs of oesophageal injury on CMR after PVI. Due to its tissue selectivity, PFA may improve safety for catheter ablation of AF.

Pulsed field ablation prevents chronic atrial fibrotic changes and restrictive mechanics after catheter ablation for atrial fibrillation.

AIMS: Pulsed field ablation (PFA), a non-thermal ablative modality, may show different effects on the myocardial tissue compared to thermal ablation. Thus, this study aimed to compare the left atrial (LA) structural and mechanical characteristics after PFA vs. thermal ablation. METHODS AND RESULTS: Cardiac magnetic resonance was performed pre-ablation, acutely (<3 h), and 3 months post-ablation in 41 patients with paroxysmal atrial fibrillation (AF) undergoing pulmonary vein (PV) isolation with PFA (n = 18) or thermal ablation (n = 23, 16 radiofrequency ablations, 7 cryoablations). Late gadolinium enhancement (LGE), T2-weighted, and cine images were analysed. In the acute stage, LGE volume was 60% larger after PFA vs. thermal ablation (P < 0.001), and oedema on T2 imaging was 20% smaller (P = 0.002). Tissue changes were more homogeneous after PFA than after thermal ablation, with no sign of microvascular damage or intramural haemorrhage. In the chronic stage, the majority of acute LGE had disappeared after PFA, whereas most LGE persisted after thermal ablation. The maximum strain on PV antra, the LA expansion index, and LA active emptying fraction declined acutely after both PFA and thermal ablation but recovered at the chronic stage only with PFA. CONCLUSION: Pulsed field ablation induces large acute LGE without microvascular damage or intramural haemorrhage. Most LGE lesions disappear in the chronic stage, suggesting a specific reparative process involving less chronic fibrosis. This process may contribute to a preserved tissue compliance and LA reservoir and booster pump functions.

Fibrocyte accumulation in the airway walls of COPD patients.

The remodelling mechanism and cellular players causing persistent airflow limitation in COPD remain largely elusive. We have recently demonstrated that circulating fibrocytes, a rare population of fibroblast-like cells produced by the bone marrow stroma, are increased in COPD patients during an exacerbation. We aimed to quantify fibrocyte density in situ in bronchial specimens from both control subjects and COPD patients, to define associations with relevant clinical, functional and computed tomography (CT) parameters, and to investigate the effect of the epithelial microenvironment on fibrocyte survival in vitro ("Fibrochir" study).A total of 17 COPD patients and 25 control subjects, all requiring thoracic surgery, were recruited. Using co-immunostaining and image analysis, we identified CD45+ FSP1+ cells as tissue fibrocytes, and quantified their density in distal and proximal bronchial specimens. Fibrocytes, cultured from the blood samples of six COPD patients, were exposed to primary bronchial epithelial cell secretions from control subjects or COPD patients.We demonstrate that fibrocytes are increased in both distal and proximal tissue specimens of COPD patients. The density of fibrocytes is negatively correlated with lung function parameters and positively correlated with bronchial wall thickness as assessed by CT scan. A high density of distal bronchial fibrocytes predicts the presence of COPD with a sensitivity of 83% and a specificity of 70%. Exposure of fibrocytes to COPD epithelial cell supernatant favours cell survival.Our results thus demonstrate an increased density of fibrocytes within the bronchi of COPD patients, which may be promoted by epithelial-derived survival-mediating factors.

Relationship between atrial scar on cardiac magnetic resonance and pulmonary vein reconnection after catheter ablation for paroxysmal atrial fibrillation.

INTRODUCTION: Pulmonary vein (PV) reconnection is frequent in patients showing atrial fibrillation (AF) recurrence after PV isolation (PVI). Its detection with cardiac magnetic resonance (CMR) may help predict outcome and guide redo procedures. We assessed the relationship between scar on CMR and PV reconnection after catheter ablation for paroxysmal AF. METHODS AND RESULTS: Fifty-one patients with paroxysmal AF underwent CMR before PVI using either a conventional single-electrode catheter (N = 28) or a circular multielectrode catheter (N = 23). At 3 months, a second CMR study was performed, followed by a systematic electrophysiological procedure to look for PV reconnection, regardless of AF recurrence. Preablation fibrosis and postablation scar were quantified and mapped from late gadolinium-enhanced CMR. CMR results were compared to the distribution and extent of PV reconnection. CMR and electrophysiological findings were compared between catheter types. Three months after successful PVI, scar gaps were found in 39 (76%) patients, and 78 (39%) veins. Electrical PV reconnection was detected in 45 (88%) patients, and 99 (50%) veins. The extent of PV reconnection related closely to the number of gaps (R = 0.55; P < .001), and to scar burden (R = -0.63; P < .001). However, the agreement was only fair for the localization of PV reconnection (k = 0.37; P < .001), scar gaps particularly lacking sensitivity in areas of pre-existing fibrosis. The circular catheter was associated with shorter procedures (P < .001), more scar (P = .01), less gaps (P = .01), and less reconnected veins (P = .03). CONCLUSION: PV reconnection is extremely frequent after PVI. CMR scar imaging accurately predicts its extent, but poorly predicts its location. Multielectrode circular catheters induce more complete ablation.

High-resolution three-dimensional late gadolinium-enhanced cardiac magnetic resonance imaging to identify the underlying substrate of ventricular arrhythmia.

Aims: Cardiac magnetic resonance (CMR) is recommended as a second-line method to diagnose ventricular arrhythmia (VA) substrate. We assessed the diagnostic yield of CMR including high-resolution late gadolinium-enhanced (LGE) imaging. Methods and results: Consecutive patients with sustained ventricular tachycardia (VT), non-sustained VT (NSVT), or ventricular fibrillation/aborted sudden death (VF/SCD) underwent a non-CMR diagnostic workup according to current guidelines, and CMR including LGE imaging with both a conventional breath-held and a free-breathing method enabling higher spatial resolution (HR-LGE). The diagnostic yield of CMR was compared with the non-CMR workup, including the incremental value of HR-LGE. A total of 157 patients were enrolled [age 54 ± 17 years; 75% males; 88 (56%) sustained VT, 52 (33%) NSVT, 17 (11%) VF/SCD]. Of these, 112 (71%) patients had no history of structural heart disease (SHD). All patients underwent electrocardiography and echocardiography, 72% coronary angiography, and 51% exercise testing. Pre-CMR diagnoses were 84 (54%) no SHD, 39 (25%) ischaemic cardiomyopathy (ICM), 11 (7%) non-ischaemic cardiomyopathy (NICM), 3 (2%) arrhythmogenic right ventricular cardiomyopathy (ARVC), 2 (1%) hypertrophic cardiomyopathy (HCM), and 18 (11%) other. CMR modified these diagnoses in 48 patients (31% of all and 43% of those with no SHD history). New diagnoses were 9 ICM, 28 NICM, 8 ARVC, 1 HCM, and 2 other. CMR modified therapy in 19 (12%) patients. In patients with no SHD after non-CMR tests, SHD was found in 32 of 84 (38%) patients. Eighteen of these patients showed positive HR-LGE and negative conventional LGE. Thus, HR-LGE significantly increased the CMR detection of SHD (17-38%, P < 0.001). Conclusion: CMR including HR-LGE imaging has high diagnostic value in patients with VAs. This has major prognostic and therapeutic implications, particularly in patients with negative pre-CMR workup.

Allergic Bronchopulmonary Aspergillosis in Cystic Fibrosis: MR Imaging of Airway Mucus Contrasts as a Tool for Diagnosis.

Purpose To assess the diagnostic accuracy of mucus contrast characterization by using magnetic resonance (MR) imaging to discriminate allergic bronchopulmonary aspergillosis (ABPA) in cystic fibrosis (CF). Materials and Methods The study was approved by the local Ethics Committee, and all patients or their parents gave written informed consent. One hundred ten consecutive patients with CF were screened between January 2014 and July 2015. All patients underwent a non-contrast material-enhanced MR protocol that included routine T1-weighted and T2-weighted sequences. The presence of mucus with both high T1 and low T2 signal intensities and the so-called inverted mucoid impaction signal (IMIS) sign was qualitatively and quantitatively assessed by two physicians who were blinded to all other data. The reference standard for a diagnosis of ABPA was the criteria of the Cystic Fibrosis Foundation Consensus Conference. ABPA status was followed up for 1 year. Reproducibility was assessed by using the κ test, correlation was assessed by using the Spearman coefficient, and diagnostic accuracy was assessed by calculating the sensitivity and specificity of IMIS. Results One hundred eight patients with CF were included (mean age, 20 years ± 11 [standard deviation]; range, 6-53 years): 18 patients with ABPA and 90 patients without ABPA. At the lobar level, inter- and intrareader reproducibility were very good (κ > 0.90). IMIS had 94% sensitivity (95% confidence interval [CI]: 73%, 99%) and 100% specificity (95% CI: 96%, 100%) for the diagnosis of ABPA. A complete resolution of IMIS was observed in patients with ABPA after 3 months of specific treatment that was significantly correlated with decrease in total immunoglobulin E level (ρ = 0.47; P = .04). Conclusion The IMIS sign was both specific and sensitive for the diagnosis of ABPA in CF. Allergic fungal inflammation appears to induce characteristic modifications of mucus contrasts that are assessable by using a noninvasive, contrast material-free, and radiation-free method. © RSNA, 2017 Online supplemental material is available for this article.

CT evaluation of small pulmonary vessels area in patients with COPD with severe pulmonary hypertension.

RATIONALE: Severe pulmonary hypertension (PH) is very uncommon in COPD, and a distinct phenotype has been hypothesised. We aimed to evaluate whether CT can help to recognise this condition non-invasively by measuring small pulmonary vessels. MATERIAL AND METHODS: Patients with COPD who underwent pulmonary function tests, unenhanced CT of the chest and right heart catheterisation (RHC) during a period of stability were included in the study. From 105 included patients, 20 patients with COPD with severe PH (mean pulmonary arterial pressure, mPAP>35 mm Hg) were compared with 20 FEV1-matched and age-matched patients with COPD with mild or without PH (mPAP<35 mm Hg). The percentage of total cross-sectional area of vessels less than 5 mm(2) normalised by lung area (%CSA<5) and 5-10 mm(2) (%CSA5-10), the mean number of cross-sectioned vessels (CSNs) and bronchial wall thickness (WT) were measured on CT examination and compared between groups. Paw scores combining PaO2 measurement and CT parameters best correlated with mPAP were compared by receiver operating characteristic analysis to predict severe PH in COPD. RESULTS: Patients with severe PH COPD had higher %CSA and CSN values than those of patients with COPD without severe PH. Using multiple regression analysis, %CSA<5 and WT were the best predictors of mPAP in patients with and without severe PH, respectively. A score combining %CSA<5, PaO2 and WT best predicted severe PH in patients with COPD. CONCLUSIONS: CT measurements of small vessels support a distinct vessel-related phenotype in patients with COPD with severe PH, and combined with WT and PaO2 parameters in the paw score, which may offer a non-invasive tool to select patients for RHC.

Image Integration to Guide Catheter Ablation in Scar-Related Ventricular Tachycardia.

BACKGROUND: Although multi-detector computed tomography (MDCT) and cardiac magnetic resonance (CMR) can assess the structural substrate of ventricular tachycardia (VT) in ischemic cardiomyopathy (ICM), non-ICM (NICM), and arrhythmogenic right ventricular cardiomyopathy (ARVC), the usefulness of systematic image integration during VT ablation remains undetermined. METHODS AND RESULTS: A total of 116 consecutive patients (67 ICM; 30 NICM; 19 ARVC) underwent VT ablation with image integration (MDCT 91%; CMR 30%; both 22%). Substrate was defined as wall thinning on MDCT and late gadolinium-enhancement on CMR in ICM/NICM, and as myocardial hypo-attenuation on MDCT in ARVC. This substrate was compared to mapping and ablation results with the endpoint of complete elimination of local abnormal ventricular activity (LAVA), and the impact of image integration on procedural management was analyzed. Imaging-derived substrate identified 89% of critical VT isthmuses and 85% of LAVA, and was more efficient in identifying LAVA in ICM and ARVC than in NICM (90% and 90% vs. 72%, P < 0.0001), and when defined from CMR than MDCT (ICM: 92% vs. 88%, P = 0.026, NICM: 88% vs. 72%, P < 0.001). Image integration motivated additional mapping and epicardial access in 57% and 33% of patients. Coronary and phrenic nerve integration modified epicardial ablation strategy in 43% of patients. The impact of image integration on procedural management was higher in ARVC/NICM than in ICM (P < 0.01), and higher in case of epicardial approach (P < 0.0001). CONCLUSIONS: Image integration is feasible in large series of patients, provides information on VT substrate, and impacts procedural management, particularly in ARVC/NICM, and in case of epicardial approach.

Lung morphology assessment of cystic fibrosis using MRI with ultra-short echo time at submillimeter spatial resolution.

OBJECTIVES: We hypothesized that non-contrast-enhanced PETRA (pointwise encoding time reduction with radial acquisition) MR (magnetic resonance) sequencing could be an alternative to unenhanced computed tomography (CT) in assessing cystic fibrosis (CF) lung structural alterations, as well as compared agreements and concordances with those of conventional T1-weighted and T2-weighted sequences. MATERIAL AND METHODS: Thirty consecutive CF patients completed both CT and MRI the same day. No contrast injection was used. Agreement in identifying structural alterations was evaluated at the segmental level using a kappa test. Intraclass correlation coefficients (ICC) and Bland-Altman analysis were used to assess concordances and reproducibility in Helbich-Bhalla disease severity scoring. RESULTS: Agreement between PETRA and CT was higher than that of T1- or T2-weighted sequences, notably in assessing the segmental presence of bronchiectasis (Kappa = 0.83; 0.51; 0.49, respectively). The concordance in Helbich-Bhalla scores was very good using PETRA (ICC = 0.97), independently from its magnitude (mean difference (MD) = -0.3 [-2.8; 2.2]), whereas scoring was underestimated using both conventional T1 and T2 sequences (MD = -3.6 [-7.4; 0.1]) and MD = -4.6 [-8.2; -1.0], respectively). Intra- and interobserver reproducibility were very good for all imaging modalities (ICC = 0.86-0.98). CONCLUSION: PETRA showed higher agreement in describing CF lung morphological changes than that of conventional sequences, whereas the Helbich-Bhalla scoring matched closely with that of CT. KEY POINTS: • Spatial resolution of lung MRI is limited using non-ultra-short TE MRI technique • Ultra-short echo time (UTE) technique enables submillimeter 3D-MRI of airways • 3D-UTE MRI shows very good concordance with CT in assessing cystic fibrosis • Radiation-free 3D-UTE MRI enables the Helbich-Bhalla scoring without a need for contrast injection.

Three-Dimensional Measurement of Hepatocellular Carcinoma Ablation Zones and Margins for Predicting Local Tumor Progression.

PURPOSE: To propose a postprocessing technique that measures tumor surface with insufficient ablative margins (≤ 5 mm) on magnetic resonance (MR) imaging to predict local tumor progression (LTP) following radiofrequency (RF) ablation. MATERIALS AND METHODS: A diagnostic method is proposed based on measurement of tumor surface with a margin ≤ 5 mm on MR imaging. The postprocessing technique includes fully automatic registration of pre- and post-RF ablation MR imaging, a semiautomatic segmentation of pre-RF ablation tumor and post-RF ablation volume, and a subsequent calculation of the three-dimensional exposed tumor surface area. The ability to use this surface margin ≤ 5 mm to predict local recurrence at 2 years was then tested on 16 patients with cirrhosis who were treated by RF ablation with a margin ≤ 5 mm in 2012: eight with LTP matched according to tumor size and number and α-fetoprotein level versus eight without local recurrence. RESULTS: The error of estimated tumor surface with a margin ≤ 5 mm was less than 12%. Results of a log-rank test showed that patients with a tumor surface area > 425 mm(2) had a 2-year LTP rate of 77.5%, compared with 25% for patients with a tumor surface area ≤ 425 mm(2) (P = .018). CONCLUSIONS: This proof-of-concept study proposes an accurate and reliable postprocessing technique to estimate tumor surface with insufficient ablative margins, and underscores the potential usefulness of tumor surface with a margin ≤ 5 mm to stratify patients with HCC treated by RF ablation according to their risk of LTP.

Computed tomographic measurement of airway remodeling and emphysema in advanced chronic obstructive pulmonary disease. Correlation with pulmonary hypertension.

RATIONALE: Pulmonary hypertension (PH) is an established complication of advanced chronic obstructive pulmonary disease (COPD) associated with increased mortality. The mechanisms coupling PH and bronchial obstruction are unknown; in particular, PH appears to be unrelated to emphysema. We hypothesized that computed tomographic (CT) measurement of airway remodeling instead of emphysema may correlate with PH in COPD. OBJECTIVES: We aimed to describe the clinical and CT characteristics of patients with COPD with or without PH and to correlate CT measurements of airway remodeling and emphysema with PH. METHODS: Data were retrieved from 60 COPD patients who underwent both right heart catheterization and computed tomography in a period of stability and had no other disease known to cause PH. CT measurement of airway wall thickness (WT-Pi10) was used to assess airway remodeling and low lung area percentage (LAA%) to quantify emphysema extent. MEASUREMENTS AND MAIN RESULTS: Thirty-four of the sixty patients with COPD had PH (mean pulmonary arterial pressure [PAPm] ≥ 25 mm Hg). There was no difference between the two groups regarding age, sex, and spirometric results, whereas there was more profound hypoxemia in the PH group. WT-Pi10 was increased in the patients with COPD and PH and correlated with PAPm (ρ = 0.62; P < 0.001). Conversely, there was no difference or correlation between PAPm and LAA% (ρ = 0.12; P = 0.33). In multivariate analysis (R(2) = 0.53), WT-Pi10 was the independent predictor most associated with PAPm elevation, as compared to hypoxia (PaO2) or pulmonary arterial enlargement (diameter ratio between the pulmonary arterial truncus and the ascending aorta). CONCLUSIONS: This study demonstrates, for the first time to our knowledge, an association between structural alterations of bronchi and PH in COPD. Unlike quantification of emphysema, CT measurement of airway remodeling correlates with PAPm and could be used to estimate the severity of PH in COPD. Airway remodeling burden is not limited to airflow limitation in the assessment of COPD severity and mortality.

Calcium channel blocker reduces airway remodeling in severe asthma. A proof-of-concept study.

RATIONALE: Severe asthma is a major public health issue throughout the world. Increased bronchial smooth muscle (BSM) mass, a characteristic feature of airway remodeling in severe asthma, is associated with resistance to high-intensity treatment and poor prognosis. In vitro, the Ca(2+)-channel blocker gallopamil decreased the proliferation of BSM cells from patients with severe asthma. OBJECTIVES: We conducted a double-blind, randomized, placebo-controlled study to evaluate the effect of gallopamil on airway remodeling in patients with severe asthma. METHODS: Subjects received either gallopamil (n = 16) or placebo (n = 15) for 1 year and were monitored for an additional 3-month period. Airway remodeling was analyzed at baseline and after treatment phase using both fiberoptic bronchoscopy and computed tomography scan. The primary end point was the BSM area. Secondary end points included normalized BSM thickness and frequency of asthma exacerbations. MEASUREMENTS AND MAIN RESULTS: BSM area was reduced in the gallopamil group (baseline vs. end of treatment) but was unchanged in the placebo group. Between-group differences in BSM area were not significantly different in gallopamil versus placebo groups. By contrast, between-group differences in normalized BSM thickness were significantly different between the two groups. The mean number of exacerbations per month was not different during the treatment phase in gallopamil versus placebo group but was significantly lower in patients previously treated with gallopamil during the follow-up period. There were no differences between the groups with respect to overall side effects. CONCLUSIONS: Gallopamil treatment for 12 months reduces BSM remodeling and prevents the occurrence of asthma exacerbations. Clinical trial registered with www.clinicaltrials.gov (NCT 00896428).

Quiet Submillimeter MR Imaging of the Lung Is Feasible with a PETRA Sequence at 1.5 T.

PURPOSE: To assess lung magnetic resonance (MR) imaging with a respiratory-gated pointwise encoding time reduction with radial acquisition (PETRA) sequence at 1.5 T and compare it with imaging with a standard volumetric interpolated breath-hold examination (VIBE) sequence, with extra focus on the visibility of bronchi and the signal intensity of lung parenchyma. MATERIALS AND METHODS: The study was approved by the local ethics committee, and all subjects gave written informed consent. Twelve healthy volunteers were imaged with PETRA and VIBE sequences. Image quality was evaluated by using visual scoring, numbering of visible bronchi, and quantitative measurement of the apparent contrast-to-noise ratio (CNR) and signal-to-noise ratio (SNR). For preliminary clinical assessment, three young patients with cystic fibrosis underwent both MR imaging and computed tomography (CT). Comparisons were made by using the Wilcoxon signed-rank test for means and the McNemar test for ratios. Agreement between CT and MR imaging disease scores was assessed by using the κ test. RESULTS: PETRA imaging was performed with a voxel size of 0.86 mm(3). Overall image quality was good, with little motion artifact. Bronchi were visible consistently up to the fourth generation and in some cases up to the sixth generation. Mean CNR and SNR with PETRA were 32.4% ± 7.6 (standard deviation) and 322.2% ± 37.9, respectively, higher than those with VIBE (P < .001). Good agreement was found between CT and PETRA cystic fibrosis scores (κ = 1.0). CONCLUSION: PETRA enables silent, free-breathing, isotropic, and submillimeter imaging of the bronchi and lung parenchyma with high CNR and SNR and may be an alternative to CT for patients with cystic fibrosis.

Automated Quantification of Right Ventricular Fat at Contrast-enhanced Cardiac Multidetector CT in Arrhythmogenic Right Ventricular Cardiomyopathy.

PURPOSE: To evaluate an automated method for the quantification of fat in the right ventricular (RV) free wall on multidetector computed tomography (CT) images and assess its diagnostic value in arrhythmogenic RV cardiomyopathy (ARVC). MATERIALS AND METHODS: This study was approved by the institutional review board, and all patients gave informed consent. Thirty-six patients with ARVC (mean age ± standard deviation, 46 years ± 15; seven women) were compared with 36 age- and sex-matched subjects with no structural heart disease (control group), as well as 36 patients with ischemic cardiomyopathy (ischemic group). Patients underwent contrast material-enhanced electrocardiography-gated cardiac multidetector CT. A 2-mm-thick RV free wall layer was automatically segmented and myocardial fat, expressed as percentage of RV free wall, was quantified as pixels with attenuation less than -10 HU. Patient-specific segmentations were registered to a template to study fat distribution. Receiver operating characteristic (ROC) analysis was performed to assess the diagnostic value of fat quantification by using task force criteria as a reference. RESULTS: Fat extent was 16.5% ± 6.1 in ARVC and 4.6% ± 2.7 in non-ARVC (P < .0001). No significant difference was observed between control and ischemic groups (P = .23). A fat extent threshold of 8.5% of RV free wall was used to diagnose ARVC with 94% sensitivity (95% confidence interval [CI]: 82%, 98%) and 92% specificity (95% CI: 83%, 96%). This diagnostic performance was higher than the one for RV volume (mean area under the ROC curve, 0.96 ± 0.02 vs 0.88 ± 0.04; P = .009). In patients with ARVC, fat correlated to RV volume (R = 0.63, P < .0001), RV function (R = -0.67, P = .001), epsilon waves (R = 0.39, P = .02), inverted T waves in V1-V3 (R = 0.38, P = .02), and presence of PKP2 mutations (R = 0.59, P = .02). Fat distribution differed between patients with ARVC and those without, with posterolateral RV wall being the most ARVC-specific area. CONCLUSION: Automated quantification of RV myocardial fat on multidetector CT images is feasible and performs better than RV volume in the diagnosis of ARVC. Online supplemental material is available for this article.

Age, atrial fibrillation, and structural heart disease are the main determinants of left atrial fibrosis detected by delayed-enhanced magnetic resonance imaging in a general cardiology population.

INTRODUCTION: We studied the extent and distribution of left atrial (LA) fibrosis on delayed-enhanced (DE) MRI in a general cardiology population. METHODS AND RESULTS: One hundred ninety consecutive patients referred for cardiac MRI underwent DE imaging using a free breathing method. The population comprised 60 AF patients and 130 patients without AF, including 75 with structural heart disease (SHD). DE was quantified using histogram thresholding, expressed in % of the wall. Regression analysis was performed to identify predictors of DE. Additionally, DE was registered on a template to study its distribution in subpopulations. In the total population, age, AF, and SHD were independently associated with DE. DE was increasingly observed from 11.1 ± 4.7% in patients with no SHD nor AF, 18.8 ± 7.8% in SHD and no AF history, 22.9 ± 7.8% in paroxysmal AF, to 27.8 ± 7.7% in persistent AF. Among non-AF patients, age and SHD were independently associated with DE. Among AF patients, female gender and AF persistence were independently associated with DE. DE was variably distributed but more frequently detected in the posterior wall. CONCLUSION: Age, history of AF, and SHD are the most powerful predictors of atrial fibrosis, as detected by MRI, in a general cardiology population. Atrial fibrosis predominates in the posterior LA wall.

Radiofrequency ablation versus surgical resection for hepatocellular carcinoma within the Milan criteria: A study of 281 Western patients.

OBJECTIVES: The aim of this study was to compare survival between radiofrequency ablation (RFA) and surgical resection (SR) in patients with hepatocellular carcinoma (HCC) within Milan criteria. METHODS: From January 2004 to December 2013 we consecutively and retrospectively included all patients with first occurrence of HCC within Milan criteria receiving SR or RFA as first-line treatment. The cumulative overall survival (OS) and disease-free survival (DFS) were compared after inverse probability weighting (including confounding factor). RESULTS: A total of 281 patients (RFA 178, SR 103) were enrolled. In multivariate Cox regression RFA and SR were not independent predictors of survival or recurrence. The respective weighted 5 years OS and DFS for patients with propensity scores between 0.1-0.9 in the SR and RFA groups were 54-33% and 60-16.9%, P = 0.695 and P = 0.426, respectively. Local tumour progression rate did not differ according to treatment (P = 0.523). Major complication rate was higher in the SR group, P = 0.001. Hospitalisation duration was lower in the RFA group (mean 2.19 days, range 2-7) than in the SR group (mean 10.2 days, range 3-30), P < 0.001. CONCLUSION: This large Western study has shown that OS and DFS did not differ after RFA (using mainly multipolar devices) and SR, for HCC within the Milan criteria in a European population, with a shorter hospitalisation time and a lower complication rate for RFA.

Non-invasive assessment of liver fibrosis with impulse elastography: comparison of Supersonic Shear Imaging with ARFI and FibroScan®.

BACKGROUND & AIMS: Non-invasive assessment of liver fibrosis by elastography is a rapidly developing field with frequent technological innovations. The aim of this study was to assess the diagnostic performances of Supersonic Shear Imaging (SSI) for the diagnosis of liver fibrosis in chronic liver disease. METHODS: A total of 349 consecutive patients with chronic liver diseases who underwent liver biopsy from November 2011 to October 2013 were prospectively enrolled. For each patient, liver stiffness was assessed by SSI, ARFI, FibroScan® (M probe for patients with BMI <30 kg/m(2), and XL probe for patients with BMI ⩾30 kg/m(2)), performed within two weeks of liver biopsy. Areas under the receiver operating curves (AUROCs) were performed and compared for each degree of liver fibrosis. RESULTS: SSI, FibroScan®, and ARFI correlated significantly with histological fibrosis score (r=0.79, p<0.00001; r=0.70, p<0.00001; r=0.64, p<0.00001, respectively). AUROCs of SSI, FibroScan®, and ARFI were 0.89, 0.86, and 0.84 for the diagnosis of mild fibrosis; 0.88, 0.84, and 0.81 for the diagnosis of significant fibrosis; 0.93, 0.87, and 0.89, for the diagnosis of severe fibrosis; 0.93, 0.90, and 0.90 for the diagnosis of cirrhosis, respectively. SSI had a higher accuracy than FibroScan® for the diagnosis of severe fibrosis (⩾F3) (p=0.0016), and a higher accuracy than ARFI for the diagnosis of significant fibrosis (⩾F2) (p=0.0003). No significant difference was observed for the diagnosis of mild fibrosis and cirrhosis. CONCLUSIONS: SSI is an efficient method for the assessment of liver fibrosis in chronic liver diseases, comparing favourably to FibroScan® and ARFI.

Cardiac arrythmias: multimodal assessment integrating body surface ECG mapping into cardiac imaging.

PURPOSE: To demonstrate the feasibility of comprehensive assessment of cardiac arrhythmias by combining body surface electrocardiographic (ECG) mapping (BSM) and imaging. MATERIALS AND METHODS: This study was approved by the institutional review board, and all patients gave written informed consent. Twenty-seven patients referred for electrophysiologic procedures in the context of ventricular tachycardia (VT) (n = 9), Wolff-Parkinson-White (WPW) syndrome (n = 2), atrial fibrillation (AF) (n = 13), or scar-related ventricular fibrillation (VF) (n = 3) were examined. Patients underwent BSM and imaging with multidetector computed tomography (CT) (n = 12) and/or delayed enhanced magnetic resonance (MR) imaging (n = 23). BSM was performed by using a 252-electrode vest that enabled the computation of epicardial electrograms from body surface potentials. The epicardial geometry used for BSM was registered to the epicardial geometry segmented from imaging data by using an automatic algorithm. The output was a three-dimensional cardiac model that integrated cardiac anatomy, myocardial substrate, and epicardial activation. RESULTS: Acquisition, segmentation, and registration were feasible in all patients. In VT, this enabled a noninvasive assessment of the arrhythmia mechanism and its location with respect to the myocardial substrate, coronary vessels, and phrenic nerve. In WPW syndrome, this enabled understanding of complex accessory pathways resistant to previous ablation. In AF and VF, this enabled the noninvasive assessment of arrhythmia mechanisms and the analysis of rotor trajectories with respect to the myocardial substrate. In all patients, models were successfully integrated in navigation systems and used to guide mapping and ablation. CONCLUSION: By combining information on anatomy, substrate, and electrical activation, the fusion of BSM and imaging enables comprehensive noninvasive assessment of cardiac arrhythmias, with potential applications for diagnosis, prognosis, and ablation targeting. Online supplemental material is available for this article.

Locally advanced pancreatic adenocarcinoma: reassessment of response with CT after neoadjuvant chemotherapy and radiation therapy.

PURPOSE: To prospectively evaluate the utility of computed tomography (CT) for determination of tumor response and prediction of resectability after neoadjuvant combined chemotherapy and radiation therapy (CRT) in patients with nonmetastatic locally advanced pancreatic cancer. MATERIALS AND METHODS: This study received institutional review board approval, and all participants provided written informed consent. Consecutive patients with cephalic locally advanced pancreatic cancer who underwent surgical exploration and/or resection following neoadjuvant CRT were prospectively enrolled from June 2009 to May 2013. Two radiologists independently analyzed the baseline and post-CRT CT scans for the size, attenuation, and circumferential vascular contacts of the tumor. Associations between the postoperative histologic grade of the tumor response (pTNM) and the clinical, biologic, and CT criteria were assessed by using Spearman correlation coefficients. CT criteria related to the presence of complete (ie, R0) resection were assessed by using logistic regression. RESULTS: Forty-seven patients were included, 33 with an R0 resection and 14 with positive margins (ie, R1) or no resection. Variables demonstrating a significant correlation with the histologic tumor classification of tumor response were post-CRT carbohydrate antigen 19-9 level (r = 0.46), post-CRT largest tumor axis (r = 0.44), post-CRT sum of the largest and smallest tumor axes (r = 0.46), change in the largest axis (r = -0.31), change in the sum of the largest and smallest axes (r = -0.39), change in superior mesenteric vein (SMV) and/or portal vein (hereafter, SMV/portal vein) contact (r = -0.38), and post-CRT superior mesenteric artery contact (r = 0.34). Partial regression of tumor contact with the SMV/portal vein was associated in all cases with R0 resection (10 of 10 patients, positive predictive value = 100%), and partial regression of tumor contact with any peripancreatic vascular axis was associated with R0 resection in 91% of cases (20 of 22 patients, positive predictive value = 91%). Persistence of SMV/portal vein stenosis after CRT was not predictive of R1 resection. CONCLUSION: Partial regression of tumor-vessel contact indicates suitability for surgical exploration, irrespective of the degree of decrease in tumor size or the degree of residual vascular involvement.

Atrial structure and function 5 years after successful ablation for persistent atrial fibrillation: an MRI study.

INTRODUCTION: The atrial outcome after extensive ablation is unknown. We sought to quantify atrial structure and function years after successful ablation for persistent atrial fibrillation (PsAF). METHODS AND RESULTS: We studied after 80 ± 15 months 26 patients (54 ± 8 years, 1 woman) with PsAF successfully treated by ablation (2.2 ± 0.7 stepwise approach procedures, cumulative RF duration 126 ± 37 minutes). At follow-up atrial scar burden and atrial outflows were quantified using delayed-enhanced and velocity-encoded MRI, respectively. Cine imaging was used to quantify atrial conduit function (CF), active emptying fraction (AEF), expansion index (EI), and the inter-appendage mechanical activation delay. Patients underwent exercise testing at baseline and follow-up. LA and RA scar extent were 29 ± 6 and 4.3 ± 2.8%, respectively. LA and RA AEF were 10.0 ± 5.3 and 30 ± 8%. Mean inter-appendage delay was 83 ± 47 ms [42-217]. Complete LAA isolation was found in 3 patients. A wave was absent in 9/26 patients. LA scar extent related to the number of procedures (R = 0.58, P = 0.002) and total RF duration (R = 0.56, P = 0.003). Among follow-up characteristics, LA scar extent related to LAAEF (R = -0.73, P < 0.0001), LAEI (R = -0.64, P = 0.0003), A-wave peak (R = -0.72, P < 0.0001), and inter-appendage mechanical delay (R = 0.47, P = 0.02). At multivariable analysis, LA scar extent was independently related to LAAEF and LAEI. LAAEF and LA scar extent correlated with exercise capacity at follow-up (R = 0.44, P = 0.02, and R = -0.40; P = 0.04). CONCLUSION: LA contractility and compliance are markedly impaired years after successful PsAF ablation. LA dysfunction is closely related to scar burden.