High tissue contrast image synthesis via multistage attention-GAN: Application to segmenting brain MR scans.

Magnetic resonance imaging (MRI) presents a detailed image of the internal organs via a magnetic field. Given MRI's non-invasive advantage in repeated imaging, the low-contrast MR images in the target area make segmentation of tissue a challenging problem. This study shows the potential advantages of synthetic high tissue contrast (HTC) images through image-to-image translation techniques. Mainly, we use a novel cycle generative adversarial network (Cycle-GAN), which provides a mechanism of attention to increase the contrast within the tissue. The attention block and training on HTC images are beneficial to our model to enhance tissue visibility. We use a multistage architecture to concentrate on a single tissue as a preliminary and filter out the irrelevant context in every stage in order to increase the resolution of HTC images. The multistage architecture reduces the gap between source and target domains and alleviates synthetic images' artefacts. We apply our HTC image synthesising method to two public datasets. In order to validate the effectiveness of these images we use HTC MR images in both end-to-end and two-stage segmentation structures. The experiments on three segmentation baselines on BraTS'18 demonstrate that joining the synthetic HTC images in the multimodal segmentation framework develops the average Dice similarity scores (DSCs) of 0.8%, 0.6%, and 0.5% respectively on the whole tumour (WT), tumour core (TC), and enhancing tumour (ET) while removing one real MRI channels from the segmentation pipeline. Moreover, segmentation of infant brain tissue in T1w MR slices through our framework improves DSCs approximately 1% in cerebrospinal fluid (CSF), grey matter (GM), and white matter (WM) compared to state-of-the-art segmentation techniques. The source code of synthesising HTC images is publicly available.

Prostate MRI technical parameters standardization: A systematic review on adherence to PI-RADSv2 acquisition protocol.

PURPOSE: The Prostate Imaging-Reporting and Data System has been developed to standardize prostate MRI in terms of acquisition, interpretation and reporting. It received a major revision in late 2014 (PI-RADSv2). Recently, doubts have been raised on imaging facilities adherence to its acquisition protocol. With this systematic review, we assessed adherence to PI-RADSv2 minimum technical specifications in literature, to achieve a better understanding of issues limiting their diffusion. METHOD: Multiple medical literature databases were extensively searched to retrieve original studies published after January 2016 performing prostate MRI. Information pertaining acquisition protocols and patient enrolment were recorded for analysis. Technical parameters were dichotomized in relation to adherence to the corresponding minimal technical requirements. RESULTS: A total of 150 studies were included for analysis. Only 5% reported every technical parameter specified in the PI-RADSv2 document requirements, none of which completely met guideline specifications. Overall, 19% were in line with PI-RADSv2 for all reported MRI acquisition parameters. The adherence was lowest for T2-weighted frequency in-plane resolution (12%), diffusion-weighted imaging field of view (40%), apparent diffusion coefficient map low b-value (27%) and dynamic contrast-enhanced imaging temporal resolution (43%). Considering its role in image interpretation, it must be highlighted that only 59% of studies reporting diffusion-weighted imaging high b-value follow recommendations. CONCLUSIONS: Adherence to PI-RADSv2 minimum technical standards is heterogeneous in the scientific community. Our findings endorse the need for greater diffusion of PI-RADSv2 guidelines to achieve protocol standardization and support the notion that some requirements might benefit from streamlining to improve clinical applicability.

Technological Advances in Endoscopic Equipment in Exotic Pet Medicine.

The aim of this article is to review some of the technological advances in endoscopy and endosurgery. The article focuses on a few key areas relevant to exotic pets, including advances in urolith management, visualization, and laparoscopic surgery.

Optimization of Whole-Body CT Examinations of Polytrauma Patients in Comparison with the Current Diagnostic Reference Levels. / Optimierung von Ganzkörper-CT-Untersuchungen an Polytraumatisierten anhand des Vergleichs mit den aktuellen diagnostischen Referenzwerten.

PURPOSE: Evaluation of the dose values of a polytrauma whole-body CT examination used in clinical practice with regard to the 2016 updated diagnostic reference levels and reduction of the mean exposure levels using simple optimization steps. MATERIALS AND METHODS: In each case, 100 exposure values before and after dose optimization were compared with the old and new diagnostic reference levels. The grayscale values and the signal-to-noise ratio (SNR) were determined for the lung, the aortic arch and the liver. A visual assessment of the image quality was performed by two radiologists on the basis of a Likert scale (0 - non-diagnostic, 1 - poor visualization, 2 - moderate visualization, 3 - good visualization, 4 - excellent visualization) for CT examinations both before and after optimization. RESULTS: The acquired exposure values after dose optimization were below the old and new diagnostic reference levels (1319.98 ±â€Š463.16 mGy ·â€Šcm) while the mean value of the exposure values before optimization (1774.96 ±â€Š608.78 mGy ·â€Šcm) exceeded the current diagnostic reference levels. The measured grayscale values (HU) were (before versus after optimization): lung - 833 HU vs. - 827 HU (p = 0.43), aortic arch 341 HU vs. 343 HU (p = 0.70) and liver 68 HU vs. 67 HU (p = 0.35). After dose optimization the SNR in the lung was minimally higher, while it was minimally lower in the two other regions than before the optimization. Visual assessment of the image quality showed almost identical values with 3.85 evaluation points before and 3.82 evaluation points after dose optimization (p = 0.57). CONCLUSION: Due to the updating of the diagnostic reference levels, an analysis of the own exposure values is necessary in order to be able to detect high values promptly and to initiate appropriate measures for dose reduction. Appropriate adaptation of the examination parameters with consideration of the necessary image quality allows a significant reduction of the radiation exposure in most cases, also on CT devices of older generations. KEY POINTS: · In many cases a dose reduction below the DRLs is already possible by optimizing the examination technique.. · In order to ensure a diagnostic image quality, the control of the image quality is unavoidable in a dose reduction.. · Through suitable parameter adjustments a compliance with the DRLs is also possible, using CT devices of older generation without iterative image reconstruction.. CITATION FORMAT: · Schäfer SB, Rudolph C, Kolodziej M et al. Optimization of Whole-Body CT Examinations of Polytrauma Patients in Comparison with the Current Diagnostic Reference Levels. Fortschr Röntgenstr 2019; 191: 1015 - 1025.

Referring Physicians Assess the Quality of Outpatient Diagnostic Imaging Services: Development and Psychometric Evaluation of a Questionnaire.

GOAL: In order to ensure high-quality cooperation between referring physicians and imaging services, it is important to assess the quality of imaging services as perceived by referring physicians. The present study aimed to develop and validate a questionnaire for referring physicians to assess the quality of outpatient diagnostic imaging services. MATERIALS & METHODS: The questionnaire was developed by discussing and modifying an existing instrument by the German Association of Surgeons. After qualitative pretesting, the instrument was tested with physicians referring to four outpatient diagnostic imaging services in Switzerland. The results were first assessed using descriptive statistics. The final instrument was tested for validity using the concept of known-groups validity. The hypothesis underlying this procedure was that physicians referring frequently to services estimated the quality of these services to be higher than physicians who referred less often to services. The differences in ratings were assessed using a one-sided two-sample Wilcoxon test. The final questionnaire was tested for internal consistency and reliability using Cronbach's Alpha. RESULTS: Results show a high level of satisfaction of referring physicians with the relevant services but also potential for quality improvement initiatives. The psychometric evaluation of the final questionnaire shows that it is a valid instrument, showing significant differences between the ratings of physicians referring with high and low frequency. Furthermore, the instrument proves to be consistent and reliable. CONCLUSION: The final instrument presents a valid, consistent and reliable option for assess the quality of outpatient diagnostic imaging services as perceived by referring physicians. Results can be used as a basis for quality improvement. KEY POINTS: · A newly developed questionnaire assesses the quality of outpatient diagnostic imaging services as perceived by referring physicians. The questionnaire was developed and tested in Switzerland.. · Psychometric evaluation showed the questionnaire to be a valid, consistent and reliable instrument.. · Results are of interest for imaging services as well as for initiatives encompassing several services.. CITATION FORMAT: · Jossen M, Valeri F, Heilmaier C et al. Referring Physicians Assess the Quality of Outpatient Diagnostic Imaging Services: Development and Psychometric Evaluation of a Questionnaire. Fortschr Röntgenstr 2019; 191: 725 - 731.

Decreasing Radiation Emission in Minimally Invasive Spine Surgery Using Ultra-Low-Radiation Imaging with Image Enhancement: A Prospective Cohort Study.

BACKGROUND: Visualization of the anatomy in minimally invasive surgery (MIS) of the spine is limited and dependent on radiographic imaging, leading to increased radiation exposure to patients and surgical staff. Ultra-low-radiation imaging (ULRI) with image enhancement is a novel technology that may reduce radiation in the operating room. The aim of this study was to compare radiation emission between standard-dose and ULRI fluoroscopy with image enhancement in patients undergoing MIS of the spine. METHODS: This study prospectively enrolled 60 consecutive patients who underwent lateral lumbar interbody fusion, lateral lumbar interbody fusion with percutaneous pedicle screws, or MIS transforaminal lumbar interbody fusion. Standard-dose fluoroscopy was used in 31 cases, and ULRI with image enhancement was used in 29 cases. All imaging emission and radiation doses were recorded. RESULTS: Radiation emission per level was significantly less with ULRI than with standard-dose fluoroscopy for lateral lumbar interbody fusion (36.4 mGy vs. 119.8 mGy, P < 0.001), per screw placed in lateral lumbar interbody fusion (15.4 mGy per screw vs. 47.1 mGy per screw, P < 0.001), and MIS transforaminal lumbar interbody fusion (24.4 mGy vs. 121.6 mGy, P = 0.003). These differences represented reductions in radiation emission of 69.6%, 67.3%, and 79.9%. Total radiation doses per case were also significantly decreased for the transpsoas approach by 68.8%, lateral lumbar interbody fusion with percutaneous pedicle screws by 65.8%, and MIS transforaminal lumbar interbody fusion by 81.0% (P ≤ 0.004). CONCLUSIONS: ULRI with image enhancement has the capacity to significantly decrease radiation emission in minimally invasive procedures without compromising visualization of anatomy or procedure safety.

Unique Gadolinium Enhancement Pattern in Spinal Dural Arteriovenous Fistulas.

Importance: Spinal dural arteriovenous fistula (sDAVF) is often misdiagnosed as an inflammatory or a neoplastic myelopathy, often because of intraparenchymal gadolinium enhancement on magnetic resonance imaging (MRI); proper early diagnosis is important because deficits are reversible and a delay in treatment is associated with permanent morbidity. Tortuous flow voids on MRI are not universally present; thus, recognition of a unique gadolinium enhancement pattern may also aid in the early recognition and treatment of sDAVF. Objective: To describe a unique pattern of spinal cord gadolinium enhancement on MRI in sDAVF. Design, Setting, and Participants: This retrospective evaluation included pretreatment MRIs from 80 patients referred to the Mayo Clinic, Rochester, Minnesota, from January 1, 1997, through December 31, 2017, with a confirmed diagnosis of sDAVF and a control group of 144 patients with alternative confirmed myelopathy diagnoses. All participants underwent a neurologic evaluation at the Mayo Clinic. Main Outcomes and Measures: Evidence of at least 1 focal geographic nonenhancing area within a long segment of intense holocord gadolinium enhancement (termed the missing-piece sign) on MRI. Results: Of 51 patients with an sDAVF and a pretreatment MRI with gadolinium enhancement, 44 (86%) had intraparenchymal contrast enhancement, and 19 of these patients (43%) displayed the characteristic missing-piece sign. Of these 19 patients, symptom onset occurred at a median age of 67 years (range, 27-80 years); 15 patients were men. Progressive myelopathy features affecting the lower extremities occurred during a median of 33 months (range, 1-84 months). Eleven patients (58%) received an alternative diagnosis before confirmation of sDAVF. Tortuous flow voids were present on T2-weighted MRI in 13 of 19 patients. More than 1 digital subtraction angiogram was required for 5 patients to confirm the diagnosis. The missing-piece sign was not seen in any patients from the control group. Conclusions and Relevance: This unique gadolinium enhancement pattern in sDAVF was not found in a large control group of patients with other myelopathy. Identifying the missing-piece sign on MRI could potentially result in earlier time to angiography with improved outcomes for patients with an sDAVF.

Methylene blue MMX® tablets for chromoendoscopy. Bioavailability, colon staining and safety in healthy volunteers undergoing a full colonoscopy.

Methylene blue-MMX® tablets are proposed as an aid for detection and visualisation of adenomas and carcinomas in patients undergoing colonoscopy, by improving their detection rate and highlighting the presence of the intestinal dysplastic lesions. Single total doses of 100 and 200 mg were administered to healthy volunteers undergoing a bowel cleansing preparation and a full colonoscopy to investigate the colonic staining. The pharmacokinetics of methylene blue and the safety after exposure to the tablets were also investigated. With 200 mg, the best staining, assessed as the sum of acceptable and good staining, was achieved in the ascending colon and rectosigmoid (75% subjects each), the transverse and the descending colon (approximately 63% each). Absence of staining or overstaining were reported for no colonic region of interest in any subject. Similar results were observed in the 100 mg dose group. Methylene blue blood concentrations reached a peak (Cmax) in a median time (Tmax) of 12 h with 100 mg and 16 h with 200 mg. AUC0-t was 10.7 ±â€¯6.7 µg/mLxh after 100 mg and 25.2 ±â€¯7.4 µg/mLxh after 200 mg. Half-life ranged between 9 and 22 h after the lower dose and between 6 and 26 h after the higher dose. The cumulative urinary excretion was about 28% after 100 mg and about 39% after 200 mg up to 60 h post-dose. The overall frequency of adverse events after single dose of the test product administered along with a bowel cleansing preparation was 39%, but only one was related to the test product: abnormal transaminases. The most frequent adverse event was a transient polyuria (17%). One serious adverse event (gastrointestinal haemorrhage) led the subject to study discontinuation and hospitalisation and another subject withdrew the study due to one adverse event (haematemesis). Either event was not related to methylene blue.

Evaluation of photoshop based image analysis in cytologic diagnosis of pleural fluid in comparison with conventional modalities.

BACKGROUND: The aim of this study is to investigate and compare the results of digital image analysis in pleural effusion cytology samples with conventional modalities. MATERIALS AND METHODS: In this cross-sectional study, 53 pleural fluid cytology smears from Qaem hospital pathology department, located in Mashhad, Iran were investigated. Prior to digital analysis, all specimens were evaluated by two pathologists and categorized into three groups as: benign, suspicious, and malignant. Using an Olympus microscope and Olympus DP3 digital camera, digital images from cytology slides were captured. Appropriate images (n = 130) were separately imported to Adobe Photoshop CS5 and parameters including area and perimeter, circularity, Gray Value mean, integrated density, and nucleus to cytoplasm area ratio were analyzed. RESULTS: Gray Value mean, nucleus to cytoplasm area ratio, and circularity showed the best sensitivity and specificity rates as well as significant differences between all groups. Also, nucleus area and perimeter showed a significant relation between suspicious and malignant groups with benign group. Whereas, there was no such difference between suspicious and malignant groups. CONCLUSION: We concluded that digital image analysis is welcomed in the field of research on pleural fluid smears as it can provide quantitative data to apply various comparisons and reduce interobserver variation which could assist pathologists to achieve a more accurate diagnosis.

Multi-radial LBP Features as a Tool for Rapid Glomerular Detection and Assessment in Whole Slide Histopathology Images.

We demonstrate a simple and effective automated method for the localization of glomeruli in large (~1 gigapixel) histopathological whole-slide images (WSIs) of thin renal tissue sections and biopsies, using an adaptation of the well-known local binary patterns (LBP) image feature vector to train a support vector machine (SVM) model. Our method offers high precision (>90%) and reasonable recall (>70%) for glomeruli from WSIs, is readily adaptable to glomeruli from multiple species, including mouse, rat, and human, and is robust to diverse slide staining methods. Using 5 Intel(R) Core(TM) i7-4790 CPUs with 40 GB RAM, our method typically requires ~15 sec for training and ~2 min to extract glomeruli reproducibly from a WSI. Deploying a deep convolutional neural network trained for glomerular recognition in tandem with the SVM suffices to reduce false positives to below 3%. We also apply our LBP-based descriptor to successfully detect pathologic changes in a mouse model of diabetic nephropathy. We envision potential clinical and laboratory applications for this approach in the study and diagnosis of glomerular disease, and as a means of greatly accelerating the construction of feature sets to fuel deep learning studies into tissue structure and pathology.

T2-weighted images are superior to other MR image types for the determination of diffuse intrinsic pontine glioma intratumoral heterogeneity.

PURPOSE: Diffuse intrinsic pontine glioma (DIPG) remains the main cause of death in children with brain tumors. Given the inefficacy of numerous peripherally delivered agents to treat DIPG, convection enhanced delivery (CED) of therapeutic agents is a promising treatment modality. The purpose of this study was to determine which MR imaging type provides the best discrimination of intratumoral heterogeneity to guide future stereotactic implantation of CED catheters into the most cellular tumor regions. METHODS: Patients ages 18 years or younger with a diagnosis of DIPG from 2000 to 2015 were included. Radiographic heterogeneity index (HI) of the tumor was calculated by measuring the standard deviation of signal intensity of the tumor (SDTumor) normalized to the genu of the corpus callosum (SDCorpus Callosum). Four MR image types (T2-weighted, contrast-enhanced T1-weighted, FLAIR, and ADC) were analyzed at several time points both before and after radiotherapy and chemotherapy. HI values across these MR image types were compared and correlated with patient survival. RESULTS: MR images from 18 patients with DIPG were evaluated. The mean survival ± standard deviation was 13.8 ± 13.7 months. T2-weighted images had the highest HI (mean ± SD, 5.1 ± 2.5) followed by contrast-enhanced T1-weighted images (3.7 ± 1.5), FLAIR images (3.0 ± 1.1), and ADC maps (1.6 ± 0.4). ANOVA demonstrated that HI values were significantly higher for T2-weighted images than FLAIR (p < 0.01) and ADC (p < 0.0001). Following radiotherapy, T2-weighted and contrast-enhanced T1-weighted image HI values increased, while FLAIR and ADC HI values decreased. Univariate and multivariate analyses did not reveal a relationship between HI values and patient survival (p > 0.05). CONCLUSIONS: For children with DIPG, T2-weighted MRI demonstrates the greatest signal intensity variance suggesting tumor heterogeneity. Within this heterogeneity, T2-weighted signal hypointensity is known to correlate with increased cellularity and thus may represent a putative target for CED catheter placement in future clinical trials.

Assessment of Image Quality of Repeated Limited Transthoracic Echocardiography After Cardiac Surgery.

OBJECTIVES: The use of limited transthoracic echocardiography (TTE) has been restricted in patients after cardiac surgery due to reported poor image quality. The authors hypothesized that the hemodynamic state could be evaluated in a high proportion of patients at repeated intervals after cardiac surgery. DESIGN: Prospective observational study. SETTING: Tertiary university hospital. PARTICIPANTS: The study comprised 51 patients aged 18 years or older presenting for cardiac surgery. INTERVENTIONS: Patients underwent TTE before surgery and at 3 time points after cardiac surgery. Images were assessed offline using an image quality scoring system by 2 expert observers. Hemodynamic state was assessed using the iHeartScan protocol, and the primary endpoint was the proportion of limited TTE studies in which the hemodynamic state was interpretable at each of the 3 postoperative time points. MEASUREMENTS AND MAIN RESULTS: Hemodynamic state interpretability varied over time and was highest before surgery (90%) and lowest on the first postoperative day (49%) (p<0.01). This variation in interpretability over time was reflected in all 3 transthoracic windows, ranging from 43% to 80% before surgery and from 2% to 35% on the first postoperative day (p<0.01). Image quality scores were highest with the apical window, ranging from 53% to 77% across time points, and lowest with the subcostal window, ranging from 4% to 70% across time points (p< 0.01). CONCLUSIONS: Hemodynamic state can be determined with TTE in a high proportion of cardiac surgery patients after extubation and removal of surgical drains.

Metal artifact reduction in MRI-based cervical cancer intracavitary brachytherapy.

Magnetic resonance imaging (MRI) plays an increasingly important role in brachytherapy planning for cervical cancer. Yet, metal tandem, ovoid intracavitary applicators, and fiducial markers used in brachytherapy cause magnetic susceptibility artifacts in standard MRI. These artifacts may impact the accuracy of brachytherapy treatment and the evaluation of tumor response by misrepresenting the size and location of the metal implant, and distorting the surrounding anatomy and tissue. Metal artifact reduction sequences (MARS) with high bandwidth RF selective excitations and turbo spin-echo readouts were developed for MRI of orthopedic implants. In this study, metal artifact reduction was applied to brachytherapy of cervical cancer using the orthopedic metal artifact reduction (O-MAR) sequence. O-MAR combined MARS features with view angle tilting and slice encoding for metal artifact correction (SEMAC) to minimize in-plane and through-plane susceptibility artifacts. O-MAR improved visualization of the tandem tip on T2 and proton density weighted (PDW) imaging in phantoms and accurately represented the diameter of the tandem. In a pilot group of cervical cancer patients (N = 7), O-MAR significantly minimized the blooming artifact at the tip of the tandem in PDW MRI. There was no significant difference observed in artifact reduction between the weak (5 kHz, 7 z-phase encodes) and medium (10 kHz, 13 z-phase encodes) SEMAC settings. However, the weak setting allowed a significantly shorter acquisition time than the medium setting. O-MAR also reduced susceptibility artifacts associated with metal fiducial markers so that they appeared on MRI at their true dimensions.

Improved Image Quality of Low-Dose CT Pulmonary Angiograms.

OBJECTIVE: The use of CT pulmonary angiography (CTPA) to evaluate for pulmonary embolism has been increasing, and carries a significant radiation dose. We evaluate image quality of lower-dose images, taking into account patient size as well as the effects of image postprocessing. METHODS: A total of 250 CTPAs were retrospectively reviewed. The following parameters were obtained: kVp, mA, dose length product, Hounsfield units (HU) with standard deviation in the main pulmonary artery, transverse scout measurement, and subjective image quality. RESULTS: Radiation dose decreased 55% by reducing kVp from 120 to 100, and 60% from 100 to 80 kVp. Radiation dose decreased 82% from 120 to 80 kVp. Noise increased 38% from 120 kVp to 100 kVp, and increased 23% from 100 kVp to 80 kVp. Adding an overlapped reconstructed image decreased noise by 16% to 21%. Despite the increase in image noise, diagnostic quality was significantly improved at 80 and 100 kVp, compared with 120 kVp, with an average subjective quality rating of 3.8, 4.0, and 3.2, respectively, and an average pulmonary artery density of 536, 423, and 278 HU. Even in larger patients, qualitative image quality was better at 100 kVp compared with 120 kVp, with an average quality rating of 3.6 versus 2.9, respectively. CONCLUSIONS: Radiation dose exposure can be easily reduced on CTPA by lowering kVp, which at the same time improves image quality. Studies using a lower kVp were of significantly higher diagnostic quality. This held true even in larger patients.

MRI of the Prostate: Recommendations on Patient Preparation and Scanning Protocol.

The Working Group Uroradiology and Urogenital Diagnosis of the German Roentgen Society has developed uniform recommendations for the preparation and implementation of prostate MRI. In the first part detailed recommendations are given in tabular form regarding 1. anamnestic data before prostate MRI, 2. termination of examinations and preparation of examinations, 3. examination protocol and 4. MRI-guided in-bore biopsy. In the second part, the recommendations are discussed in detail and relevant background information is provided. Key Points: · Uniform recommendations for prostate MRI has been developed from the Working Group Uroradiology and Urogenital Diagnosis of the German Roentgen Society.. · Necessary anamnestic data, recommendations for termination of examinations and prepararion of examinations, examination protocol and MRI guided in-bore biopsy are detailed expressed and documented.. Citation Format · Franiel T., Quentin M., Mueller-Lisse U. G. et al. MRI of the Prostate: Recommendations on Patient Preparation and Scanning Protocol. Fortschr Röntgenstr 2017; 189: 21 - 28.

Performance of Gadoxetic Acid-Enhanced Liver Magnetic Resonance Imaging for Predicting Patient Eligibility for Liver Transplantation Based on the Milan Criteria.

PURPOSE: This study aimed to evaluate the accuracy of gadoxetic acid-enhanced magnetic resonance imaging (Gd-EOB-MRI) in predicting eligibility for liver transplantation in patients with hepatocellular carcinoma (HCC) based on Milan criteria (MC). MATERIALS AND METHODS: We reviewed Gd-EOB-MRI of 44 patients who underwent liver transplantation for HCC with cirrhosis for the presence/size of HCCs, vascular invasion, and transplant eligibility based on MC. Hepatocellular carcinoma was diagnosed based on conventional radiological hallmarks (arterial enhancement and washout) or the modified criteria. RESULTS: Among 44 patients, 16 was beyond MC. Sensitivity, specificity, and accuracy of conventional radiological hallmark and the modified criteria for predicting eligibility by MC were 31.3%, 96.3%, and 72.7%, and 68.8%, 96.3%, and 86.4%, respectively. CONCLUSIONS: Gd-EOB-MRI showed high specificity but poor sensitivity for assessing transplant eligibility based on MC when adopting the conventional radiological hallmarks of HCC. Our modified criteria showed significantly better sensitivity and accuracy than the conventional radiological hallmarks.

Critical Review of Current Approaches for Echocardiographic Reproducibility and Reliability Assessment in Clinical Research.

BACKGROUND: There is no broadly accepted standard method for assessing the quality of echocardiographic measurements in clinical research reports, despite the recognized importance of this information in assessing the quality of study results. METHODS: Twenty unique clinical studies were identified reporting echocardiographic data quality for determinations of left ventricular (LV) volumes (n = 13), ejection fraction (n = 12), mass (n = 9), outflow tract diameter (n = 3), and mitral Doppler peak early velocity (n = 4). To better understand the range of possible estimates of data quality and to compare their utility, reported reproducibility measures were tabulated, and de novo estimates were then calculated for missing measures, including intraclass correlation coefficient (ICC), 95% limits of agreement, coefficient of variation (CV), coverage probability, and total deviation index, for each variable for each study. RESULTS: The studies varied in approaches to reproducibility testing, sample size, and metrics assessed and values reported. Reported metrics included mean difference and its SD (n = 7 studies), ICC (n = 5), CV (n = 4), and Bland-Altman limits of agreement (n = 4). Once de novo estimates of all missing indices were determined, reasonable reproducibility targets for each were identified as those achieved by the majority of studies. These included, for LV end-diastolic volume, ICC > 0.95, CV < 7%, and coverage probability > 0.93 within 30 mL; for LV ejection fraction, ICC > 0.85, CV < 8%, and coverage probability > 0.85 within 10%; and for LV mass, ICC > 0.85, CV < 10%, and coverage probability > 0.60 within 20 g. CONCLUSIONS: Assessment of data quality in echocardiographic clinical research is infrequent, and methods vary substantially. A first step to standardizing echocardiographic quality reporting is to standardize assessments and reporting metrics. Potential benefits include clearer communication of data quality and the identification of achievable targets to benchmark quality improvement initiatives.

Implementation of a Quality Improvement Bundle Improves Echocardiographic Imaging after Congenital Heart Surgery in Children.

BACKGROUND: Postoperative echocardiography after congenital heart disease surgery is of prognostic importance, but variable image quality is problematic. We implemented a quality improvement bundle comprising of focused imaging protocols, procedural sedation, and sonographer education to improve the rate of optimal imaging (OI). METHODS: Predischarge echocardiograms were evaluated in 116 children (median age, 0.51 years; range, 0.01-5.6 years) from two centers after tetralogy of Fallot repair, arterial switch operation, and bidirectional Glenn and Fontan procedures. OI rates were compared between the centers before and after the implementation of a quality improvement bundle at center 1, with center 2 serving as the comparator. Echocardiographic images were independently scored by a single reader from each center, blinded to center and time period. For each echocardiographic variable, quality score was assigned as 0 (not imaged or suboptimally imaged) or 1 (optimally imaged); structures were classified as intra- or extracardiac. The rate of OI was calculated for each variable as the percentage of patients assigned a score of 1. RESULTS: Intracardiac structures had higher OI than extracardiac structures (81% vs 57%; adjusted odds ratio [OR], 3.47; P < .01). Center 1 improved overall OI from 48% to 73% (OR, 4.44; P < .01), intracardiac OI from 69% to 85% (OR, 3.53; P = .01), and extracardiac OI from 35% to 67% (OR, 5.16; P < .01). There was no temporal difference for center 2. CONCLUSIONS: After congenital heart disease surgery in children, intracardiac structures are imaged more optimally than extracardiac structures. Focused imaging protocols, patient sedation, and sonographer education can improve OI rates.

Three-Dimensional Field Optimization Method: Clinical Validation of a Novel Color Doppler Method for Quantifying Mitral Regurgitation.

BACKGROUND: Assessment of mitral regurgitation (MR) severity by echocardiography is important for clinical decision making, but MR severity can be challenging to quantitate accurately and reproducibly. The accuracy of effective regurgitant orifice area (EROA) and regurgitant volume (RVol) calculated using two-dimensional (2D) proximal isovelocity surface area is limited by the geometric assumptions of proximal isovelocity surface area shape, and both variables demonstrate interobserver variability. The aim of this study was to compare a novel automated three-dimensional (3D) echocardiographic method for calculating MR regurgitant flow using standard 2D techniques. METHODS: A sheep model of ischemic MR and patients with MR were prospectively examined. Patients with a range of severity of MR were examined. EROA and RVol were calculated from 3D color Doppler acquisitions using a novel computer-automated algorithm based on the field optimization method to measure EROA and RVol. For an independent comparison group, the 3D field optimization method was compared with 2D methods for grading MR in an experimental ovine model of MR. RESULTS: Fifteen 3D data sets from nine sheep (open-chest transthoracic echocardiographic data sets) and 33 transesophageal data sets from patients with MR were prospectively examined. For sheep data sets, mean 2D EROA was 0.16 ± 0.05 cm2, and mean 2D RVol was 21.84 ± 8.03 mL. Mean 3D EROA was 0.09 ± 0.04 cm2, and mean 3D RVol was 14.40 ± 5.79 cm3. There was good correlation between 2D and 3D EROA (R = 0.70) and RVol (R = 0.80). For patient data sets, mean 2D EROA was 0.35 ± 0.35 cm2, and mean 2D RVol was 58.9 ± 52.9 mL. Mean 3D EROA was 0.34 ± 0.29 cm2, and mean 3D RVol was 54.6 ± 36.5 mL. There was excellent correlation between 2D and 3D EROA (R = 0.94) and RVol (R = 0.84). Bland-Altman analysis revealed greater interobserver variability for 2D RVol measurements compared with 3D RVol using the 3D field optimization method measurements, but variability was statistically significant only for RVol. CONCLUSIONS: Direct automated measurement of proximal isovelocity surface area region for EROA calculation using real-time 3D color Doppler echocardiography is feasible, with a high correlation to current 2D EROA methods but less variability. This novel automated method provides an accurate and highly reproducible method for calculating EROA.