BackgroundCongenital Bicuspid Aortic Valve (BAV) is a significant risk factor for serious complications including valve dysfunction, aortic dilatation, dissection, and sudden death. Clinical tools for identification and monitoring of BAV patients at high risk for development of aortic dilatation, an early complication, are not available.MethodsThis paper reports an investigation in 18 pediatric BAV patients and 10 normal controls of links between abnormal blood flow patterns in the ascending aorta and aortic dilatation using velocity-encoded cardiovascular magnetic resonance. Blood flow patterns were quantitatively expressed in the angle between systolic left ventricular outflow and the aortic root channel axis, and also correlated with known biochemical markers of vessel wall disease.ResultsThe data confirm larger ascending aortas in BAV patients than in controls, and show more angled LV outflow in BAV (17.54 ± 0.87 degrees) than controls (10.01 ± 1.29) (p = 0.01). Significant correlation of systolic LV outflow jet angles with dilatation was found at different levels of the aorta in BAV patients STJ: r = 0.386 (N = 18, p = 0.048), AAO: r = 0.536 (N = 18, p = 0.022), and stronger correlation was found with patients and controls combined into one population: SOV: r = 0.405 (N = 28, p = 0.033), STJ: r = 0.562 (N = 28, p = 0.002), and AAO r = 0.645 (N = 28, p < 0.001). Dilatation and the flow jet angle were also found to correlate with plasma levels of matrix metallo-proteinase 2.ConclusionsThe results of this study provide new insights into the pathophysiological processes underlying aortic dilatation in BAV patients. These results show a possible path towards the development of clinical risk stratification protocols in order to reduce morbidity and mortality for this common congenital heart defect.

Surgical tool detection is attracting increasing attention from the medical image analysis community. The goal generally is not to precisely locate tools in images, but rather to indicate which tools are being used by the surgeon at each instant. The main motivation for annotating tool usage is to design efficient solutions for surgical workflow analysis, with potential applications in report generation, surgical training and even real-time decision support. Most existing tool annotation algorithms focus on laparoscopic surgeries. However, with 19 million interventions per year, the most common surgical procedure in the world is cataract surgery. The CATARACTS challenge was organized in 2017 to evaluate tool annotation algorithms in the specific context of cataract surgery. It relies on more than nine hours of videos, from 50 cataract surgeries, in which the presence of 21 surgical tools was manually annotated by two experts. With 14 participating teams, this challenge can be considered a success. As might be expected, the submitted solutions are based on deep learning. This paper thoroughly evaluates these solutions: in particular, the quality of their annotations are compared to that of human interpretations. Next, lessons learnt from the differential analysis of these solutions are discussed. We expect that they will guide the design of efficient surgery monitoring tools in the near future.

Purpose:To implement and evaluate a novel single-volume two-dimensional localized constant-time-based correlated spectroscopy (2D LCT-COSY) sequence on a clinical 3T MR scanner. This sequence exhibits homonuclear decoupling along the F1 dimension, leading to improved spectral resolution compared to that of non-constant-time localized correlated spectroscopy (L-COSY). Materials and Methods:A GE 3T MR scanner equipped with a quadrature transmit and receive extremity coil was used in this study. The 2D LCT-COSY sequence was programmed using General Electric's EPIC compiler. Simulations for a two-spin 1/2 system were performed using GAMMA libraries to evaluate the theoretical performance of the sequences, and were also compared with corresponding phantom experiments using trans-cinnamic acid. Finally, spectra were acquired from the soleus muscle of healthy volunteers in order to evaluate performance in vivo.Results: Simulations and experimental results confirmed the improved spectral resolution of LCT-COSY over L-COSY, as well as its homonuclear decoupling performance. The behavior of resonance amplitudes as a function of evolution time in the experiment also was appropriately reflected by the simulation. Corresponding results were obtained for the in vivo muscle spectra, in which separation of overlapping olefinic and allylic methylene protons from the intra-and extramyocellular lipids (IMCL and EMCL, respectively) was achieved. Conclusion:Simulations and experimental results in vitro and in vivo demonstrate the strengths of LCT-COSY. This technique can be implemented on systems of any field strength, and has the potential to separate overlapping metabolites in tissue when employed on high-field clinical MRI scanners equipped for proton spectroscopy. LOCALIZED MAGNETIC RESONANCE SPECTROS-COPY (MRS) enables the detection and quantification of metabolites within a selected volume in vivo (1-4). The challenges of in vivo proton ( 1 H) MRS include low sensitivity and significant overlap of resonance lines due to a relatively narrow chemical-shift range and significant inhomogeneous broadening at typical clinical field strengths. This limitation on accurate resonance quantification has resulted in a significant interest in developing MRS methodology to improve spectral resolution.One approach to this is the implementation of twodimensional (2D) spectroscopy. The main advantages of 2D over one-dimensional (1D) MRS are that connectivity between distinct individual spins is delineated, and J-coupled multiplet resonance peaks are spread over two spectral dimensions. This leads to a substantial improvement in peak separation, and more definite identification of the resonances corresponding to each individual metabolite. In particular, 2D localized correlated spectroscopy (2D L-COSY) was recently implemented and shown to result in a significant improvement in spectral resolution over that offered by localized 1D MRS (5,6). Longer experimental times are intrinsic to 2D approaches, since a sequence of evolution times, each requ...

OBJECTIVE The objective of our study was to evaluate whether facial and chest photographs obtained simultaneously with radiographs increase radiologists’ detection rate of labeling errors. MATERIALS AND METHODS We obtained simultaneous portable radiographs and photographs of 34 patients. We generated 88 pairs of chest radiographs (one recent radiograph, one prior radiograph) and compiled a set of 20 pairs for reader review. Two, three, or four mismatched pairs (i.e., pairs containing radiographs of different patients) were introduced into each list. Ten radiologist readers blinded to the presence of mismatches interpreted the 20 radiograph pairs. Readers then reviewed a second set of 20 pairs containing mismatches but photographs of the patients obtained at the time of imaging were attached to the radiographs. Readers were not instructed regarding the purpose of the photographs. The mismatch detection rate and time for interpretation was recorded for both sessions. The two-tailed Fisher exact test was used to evaluate differences in mismatch detection rates between sessions, with a p value of less than 0.05 being considered significant. RESULTS The error detection rates without (3/24 = 12.5%) and with (16/25 = 64%) photographs significantly differed (p = 0.0003). The average interpretation times without and with photographs were 35.73 and 26.51 minutes, respectively (two-tailed Student t test, p = 0.1165). CONCLUSION The use of photographs increased the detection of errors without a concomitant increase in film interpretation time, which may translate into improvements in patient safety without an increase in interpretation time.

Objectives To evaluate whether the presence of facial photographs obtained at the point-of-care of portable radiography leads to increased detection of wrong-patient errors. Materials and Methods In this IRB-approved study, 166 radiograph-photograph combinations were obtained from 30 patients. Consecutive radiographs from the same patients resulted in 83 unique pairs (i.e., a new radiograph and prior, comparison radiograph) for interpretation. To simulate wrong-patient errors, mismatched pairs were generated by pairing radiographs from different patients chosen randomly from the sample. Ninety radiologists each interpreted a unique randomly chosen set of 10 radiographic pairs, containing up to 10% mismatches (i.e., error pairs). Radiologists were randomly assigned to interpret radiographs with or without photographs. The number of mismatches identified and interpretation times were recorded. Results Ninety radiologists with 21 ± 10 (mean ± SD) years of experience were recruited to participate in this observer study. With the introduction of photographs, the proportion of errors detected increased from 31% (9/29) to 77% (23/30) (P = 0.006). The odds ratio for detection of error with photographs to detection without photographs was 7.3 (95% CI: 2.29, 23.18). Observer qualifications, training or practice in cardiothoracic radiology did not influence sensitivity for error detection. There is no significant difference in interpretation time for studies without photographs and those with photographs (60 ± 22 seconds vs 61 ± 25 seconds; P=0.77). Conclusion In this observer study, facial photographs obtained simultaneously with portable chest radiographs increased the identification of any wrong-patient errors, without substantial increase in interpretation time. This technique offers a potential means to increase patient safety through correct patient identification.