Transurethral injection of autologous muscle precursor cells for treatment of female stress urinary incontinence: a prospective phase I clinical trial.

INTRODUCTION AND HYPOTHESIS: The purpose was to investigate the safety and feasibility of transurethral injections of autologous muscle precursor cells (MPCs) into the external urinary sphincter (EUS) to treat stress urinary incontinence (SUI) in female patients. METHODS: Prospective and randomised phase I clinical trial. Standardised 1-h pad test, International Consultation on Incontinence Questionnaire-Urinary Incontinence Short Form (ICIQ-UI-SF), urodynamic study, and MRI of the pelvis were performed at baseline and 6 months after treatment. MPCs gained through open muscle biopsy were transported to a GMP facility for processing and cell expansion. The final product was injected into the EUS via a transurethral ultrasound-guided route. Primary outcomes were defined as any adverse events (AEs) during follow-up. Secondary outcomes were functional, questionnaire, and radiological results. RESULTS: Ten female patients with SUI grades I-II were included in the study and 9 received treatment. Out of 8 AEs, 3 (37.5%) were potentially related to treatment and treated conservatively: 1 urinary tract infection healed with antibiotics treatment, 1 dysuria and 1 discomfort at biopsy site. Functional urethral length under stress was 25 mm at baseline compared with 30 mm at 6 months' follow-up (p=0.009). ICIQ-UI-SF scores improved from 7 points at baseline to 4 points at follow-up (p=0.035). MRI of the pelvis revealed no evidence of tumour or necrosis, whereas the diameter of the EUS muscle increased from 1.8 mm at baseline to 1.9 mm at follow-up (p=0.009). CONCLUSION: Transurethral injections of autologous MPCs into the EUS for treatment of SUI in female patients can be regarded as safe and feasible. Only a minimal number of expected and easily treatable AEs were documented.

Mammographic calcifications undergoing percutaneous biopsy: outcome in women with and without a personal history of breast cancer.

PURPOSE: To compare the positive predictive values (PPVs) of BI-RADS categories used to assess pure mammographic calcifications in women with and without a previous history of breast cancer (PHBC). MATERIALS AND METHODS: In this retrospective study, all consecutive pure mammographic calcifications (n = 320) undergoing a stereotactic biopsy between 2016 and 2018 were identified. Mammograms were evaluated in consensus by two radiologists according to BI-RADS and blinded to patient history and pathology results. Final pathologic results were used as the standard of reference. PPV of BI-RADS categories were compared between the two groups. Data were evaluated using standard statistics, Mann-Whitney U tests and Chi-square tests. RESULTS: Two hundred sixty-eight patients (274 lesions, median age 54 years, inter-quartile range, 50-65 years) with a PHBC (n = 46) and without a PHBC (n = 222) were included. Overall PPVs were the following: BI-RADS 2, 0% (0 of 56); BI-RADS 3, 9.1% (1 of 11); BI-RADS 4a, 16.2% (6 of 37); BI-RADS 4b, 37.5% (48 of 128); BI-RADS 4c, 47.3% (18 of 38) and BI-RADS 5, 100% (4 of 4). The PPV of BI-RADS categories was similar in patients with and without a PHBC (P = .715). Calcifications were more often malignant in patients with a PHBC older than 10 years (47.3%, 9 of 19) compared to 1-2 years (25%, 1 of 4), 2-5 years (20%, 2 of 10) and 5-10 years (0%, of 13) from the first breast cancer (P = .005). CONCLUSION: PPV of mammographic calcifications is similar in women with or without PHBC when BI-RADS classification is strictly applied. A higher risk of malignancy was observed in patients with a PHBC longer than 10 years.

Assessment of iron nanoparticle distribution in mouse models using ultrashort-echo-time MRI.

Microscopic magnetic field inhomogeneities caused by iron deposition or tissue-air interfaces may result in rapid decay of transverse magnetization in MRI. The aim of this study is to detect and quantify the distribution of iron-based nanoparticles in mouse models by applying ultrashort-echo-time (UTE) sequences in tissues exhibiting extremely fast transverse relaxation. In 24 C57BL/6 mice (two controls), suspensions containing either non-oxidic Fe or AuFeOx nanoparticles were injected into the tail vein at two doses (200 µg and 600 µg per mouse). Mice underwent MRI using a UTE sequence at 4.7 T field strength with five different echo times between 100 µs and 5000 µs. Transverse relaxation times T2 * were computed for the lung, liver, and spleen by mono-exponential fitting. In UTE imaging, the MRI signal could reliably be detected even in liver parenchyma exhibiting the highest deposition of nanoparticles. In animals treated with Fe nanoparticles (600 µg per mouse), the relaxation time substantially decreased in the liver (3418 ± 1534 µs (control) versus 228 ± 67 µs), the spleen (2170 ± 728 µs versus 299 ± 97 µs), and the lungs (663 ± 101 µs versus 413 ± 99 µs). The change in transverse relaxation was dependent on the number and composition of the nanoparticles. By pixel-wise curve fitting, T2 * maps were calculated showing nanoparticle distribution. In conclusion, UTE sequences may be used to assess and quantify nanoparticle distribution in tissues exhibiting ultrafast signal decay in MRI.

Fully automatic classification of automated breast ultrasound (ABUS) imaging according to BI-RADS using a deep convolutional neural network.

PURPOSE: The aim of this study was to develop and test a post-processing technique for detection and classification of lesions according to the BI-RADS atlas in automated breast ultrasound (ABUS) based on deep convolutional neural networks (dCNNs). METHODS AND MATERIALS: In this retrospective study, 645 ABUS datasets from 113 patients were included; 55 patients had lesions classified as high malignancy probability. Lesions were categorized in BI-RADS 2 (no suspicion of malignancy), BI-RADS 3 (probability of malignancy < 3%), and BI-RADS 4/5 (probability of malignancy > 3%). A deep convolutional neural network was trained after data augmentation with images of lesions and normal breast tissue, and a sliding-window approach for lesion detection was implemented. The algorithm was applied to a test dataset containing 128 images and performance was compared with readings of 2 experienced radiologists. RESULTS: Results of calculations performed on single images showed accuracy of 79.7% and AUC of 0.91 [95% CI: 0.85-0.96] in categorization according to BI-RADS. Moderate agreement between dCNN and ground truth has been achieved (κ: 0.57 [95% CI: 0.50-0.64]) what is comparable with human readers. Analysis of whole dataset improved categorization accuracy to 90.9% and AUC of 0.91 [95% CI: 0.77-1.00], while achieving almost perfect agreement with ground truth (κ: 0.82 [95% CI: 0.69-0.95]), performing on par with human readers. Furthermore, the object localization technique allowed the detection of lesion position slice-wise. CONCLUSIONS: Our results show that a dCNN can be trained to detect and distinguish lesions in ABUS according to the BI-RADS classification with similar accuracy as experienced radiologists. KEY POINTS: • A deep convolutional neural network (dCNN) was trained for classification of ABUS lesions according to the BI-RADS atlas. • A sliding-window approach allows accurate automatic detection and classification of lesions in ABUS examinations.

Fully automated breast segmentation on spiral breast computed tomography images.

INTRODUCTION: The quantification of the amount of the glandular tissue and breast density is important to assess breast cancer risk. Novel photon-counting breast computed tomography (CT) technology has the potential to quantify them. For accurate analysis, a dedicated method to segment the breast components-the adipose and glandular tissue, skin, pectoralis muscle, skinfold section, rib, and implant-is required. We propose a fully automated breast segmentation method for breast CT images. METHODS: The framework consists of four parts: (1) investigate, (2) segment the components excluding adipose and glandular tissue, (3) assess the breast density, and (4) iteratively segment the glandular tissue according to the estimated density. For the method, adapted seeded watershed and region growing algorithm were dedicatedly developed for the breast CT images and optimized on 68 breast images. The segmentation performance was qualitatively (five-point Likert scale) and quantitatively (Dice similarity coefficient [DSC] and difference coefficient [DC]) demonstrated according to human reading by experienced radiologists. RESULTS: The performance evaluation on each component and overall segmentation for 17 breast CT images resulted in DSCs ranging 0.90-0.97 and in DCs 0.01-0.08. The readers rated 4.5-4.8 (5 highest score) with an excellent inter-reader agreement. The breast density varied by 3.7%-7.1% when including mis-segmented muscle or skin. CONCLUSION: The automatic segmentation results coincided with the human expert's reading. The accurate segmentation is important to avoid the significant bias in breast density analysis. Our method enables accurate quantification of the breast density and amount of the glandular tissue that is directly related to breast cancer risk.

Post-exercise intramuscular O2 supply is tightly coupled with a higher proximal-to-distal ATP synthesis rate in human tibialis anterior.

KEY POINTS: The post-exercise recovery of phosphocreatine, a measure of the oxidative capacity of muscles, as assessed by 31 P MR spectroscopy, shows a striking increase from distal to proximal along the human tibialis anterior muscle. To investigate why this muscle exhibits a greater oxidative capacity proximally, we tested whether the spatial variation in phosphocreatine recovery rate is related to oxygen supply, muscle fibre type or type of exercise. We revealed that oxygen supply also increases from distal to proximal along the tibialis anterior, and that it strongly correlated with phosphocreatine recovery. Carnosine level, a surrogate measure for muscle fibre type was not different between proximal and distal, and type of exercise did not affect the gradient in phosphocreatine recovery rate. Taken together, the findings of this study suggest that the post-exercise spatial gradients in oxygen supply and phosphocreatine recovery are driven by a higher intrinsic mitochondrial oxidative capacity proximally. ABSTRACT: Phosphorus magnetic resonance spectroscopy (31 P MRS) of human tibialis anterior (TA) revealed a strong proximo-distal gradient in the post-exercise phosphocreatine (PCr) recovery rate constant (kPCr ), a measure of muscle oxidative capacity. The aim of this study was to investigate whether this kPCr gradient is related to O2 supply, resting phosphorylation potential, muscle fibre type, or type of exercise. Fifteen male volunteers performed continuous isometric ankle dorsiflexion at 30% maximum force until exhaustion. At multiple locations along the TA, we measured the oxidative PCr resynthesis rate (VPCr = kPCr × PCr depletion) by 31 P MRS, the oxyhaemoglobin recovery rate constant (kO2Hb ) by near infrared spectroscopy, and muscle perfusion with MR intravoxel incoherent motion imaging. The kO2Hb , kPCr , VPCr and muscle perfusion depended on measurement location (P < 0.001, P < 0.001, P = 0.032 and P = 0.003, respectively), all being greater proximally. The kO2Hb and muscle perfusion correlated with kPCr (r = 0.956 and r = 0.852, respectively) and VPCr (r = 0.932 and r = 0.985, respectively), the latter reflecting metabolic O2 consumption. Resting phosphorylation potential (PCr/inorganic phosphate) was also higher proximally (P < 0.001). The surrogate for fibre type, carnosine content measured by 1 H MRS, did not differ between distal and proximal TA (P = 0.884). Performing intermittent exercise to avoid exercise ischaemia, still led to larger kPCr proximally than distally (P = 0.013). In conclusion, the spatial kPCr gradient is strongly associated with the spatial variation in O2 supply. It cannot be explained by exercise-induced ischaemia nor by fibre type. Our findings suggest it is driven by a higher proximal intrinsic mitochondrial oxidative capacity, apparently to support contractile performance of the TA.

Spiral breast computed tomography (CT): signal-to-noise and dose optimization using 3D-printed phantoms.

OBJECTIVES: To investigate the dependence of signal-to-noise ratio (SNR) and calculated average dose per volume of spiral breast-CT (B-CT) on breast size and breast density and to provide a guideline for choosing the optimal tube current for each B-CT examination. MATERIALS AND METHODS: Three representative B-CT datasets (small, medium, large breast size) were chosen to create 3D-printed breast phantoms. The phantoms were filled with four different agarose-oil-emulsions mimicking differences in breast densities. Phantoms were scanned in a B-CT system with systematic variation of the tube current (6, 12.5, 25, 32, 40, 50, 64, 80, 100, 125 mA). Evaluation of SNR and the average dose per volume using Monte Carlo simulations were performed for high (HR) and standard (STD) spatial resolution. RESULTS: SNR and average dose per volume increased with increasing tube current. Artifacts had negligible influence on image evaluation. SNR values ≥ 35 (HR) and ≥ 100 (STD) offer sufficient image quality for clinical evaluation with SNR being more dependent on breast density than on breast size. For an average absorbed dose limit of 6.5 mGy for the medium and large phantoms and 7 mGy for the small phantom, optimal tube currents were either 25 or 32 mA. CONCLUSIONS: B-CT offers the possibility to vary the X-ray tube current, allowing image quality optimization based on individual patient's characteristics such as breast size and density. This study describes the optimal B-CT acquisition parameters, which provide diagnostic image quality for various breast sizes and densities, while keeping the average dose at a level similar to digital mammography. KEY POINTS: • Image quality optimization based on breast size and density varying the tube current using spiral B-CT.

Structured manual for MRI assessment of deep infiltrating endometriosis using the ENZIAN classification.

PURPOSE: Proposal of a systematic approach to assess Deep infiltrating endometriosis (DIE) through pelvic Magnetic resonance imaging (MRI) using the Enzian classification and examination of inter-rater agreement. METHODS: Three radiologists reviewed 23 MRI of patients with pelvic DIE at one tertiary referral center retrospectively and independently. Inclusion criteria were intraoperative confirmation of DIE and MR imaging according to ESUR (European Society of Urogenital Radiology) guidelines. Assessment of the anatomical pelvic compartments was performed using a manual based on the Enzian classification with step-by-step instructions using recommended planes and sequences presented here. Interrater agreement was measured using kappa statistics. RESULTS: According to the intraoperative site lesions in 53 anatomical compartments were present. Interrater agreement was best for compartments A (0.255) and FB (0.642). For FI (0.204) and B (0.146) it was slight, there was poor agreement for C (- 0.263), FA (- 0.022), and FO (- 0.030), respectively, and as for FU, no ureter infiltration was described. CONCLUSION: MRI as a noninvasive diagnostic tool offers essential advantages regarding classification and therapy planning for patients with DIE. However, its assessment is difficult and a more systematic approach is needed. Our proposed manual based on the Enzian classification is reproducible and could support radiologists and gynecologists.

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.

Contrast media kinetics in multiparametric magnetic resonance imaging before radical prostatectomy predicts the probability of postoperative incontinence.

PURPOSE: To evaluate the role of preoperative multiparametric magnetic resonance imaging (MRI) as predictor of post-prostatectomy incontinence (PPI). METHODS: We analyzed patients who underwent robot-assisted radical prostatectomy for localized prostate cancer at our institution between July 2015 and April 2017. In these patients, we measured the perfusion quality of the pelvic floor with contrast media kinetics in the preoperative MRI of the prostate and compared the levator ani muscle (region of interest) to the surrounding pelvic muscle structures (reference). Prospectively collected questionnaires regarding urinary incontinence were then evaluated 1 year postoperatively. Outcomes were dichotomized into "continent" (ICIQ-Score = 0-5) and "incontinent" (ICIQ-Score ≥ 6). In each patient, we determined the perfusion ratio of the levator ani muscle divided by the surrounding pelvic muscle structures and compared them among the groups. RESULTS: Forty-two patients were included in the study (n = 22 in "continent", n = 20 in "incontinent" group). The median perfusion ratio from the continent group was significantly higher compared to the incontinent group (1.61 vs. 1.15; 95% CI 0.09-0.81, p = 0.015). The median perfusion ratio in "excellent" (ICIQ-Score = 0) was significantly higher than in "poor" (ICIQ-Score ≥ 11) outcomes (1.48 vs. 0.94; 95% CI 0.04-1.03, p = 0.036). Further, a higher perfusion ratio was negatively correlated with ICIQ-Score (r = - 0.33; 95% CI - 0.58 to 0.03; p = 0.031). CONCLUSIONS: Our data demonstrate a promising new strategy to predict PPI through the perfusion quality of pelvic muscle structures with contrast media kinetics. This may facilitate preoperative patient consulting and decision-making.

Atypical ductal hyperplasia: breast DCE-MRI can be used to reduce unnecessary open surgical excision.

PURPOSE: To evaluate the diagnostic performance of dynamic contrast-enhanced (DCE)-MRI in predicting malignancy after percutaneous biopsy diagnosis of atypical ductal hyperplasia (ADH). METHODS AND MATERIALS: In this retrospective study, 68 lesions (66 women) with percutaneous biopsy diagnosis of ADH and pre-operative breast DCE-MRI performed between January 2016 and December 2017 were included. Two radiologists reviewed in consensus mammography, ultrasound, and MR images. The final diagnosis after surgical excision was used as standard of reference. Clinical and imaging features were compared in patients with and without upgrade to malignancy after surgery. The diagnostic performance of DCE-MRI in predicting malignant upgrade was evaluated. RESULTS: A 9-gauge vacuum-assisted biopsy was performed in 40 (58.8%) cases and a 14-gauge core needle biopsy in 28 (41.2%) cases. Upgrade to malignancy was observed in 17/68 (25%) lesions, including 4/17 (23.5%) cases of invasive cancer and 13/17 (76.5%) cases of ductal carcinoma in situ (DCIS). In 16/17 (94.1%) malignant and 20/51 (39.2%) benign lesions, a suspicious enhancement could be recognized in DCE-MRI. The malignant lesion without suspicious enhancement was a low-grade DCIS (4 mm size). Sensitivity, specificity, positive predictive value, and negative predictive value of DCE-MRI on predicting malignancy were respectively 94.1%, 60.7%, 44.4%, and 96.8%. No other clinical or imaging features were significantly different in patients with and without upgrade to malignancy. CONCLUSION: After a percutaneous biopsy diagnosis of ADH, malignancy can be ruled out in most of the cases, if no suspicious enhancement is present in the biopsy area at DCE-MRI. Breast DCE-MRI may be used to avoid surgery in more than half of the patients with final benign diagnosis. KEY POINTS: • Breast DCE-MRI can safely rule out malignancy if no suspicious enhancement is present in the biopsy area after a percutaneous biopsy diagnosis of ADH. • All cases of upgrade to high-grade DCIS and invasive cancers can be identified at breast DCE-MRI after a percutaneous biopsy diagnosis of ADH. • Breast DCE-MRI may be used to avoid surgery in more than half of the patients with final benign diagnosis.

Correction to: Towards clinical grating-interferometry mammography.

The article Towards clinical grating-interferometry mammography, written by Carolina Arboleda, Zhentian Wang, Konstantins Jefimovs, Thomas Koehler, Udo Van Stevendaal, Norbert Kuhn, Bernd David, Sven Prevrhal, Kristina Lång, Serafino Forte, Rahel Antonia Kubik-Huch, Cornelia Leo.

Towards clinical grating-interferometry mammography.

OBJECTIVES: Grating-interferometry-based mammography (GIM) might facilitate breast cancer detection, as several research works have demonstrated in a pre-clinical setting, since it is able to provide attenuation, differential phase contrast, and scattering images simultaneously. In order to translate this technique to the clinics, it has to be adapted to cover a large field-of-view within a clinically acceptable exposure time and radiation dose. METHODS: We set up a grating interferometer that fits into a standard mammography system and fulfilled the aforementioned conditions. Here, we present the first mastectomy images acquired with this experimental device. RESULTS AND CONCLUSION: Our system performs at a mean glandular dose of 1.6 mGy for a 5-cm-thick, 18%-dense breast, and a field-of-view of 26 × 21 cm2. It seems to be well-suited as basis for a clinical-environment device. Further, dark-field signals seem to support an improved lesion visualization. Evidently, the effective impact of such indications must be evaluated and quantified within the context of a proper reader study. KEY POINTS: • Grating-interferometry-based mammography (GIM) might facilitate breast cancer detection, since it is sensitive to refraction and scattering and thus provides additional tissue information. • The most straightforward way to do grating-interferometry in the clinics is to modify a standard mammography device. • In a first approximation, the doses given with this technique seem to be similar to those of conventional mammography.

Ossified blood vessels in primary familial brain calcification elicit a neurotoxic astrocyte response.

Brain calcifications are commonly detected in aged individuals and accompany numerous brain diseases, but their functional importance is not understood. In cases of primary familial brain calcification, an autosomally inherited neuropsychiatric disorder, the presence of bilateral brain calcifications in the absence of secondary causes of brain calcification is a diagnostic criterion. To date, mutations in five genes including solute carrier 20 member 2 (SLC20A2), xenotropic and polytropic retrovirus receptor 1 (XPR1), myogenesis regulating glycosidase (MYORG), platelet-derived growth factor B (PDGFB) and platelet-derived growth factor receptor ß (PDGFRB), are considered causal. Previously, we have reported that mutations in PDGFB in humans are associated with primary familial brain calcification, and mice hypomorphic for PDGFB (Pdgfbret/ret) present with brain vessel calcifications in the deep regions of the brain that increase with age, mimicking the pathology observed in human mutation carriers. In this study, we characterize the cellular environment surrounding calcifications in Pdgfbret/ret animals and show that cells around vessel-associated calcifications express markers for osteoblasts, osteoclasts and osteocytes, and that bone matrix proteins are present in vessel-associated calcifications. Additionally, we also demonstrate the osteogenic environment around brain calcifications in genetically confirmed primary familial brain calcification cases. We show that calcifications cause oxidative stress in astrocytes and evoke expression of neurotoxic astrocyte markers. Similar to previously reported human primary familial brain calcification cases, we describe high interindividual variation in calcification load in Pdgfbret/ret animals, as assessed by ex vivo and in vivo quantification of calcifications. We also report that serum of Pdgfbret/ret animals does not differ in calcification propensity from control animals and that vessel calcification occurs only in the brains of Pdgfbret/ret animals. Notably, ossification of vessels and astrocytic neurotoxic response is associated with specific behavioural and cognitive alterations, some of which are associated with primary familial brain calcification in a subset of patients.

Does lipofilling after oncologic breast surgery increase the amount of suspicious imaging and required biopsies?-A systematic meta-analysis.

OBJECTIVE: The aim of our systematic meta-analysis was to find out if lipofilling to the breast alters follow-up imaging procedures and leads to an increased number of biopsies because of suspicious findings. METHODS: We conducted a systematic meta-analysis of the literature including all prospective and retrospective studies focusing on imaging outcomes in patients with a history of breast cancer who have received one or more lipofilling procedures after oncologic surgery to the breast. RESULTS: Twelve studies met the inclusion criteria, comprising 1711 patients and at least 2261 lipofilling procedures. 564 patients (33%) were followed up only with ultrasound, 735 patients (43%) only received mammography, 273 (16%) had a combination of ultrasound, mammography and MRI, and 37 patients (2.1%) were followed up via ultrasound and mammography. A collective of 102 patients making up a matched-cohort study received ultrasound, mammography, MRI, and PET/CT, while only 51 of them made up the investigation group who had autologous fat grafting (3%). Biopsy rates were 1%-24% with a medium of 6.5% over all groups. Medium follow-up was 18.8 months (range 6-50 months). The rate of local oncologic events among the patients with lipofilling procedures detected during the study periods was 0.7%. CONCLUSION: Lipofilling to the breast after oncologic operations appears to be a safe procedure with overall low biopsy and local recurrence rate. Suspicious imaging occurs in most cases out of physiologic remodeling and inflammation processes at the operation site and needs to be distinguished from malignant focusses. The amount of required biopsies stands in relation to the used imaging method and the time to follow-up.

[New Trends in Breast Imaging]. / Neue Wege in der Senologischen Bildgebung.

New Trends in Breast Imaging Abstract. The examination of the breast, especially as a screening examination for breast cancer, has so far been carried out primarily by means of mammography and occasionally supplementary ultrasound. These check-ups have become established because early diagnosis of breast cancer increases the chances of recovery. Breast cancer is the most common cancer in women (approximately every 8th woman is affected). While the MRI examination, which offers a high level of sensitivity and specificity, has so far established itself as a further clarification, new examination methods have emerged in the recent past, which on the one hand make the examination more pleasant for women (e. g. no compression of the mammary gland tissue, as is the case with mammography) and which could potentially be diagnostically equivalent. In particular, this article mentions automatic breast ultrasound (ABUS) and computer tomography of the breast (breast CT). In the future, programs with artificial intelligence could also help confirm the diagnoses or increase accuracy so that no relevant lesion is overlooked.

Effects of short-term continuous positive airway pressure withdrawal on cerebral vascular reactivity measured by blood oxygen level-dependent magnetic resonance imaging in obstructive sleep apnoea: a randomised controlled trial.

Impaired cerebral vascular reactivity (CVR) increases long-term stroke risk. Obstructive sleep apnoea (OSA) is associated with peripheral vascular dysfunction and vascular events. The aim of this trial was to evaluate the effect of continuous positive airway pressure (CPAP) withdrawal on CVR.41 OSA patients (88% male, mean age 57±10 years) were randomised to either subtherapeutic or continuation of therapeutic CPAP. At baseline and after 2 weeks, patients underwent a sleep study and magnetic resonance imaging (MRI). CVR was estimated by quantifying the blood oxygen level-dependent (BOLD) MRI response to breathing stimuli.OSA did recur in the subtherapeutic CPAP group (mean treatment effect apnoea-hypopnoea index +38.0 events·h-1, 95% CI 24.2-52.0; p<0.001) but remained controlled in the therapeutic group. Although there was a significant increase in blood pressure upon CPAP withdrawal (mean treatment effect +9.37 mmHg, 95% CI 1.36-17.39; p=0.023), there was no significant effect of CPAP withdrawal on CVR assessed via BOLD MRI under either hyperoxic or hypercapnic conditions.Short-term CPAP withdrawal did not result in statistically significant changes in CVR as assessed by functional MRI, despite the recurrence of OSA. We thus conclude that, unlike peripheral endothelial function, CVR is not affected by short-term CPAP withdrawal.

Automatic classification of ultrasound breast lesions using a deep convolutional neural network mimicking human decision-making.

OBJECTIVES: To evaluate a deep convolutional neural network (dCNN) for detection, highlighting, and classification of ultrasound (US) breast lesions mimicking human decision-making according to the Breast Imaging Reporting and Data System (BI-RADS). METHODS AND MATERIALS: One thousand nineteen breast ultrasound images from 582 patients (age 56.3 ± 11.5 years) were linked to the corresponding radiological report. Lesions were categorized into the following classes: no tissue, normal breast tissue, BI-RADS 2 (cysts, lymph nodes), BI-RADS 3 (non-cystic mass), and BI-RADS 4-5 (suspicious). To test the accuracy of the dCNN, one internal dataset (101 images) and one external test dataset (43 images) were evaluated by the dCNN and two independent readers. Radiological reports, histopathological results, and follow-up examinations served as reference. The performances of the dCNN and the humans were quantified in terms of classification accuracies and receiver operating characteristic (ROC) curves. RESULTS: In the internal test dataset, the classification accuracy of the dCNN differentiating BI-RADS 2 from BI-RADS 3-5 lesions was 87.1% (external 93.0%) compared with that of human readers with 79.2 ± 1.9% (external 95.3 ± 2.3%). For the classification of BI-RADS 2-3 versus BI-RADS 4-5, the dCNN reached a classification accuracy of 93.1% (external 95.3%), whereas the classification accuracy of humans yielded 91.6 ± 5.4% (external 94.1 ± 1.2%). The AUC on the internal dataset was 83.8 (external 96.7) for the dCNN and 84.6 ± 2.3 (external 90.9 ± 2.9) for the humans. CONCLUSION: dCNNs may be used to mimic human decision-making in the evaluation of single US images of breast lesion according to the BI-RADS catalog. The technique reaches high accuracies and may serve for standardization of highly observer-dependent US assessment. KEY POINTS: • Deep convolutional neural networks could be used to classify US breast lesions. • The implemented dCNN with its sliding window approach reaches high accuracies in the classification of US breast lesions. • Deep convolutional neural networks may serve for standardization in US BI-RADS classification.

Impact of hypertension on cerebral microvascular structure in CPAP-treated obstructive sleep apnoea patients: a diffusion magnetic resonance imaging study.

PURPOSE: Obstructive sleep apnoea (OSA) is a highly prevalent sleep-related breathing disorder associated with hypertension, impaired peripheral vascular function and an increased risk of stroke. Evidence suggests that abnormalities of the cerebral microcirculation, such as capillary rarefication, may be present in these patients. We evaluated whether the presence of hypertension may affect the cerebral capillary architecture and function assessed by Intravoxel Incoherent Motion (IVIM) magnetic resonance imaging (MRI) in patients with continuous positive airway pressure (CPAP)-treated OSA. METHODS: Forty-one patients (88% male, mean age 57 ± 10 years) with moderate-to-severe OSA were selected and divided into two groups (normotensive vs. hypertensive). All hypertensive OSA patients were adherent with their antihypertensive medication. Cerebral microvascular structure was assessed in grey (GM) and white matter (WM) using an echo-planar diffusion imaging sequence with 14 different b values. A step-wise IVIM analysis algorithm was applied to compute true diffusion (D), perfusion fraction (f) and pseudo-diffusion (D*) values. Group comparisons were performed with the Wilcoxon-Mann-Whitney-Test. Regression analysis was adjusted for age. RESULTS: Diffusion- and perfusion-related indexes in middle-aged OSA normotensive patients were quantified in both tissue types (D [10-3 mm2/s]: GM = 0.83 ± 0.03; WM = 0.72 ± 0.03; f (%) GM = 0.09 ± 0.01; WM = 0.06 ± 0.01; D* [10-3 mm2/s]: GM = 7.72 ± 0.89; WM = 7.38 ± 0.98). In the examined tissue types, hypertension did not result in changes on the estimated MRI IVIM index values. CONCLUSION: Based on IVIM analysis, cerebral microvascular structure and function showed no difference between hypertensive and normotensive patients with moderate-to-severe OSA treated with CPAP. Treatment adherence with antihypertensive drug regime and, in turn, controlled hypertension seems not to affect microvascular structure and perfusion of the brain. TRIAL REGISTRATION: ClinicalTrials.gov Identifier: NCT02493673.

Dependency of the blood oxygen level dependent-response to hyperoxic challenges on the order of gas administration in intracranial malignancies.

PURPOSE: Literature reports contradicting results on the response of brain tumors to vascular stimuli measured in T2*-weighted MRI. Here, we analyzed the potential dependency of the MRI-response to (hypercapnic) hyperoxia on the order of the gas administration. METHODS: T2* values were quantified at 3 Tesla in eight consenting patients at rest and during inhalation of hyperoxic/hypercapnic gas mixtures. Patients were randomly divided into two groups undergoing different gas administration protocols (group A: medical air-pure oxygen-carbogen; group B: medical air-carbogen-pure oxygen). Mann-Whitney U test and Wilcoxon signed rank test have been used to proof differences in T2* regarding respiratory challenge or different groups, respectively. RESULTS: T2* values at rest for gray and white matter were 50.3 ± 2.6 ms and 46.1 ± 2.0 ms, respectively, and slightly increased during challenge. In tumor areas, T2* at rest were: necrosis = 74.1 ± 10.1 ms; edema = 60.3 ± 17.6 ms; contrast-enhancing lesions = 48.6 ± 20.7 ms; and solid T2-hyperintense lesions = 45.0 ± 3.0 ms. Contrast-enhancing lesions strongly responded to oxygen (+ 20.7%) regardless on the gas protocol (p = 0.482). However, the response to carbogen significantly depended on the order of gas administration (group A, + 18.6%; group B, - 6.4%, p = 0.042). In edemas, a different trend between group was found when breathing oxygen (group A, - 9.9%; group B, + 19.5%, p = 0.057). CONCLUSION: Preliminary results show a dependency of the T2* response of contrast-enhancing brain tumor lesions on the order of the gas administration. The gas administration protocol is an important factor in the interpretation of the T2*-response in areas of abnormal vascular growth.