Optimizing the selection of fillers in police lineups.

A typical police lineup contains a photo of one suspect (who is innocent in a target-absent lineup and guilty in a target-present lineup) plus photos of five or more fillers who are known to be innocent. To create a fair lineup in which the suspect does not stand out, two filler selection methods are commonly used. In the first, fillers are selected if they are similar in appearance to the suspect. In the second, fillers are selected if they possess facial features included in the witness's description of the culprit (e.g., "20-y-old white male"). The police sometimes use a combination of the two methods by selecting description-matched fillers whose appearance is also similar to that of the suspect in the lineup. Decades of research on which approach is better remains unsettled. Here, we tested a counterintuitive prediction made by a formal model based on signal detection theory: From a pool of acceptable description-matched photos, selecting fillers whose appearance is otherwise dissimilar to the suspect should increase the hit rate without affecting the false-alarm rate (increasing discriminability). In Experiment 1, we confirmed this prediction using a standard mock-crime paradigm. In Experiment 2, the effect on discriminability was reversed (as also predicted by the model) when fillers were matched on similarity to the perpetrator in both target-present and target-absent lineups. These findings suggest that signal-detection theory offers a useful theoretical framework for understanding eyewitness identification decisions made from a police lineup.

Prospective randomised placebo-controlled trial assessing the efficacy of silver dressings to enhance healing of acute diabetes-related foot ulcers.

AIMS/HYPOTHESIS: Silver dressings are used for their antimicrobial properties but there is limited evidence of clinical benefit when managing diabetes-related foot ulcers (DFUs). We aimed to assess whether silver dressings in acute DFUs increased the proportion of ulcers healed compared with non-silver dressings. METHODS: In this open-labelled, randomised controlled trial, consecutive individuals who presented to a tertiary multidisciplinary diabetic foot service with a DFU without osteomyelitis or tendon on view of <6 weeks' duration were randomised 1:1 via a computer-generated randomisation process to receive Acticoat (Smith & Nephew, England) dressing (silver group) or dressing without silver (control group) in addition to standard care. Stratified randomisation was performed to ensure that the presence of peripheral arterial disease and infection were equally managed within the two groups. The primary outcome was the proportion of ulcers healed at 12 weeks. Secondary outcomes included time to heal and to 50% ulcer reduction, rates of osteomyelitis and amputation, and need for and duration of antibiotics. RESULTS: Seventy-six ulcers (55 participants) in the control group and 91 ulcers (63 participants) in the silver group were included. There was no difference in the proportion of ulcers healed by 12 weeks in the control vs silver group (75% vs 69%, p=0.49). After adjustment for presence of peripheral arterial disease, infection and initial ulcer size, silver dressing was not associated with odds of healing (OR 0.92; CI 0.26, 3.22; p=0.53). There was no difference in time to healing, progression to osteomyelitis, need for amputation, or duration of or need for antibiotic treatment. CONCLUSIONS/INTERPRETATION: In individuals with acute DFUs without osteomyelitis or tendon on view, Acticoat silver dressings did not improve wound healing or reduce need for antibiotics compared with non-silver dressings. TRIAL REGISTRATION: Australian New Zealand Clinical Trials Registry ACTRN12614001234606 FUNDING: Australian Diabetes Society-unrestricted research award.

Science is not a signal detection problem.

The perceived replication crisis and the reforms designed to address it are grounded in the notion that science is a binary signal detection problem. However, contrary to null hypothesis significance testing (NHST) logic, the magnitude of the underlying effect size for a given experiment is best conceptualized as a random draw from a continuous distribution, not as a random draw from a dichotomous distribution (null vs. alternative). Moreover, because continuously distributed effects selected using a P < 0.05 filter must be inflated, the fact that they are smaller when replicated (reflecting regression to the mean) is no reason to sound the alarm. Considered from this perspective, recent replication efforts suggest that most published P < 0.05 scientific findings are "true" (i.e., in the correct direction), with observed effect sizes that are inflated to varying degrees. We propose that original science is a screening process, one that adopts NHST logic as a useful fiction for selecting true effects that are potentially large enough to be of interest to other scientists. Unlike original science, replication science seeks to precisely measure the underlying effect size associated with an experimental protocol via large-N direct replication, without regard for statistical significance. Registered reports are well suited to (often resource-intensive) direct replications, which should focus on influential findings and be published regardless of outcome. Conceptual replications play an important but separate role in validating theories. However, because they are part of NHST-based original science, conceptual replications cannot serve as the field's self-correction mechanism. Only direct replications can do that.

The reveal procedure: A way to enhance evidence of innocence from police lineups.

OBJECTIVE: Recent work has established that high-confidence identifications (IDs) from a police lineup can provide compelling evidence of guilt. By contrast, when a witness rejects the lineup, it may offer only limited evidence of innocence. Moreover, confidence in a lineup rejection often provides little additional information beyond the rejection itself. Thus, although lineups are useful for incriminating the guilty, they are less useful for clearing the innocent of suspicion. Here, we test predictions from a signal-detection-based model of eyewitness ID to create a lineup that is capable of increasing information about innocence. HYPOTHESES: Our model-based simulations suggest that high-confidence rejections should exonerate many more innocent suspects and do so with higher accuracy if, after a witness rejects a lineup but before they report their confidence, they are shown the suspect and asked, "How sure are you that this person is not the perpetrator?" METHOD: Participants (N = 3,346) recruited from Amazon Mechanical Turk watched a 30-s mock-crime video of a perpetrator. Afterward, they were randomly assigned to lineup procedures using a 2 (standard control vs. reveal condition) × 2 (target present vs. target absent) design. A standard simultaneous lineup served as the control condition. The reveal condition was identical to the control condition except in cases of lineup rejection: When a lineup rejection occurred, the suspect appeared on the screen, and participants provided a confidence rating indicating their belief that the suspect was not the perpetrator. RESULTS: The reveal procedure increased both the accuracy and frequency of high-confidence rejections relative to the standard simultaneous lineup. CONCLUSIONS: Collecting a confidence rating about the suspect after a lineup is rejected may make it possible to quickly clear innocent suspects of suspicion and reduce the amount of contact that innocent people have with the legal system. (PsycInfo Database Record (c) 2022 APA, all rights reserved).

Atrial fibrosis in embolic stroke of undetermined source: A multicenter study.

BACKGROUND AND PURPOSE: Left atrial (LA) cardiac disease is a suspected cause of embolic stroke of undetermined source (ESUS). We tested the hypothesis that LA fibrosis, quantified using late-gadolinium-enhancement magnetic resonance imaging (LGE-MRI), predicts recurrent stroke or atrial fibrillation (AF) in patients with ESUS. METHODS: We compared atrial fibrosis in healthy controls and patients with lacunar stroke, ESUS, and known AF with or without prior stroke. We followed patients with ESUS prospectively for the primary outcome of recurrent ischemic stroke, incident AF, or both. RESULTS: We enrolled 203 patients from three centers: 103 patients without AF (35 healthy controls, 15 with lacunar strokes, 53 with ESUS) and 100 patients with AF (50 with and 50 without prior stroke). Patients with ESUS had significantly higher atrial fibrosis (15.0 ± 6.2%) compared to healthy controls (8.1 ± 7.9%; <0.0001) and compared to lacunar stroke patients (10.8 ± 8.4; p = 0.02), but had comparable fibrosis to patients with AF with (17.9 ± 11.4%) or without prior stroke (16.6 ± 9.2%; p = NS for both). Over a mean follow-up of 19 months, nine of 53 patients (16.9%) with ESUS experienced the combined primary outcome, which included six patients (11.3%) with recurrent ischemic stroke and five patients with incident AF (9.4%). Patients with ESUS with fibrosis ≥12% had a higher proportion of the combined outcome: 25.0% vs. 4.8%; p = 0.039. CONCLUSIONS: Patients with ESUS demonstrate atrial fibrosis comparable to that seen in AF. Atrial fibrosis ≥12% was associated with recurrent stroke, incident AF or both. This subgroup of ESUS patients may benefit from anticoagulation for secondary prevention of ischemic stroke.

Constrictive pericarditis in the setting of repeated chest trauma in a mixed martial arts fighter.

BACKGROUND: Constrictive pericarditis (CP) is characterized by scarring and loss of elasticity of the pericardium. This case demonstrates that mixed martial arts (MMA) is a previously unrecognized risk factor for CP, diagnosis of which is supported by cardiac imaging, right and left heart catheterization, and histological findings of dense fibrous tissue without chronic inflammation. CASE PRESENTATION: A 47-year-old Caucasian male former mixed martial arts (MMA) fighter from the Western United States presented to liver clinic for elevated liver injury tests (LIT) and a 35-pound weight loss with associated diarrhea, lower extremity edema, dyspnea on exertion, and worsening fatigue over a period of 6 months. Past medical history includes concussion, right bundle branch block, migraine headache, hypertension, chronic pain related to musculoskeletal injuries and fractures secondary to MMA competition. Involvement in MMA was extensive with an 8-year history of professional MMA competition and 13-year history of MMA fighting with recurrent trauma to the chest wall. The patient also reported a 20-year history of performance enhancing drugs including testosterone. Physical exam was notable for elevated jugular venous pressure, hepatomegaly, and trace peripheral edema. An extensive workup was performed including laboratory studies, abdominal computerized tomography, liver biopsy, echocardiogram, and cardiac magnetic resonance imaging. Finally, right and left heart catheterization-the gold standard-confirmed discordance of the right ventricle-left ventricle, consistent with constrictive physiology. Pericardiectomy was performed with histologic evidence of chronic pericarditis. The patient's hospital course was uncomplicated and he returned to NYHA functional class I. CONCLUSIONS: CP can be a sequela of recurrent pericarditis or hemorrhagic effusions and may have a delayed presentation. In cases of recurrent trauma, CP may be managed with pericardiectomy with apparent good outcome. Further studies are warranted to analyze the occurrence of CP in MMA so as to better define the risk in such adults.

Whole-heart, ungated, free-breathing, cardiac-phase-resolved myocardial perfusion MRI by using Continuous Radial Interleaved simultaneous Multi-slice acquisitions at sPoiled steady-state (CRIMP).

PURPOSE: To develop a whole-heart, free-breathing, non-electrocardiograph (ECG)-gated, cardiac-phase-resolved myocardial perfusion MRI framework (CRIMP; Continuous Radial Interleaved simultaneous Multi-slice acquisitions at sPoiled steady-state) and test its quantification feasibility. METHODS: CRIMP used interleaved radial simultaneous multi-slice (SMS) slice groups to cover the whole heart in 9 or 12 short-axis slices. The sequence continuously acquired data without magnetization preparation, ECG gating or breath-holding, and captured multiple cardiac phases. Images were reconstructed by a motion-compensated patch-based locally low-rank reconstruction. Bloch simulations were performed to study the signal-to-noise ratio/contrast-to-noise ratio (SNR/CNR) for CRIMP and to study the steady-state signal under motion. Seven patients were scanned with CRIMP at stress and rest to develop the sequence. One human and two dogs were scanned at rest with a dual-bolus method to test the quantification feasibility of CRIMP. The dual-bolus scans were performed using both CRIMP and an ungated radial SMS saturation recovery (SMS-SR) sequence with injection dose = 0.075 mmol/kg to compare the sequences in terms of SNR, cardiac phase resolution and quantitative myocardial blood flow (MBF). RESULTS: Perfusion images with multiple cardiac phases in all image slices with a temporal resolution of 72 ms/frame were obtained. Simulations and in-vivo acquisitions showed CRIMP kept the inner slices in steady-state regardless of motion. CRIMP outperformed SMS-SR in slice coverage (9 over 6), SNR (mean 20% improvement), and provided cardiac phase resolution. CRIMP and SMS-SR sequences provided comparable MBF values (rest systolic CRIMP = 0.58 ± 0.07, SMS-SR = 0.61 ± 0.16). CONCLUSION: CRIMP allows for whole-heart, cardiac-phase-resolved myocardial perfusion images without ECG-gating or breath-holding. The sequence can provide MBF if an accurate arterial input function is obtained separately.

Quantitative 3D myocardial perfusion with an efficient arterial input function.

PURPOSE: The purpose of this study was to further develop and combine several innovative sequence designs to achieve quantitative 3D myocardial perfusion. These developments include an optimized 3D stack-of-stars readout (150 ms per beat), efficient acquisition of a 2D arterial input function, tailored saturation pulse design, and potential whole heart coverage during quantitative stress perfusion. THEORY AND METHODS: All studies were performed free-breathing on a Prisma 3T MRI scanner. Phantom validation was used to verify sequence accuracy. A total of 21 subjects (3 patients with known disease) were scanned, 12 with a rest only protocol and 9 with both stress (regadenoson) and rest protocols. First pass quantitative perfusion was performed with gadoteridol (0.075 mmol/kg). RESULTS: Implementation and quantitative perfusion results are shown for healthy subjects and subjects with known coronary disease. Average rest perfusion for the 15 included healthy subjects was 0.79 ± 0.19 mL/g/min, the average stress perfusion for 6 healthy subject studies was 2.44 ± 0.61 mL/g/min, and the average global myocardial perfusion reserve ratio for 6 healthy subjects was 3.10 ± 0.24. Perfusion deficits for 3 patients with ischemia are shown. Average resting heart rate was 59 ± 7 bpm and the average stress heart rate was 81 ± 10 bpm. CONCLUSION: This work demonstrates that a quantitative 3D myocardial perfusion sequence with the acquisition of a 2D arterial input function is feasible at high stress heart rates such as during stress. T1 values and gadolinium concentrations of the sequence match the reference standard well in a phantom, and myocardial rest and stress perfusion and myocardial perfusion reserve values are consistent with those published in literature.

Left atrial fibrosis progression detected by LGE-MRI after ablation of atrial fibrillation.

BACKGROUND: Left atrial (LA) fibrosis is thought to be a substrate for atrial fibrillation (AF) and can be quantified by late gadolinium enhancement magnetic resonance imaging (LGE-MRI). Fibrosis formation in LA is a dynamic process and may either progress or regress following AF ablation. We examined the impact of postablation progression in LA fibrosis on AF recurrence. METHODS: LA enhancement in LGE-MRI was quantified in 127 consecutive patients who underwent first time AF ablation. Serial LGE-MRIs were done prior to AF ablation, 3 months postablation and at least 12 months after second LGE-MRI. Transient postablation lesion (TL) was defined as atrial enhancement caused by ablation lesions that was detected on the first (3 month) but not on the second postablation LGE-MRI. New fibrosis (NF) was defined as atrial enhancement detected on the most recent LGE-MRI, at least 15 months after the ablation procedure. AF recurrence and its correlation with TL and NF was assessed in all patients during the follow-up period. RESULTS: An increase of 1% NF increased the chance of postablation AF recurrence by 3% (hazard ratio [HR] 1.03, 95% CI 1-1.06, P = .05). TL had no significant impact on recurrence (P = .057). After adjusting for cardiovascular risk factors, HR increased as NF became greater. Greater volume of NF (≥21%) corresponded with lower arrhythmia-free survival (37% vs 62%, P = .01). CONCLUSION: NF formation postablation of AF is a novel marker of long-term procedural outcome. Extensive NF is associated with significantly higher risk of atrial arrhythmia recurrence.

Modified telehealth for care of chronic wounds during the Coronavirus disease 2019 pandemic: A rapid literature review of alternative care modalities.

Due to the changes in delivering medical care during the Coronavirus disease 2019 (COVID-19) pandemic, such as the heavy reliance on telehealth, it is worth exploring if this is suitable when treating complex wounds. A literature rapid review was performed to explore the existing evidence around alternative service delivery modalities. While there are organisations that have successful telehealth systems and infrastructure, for services that do not already widely use telehealth it is difficult to implement a standardised system in the current state of emergency. The evidence reviewed demonstrates that telehealth appears to currently have a limited place in chronic wound management; therefore, standardisation on determining suitability in conjunction with evaluation of telehealth during this period is needed to shape implementation of telehealth systems in the future.

Atrial fibrosis in non-atrial fibrillation individuals and prediction of atrial fibrillation by use of late gadolinium enhancement magnetic resonance imaging.

INTRODUCTION: Besides the traditional concept of atrial fibrillation (AF) perpetuating atrial structural remodeling, there is increasing evidence that atrial fibrosis might precede AF, highlighting the need for better characterization of the fibrotic substrate. We aimed to assess atrial fibrosis by use of late gadolinium enhancement magnetic resonance imaging (LGE-MRI) in non-AF individuals and to identify predisposing risk factors. A second aim was to establish a risk score for the prevalence of AF using atrial fibrosis in addition to established clinical variables. METHODS AND RESULTS: Non-AF individuals without structural heart disease (n = 91) and matched AF controls (n = 91) underwent MRI for assessment of LGE. According to the established UTAH classification, atrial LGE ≥20% was considered extensive. Mean left atrial (LA) fibrosis in non-AF and AF individuals were 8.8 ± 6.5% and 12.5 ± 5.8%, respectively. Body mass index (BMI) >30 kg/m 2 and LA volume were predictors of atrial fibrosis. Diastolic function was not significantly different with respect to atrial fibrosis. A novel scoring system for the prevalence of AF (2 points for arterial hypertension and/or left ventricular ejection fraction <55%; 3 points for atrial fibrosis >6%) was derived demonstrating that patients in the intermediate/high-risk group had a significantly increased risk of AF. CONCLUSION: This study reports unexpectedly high atrial fibrosis in non-AF patients without apparent heart disease, highlighting the concept that structural fibrotic alterations may precede AF onset in a significant proportion of individuals. BMI as a predictor of atrial fibrosis suggests that lifestyle and drug intervention, that is, weight reduction, could positively influence fibrosis development. The derived risk score for AF prevalence provides the basis for prospective studies on AF incidence.

Left atrial shape predicts recurrence after atrial fibrillation catheter ablation.

INTRODUCTION: Multiple markers left atrium (LA) remodeling, including LA shape, correlate with outcomes in atrial fibrillation (AF). Catheter ablation is an important treatment of AF, but better tools are needed to determine which patients will benefit. In this study, we use particle-based modeling to quantitatively assess LA shape, and determine to what degree it predicts AF recurrence after catheter ablation. METHODS AND RESULTS: There were 254 patients enrolled in the DECAAF study who underwent cardiac magnetic resonance imaging of the LA prior to AF ablation and were followed for recurrence for up to 475 days. We performed particle-based shape modeling on each patient's LA shape. We selected shape parameters using the LASSO method and factor analysis, and then added them to a Cox regression model, which included multiple clinical parameters and LA fibrosis. We computed Harrell's C-statistic with and without shape in the model. We used the model to stratify patients into recurrence risk classes by both shape and shape and fibrosis combined. Three shape parameters were selected for inclusion. The C-statistic increased from 0.68 to 0.72 when shape was added to the model (P < 0.05). Visualized shapes showed that a more round LA shape with a shorter, more laterally rotated appendage was predictive of recurrence. CONCLUSION: LA shape is an independent predictor of recurrence after AF ablation. When combined with LA fibrosis, shape analysis using PBM may improve patient selection for ablation.

Models of lineup memory.

Face recognition memory is often tested by the police using a photo lineup, which consists of one suspect, who is either innocent or guilty, and five or more physically similar fillers, all of whom are known to be innocent. For many years, lineups were investigated in lab studies without guidance from standard models of recognition memory. More recently, signal detection theory has been used to conceptualize lineup memory and to motivate receiver operating characteristic (ROC) analysis of lineup performance. Here, we describe three competing signal-detection models of lineup memory, derive their likelihood functions, and fit them to empirical ROC data. We also introduce the notion that memory signals generated by the faces in a lineup are likely to be correlated because, by design, those faces share features. The models we investigate differ in their predictions about the effect that correlated memory signals should have on the ability to discriminate innocent from guilty suspects. A popular compound signal detection model known as the Integration model predicts that correlated memory signals should impair discriminability. Empirically, this model performed so poorly that, going forward, it should probably be abandoned. The best-fitting model incorporates a principle known as "ensemble coding," which predicts that correlated memory signals should enhance discriminability. The ensemble model aligns with a previously proposed theory of eyewitness identification according to which the simultaneous presentation of faces in a lineup enhances discriminability compared to when faces are presented in isolation because it permits eyewitnesses to detect and discount non-diagnostic facial features.

Interstudy repeatability of self-gated quantitative myocardial perfusion MRI.

PURPOSE: To evaluate the interstudy repeatability of multislice quantitative cardiovascular magnetic resonance myocardial blood flow (MBF), myocardial perfusion reserve (MPR), and extracellular volume (ECV). A unique saturation recovery self-gated acquisition was used for the perfusion scans. MATERIALS AND METHODS: An ungated golden angle radial turboFLASH pulse sequence was used to scan 10 subjects on two separate days on a 3T scanner. A single saturation pulse was followed by a set of four slices. Rest and hyperemia scans were acquired during free breathing. The images were reconstructed using an iterative algorithm with spatiotemporal constraints. The ungated images were retrospectively binned (self-gated) into near-systole and near-diastole. Deformable registration was performed to adjust for respiratory and residual cardiac motion, and the data were fit with a Fermi model to estimate the interstudy repeatability of quantitative self-gated MBF and MPR. RESULTS: The coefficient of variation (CoV) of the territorial MPR using the self-gated near-systole data was 18.6%. The self-gated near-diastole data gave less good CoV of MPR, equal to 46.2%. For MBFs, and using smaller (segmental) regions, the CoVs were 20.1% and 22.7% for the estimation of myocardial blood flow at stress and rest, respectively, using the self-gated near-systole data. The self-gated near-diastole data gave CoV = 48.6% and 44.9% for stress and rest. CONCLUSION: The self-gated free-breathing technique for quantification of myocardial blood flow showed good repeatability for near-systole, with results comparable to published studies on interstudy repeatability of quantitative myocardial perfusion MRI using ECG-gating and breath-holds. Self-gated near-diastole data results were less repeatable. J. Magn. Reson. Imaging 2016;43:1369-1378.

Increased False-Memory Susceptibility After Mindfulness Meditation.

The effect of mindfulness meditation on false-memory susceptibility was examined in three experiments. Because mindfulness meditation encourages judgment-free thoughts and feelings, we predicted that participants in the mindfulness condition would be especially likely to form false memories. In two experiments, participants were randomly assigned to either a mindfulness induction, in which they were instructed to focus attention on their breathing, or a mind-wandering induction, in which they were instructed to think about whatever came to mind. The overall number of words from the Deese-Roediger-McDermott paradigm that were correctly recalled did not differ between conditions. However, participants in the mindfulness condition were significantly more likely to report critical nonstudied items than participants in the control condition. In a third experiment, which tested recognition and used a reality-monitoring paradigm, participants had reduced reality-monitoring accuracy after completing the mindfulness induction. These results demonstrate a potential unintended consequence of mindfulness meditation in which memories become less reliable.

Wideband late gadolinium enhanced magnetic resonance imaging for imaging myocardial scar without image artefacts induced by implantable cardioverter-defibrillator: a feasibility study at 3 T.

AIM: Late gadolinium enhanced (LGE) magnetic resonance imaging (MRI) is a useful tool for facilitating ventricular tachycardia (VT) ablation. Unfortunately, most VT ablation candidates often have prophylactic implantable cardioverter-defibrillator (ICD) and do not undergo cardiac MRI largely due to image artefacts generated by ICD. A prior study has reported success of 'wideband' LGE MRI for imaging myocardial scar without image artefacts induced by ICD at 1.5T. The purpose of this study was to widen the availability of wideband LGE MRI to 3T, since it has the potential to achieve higher spatial resolution than 1.5T. METHODS AND RESULTS: We compared the performance of standard and wideband LGE MRI pulse sequences in phantoms and canines with myocardial lesions created by radiofrequency ablation. Standard LGE MRI produced image artefacts induced by ICD and 49% accuracy in detecting 97 myocardial scars examined in this study, whereas wideband LGE MRI produced artefact-free images and 94% accuracy in detecting scars. The mean image quality score (1 = nondiagnostic, 2 = poor, 3 = adequate, 4 = good, 5 = excellent) was significantly (P < 0.001) higher for wideband (3.7 ± 0.8) than for standard LGE MRI (2.1 ± 0.7). The mean artefact level score (1 = minimal, 2 = mild, 3 = moderate, 4 = severe, 5 = nondiagnostic) was significantly (P < 0.001) lower for wideband (2.1 ± 0.8) than for standard LGE MRI (4.0 ± 0.6). Wideband LGE MRI agreed better with gross pathology than standard LGE MRI. CONCLUSION: This study demonstrates the feasibility of wideband LGE MRI for suppression of image artefacts induced by ICD at 3T.

Evaluation of highly accelerated real-time cardiac cine MRI in tachycardia.

Electrocardiogram (ECG)-gated breath-hold cine MRI is considered to be the gold standard test for the assessment of cardiac function. However, it may fail in patients with arrhythmia, impaired breath-hold capacity and poor ECG gating. Although ungated real-time cine MRI may mitigate these problems, commercially available real-time cine MRI pulse sequences using parallel imaging typically yield relatively poor spatiotemporal resolution because of their low image acquisition efficiency. As an extension of our previous work, the purpose of this study was to evaluate the diagnostic quality and accuracy of eight-fold-accelerated real-time cine MRI with compressed sensing (CS) for the quantification of cardiac function in tachycardia, where it is challenging for real-time cine MRI to provide sufficient spatiotemporal resolution. We evaluated the performances of eight-fold-accelerated cine MRI with CS, three-fold-accelerated real-time cine MRI with temporal generalized autocalibrating partially parallel acquisitions (TGRAPPA) and ECG-gated breath-hold cine MRI in 21 large animals with tachycardia (mean heart rate, 104 beats per minute) at 3T. For each cine MRI method, two expert readers evaluated the diagnostic quality in four categories (image quality, temporal fidelity of wall motion, artifacts and apparent noise) using a Likert scale (1-5, worst to best). One reader evaluated the left ventricular functional parameters. The diagnostic quality scores were significantly different between the three cine pulse sequences, except for the artifact level between CS and TGRAPPA real-time cine MRI. Both ECG-gated breath-hold cine MRI and eight-fold accelerated real-time cine MRI yielded all four scores of ≥ 3.0 (acceptable), whereas three-fold-accelerated real-time cine MRI yielded all scores below 3.0, except for artifact (3.0). The left ventricular ejection fraction (LVEF) measurements agreed better between ECG-gated cine MRI and eight-fold-accelerated real-time cine MRI (mean difference, -1.6%) than between ECG-gated cine MRI and three-fold-accelerated real-time cine MRI (mean difference, -5.7%). Eight-fold-accelerated real-time cine MRI with CS yields acceptable diagnostic quality and relatively accurate LVEF measurements in the challenging setting of tachycardia.

Association of atrial fibrosis quantified using LGE-MRI with atrial appendage thrombus and spontaneous contrast on transesophageal echocardiography in patients with atrial fibrillation.

INTRODUCTION: Transesophageal echocardiography (TEE) is used to evaluate for left atrial appendage (LAA) thrombi prior to restoration of sinus rhythm in atrial fibrillation (AF). We examined the relationship of atrial fibrosis quantified using late gadolinium enhancement MRI (LGE-MRI) with TEE findings. METHODS AND RESULTS: We included 178 patients with AF, undergoing TEE and LGE-MRI prior to ablation or cardioversion. LGE-MRI and subsequent image processing was used to quantify atrial fibrosis based on signal intensity analysis. The mean CHADS2 score was 1.24 ± 1.08 and CHA2 DS2 -VASc was 2.08 ± 1.33. The LAA was classified as normal, spontaneous echocardiographic contrast (SEC) present or thrombus present. LAA thrombus was found in 12 patients (6.7%) while SEC was identified in 19 patients (10.7%). Patients with thrombus had higher atrial fibrosis compared to patients without thrombus (26.9 ± 17.4% vs 16.7 ± 10.5%; P < 0.01). Atrial fibrosis was also higher in patients with SEC (23.3 ± 13.7%) compared to those without SEC (16.7 ± 10.8%; P = 0.01). Patients with high atrial fibrosis (>20%) were more likely to have a LAA thrombus (odds ratio 4.6; P = 0.02) and SEC (odds ratio 2.6; P = 0.06). Multivariate logistic regression showed high fibrosis (odds ratio 3.6; P < 0.01) and CHADS2 ≥2 (odds ratio 3.5; P < 0.01) were significant predictors of TEE abnormalities (LAA thrombus or SEC). The area under the curve for the model including high fibrosis, AF type and CHADS2 ≥2 or CHA2 DS2 -VASc ≥2 was 0.73 compared to 0.63 and 0.65 for CHADS2 and CHA2 DS2 -VASc alone. CONCLUSIONS: Atrial fibrosis is independently associated with appendage thrombus and spontaneous contrast. It provides additional risk stratification not captured by clinical parameters.