Ultrahigh-Spatial-Resolution Photon-counting Detector CT Angiography of Coronary Artery Disease for Stenosis Assessment.

Background Coronary CT angiography is a first-line test in coronary artery disease but is limited by severe calcifications. Photon-counting-detector (PCD) CT improves spatial resolution. Purpose To investigate the effect of improved spatial resolution on coronary stenosis assessment and reclassification. Materials and Methods Coronary stenoses were evaluated prospectively in a vessel phantom (in vitro) containing two stenoses (25%, 50%), and retrospectively in patients (in vivo) who underwent ultrahigh-spatial-resolution cardiac PCD CT (from July 2022 to April 2023). Images were reconstructed at standard resolution (section thickness, 0.6 mm; increment, 0.4 mm; Bv44 kernel), high spatial resolution (section thickness, 0.4 mm; increment, 0.2 mm; Bv44 kernel), and ultrahigh spatial resolution (section thickness, 0.2; increment, 0.1 mm; Bv64 kernel). Percentages of diameter stenosis (DS) were compared between reconstructions. In vitro values were compared with the manufacturer specifications of the phantom and patient results were assessed regarding effects on Coronary Artery Disease Reporting and Data System (CAD-RADS) reclassification. Results The in vivo sample included 114 patients (mean age, 68 years ± 9 [SD]; 71 male patients). In vitro percentage DS measurements were more accurate with increasing spatial resolution for both 25% and 50% stenoses (mean bias for standard resolution, high spatial resolution, and ultrahigh spatial resolution, respectively: 10.1%, 8.0%, and 2.3%; P < .001). In vivo results confirmed decreasing median percentage DS with increasing spatial resolution for calcified stenoses (n = 161) (standard resolution, high spatial resolution, and ultrahigh spatial resolution, respectively: 41.5% [IQR, 27.3%-58.2%], 34.8% [IQR, 23.7%-55.1%], and 26.7% [IQR, 18.6%-44.3%]; P < .001), whereas noncalcified (n = 13) and mixed plaques (n = 19) did not show evidence of a difference (P ≥ .88). Ultrahigh-spatial-resolution reconstructions led to reclassification of 62 of 114 (54.4%) patients to lower CAD-RADS category than that assigned using standard resolution. Conclusion In vivo and in vitro coronary stenosis assessment improved for calcified stenoses by using ultrahigh-spatial-resolution PCD CT reconstructions, leading to lower percentage DS compared with standard resolution and clinically relevant rates of reclassification. © RSNA, 2024 Supplemental material is available for this article. See also the editorial by McCollough in this issue.

Early response monitoring during [177Lu]Lu-PSMA I&T therapy with quantitated SPECT/CT predicts overall survival of mCRPC patients: subgroup analysis of a Swiss-wide prospective registry study.

PURPOSE: To assess early tumor response with quantitated SPECT/CT and to correlate it with clinical outcome in metastatic castration-resistant prostate cancer (mCRPC) patients treated with 177Lutetium-PSMA I&T therapy. METHODS: Single-center, observational study, part of the prospective Swiss national cancer registry study investigating the safety and efficacy of [177Lu]Lu-PSMA I&T (EKNZ: 2021-01271) in mCRPC patients treated with at least two cycles of [177Lu]Lu-PSMA I&T 6-weekly. After the first and second cycle quantitated SPECT/CT (Symbia Intevo, Siemens) was acquired 48 h after injection (three fields of view from head to thigh, 5 s/frame) and reconstructed using xQuant® (48i, 1 s, 10-mm Gauss). Image analysis: The PSMA-positive total tumor volumes (TTV) were semi-automatically delineated using a SUV threshold of 3 with MIMencore® (version 7.1.3, Medical Image Merge Software Inc.). Changes in TTV, highest tumor SUVmax, and total tumor SUVmean between cycles 1 and 2 were calculated and grouped into a) stable or decrease and b) increase. Serum PSA levels were assessed at each therapy cycle and at follow-up until progression or death. Changes in TTV, PSA, SUVmax, and SUVmean were correlated with PSA-progression-free survival (PSA-PFS) and the overall survival (OS) using the Kaplan-Meier methodology (log-rank test). RESULTS: Between 07/2020 and 04/2022, 111 patients were screened and 73 finally included in the data analysis. The median follow-up was 8.9 months (range 1.4-26.6 months). Stable or decreased TTV at cycle 2 was associated with longer OS (hazard ratio (HR) 0.28, 95% confidence interval (CI) 0.09-0.86, p < 0.01). Similar, stable, or decreased PSA was associated with longer OS (HR 0.21; CI 0.07-0.62, p < 0.01) and PSA-PFS (HR 0.34; 95% CI 0.16-0.72, p < 0.01). Combining TTV and PSA will result in an augmented prognostic value for OS (HR 0.09; CI 0.01-0.63; p < 0.01) and for PSA-PFS (HR 0.11; CI 0.02-0.68; p < 0.01). A reduction of SUVmax or SUVmean was not prognostically relevant, neither for OS (p 0.88 and 0.7) nor for PSA-PFS (p 0.73 and 0.62, respectively). CONCLUSION: Six weeks after initiating [177Lu]Lu-PSMA I&T, TTV and serum PSA appear to be good prognosticators for OS. Combined together, TTV + PSA change demonstrates augmented prognostic value and can better predict PSA-PFS. Larger studies using TTV change prospectively as an early-response biomarker are warranted for implementing management change towards a more personalized clinical practice.

Generative Pre-trained Transformer 4 analysis of cardiovascular magnetic resonance reports in suspected myocarditis: A multicenter study.

BACKGROUND: Diagnosing myocarditis relies on multimodal data, including cardiovascular magnetic resonance (CMR), clinical symptoms, and blood values. The correct interpretation and integration of CMR findings require radiological expertise and knowledge. We aimed to investigate the performance of Generative Pre-trained Transformer 4 (GPT-4), a large language model, for report-based medical decision-making in the context of cardiac MRI for suspected myocarditis. METHODS: This retrospective study includes CMR reports from 396 patients with suspected myocarditis and eight centers, respectively. CMR reports and patient data including blood values, age, and further clinical information were provided to GPT-4 and radiologists with 1 (resident 1), 2 (resident 2), and 4 years (resident 3) of experience in CMR and knowledge of the 2018 Lake Louise Criteria. The final impression of the report regarding the radiological assessment of whether myocarditis is present or not was not provided. The performance of Generative pre-trained transformer 4 (GPT-4) and the human readers were compared to a consensus reading (two board-certified radiologists with 8 and 10 years of experience in CMR). Sensitivity, specificity, and accuracy were calculated. RESULTS: GPT-4 yielded an accuracy of 83%, sensitivity of 90%, and specificity of 78%, which was comparable to the physician with 1 year of experience (R1: 86%, 90%, 84%, p = 0.14) and lower than that of more experienced physicians (R2: 89%, 86%, 91%, p = 0.007 and R3: 91%, 85%, 96%, p < 0.001). GPT-4 and human readers showed a higher diagnostic performance when results from T1- and T2-mapping sequences were part of the reports, for residents 1 and 3 with statistical significance (p = 0.004 and p = 0.02, respectively). CONCLUSION: GPT-4 yielded good accuracy for diagnosing myocarditis based on CMR reports in a large dataset from multiple centers and therefore holds the potential to serve as a diagnostic decision-supporting tool in this capacity, particularly for less experienced physicians. Further studies are required to explore the full potential and elucidate educational aspects of the integration of large language models in medical decision-making.

Photon-Counting Detector CT Virtual Monoenergetic Images for Coronary Artery Stenosis Quantification: Phantom and In Vivo Evaluation.

BACKGROUND. Calcium blooming causes stenosis overestimation on coronary CTA. OBJECTIVE. The purpose of this article was to evaluate the impact of virtual monoenergetic imaging (VMI) reconstruction level on coronary artery stenosis quantification using photon-counting detector (PCD) CT. METHODS. A phantom containing two custom-made vessels (representing 25% and 50% stenosis) underwent PCD CT acquisitions without and with simulated cardiac motion. A retrospective analysis was performed of 33 patients (seven women, 26 men; mean age, 71.3 ± 9.0 [SD] years; 64 coronary artery stenoses) who underwent coronary CTA by PCD CT followed by invasive coronary angiography (ICA). Scans were reconstructed at nine VMI energy levels (40-140 keV). Percentage diameter stenosis (PDS) was measured, and bias was determined from the ground-truth stenosis percentage in the phantom and ICA-derived quantitative coronary angiography measurements in patients. Extent of blooming artifact was measured in the phantom and in calcified and mixed plaques in patients. RESULTS. In the phantom, PDS decreased for 25% stenosis from 59.9% (40 keV) to 13.4% (140 keV) and for 50% stenosis from 81.6% (40 keV) to 42.3% (140 keV). PDS showed lowest bias for 25% stenosis at 90 keV (bias, 1.4%) and for 50% stenosis at 100 keV (bias, -0.4%). Blooming artifacts decreased for 25% stenosis from 61.5% (40 keV) to 35.4% (140 keV) and for 50% stenosis from 82.7% (40 keV) to 52.1% (140 keV). In patients, PDS for calcified plaque decreased from 70.8% (40 keV) to 57.3% (140 keV), for mixed plaque decreased from 69.8% (40 keV) to 56.3% (140 keV), and for noncalcified plaque was 46.6% at 40 keV and 54.6% at 140 keV. PDS showed lowest bias for calcified plaque at 100 keV (bias, 17.2%), for mixed plaque at 140 keV (bias, 5.0%), and for noncalcified plaque at 40 keV (bias, -0.5%). Blooming artifacts decreased for calcified plaque from 78.4% (40 keV) to 48.6% (140 keV) and for mixed plaque from 73.1% (40 keV) to 44.7% (140 keV). CONCLUSION. For calcified and mixed plaque, stenosis severity measurements and blooming artifacts decreased at increasing VMI reconstruction levels. CLINICAL IMPACT. PCD CT with VMI reconstruction helps overcome current limitations in stenosis quantification on coronary CTA.

Supplementary value and diagnostic performance of computed tomography scout view in the detection of thoracolumbar spine injuries.

PURPOSE: Assessing the diagnostic performance and supplementary value of whole-body computed tomography scout view (SV) images in the detection of thoracolumbar spine injuries in early resuscitation phase and identifying frequent image quality confounders. METHODS: In this retrospective database analysis at a tertiary emergency center, three blinded senior experts independently assessed SV to detect thoracolumbar spine injuries. The findings were categorized according to the AO Spine classification system. Confounders impacting SV image quality were identified. The suspected injury level and severity, along with the confidence level, were indicated. Diagnostic performance was estimated using the caret package in R programming language. RESULTS: We assessed images of 199 patients, encompassing 1592 vertebrae (T10-L5), and identified 56 spinal injuries (3.5%). Among the 199 cases, 39 (19.6%) exhibited at least one injury in the thoracolumbar spine, with 12 (6.0%) of them displaying multiple spinal injuries. The pooled sensitivity, specificity, and accuracy were 47%, 99%, and 97%, respectively. All experts correctly identified the most severe injury of AO type C. The most common image confounders were medical equipment (44.6%), hand position (37.6%), and bowel gas (37.5%). CONCLUSION: SV examination holds potential as a valuable supplementary tool for thoracolumbar spinal injury detection when CT reconstructions are not yet available. Our data show high specificity and accuracy but moderate sensitivity. While not sufficient for standalone screening, reviewing SV images expedites spinal screening in mass casualty incidents. Addressing modifiable factors like medical equipment or hand positioning can enhance SV image quality and assessment.

Halide-Coupled Double Electron Transfer with Electron-Rich Diboranes.

The ditriflato-diborane B2 (µ-hpp)2 (OTf)2 (hpp=1,3,4,6,7,8-hexahydro-2H-pyrimido[1,2-a]pyrimidinate) acts as a stable surrogate of the elusive dication [B2 (hpp)2 ]2+ , being both electrophilic (vacant boron p orbitals) and nucleophilic (filled B-B bond orbital). This combination of seemingly contrasting behaviors could be used to develop a metallomimetic diborane chemistry, with Lewis σ-basic and π-acidic substrates being bound and reduced at the diborane. Here, we report on a novel reaction type within this general theme, in which double electron transfer from the diboron unit to the boron-bound organic substrate is coupled with halide transfer in the other direction. Novel diborylated dienamines are synthesized in this way. The scope of this unprecedented reaction motif and the reaction pathways are elucidated.

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.

Cardiac MRI-based right-to-left ventricular blood pool T2 relaxation times ratio correlates with exercise capacity in patients with chronic heart failure.

BACKGROUND: MRI T2 mapping has been proven to be sensitive to the level of blood oxygenation. We hypothesized that impaired exercise capacity in chronic heart failure is associated with a greater difference between right (RV) to left ventricular (LV) blood pool T2 relaxation times due to a higher level of peripheral blood desaturation, compared to patients with preserved exercise capacity and to healthy controls. METHODS: Patients with chronic heart failure (n = 70) who had undergone both cardiac MRI (CMR) and a 6-min walk test (6MWT) were retrospectively identified. Propensity score matched healthy individuals (n = 35) served as control group. CMR analyses included cine acquisitions and T2 mapping to obtain blood pool T2 relaxation times of the RV and LV. Following common practice, age- and gender-adjusted nominal distances and respective percentiles were calculated for the 6MWT. The relationship between the RV/LV T2 blood pool ratio and the results from 6MWT were evaluated by Spearman's correlation coefficients and regression analyses. Inter-group differences were assessed by independent t-tests and univariate analysis of variance. RESULTS: The RV/LV T2 ratio moderately correlated with the percentiles of nominal distances in the 6MWT (r = 0.66) while ejection fraction, end-diastolic and end-systolic volumes showed no correlation (r = 0.09, 0.07 and - 0.01, respectively). In addition, there were significant differences in the RV/LV T2 ratio between patients with and without significant post-exercise dyspnea (p = 0.001). Regression analyses showed that RV/LV T2 ratio was an independent predictor of the distance walked and the presence of post-exercise dyspnea (p < 0.001). CONCLUSION: The proposed RV/LV T2 ratio, obtained by two simple measurements on a routinely acquired four-chamber T2 map, was superior to established parameters of cardiac function to predict exercise capacity and the presence of post-exercise dyspnea in patients with chronic heart failure.

Convolutional neural network-based kidney volume estimation from low-dose unenhanced computed tomography scans.

PURPOSE: Kidney volume is important in the management of renal diseases. Unfortunately, the currently available, semi-automated kidney volume determination is time-consuming and prone to errors. Recent advances in its automation are promising but mostly require contrast-enhanced computed tomography (CT) scans. This study aimed at establishing an automated estimation of kidney volume in non-contrast, low-dose CT scans of patients with suspected urolithiasis. METHODS: The kidney segmentation process was automated with 2D Convolutional Neural Network (CNN) models trained on manually segmented 2D transverse images extracted from low-dose, unenhanced CT scans of 210 patients. The models' segmentation accuracy was assessed using Dice Similarity Coefficient (DSC), for the overlap with manually-generated masks on a set of images not used in the training. Next, the models were applied to 22 previously unseen cases to segment kidney regions. The volume of each kidney was calculated from the product of voxel number and their volume in each segmented mask. Kidney volume results were then validated against results semi-automatically obtained by radiologists. RESULTS: The CNN-enabled kidney volume estimation took a mean of 32 s for both kidneys in a CT scan with an average of 1026 slices. The DSC was 0.91 and 0.86 and for left and right kidneys, respectively. Inter-rater variability had consistencies of ICC = 0.89 (right), 0.92 (left), and absolute agreements of ICC = 0.89 (right), 0.93 (left) between the CNN-enabled and semi-automated volume estimations. CONCLUSION: In our work, we demonstrated that CNN-enabled kidney volume estimation is feasible and highly reproducible in low-dose, non-enhanced CT scans. Automatic segmentation can thereby quantitatively enhance radiological reports.

Anterior thoracolumbar column reconstruction with the vertebral body stent-safety and efficacy.

PURPOSE: The aim of this study was to assess safety and efficacy of vertebral body stenting (VBS) by analyzing (1) radiographic outcome, (2) clinical outcome, and (3) perioperative complications in patients with vertebral compression fractures treated with VBS at minimum 6-month follow-up. METHODS: In this retrospective cohort study, 78 patients (61 ± 14 [21-90] years; 67% female) who have received a vertebral body stent due to a traumatic, osteoporotic or metastatic thoracolumbar compression fracture at our hospital between 2012 and 2020 were included. Median follow-up was 0.9 years with a minimum follow-up of 6 months. Radiographic and clinical outcome was analyzed directly, 6 weeks, 12 weeks, 6 months postoperatively, and at last follow-up. RESULTS: Anterior vertebral body height of all patients improved significantly by mean 6.2 ± 4.8 mm directly postoperatively (p < 0.0001) and remained at 4.3 ± 5.1 mm at last follow-up compared to preoperatively (p < 0.0001). The fracture kyphosis angle of all patients improved significantly by mean 5.8 ± 6.9 degrees directly postoperatively (p < 0.0001) and remained at mean 4.9 ± 6.9 degrees at last follow-up compared to preoperatively (p < 0.0001). The segmental kyphosis angle of all patients improved significantly by mean 7.1 ± 7.6 degrees directly postoperatively (p < 0.0001) and remained at mean 2.8 ± 7.8 degrees at last follow-up compared to preoperatively (p = 0.03). Back pain was ameliorated from a preoperative median Numeric Rating Scale value of 6.5 to 3.0 directly postoperatively and further bettered to 1.0 six months postoperatively (p = 0.0001). Revision surgery was required in one patient after 0.4 years. CONCLUSION: Vertebral body stenting is a safe and effective treatment option for osteoporotic, traumatic and metastatic compression fractures.

Multimodal assessment of autonomic dysfunction in amyotrophic lateral sclerosis.

BACKGROUND AND PURPOSE: Amyotrophic lateral sclerosis (ALS) is a neurodegenerative disorder with predominant progressive degeneration of motor neurons and motor deficits, but non-motor symptoms (NMS) such as cognitive and behavioural deficits are frequent and underestimated in current diagnostic pathways. Autonomic dysfunction has occasionally been described, although its frequency and relevance are unclear. The aim of this study was to investigate the role of the autonomic nervous system in ALS using a multimodal approach. METHODS: Thirty-seven ALS patients and 40 healthy sex- and age-matched controls were included. NMS were studied with the NMS assessment scale for Parkinson's disease and an autonomic subscale was calculated. Cardioautonomic innervation at rest and whilst standing was assessed by different parameters of heart rate variability. Morphological changes (cross-sectional area) of the vagus and median nerves for control were measured with high-resolution ultrasound. RESULTS: Non-motor symptoms in general were more frequent in ALS patients and correlated inversely with the ALS Functional Rating Scale whereas the autonomic subscore of the NMS assessment scale for Parkinson's disease did not differ between the two groups and was not related to functional impairment. Cardioautonomic assessment solely revealed an increased heart rate at rest in ALS patients, whereas the other heart rate variability parameters did not differ from controls. Structural sonographic investigation of the vagus and median nerves was similar in both groups. CONCLUSIONS: Using a multimodal approach evidence was found for a rather mild cardio-sympathetic overactivity in ALS patients. Overall, autonomic dysfunction seems to be subtle and is not related to the functional state of ALS patients.

Surgical treatment of severe tricuspid regurgitation.

PURPOSE OF REVIEW: Severe tricuspid regurgitation is associated with both significant symptoms as well as decreased survival. Surgical correction is possible in most cases but is markedly under used in this population. The purpose of this manuscript is to review the indications for treating severe tricuspid regurgitation and the surgical options available. RECENT FINDINGS: Surgical correction of isolated severe tricuspid regurgitation has been associated with a high mortality in the surgical literature. This occurs generally from right heart failure associated with the late referral of isolated tricuspid regurgitation for correction. Recent outcomes are improving and tricuspid repair appears to be where mitral valve repair was 30 years ago. SUMMARY: Severe tricuspid regurgitation is associated with severe symptoms as well as decreased survival. Tricuspid valve repair (TVr) for severe regurgitation is almost always technically possible. The high mortality thought to be associated with isolated TVr is likely due to late referral when right heart failure is already far advanced. Consideration for earlier referral for isolated severe tricuspid regurgitation should be considered.

Transcatheter treatment of severe tricuspid regurgitation.

PURPOSE OF REVIEW: Severe tricuspid regurgitation is a commonly prevalent valvular heart disease that is an independent adverse prognostic marker. However, the majority of patients with tricuspid regurgitation are managed medically; isolated tricuspid valve surgery is rarely performed, partly owing to high associated in-hospital mortality. Therefore, several transcatheter tricuspid valve interventions (TTVIs) that have been developed over the last few years to address this unmet clinical need. RECENT FINDINGS: The early experience with TTVI has shown that most devices can be safely implanted with excellent rates of technical success and acceptable safety outcomes. Most TTVI recipients have significant improvement in tricuspid regurgitation severity, functional class, and quality of life. Recent retrospective data also suggest mortality benefit of TTVI compared with medical management. There are several issues that need to be addressed prior to widespread adoption of TTVI, including more effective tricuspid regurgitation reduction and need for longer term efficacy data. SUMMARY: TTVI has emerged as an attractive treatment option for management of high-risk patients with tricuspid regurgitation. In this review, we will discuss the anatomical considerations specific to tricuspid valve, patient selection, preprocedure planning, and summarize the current evidence and future perspectives on TTVI.

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.

"How to measure the outcome in the surgical treatment of vertebral compression fractures? A systematic literature review of highly cited level-I studies".

BACKGROUND: The economic burden of vertebral compression fractures (VCF) caused by osteoporosis was estimated at 37 billion euros in the European Union in 2010. In addition, the incidence is expected to increase by 25% in 2025. The recommendations for the therapy of VCFs (conservative treatment versus cement augmentation procedures) are controversial, what could be partly explained by the lack of standardized outcomes for measuring the success of both treatments. Consensus on outcome parameters may improve the relevance of a study and for further comparisons in meta-analyses. The aim of this study was to analyze outcome measures from frequently cited randomized controlled trials (RCTs) about VCF treatments in order to provide guidance for future studies. MATERIAL AND METHODS: We carried out a systematic search of all implemented databases from 1973 to 2019 using the Web of Science database. The terms "spine" and "random" were used for the search. We included: Level I RCTs, conservative treatment or cement augmentation of osteoporotic vertebral fractures, cited ≥50 times. The outcome parameters of each study were extracted and sorted according to the frequency of use. RESULTS: Nine studies met the inclusion criteria. In total, 23 different outcome parameters were used in the nine analyzed studies. Overall, the five most frequently used outcome parameters (≥ 4 times used) were the visual analogue scale (VAS) for pain (n = 9), European Quality of Life-5 Dimensions (EQ-5D; n = 4) and Roland-Morris Disability Questionnaire (RMDQ, n = 4). CONCLUSION: With our study, we demonstrated that a large inconsistency exists between outcome measures in highly cited Level I studies of VCF treatment. Pain (VAS), followed by HrQoL (EQ-5D) and disability and function (RMDQ), opioid use, and radiological outcome (kyphotic angle, VBH, and new VCFs) were the most commonly used outcome parameters.

Improving the prediction of long-term readmission and mortality using a novel biomarker panel.

OBJECTIVE: Several short-term readmission and mortality prediction models have been developed using clinical risk factors or biomarkers among patients undergoing coronary artery bypass graft (CABG) surgery. The use of biomarkers for long-term prediction of readmission and mortality is less well understood. Given the established association of cardiac biomarkers with short-term adverse outcomes, we hypothesized that 5-year prediction of readmission or mortality may be significantly improved using cardiac biomarkers. MATERIALS AND METHODS: Plasma biomarkers from 1149 patients discharged alive after isolated CABG surgery from eight medical centers were measured in a cohort from the Northern New England Cardiovascular Disease Study Group between 2004 and 2007. We assessed the added predictive value of a biomarker panel with a clinical model against the clinical model alone and compared the model discrimination using the area under the receiver operating characteristic (AUROC) curves. RESULTS: In our cohort, 461 (40%) patients were readmitted or died within 5 years. Long-term outcomes were predicted by applying the STS ASCERT clinical model with an AUROC of 0.69. The biomarker panel with the clinical model resulted in a significantly improved AUROC of 0.74 (p value <.0001). Across 5 years, the hazard ratio for patients in the second to fifth quintile predicted probabilities from the biomarker augmented STS ASCERT model ranged from 2.2 to 7.9 (p values <.001). CONCLUSIONS: We report that a panel of biomarkers significantly improved prediction of long-term readmission or mortality risk following CABG surgery. Our findings suggest biomarkers help clinical care teams better assess the long-term risk of readmission or mortality.

Can texture analysis in ultrashort echo-time MRI distinguish primary graft dysfunction from acute rejection in lung transplants? A multidimensional assessment in a mouse model.

BACKGROUND: Differentiation of early postoperative complications affects treatment options after lung transplantation. PURPOSE: To assess if texture analysis in ultrashort echo-time (UTE) MRI allows distinction of primary graft dysfunction (PGD) from acute transplant rejection (ATR) in a mouse lung transplant model. STUDY TYPE: Longitudinal. ANIMAL MODEL: Single left lung transplantation was performed in two cohorts of six mice (strain C57BL/6) receiving six syngeneic (strain C57BL/6) and six allogeneic lung transplants (strain BALB/c (H-2Kd )). FIELD STRENGTH/SEQUENCE: 4.7T small-animal MRI/eight different UTE sequences (echo times: 50-5000 µs) at three different postoperative timepoints (1, 3, and 7 days after transplantation). ASSESSMENT: Nineteen different first- and higher-order texture features were computed on multiple axial slices for each combination of UTE and timepoint (24 setups) in each mouse. Texture features were compared for transplanted (graft) and contralateral native lungs between and within syngeneic and allogeneic cohorts. Histopathology served as a reference. STATISTICAL TESTS: Nonparametric tests and correlation matrix analysis were used. RESULTS: Pathology revealed PGD in the syngeneic and ATR in the allogeneic cohort. Skewness and low-gray-level run-length features were significantly different between PGD and ATR for all investigated setups (P < 0.03). These features were significantly different between graft and native lung in ATR for most setups (minimum of 20/24 setups; all P < 0.05). The number of significantly different features between PGD and ATR increased with elapsing postoperative time. Differences in significant features were highest for an echo-time of 1500 µs. DATA CONCLUSION: Our findings suggest that texture analysis in UTE-MRI might be a tool for the differentiation of PGD and ATR in the early postoperative phase after lung transplantation. LEVEL OF EVIDENCE: 1 Technical Efficacy: Stage 3 J. Magn. Reson. Imaging 2020;51:108-116.

[Imaging of the peripheral nervous system]. / Bildgebung des peripheren Nervensystems.

Imaging of the peripheral nervous system Abstract. With the technical advances in imaging achieved in recent years, the significance of radiology in everyday clinical practice has become definitely increased. This also applies to the diagnosis and evaluation of neuropathies. Highly sensitive electrophysiology is increasingly complemented by specific imaging. Therapy-relevant information from imaging includes the localization and cause, but also the distribution pattern of a neuropathy. Neurography helps to increase diagnostic certainty and is an important part in management of patients with neuropathy. In this article we would like to present the possibilities and the value of different imaging modalities including ultrasound (US), computed tomography (CT) and magnetic resonance imaging (MRI).

Childhood Lensectomy Is Associated with Static and Dynamic Reduction in Schlemm Canal Size: A Biomechanical Hypothesis of Glaucoma after Lensectomy.

PURPOSE: To compare Schlemm canal (SC) and trabecular meshwork (TM) in children with healthy eyes and those with and without glaucoma after lensectomy. DESIGN: Cross-sectional observational study. PARTICIPANTS: Fifty children 4 to 16 years of age with healthy eyes and 48 children who underwent lensectomy (124 healthy and 72 postlensectomy eyes). METHODS: Anterior segment (AS) OCT (Tomey SS-1000 CASIA; Tomey, Nagoya, Japan) of the nasal iridocorneal angle at 2 levels of accommodative effort (2.5 diopters [D] and 15 D). For each parameter and state of accommodation, a random effects model was fitted to estimate differences between healthy eyes and eyes with history of lensectomy. MAIN OUTCOME MEASURES: Dimensions of SC and TM and conventional AS OCT iridocorneal angle measurements. RESULTS: The horizontal diameter of SC and its cross-sectional area (CSA) are significantly smaller in eyes that have undergone lensectomy versus healthy eyes. Accommodative effort increases SC size in healthy eyes, but not in eyes that have undergone lensectomy. CONCLUSIONS: Lensectomy is associated with a reduction in SC size and a loss of physiologic SC dilatation during accommodative effort, which may reflect a reduction in outflow facility and may contribute to the development of glaucoma after lensectomy.

Diffusion tensor imaging of the abdominal organs: Influence of oriented intravoxel flow compartments.

Water flow in partially oriented intravoxel compartments mimics an anisotropic fast-diffusion regime, which contributes to the signal attenuation in diffusion-weighted images. In the abdominal organs, this flow may reflect physiological fluid movements (eg, tubular urine flow in kidneys, or bile flow through the liver) and have a clinical relevance. This study investigated the influence of anisotropic intravoxel water flow on diffusion tensor imaging (DTI) of the abdominal organs. Diffusion-weighted images were acquired in five healthy volunteers using an EPI sequence with diffusion preparation (TR/TE: 1000 ms/71 ms; b-values: 0, 10, 20, 40, 70, 120, 250, 450, 700, 1000 s/mm2 ; 12 noncollinear diffusion-encoding directions). DTI of liver and kidneys was performed assuming (i) monoexponential decay of the diffusion-weighted signal, and (ii) accounting for potential anisotropy of the fast-diffusion compartments using a tensorial generalization of the IVIM model. Additionally, potential dependency of the metrics of the tensors from the anatomical location was evaluated. Significant differences in the metrics of the diffusion tensor (DT) were found in both liver and kidneys when comparing the two models. In both organs, the trace and the fractional anisotropy of the DT were significantly higher in the monoexponential model than when accounting for perfusion. The comparison of areas of the liver proximal to the hilum with distal regions and of renal cortex with the medulla also proved a location dependency of the size of the fast-diffusion compartments. Pseudo-diffusion correction in DTI enables the assessment of the solid parenchyma regardless of the organ perfusion or other pseudo-diffusive fluid movements. This may have a clinical relevance in the assessment of parenchymal pathologies (eg, liver fibrosis). The fast pseudo-diffusion components present a detectable anisotropy, which may reflect the hepatic microcirculation or other sources of mesoscopic fluid movement in the abdominal organs.