Regularization-Based 2D Strain Tensor Imaging in Quasi-Static Ultrasound Elastography SAGE Publications.

Accurately estimating all strain components in quasi-static ultrasound elastography is crucial for the full analysis of biological media. In this study, 2D strain tensor imaging was investigated, focusing on the use of a regularization method to improve strain images. This method enforces the tissue property of (quasi-) incompressibility, while penalizing strong field variations, to smooth the displacement fields and reduce the noise in the strain components. The performance of the method was assessed with numerical simulations, phantoms, and in vivo breast tissues. For all the media examined, the results showed a significant improvement in both lateral displacement and strain, while axial fields were only slightly modified by the regularization. The introduction of penalty terms allowed us to obtain shear strain and rotation elastograms where the patterns around the inclusions/lesions were clearly visible. In phantom cases, the findings were consistent with the results obtained from the modeling of the experiments. Finally, the easier detectability of the inclusions/lesions in the final lateral strain images was associated with higher elastographic contrast-to-noise ratios (CNRs), with values in the range of [0.54-9.57] versus [0.08-0.38] before regularization.

Multicontrast MRI-based radiomics for the prediction of pathological complete response to neoadjuvant chemotherapy in patients with early triple negative breast cancer.

INTRODUCTION: To assess pre-therapeutic MRI-based radiomic analysis to predict the pathological complete response to neoadjuvant chemotherapy (NAC) in women with early triple negative breast cancer (TN). MATERIALS AND METHODS: This monocentric retrospective study included 75 TN female patients with MRI (T1-weighted, T2-weighted, diffusion-weighted and dynamic contrast enhancement images) performed before NAC. For each patient, the tumor(s) and the parenchyma were independently segmented and analyzed with radiomic analysis to extract shape, size, and texture features. Several sets of features were realized based on the 4 different sequence images. Performances of 4 classifiers (random forest, multilayer perceptron, support vector machine (SVM) with linear or quadratic kernel) were compared based on pathological complete response (defined on the excised tissues), on 100 draws with 75% as training set and 25% as test. RESULTS: The combination of features extracted from different MR images improved the classifier performance (more precisely, the features from T1W, T2W and DWI). The SVM with quadratic kernel showed the best performance with a mean AUC of 0.83, a sensitivity of 0.85 and a specificity of 0.75 in the test set. CONCLUSION: MRI-based radiomics may be relevant to predict NAC response in TN cancer. Our results promote the use of multi-contrast MRI sources for radiomics, providing enrich source of information to enhance model generalization.

Three-dimensional ultrasound in the management of bladder endometriosis.

STUDY OBJECTIVE: To assess the performance of three-dimensional (3D) ultrasound with color Doppler in the diagnosis of bladder endometriosis compared with magnetic resonance imaging (MRI) and cystoscopy. DESIGN: Canadian Task Force classification II-3. SETTING: Department of gynecology and obstetrics of a university hospital. PATIENTS: Eight women who reported urinary tract symptoms suggestive of bladder endometriosis between May 2012 and November 2013. INTERVENTIONS: For all cases, we assessed the size of the endometriotic nodule, its location on the bladder wall, and the distance between the lesion and the ureteral meatus, with pelvic 3D ultrasound (full bladder), uro-MRI, and cystoscopy. The results were compared with the postoperative histopathologic findings. MEASUREMENTS AND MAIN RESULTS: The pathology results differed from those produced by imaging by a mean ± SD of -3.5 ± 6.4 mm on transvaginal ultrasound (TVUS) and -5.75 ± 11.9 mm) for MRI. There was no significant difference between imaging and pathology findings (p = .20) or between the 2 imaging findings (TVUS and MRI) (p = .73). Results showed a trend toward better accuracy for 3D ultrasound than MRI with smaller SDs (p = .08). Cystoscopy and ultrasound were compared; however, without any tools to assess the distance in cystoscopy, no statistical result was possible. CONCLUSION: Ultrasound seems to be superior to cystoscopy and is at least as effective as MRI in diagnosing and planning the surgery for bladder endometriosis.

Emergency department CT examinations demonstrate no evidence of early viral circulation at the start of the COVID-19 pandemic-a multicentre epidemiological study.

BACKGROUND: Biological studies suggested that the COVID-19 outbreak in France occurred before the first official diagnosis on January 24, 2020. We investigated this controversial topic using a large collection of chest CTs performed throughout French emergency departments within 6 months before the 1st lockdown. RESULTS: Overall, 49,311 consecutive patients (median age: 60 years, 23,636/49,311 [47.9%] women) with available chest CT images and reports from 61 emergency departments between September 1, 2020, and March 16, 2020 (day before the 1st French lockdown), were retrospectively included in this multicentre study. In the macroscopic analysis of reports automatically (labelled for presence of ground glass opacities [GGOs], reticulations, and bilateral and subpleural abnormalities), we found a significant breakpoint on February 17, 2020, for the weekly time series with 1, 2 and ≥ 3 of these 4 radiological features, with 146/49,311 (0.3%) patients showing bilateral abnormalities and ground glass opacities (GGOs) from that day. According to radiologists, 22/146 (15.1%) CT images showed typical characteristics of COVID-19, including 4/146 (2.7%) before February 2020. According to hospital records, one patient remained without microbial diagnosis, two patients had proven influenza A and one patient had concomitant influenza A and mycoplasma infection. CONCLUSION: These results suggest that SARS-CoV-2 was not circulating in the areas covered by the 61 emergency departments involved in our study before the official beginning of the COVID-19 outbreak in France. In emergency patients, the strong resemblance among mycoplasma, influenza A and SARS-CoV-2 lung infections on chest CT and the nonspecificity of CT patterns in low prevalence periods is stressed. CRITICAL RELEVANCE STATEMENT: We proposed here an innovative approach to revisit a controversial 'real' start of the COVID-19 pandemic in France based on (1) a population-level approach combining text mining, time series analysis and an epidemiological dataset and (2) a patient-level approach with careful retrospective reading of chest CT scans complemented by analysis of samples performed contemporarily to the chest CT. We showed no evidence that SARS-CoV-2 was actively circulating in France before February 2020.

Conversational hypnosis versus standard of care to reduce anxiety in patients undergoing marker placement under radiographic control prior to breast cancer surgery: A randomized, multicenter trial.

Background: Surgery is a cornerstone of breast cancer management. Prior to surgery, a wire marker is placed at the site of the tumor, to enable the surgeon to accurately localize the lesion during later surgery. This procedure can generate considerable anxiety for many patients. We investigated the value of conversational hypnosis (CH) in reducing anxiety in patients undergoing preoperative wire placement under radiographic control. Methods: Randomized, multicentre study in 7 centers in France. Inclusion criteria were patients aged >18 years with an Eastern Cooperative Oncology Group performance status ≤2, scheduled to undergo preoperative wire placement in one or several breast lesions. Patients were randomized in a 1:1 ratio, stratified by center to undergo preoperative wire placement with or without the use of CH by a radiological technician trained in the CH technique. The primary endpoint was the percentage of patients with an anxiety score ≥ 6 on a visual analog scale ranging from 0 (absence of anxiety) to 10 (maximal anxiety). Secondary endpoints were pain score, perceived duration reported by the patient, technician satisfaction with their relationship with the patient, and ease of marker insertion reported by the radiologist. Semi-structured interviews were performed with patients to assess their perception of the marker placement procedure. Results: The trial was prematurely interrupted for futility after a planned interim analysis after accrual of 167 patients, i.e., half the planned sample size. Prior to marker placement, 29.3% (n = 24) of patients in the control group had an anxiety score ≥ 6, versus 42.3% (n = 33) in the CH group (p = 0.08). After marker placement, the change of anxiety score was not significantly different between groups (11.0% (n = 9) versus 14.3% (n = 11), p = 0.615). There was no significant difference in any of the secondary endpoints. In the interviews, patients from both groups frequently spoke of a feeling of trust. Conclusion: This study failed to show a benefit of conversational hypnosis on anxiety in patients undergoing marker placement prior to surgery for breast cancer. The fact that some caregivers had learned this personalized therapeutic communication technique may have had a positive impact on the whole caregiving team. Trial registration: The study was registered with ClinicalTrials.gov (NCT02867644).

2D tissue strain tensor imaging in quasi-static ultrasound elastography.

Accurately estimating all strain components in quasi-static ultrasound elastography is crucial for the full analysis of biological media. In this paper, 2D strain tensor imaging is investigated, using a partial differential equation (PDE)-based regularization method. More specifically, this method employs the tissue property of incompressibility to smooth the displacement fields and reduce the noise in the strain components. The performance of the method is assessed with phantoms and in vivo breast tissues. For all the media examined, the results showed a significant improvement in both lateral displacement and strain but also, to a lesser extent, in the shear strain. Moreover, axial displacement and strain were only slightly modified by the regularization, as expected. Finally, the easier detectability of the inclusion/lesion in the final lateral strain images is associated with higher elastographic contrast-to-noise ratios (CNRs), with values in the range [0.68 - 9.40] vs [0.09 - 0.38] before regularization.

Detailed overview on rare malignant ovarian tumors.

The group of rare malignant ovarian tumors includes the group of germ cell tumors, sex cords stromal ovarian tumors, small cell carcinoma, malignant Brenner tumors, rare epithelial tumors such as mucinous carcinoma, clear cell carcinoma, or low-grade serous carcinoma, as well as ovarian carcinosarcoma. Together they comprise about 10% of all ovarian tumors. Due to their low prevalence and their heterogeneity, data and treatment recommendations are limited. Even though all ovarian tumors are staged according to the FIGO staging of epithelial ovarian tumors, treatment differs especially in germ cell tumors and sex cords stromal ovarian tumors. Non-epithelial ovarian tumors can arise from a variety of ovarian precursor cells such as germ cells, granulosa cells, theca cells, or stromal fibroblasts. As can be expected already due to their divergent precursor lesions, these malignancies are substantially different but united by their rarity. This overview article gives a comprehensive summary on the pathology and clinical presentation, as well as therapy recommendations of a selection of those rare ovarian tumors, based on the latest national guidelines and related important publications.

Correlation between three-dimensional rectosonography and magnetic resonance imaging in the diagnosis of rectosigmoid endometriosis: a preliminary study on the first fifty cases.

OBJECTIVES: Deep infiltrating endometriosis (DIE) raises a number of diagnostic and therapeutic problems. Magnetic resonance imaging (MRI), the reference technique in endometriosis, is questioned for posterior pelvic lesions, especially in rectosigmoid locations. In this study, we describe a new technique called three-dimensional rectosonography (3D-RSG), which combines standard transvaginal ultrasonography (TVUS), 3-dimensional (3D) ultrasonography and the use of water for rectal contrast. We also assess the correlation between 3D-RSG and MRI in the diagnosis of rectosigmoid endometriosis. STUDY DESIGN: This study included 50 consecutive women with symptoms suggestive of DIE. After colorectal enema, they underwent a gynecological examination and a 3D TVUS during which 120ml of water was injected in the rectosigmoid to improve the performance of the examination. All patients also underwent an MRI and surgery was offered to the patient if there was discordance between the two procedures. RESULTS: Fifty women underwent 3D-RSG between May and November 2012. All procedures were well tolerated by patients. Two examinations (4%) were stopped for technical reasons. Nineteen rectosigmoid nodules were diagnosed in 18 women (36%). Eighteen of these nodules were also identified on MRI, and one (2%) nodule seen on MRI was not diagnosed by 3D-RSG. In 31 examinations (62%), neither technique identified an intestinal lesion. There was a concordance rate of 96% between the two techniques. Using MRI as the reference technique, 3D-RSG had a sensitivity of 0.95, a specificity of 0.97, a positive predictive values of 0.95, and a negative predictive value of 0.97. There was a 30.3 positive likelihood ratio and a 0.05 negative likelihood ratio. CONCLUSIONS: 3D-RSG seems an interesting new method for diagnosis of rectosigmoid endometriosis and is both feasible and well tolerated. 3D-RSG is highly concordant with MRI in this indication, although further studies are needed to confirm these primary results.

In Vivo response to compression of 35 breast lesions observed with a two-dimensional locally regularized strain estimation method.

The objective of this study was to assess the in vivo performance of our 2-D locally regularized strain estimation method with 35 breast lesions, mainly cysts, fibroadenomas and carcinomas. The specific 2-D deformation model used, as well as the method's adaptability, led to an algorithm that is able to track tissue motion from radiofrequency ultrasound images acquired in clinical conditions. Particular attention was paid to strain estimation reliability, implying analysis of the mean normalized correlation coefficient maps. For all lesions examined, the results indicated that strain image interpretation, as well as its comparison with B-mode data, should take into account the information provided by the mean normalized correlation coefficient map. Different trends were observed in the tissue response to compression. In particular, carcinomas appeared larger in strain images than in B-mode images, resulting in a mean strain/B-mode lesion area ratio of 2.59 ± 1.36. In comparison, the same ratio was assessed as 1.04 ± 0.26 for fibroadenomas. These results are in agreement with those of previous studies, and confirm the interest of a more thorough consideration of size difference as one parameter discriminating between malignant and benign lesions.

Whole-body MRI for metastases screening: a preliminary study using 3D VIBE sequences with automatic subtraction between noncontrast and contrast enhanced images.

OBJECTIVES: To evaluate 3D Volumetric Interpolated Breath-hold Examination (VIBE) whole-body MRI (WB-MRI) acquisition for the metastases staging. METHODS: Thirty-two consecutive patients with solid tumor were examined from head to feet before and after contrast injection. An automatic subtraction occurred between the 2 series of images. WB-MRI was compared with conventional staging techniques (CT, scintigraphy, brain MRI, and whole-body PET in 4 cases). RESULTS: WB-MRI and the reference techniques depicted metastases in 25 patients. WB-MRI depicted more bone lesions in the spine, pelvis, skull, femur, and tibia, whereas scintigraphy detected more rib lesions. WB-MRI depicted 27 cerebral metastases, whereas brain MRI depicted 40 cerebral metastases. WB-MRI depicted a total of 8 hepatic metastases, 8 adrenal lesions, and conventional staging 7 hepatic metastases and 10 adrenal lesions. WB-MRI examination depicted lung metastases in 10 patients, and CT examination in 13 patients. CONCLUSION: The results of this study indicate that WB-MRI is a feasible and promising technique for tumor staging.