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

STUDY DESIGN This study constitutes a systematic review of the literature. OBJECTIVE The aim of this study was to identify and present all available studies that report on the costs of osteobiologics used in anterior cervical discectomy and fusion (ACDF). METHODS The literature was systematically reviewed to identify studies with specific inclusion criteria: (1) randomized controlled trials and observational studies, (2) in adult patients, (3) with herniated disc(s) or degenerative cervical spine disease, (4) reporting on either direct or indirect costs of using specific osteobiologics in an ACDF operation. (5) Only studies in English were included. The quality of the included studies was assessed using the MINORS and RoB 2.0 tools. RESULTS Overall, 14 articles were included; one randomized controlled trial and 13 observational studies. The most commonly used osteobiologics other than autograft/iliac crest bone graft (ICBG) were allograft and bone morphogenetic protein (BMP). None of the studies was reported to be industry-supported. There was considerable heterogeneity on the reported costs. Overall, most studies reported on surgery-related costs, such as anesthesia, operating room, surgical materials and surgeon's fee. Only two studies, both using allograft, reported the exact cost of the osteobiologic used (450 GBP, $700). Some of the studies reported on the cost of care during hospitalization for the surgical operation, such as radiology studies, emergency room costs, cardiologic evaluation, laboratory studies, pharmacy costs, and room costs. Only a few studies reported on the cost of follow-up, reoperation, and physical therapy and rehabilitation. CONCLUSION Based on the data of this current systematic review, no recommendations can be made regarding the cost-effectiveness of using osteobiologics in ACDF. Given the high costs of osteobiologics, this remains a topic of importance. The design of future studies on the subject should include cost effectiveness.

In this retrospective, single-center study we investigate the changes of radiomics features during dynamic breast-MRI for healthy tissue compared to benign and malignant lesions.60 patients underwent breast-MRI using a dynamic 3D gradient-echo sequence. Changes of 34 texture features (TF) in 30 benign and 30 malignant lesions were calculated for 5 dynamic datasets and corresponding 4 subtraction datasets. Statistical analysis was performed with ANOVA, and systematic changes in features were described by linear and polynomial regression models.ANOVA revealed significant differences (p 0.05) between normal tissue and lesions in 13 TF, compared to 9 TF between benign and malignant lesions. Most TF showed significant differences in early dynamic and subtraction datasets. TF associated with homogeneity were suitable to discriminate between healthy parenchyma and lesions, whereas run-length features were more suitable to discriminate between benign and malignant lesions. Run length nonuniformity (RLN) was the only feature able to distinguish between all three classes with an AUC of 88.3%. Characteristic changes were observed with a systematic increase or decrease for most TF with mostly polynomial behavior. Slopes showed earlier peaks in malignant lesions, compared to benign lesions. Mean values for the coefficient of determination were higher during subtraction sequences, compared to dynamic sequences (benign: 0.98 vs 0. 72; malignant: 0.94 vs 0.74).TF of breast lesions follow characteristic patterns during dynamic breast-MRI, distinguishing benign from malignant lesions. Early dynamic and subtraction datasets are particularly suitable for texture analysis in breast-MRI. Features associated with tissue homogeneity seem to be indicative of benign lesions.

Study Design. Bibliometric Review Objective. This study aims to understand the worldwide research productivity trends in spine-related research over the past five decades. Summary of Background Data. ?? ??? Methods. We evaluated original research articles published in four prestigious journals on spine research (European Spine Journal, Journal of Neurosurgery: Spine, Spine, and The Spine Journal) from 1976 to 2020. For one year of each decade, the origin of the first and the senior author was assigned to their region of origin. For the year 2020, a detailed analysis of countries and states of origin was performed, and the number of articles was normalized by registered MDs per country (per 10,000 population). Results. We included a total of 4,436 articles and 8,776 authors for analysis. From 1976 to 2020, the percentage of publications originating from North America decreased (77% ��� 38%). In contrast, Asian contributions drastically increased (3% ��� 36%), whereas articles originating from Europe only slightly raised (20% ��� 22%). In 2020, the USA was the most productive country worldwide (34% with most articles from New York (19%), followed by China (16%) and Japan (10%). After normalization to registered MDs (per 10,000 population), the USA proved to have the highest number of articles. Besides this, India now ranked fourth and Egypt eighth in terms of the most productive countries per MDs. Conclusion. North America contributed the largest share of all articles published in the last five decades. Asia, which ranks second in 2020, has overtaken Europe. Normalization to registered MDs can be a helpful tool to reflect a country's research productivity more accurately. Level of Evidence: 3

Background The economic burden of vertebral compression fractures (VCF) caused by osteoporosis was estimated at 37 billion euros in the European Union in 2010. In addition, the incidence is expected to increase by 25% in 2025. The recommendations for the therapy of VCFs (conservative treatment versus cement augmentation procedures) are controversial, what could be partly explained by the lack of standardized outcomes for measuring the success of both treatments. Consensus on outcome parameters may improve the relevance of a study and for further comparisons in meta-analyses. The aim of this study was to analyze outcome measures from frequently cited randomized controlled trials (RCTs) about VCF treatments in order to provide guidance for future studies. Material and methods We carried out a systematic search of all implemented databases from 1973 to 2019 using the Web of Science database. The terms “spine” and “random” were used for the search. We included: Level I RCTs, conservative treatment or cement augmentation of osteoporotic vertebral fractures, cited ≥50 times. The outcome parameters of each study were extracted and sorted according to the frequency of use. Results Nine studies met the inclusion criteria. In total, 23 different outcome parameters were used in the nine analyzed studies. Overall, the five most frequently used outcome parameters (≥ 4 times used) were the visual analogue scale (VAS) for pain (n = 9), European Quality of Life–5 Dimensions (EQ-5D; n = 4) and Roland–Morris Disability Questionnaire (RMDQ, n = 4). Conclusion With our study, we demonstrated that a large inconsistency exists between outcome measures in highly cited Level I studies of VCF treatment. Pain (VAS), followed by HrQoL (EQ-5D) and disability and function (RMDQ), opioid use, and radiological outcome (kyphotic angle, VBH, and new VCFs) were the most commonly used outcome parameters. Supplementary Information The online version contains supplementary material available at 10.1186/s12891-021-04305-6.

Introduction Summer alpine sports, including mountain biking, hiking and airborne pursuits, have experienced a recent surge in popularity. Accordingly, trauma associated with these activities has increased. There is a scarcity of literature exploring clinical aspects surrounding injuries. Specifically, no single article provides a general overview, as individual studies tend to focus on one particular sport. In the present study, we performed a systematic literature review to summarize existing knowledge and explore the potential for prevention and clinical decision making in this group. Method Literature searches were performed using the PubMed and Scopus database for the most commonly ventured sports associated with injury: mountain biking, climbing, airborne sports, paragliding, and base jumping. From this search, studies were identified for qualitative and quantitative analyses. These searches were done according to PRISMA guidelines for systematic reviews. Studies were then analyzed regarding epidemiology of injuries, relevant anatomical considerations and prevention strategies were discussed. Results A broad spectrum of injury sites and mechanisms are seen in mountain biking, climbing or airborne sports. Mountain biking related injuries commonly involve the upper extremity, with fractures of the clavicle being the most common injury, followed by fractures of the hand and wrist. Scaphoid fractures remain of paramount importance in a differential diagnosis, given their often subtle clinical and radiological appearance. Paragliding, skydiving, and base jumping particularly affect transition areas of the spine, such as the thoracolumbar and the spinopelvic regions. Lower limb injuries were seen in equal frequency to spinal injuries. Regarding relative risk, mountain biking has the lowest risk for injuries, followed by climbing and airborne sports. Male alpinists are reported to be more susceptible to injuries than female alpinists. Generally, the literature surrounding hiking and water-related mountain sports is insufficient, and further work is required to elucidate injury mechanisms and effective preventative measures. A helmet seems to decrease the likelihood of face and head injuries in mountain sports and be a meaningful preventive measurement.

Zusammenfassung. Mit den in den letzten Jahren erzielten technischen Fortschritten in der Schnittbildgebung wurde der Stellenwert der Radiologie im klinischen Alltag zunehmend bedeutender. So auch in der Diagnostik und Evaluation von Neuropathien. Die hochsensitive Elektrophysiologie wird zunehmend durch spezifische Bildgebung ergänzt. Therapierelevante Informationen aus der Bildgebung sind unter anderem die Lokalisation und Ursache, aber auch das Verteilungsmuster einer Neuropathie. Die MR-Neurographie hilft, die diagnostische Sicherheit zu erhöhen und bildet einen wichtigen Pfeiler im Management der Patienten. Die Möglichkeiten und den aktuellen Stellenwert der Bildgebung von Ultraschall (US), über die Computertomographie (CT), bis zur Magnetresonanztomographie (MRT), möchten wir in diesem Artikel darstellen.

Study designThis is a retrospective cohort study.ObjectivesThis study aims to determine the proportional incidence, clinical characteristics, treatment patterns with complications and changes in treatment of vertebral fractures over 10 years at a Swiss university hospital.MethodsA retrospective cohort study was performed. All patients with an acute vertebral fracture were included in this study. The extracted anonymized data from the medical records were manually assessed. Demographic data, exact location, etiology, type of treatment and complications related to the treatment were obtained.ResultsOf 330,225 treated patients, 4772 presented with at least one vertebral fracture. In total 8307 vertebral fractures were identified, leading to a proportional incidence of 25 vertebral fractures in 1000 patients. Fractures were equally distributed between genders. Male patients were significantly younger and more likely to sustain a traumatic fracture, while female patients more commonly presented with osteoporotic fractures. The thoracolumbar junction (Th11-L2) was the most frequent fracture site in all etiologies. More than two-thirds of vertebral fractures were treated surgically (68.6%). Out of 4622 performed surgeries, we found 290 complications (6.3%). The odds for surgical treatment in osteoporotic fractures were two times higher before 2010 compared to 2010 and after (odds ratio: 2.1, 95% CI 1.5–2.9,p ConclusionTwenty-five out of 1000 patients presented with a vertebral fracture. More than 4000 patients with over 8307 vertebral body fractures were treated in 10 years. Over two-thirds of all fractures were treated surgically with 6.3% complications. There was a substantial decrease in surgeries for osteoporotic fractures after 2009.

An atypical course of the vertebral artery can be medically relevant in displaced Hangman fractures, especially if the artery course runs within the fracture gap of the C2 isthmus. During surgical reduction, the artery can be occluded inside the fracture, potentially leading to ischemic conditions of the brain. The aim of this study was to report two cases according to the CARE (case reporting) guidelines, in which intraoperative color-coded duplex-ultrasound was performed to secure safe surgical reduction of hangman fractures in two patients with an atypical course of the vertebral artery. Two patients with displaced hangman fractures (Effendi-Levine type II) were diagnosed with an atypical course of the vertebral artery running inside the fracture gap. This endangered safe surgical management with the risk of iatrogenic occlusion or injury during reduction through entrapment of the vessel inside the fracture gap. Therefore, an intraoperative color-coded duplex-ultrasound of the vertebral artery was conducted before and after reduction of the fracture, as well as at the end of the surgery. The surgical treatment in both cases included posterior unilateral spondylodesis, followed by anterior cervical discectomy and fusion (ACDF). In both patients, a safe reduction of the fracture was performed. Neither occlusion nor dissection of the vertebral artery occurred. The duplex ultrasound before and after reduction, and at the end of the procedure showed normal blood flow and morphology of both vertebral arteries. At follow-up examinations, the patients showed a favorable clinical outcome, radiographic signs of fusion, and no irregularity of the vertebral arteries. This case report serves as proof-of-concept, demonstrating the feasibility of this regimen to minimize the risk of entrapment or occlusion of the vertebral artery in the surgical management of displaced Hangman fractures with atypical course of the vertebral artery running inside the fracture gap.

Background The current standard of care for intervertebral disc (IVD) herniation, surgical discectomy, does not repair annulus fibrosus (AF) defects, which is partly due to the lack of effective methods to do so and is why new repair strategies are widely investigated and tested preclinically. There is a need to develop a standardized IVD injury model in large animals to enable comparison and interpretation across preclinical study results. The purpose of this study was to compare in vivo IVD injury models in sheep to determine which annulus fibrosus (AF) defect type combined with partial nucleus pulposus (NP) removal would better mimic degenerative human spinal pathologies. Methods Six skeletally mature sheep were randomly assigned to one of the two observation periods (1 and 3 months) and underwent creation of 3 different AF defect types (slit, cruciate, and box-cut AF defects) in conjunction with 0.1 g NP removal in three lumbar levels using a lateral retroperitoneal surgical approach. The spine was monitored by clinical CT scans pre- and postoperatively, at 2 weeks and euthanasia, and by magnetic resonance imaging (MRI) and histology after euthanasia to determine the severity of degeneration (disc height loss, Pfirrmann grading, semiquantitative histopathology grading). Results All AF defects led to significant degenerative changes detectable on CT and MR images, produced bulging of disc tissue without disc herniation and led to degenerative and inflammatory histopathological changes. However, AF defects were not equal in terms of disc height loss at 3 months postoperatively; the cruciate and box-cut AF defects showed significantly decreased disc height compared to their preoperative height, with the box-cut defect creating the greatest disc height loss, while the slit AF defect showed restoration of normal preoperative disc height. Conclusions The tested IVD injury models do not all generate comparable disc degeneration but can be considered suitable IVD injury models to investigate new treatments. Results of the current study clearly indicate that slit AF defect should be avoided if disc height is used as one of the main outcomes; additional confirmatory studies may be warranted to generalize this finding.

Background Bone marrow mesenchymal stromal cells (BMSCs) are promising for therapeutic use in cartilage repair, because of their capacity to differentiate into chondrocytes. Often, in vitro differentiation protocols employ the use of high amount of glucose, which does not reflect cartilage physiology. For this reason, we investigated how different concentrations of glucose can affect the chondrogenic differentiation of BMSCs in cell culture pellets. Additionally, we investigated how fructose could influence the chondrogenic differentiation in vitro. Methods BMSC were isolated from six donors and cultured in DMEM containing glucose at either 25 mM (HG), 5.5 mM (LG) or 1 mM (LLG), and 1% non-essential amino acids, 1% ITS+, in the presence of 100 nM dexamethasone, 50 µg/ml ascorbic acid-2 phosphate and 10 ng/ml TGF-β1. To investigate the effect of different metabolic substrates, other groups were exposed to additional 25 mM fructose. The media were replaced every second day until day 21 when all the pellets were harvested for further analyses. Biochemical analysis for glycosaminoglycans into pellets and released in medium was performed using the DMMB method. Expression of GLUT3 and GLUT5 was assayed by qPCR and validated using FACS analysis and immunofluorescence in monolayer cultures. Chondrogenic differentiation was further confirmed by qPCR analysis of COL2A1, COL1A1, COL10A1, ACAN, RUNX2, SOX9, SP7, MMP13, and PPARG, normalized on RPLP0. Type 2 collagen expression was subsequently validated by immunofluorescence analysis. Results We show for the first time the presence of fructose transporter GLUT5 in BMSC and its regulation during chondrogenic commitment. Additionally, decreasing glucose concentration during chondrogenesis dramatically decreased the yield of differentiation. However, the use of fructose alone or together with low glucose concentrations does not limit cell differentiation, but on the contrary it might help in maintaining a stable chondrogenic phenotype comparable with the standard culture conditions (high glucose). Conclusion This study provides evidence that BMSC express GLUT5 and differentially regulate GLUT3 in the presence of glucose variation. This study gives a better comprehension of BMSCs sugar use during chondrogenesis.

Study Design A single-center validation study. Objective To translate and cross-culturally adapt the AO Spine PROST (Patient Reported Outcome Spine Trauma) into German, and to test its psychometric properties among German-speaking Swiss spine trauma patients. Methods Patients were recruited from a level-1 Swiss trauma center. Next to the AO Spine PROST, the EQ-5D-3L questionnaire was used for concurrent validity. Questionnaires were filled out at two-time points for test-retest reliability. Patient characteristics were analyzed using descriptive statistics. For content validity, floor, and ceiling effects, as well as any irrelevant and missing questions were analyzed. Construct validity of the AO Spine PROST questionnaire to the EQ-5D-3L was tested using Spearman correlation tests. Results The AOSpine PROST was translated and adapted into German using established guidelines. We included 179 patients. The floor effect for all items was well within the optimal range (below 15%), while the ceiling effect of seven items was within the optimal range. None of the items displayed a problematic floor or ceiling effect. The overall test-retest reliability of the total PROST score was excellent, with an ICC of .83 (95% CI .69-.91). The Spearman correlation coefficient between the total PROST summary score and EQ-5D-3 L was ρ = .63. Conclusions The German version of the AO Spine PROST questionnaire demonstrated very good validity and reliability results.

Objectives: To investigate the technical feasibility of whole-body intravoxel incoherent motion (IVIM) imaging. Materials and Methods: Whole-body MR images of eight healthy volunteers were acquired at 3T using a spin-echo echo-planar imaging sequence with eight b-values. Coronal parametrical whole-body maps of diffusion (D), pseudodiffusion (D*), and the perfusion fraction (Fp) were calculated. Image quality was rated qualitatively by two independent radiologists, and inter-reader reliability was tested with intra-class correlation coefficients (ICCs). Region of interest (ROI) analysis was performed in the brain, liver, kidney, and erector spinae muscle. Results: Depiction of anatomic structures was rated as good on D maps and good to fair on D* and Fp maps. Exemplary mean D (10−3mm2/s), D* (10−3mm2/s) and Fp (%) values (± standard deviation) of the renal cortex were as follows: 1.7 ± 0.2; 15.6 ± 6.5; 20.9 ± 4.4. Inter-observer agreement was "substantial” to "almost perfect” (ICC = 0.80 - 0.92). The coefficient of variation of D* was significantly lower with the proposed algorithm compared to the conventional algorithm (p

BACKGROUND: To reduce the radiation exposure from chest computed tomography (CT), ultralow-dose CT (ULDCT) protocols performed at sub-millisievert levels were previously tested for the evaluation of pulmonary nodules (PNs). The purpose of our study was to investigate the effect of ULDCT and iterative image reconstruction on volumetric measurements of solid PNs. METHODS: CT datasets of an anthropomorphic chest phantom containing solid microspheres were obtained with a third-generation dual-source CT at standard dose, 1/8th, 1/20th and 1/70th of standard dose [CT volume dose index (CTDI(vol)): 0.03–2.03 mGy]. Semi-automated volumetric measurements were performed on CT datasets reconstructed with filtered back projection (FBP) and advanced modelled iterative reconstruction (ADMIRE), at strength level 3 and 5. Absolute percentage error (APE) evaluated measurement accuracy related to the effective volume. Scan repetition differences were evaluated using Bland-Altman analysis. Two-way analysis of variance (ANOVA) assessed influence of different scan parameters on APE. Proportional differences (PDs) tested the effect of dose settings and reconstruction algorithms on volumetric measurements, as compared to the standard protocol (standard dose-FBP). RESULTS: Bland-Altman analysis revealed small mean interscan differences of APE with narrow limits of agreement (–0.1%±4.3% to –0.3%±3.8%). Dose settings (P

PURPOSE The purpose of this study was to investigate the type and severity of spinal injury in airborne sports, as well as patients demographics in this unique set of athletes. Paragliding is one of the most popular airborne sports in Switzerland, which thought to be no less dangerous with a high potential for spinal injury. Few studies on spinal column injuries have been performed in these high-risk athletes with only inconsistent findings. METHODS Patient charts were analyzed for all airborne sports injuries affecting the spine from 2010 to 2017 at a level-1 trauma center in Switzerland. To classify the injuries, we used the newest AOSpine classification, ASIA-grading and the injury severity score (ISS). In total, 235 patients were admitted to the emergency department due to an airborne injury. A total of 148 patients (148/235, 63.0%) which were predominantly male (125/235, 84.5%) at a mean age of 39.4 years suffered 334 spinal fractures and 5 spinal contusions. The mean ISS was 17.3, and the L1 vertebra was most commonly affected (47.6% of cases, 68/148). RESULTS A total of 78 patients (54.5% or 78/148) required spine surgery due to instability or neurological deficits (31/148 patients; 20.9%). Concomitant injuries were identified in 64.2% of cases (n = 95). CONCLUSION Due to the increasing popularity of airborne sports, age of patients and severity of injuries (ISS) increased compared with the literature. The thoracolumbal spine is at especially high risk. To prevent further complications, the treatment procedure has to be sought carefully and algorithm should be introduced in clinics to avoid delay in diagnostics and surgery. LEVEL OF EVIDENCE III, retrospective comparative study. These slides can be retrieved under Electronic Supplementary Material.

Background MR diffusion weighted imaging (DWI) may provide important information regarding the pathophysiology of parenchymal abdominal organs. The purpose of our study was to investigate the stability of imaging biomarkers of diffusion weighted imaging (DWI), intravoxel incoherent motion (IVIM) and diffusion kurtosis imaging (DKI) in abdominal parenchymal organs regarding two body hydration states. Methods Ten healthy volunteers twice underwent DWI of abdominal organs using a double-refocused spin-echo echo-planar imaging sequences with 11 different b-values (ranging from 0 to 1,500 s/mm2): after 4 h of fluid deprivation; 45 min following 1000 ml of water intake. Four different diffusion models were evaluated and compared: standard DWI, DKI with mono-exponential fitting, multistep algorithm with variable b-value threshold for IVIM, combined IVIM-Kurtosis; in four abdominal organs: kidneys, liver, spleen and psoas muscle. Results Diffusion parameters from all four models remained similar for the renal parenchyma before and after the water challenge. Significant differences were found for the liver, spleen, and psoas muscle. The largest effects were seen for: the liver parenchyma after the water challenge by means of IVIM model's true diffusion (p < 0.02); the spleen, for IVIM's perfusion fraction (p < 0.03), the psoas muscle for the ADC value (p < 0.02). Conclusions Herein, we showed that diffusion parameters of the kidney remain remarkably stable regarding the hydration status. This may be attributed to the kidney-specific compensatory mechanisms. For the liver, spleen and psoas muscle the diffusion parameters were sensitive to changes of the hydration. This phenomenon needs to be considered when evaluating diffusion data of these organs., Magnetic Resonance; diffusion; Kurtosis; tissue hydration.

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

OBJECTIVES The aims of this study were to implement and systematically evaluate the performance of a new parameter-free segmented algorithm for analysis of diffusion imaging data using a combined intravoxel incoherent motion and diffusion kurtosis imaging (IVIM-DKI) model of spin diffusion in comparison with the simpler intravoxel incoherent motion (IVIM) model. MATERIALS AND METHODS A multistep algorithm was implemented intended to separate diffusion kurtosis from IVIM effects in multi-b-value diffusion measurements using an adaptive b-value threshold technique. For each possible b-value threshold (separating diffusion and perfusion effects), diffusion kurtosis analysis of high b-values is followed by IVIM analysis keeping kurtosis parameters fixed. The b-value threshold with smallest Akaike information criterion is chosen as best model solution. The algorithm was tested in diffusion data sets of the upper abdomen from 8 healthy volunteers with 16 different b-values and compared with a standard multistep IVIM analysis. RESULTS The proposed algorithm could successfully be applied to all data sets and provided a significantly better fit of the observed signal decay in all assessed organs (all P < 0.03). Using the proposed IVIM-DKI model of diffusion instead of an IVIM model had a systematic impact on the resulting IVIM parameters: The pure diffusion coefficient and the pseudodiffusion coefficient were significantly increased (P < 0.03 in all assessed organs), accompanied by a decrease in the perfusion fraction in liver, pancreas, renal cortex, and skeletal muscle (all P < 0.02). Optimal b-value thresholds separating diffusion from perfusion effects had a tendency to lower values when the IVIM-DKI model was used. CONCLUSIONS The proposed algorithm provides a new approach for separation of IVIM and kurtosis effects of diffusion data without organ-specific adaptation.

Purpose To compare the diagnostic performance of texture analysis (TA) against visual qualitative assessment in the differentiation of spondyloarthritis (SpA) from degenerative changes in the sacroiliac joints (SIJ). Method Ninety patients referred for suspected inflammatory lower back pain from the rheumatology department were retrospectively included at our university hospital institution. MRI at 3 T of the lumbar spine and SIJ was performed with oblique coronal T1-weighted (w), fluid-sensitive fat-saturated (fs) TIRM and fsT1w intravenously contrast-enhanced (CE) images. Subjects were divided into three age- and gender-matched groups (30 each) based on definite clinical diagnosis serving as clinical reference standard with either degenerative, inflammatory (SpA) or no changes of the SIJ. SIJ were rated qualitatively by two independent radiologists and quantitatively by region-of-interest-based TA with 304 features subjected to machine learning logistic regression with randomized ten-fold selection of training and validation data. Qualitative and quantitative results were evaluated for diagnostic performance and compared against clinical reference standard. Results Agreement of radiologist’s diagnose with clinical reference was fair for both readers (κ = 0.32 and 0.44). ROC statistics revealed significant outperformance of TA compared to qualitative ratings for differentiation of SpA from remainder (AUC = 0.89 vs. 0.75), SpA from degenerative (AUC = 0.91 vs. 0.67) and TIRM-positive SpA (i.e. with bone marrow edema) from remainder cases (AUC = 0.95 vs. 0.76). T1w-CE images were the most important discriminator for detection of SpA. Conclusions TA is superior to qualitative assessment for the differentiation of inflammatory from degenerative changes of the SIJ. Intravenous CE-images increase diagnostic yield in quantitative TA.

Study Design: Retrospective case series. Objective: Short posterior stabilization with vertebroplasty is one treatment option for thoracolumbar burst fractures (AO A3). Whether it avoids progression in segmental kyphosis, especially after implant removal, is unclear. In a retrospective case-control study, its stability and the effect on intervertebral discs with and without implant removal was studied. Methods: Fifty-nine consecutive patients were treated with bisegmental short posterior instrumentation and additional vertebroplasty of the fractured vertebra. Twenty-nine patients (male/female 17/12; age: 41.7 ± 15.4 years) underwent implant removal. Changes of segmental kyphosis and disc heights between both groups (with and without implant removal) were compared on lateral X-rays preoperative, postoperative, after 1 year and after implant removal. Risk factors for loss of reduction were analyzed. Results: Kyphosis increased up to 12 months after implant removal. The loss of bisegmental correction was 6.0 ± 4.2 (range 0° to 16°) 12 months after implant removal. Risk factors for loss of reduction are younger patient age, fractures of the thoracolumbar junction (Th12), and degree of traumatic kyphosis. Intervertebral discs traversed by the stabilization lose height and don’t recover within 1 year after implant removal. Without implant removal, disc height of the lower adjacent level is reduced after 24 months. Conclusions: Short posterior stabilization in combination with vertebroplasty is a treatment alternative for thoracic and lumbar AO A3 fractures. After implant removal kyphosis increases, predominantly in the segment above the augmented vertebra. Risk factors for loss of reduction include younger age, fractures of the thoracolumbar junction (T12), and higher fracture kyphosis.

OBJECTIVE To evaluate the feasibility of a parameter-free intravoxel incoherent motion (IVIM) approach in cervical cancer, to assess the optimal b-value threshold, and to preliminarily examine differences in the derived perfusion and diffusion parameters for different histological cancer types. MATERIALS AND METHODS After Institutional Review Board approval, 19 female patients (mean age, 54 years; age range, 37-78 years) gave consent and were enrolled in this prospective magnetic resonance imaging study. Clinical staging and biopsy results were obtained. Echo-planar diffusion weighted sequences at 13 b-values were acquired at 3 tesla field strength. Single-sliced region-of-interest IVIM analysis with adaptive b-value thresholds was applied to each tumor, yielding the optimal fit and the optimal parameters for pseudodiffusion (D*), perfusion fraction (Fp) and diffusion coefficient (D). Monoexponential apparent diffusion coefficient (ADC) was calculated for comparison with D. RESULTS Biopsy revealed squamous cell carcinoma in 10 patients and adenocarcinoma in 9. The b-value threshold (median [interquartile range]) depended on the histological type and was 35 (22.5-50) s/mm2 in squamous cell carcinoma and 150 (100-150) s/mm2 in adenocarcinoma (p < 0.05). Comparing squamous cell vs. adenocarcinoma, D* (45.1 [25.1-60.4] × 10-3 mm2/s vs. 12.4 [10.5-21.2] × 10-3 mm2/s) and Fp (7.5% [7.0-9.0%] vs. 9.9% [9.0-11.4%]) differed significantly between the subtypes (p < 0.02), whereas D did not (0.89 [0.75-0.94] × 10-3 mm2/s vs. 0.90 [0.82-0.97] × 10-3 mm2/s, p = 0.27). The residuals did not differ (0.74 [0.60-0.92] vs. 0.94 [0.67-1.01], p = 0.32). The ADC systematically underestimated the magnitude of diffusion restriction compared to D (p < 0.001). CONCLUSION The parameter-free IVIM approach is feasible in cervical cancer. The b-value threshold and perfusion-related parameters depend on the tumor histology type.

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

Carbon fibre reinforced polyether ether ketone (CFR-PEEK) is a suitable material to replace metal implants in orthopaedic surgery. The radiolucency of CFR-PEEK allows an optimal visualisation of the bone and soft tissue structures. We aimed to assess the performance and radiological and clinical outcomes of anterior cervical discectomy and fusion (ACDF) with CFR-PEEK anterior cervical plating (ACP) under first use clinical conditions. We retrospectively studied the prospectively-collected data of 42 patients who underwent ACDF with CFR-PEEK ACP between 2011 and 2016. We assessed clinical outcome (Odom&rsquo, s criteria, complications) and radiological parameters (global and segmental cervical lordosis, Bridwell score for fusion, adjacent segment degeneration) preoperatively, immediately post-operatively, and after a 12-month follow-up period. Patients&rsquo, satisfaction was excellent, good, fair, and poor in 12, 19, 3, and 1 patients, respectively. Two patients developed dysphagia. No hardware failure occurred. Compared with preoperative radiographs, we observed a gain of global cervical lordosis and segmental lordosis (7.4 &plusmn, 10.1 and 5.6 &plusmn, 7.1 degrees, respectively) at the 12-month follow-up. Bridwell IF grades I, II, and III were observed in 22, 6, and 7 patients, respectively. The 12-month adjacent segment degeneration-free and adjacent segment disease-free survival rates were 93.1% and 96.3%, respectively. We observed a dysphagia rate of 5.7% and a reoperation rate of 4.8%. In conclusion, CFR-PEEK ACP shows positive outcomes in terms of implant safety, restoration of cervical lordosis, and functional recovery, and is suitable for ACDF.

INTRODUCTION Spinopelvic dissociation is a rare type of injury which occurs in approximately 2.9% of pelvic disruptions and correlates with high-energy trauma.The purpose of this study was to systematically evaluate the incidence, demographics, treatment, clinical outcome, and complication rate associated with these injuries. METHODS A literature review on Medline, PubMed, and Google was performed. Overall, 216 abstracts were reviewed in English, German, and French, of which 50 articles were included. RESULTS Within the 50 studies, 19 publications were case reports and 16 were case series with low-level evidence. Overall, 379 patients with spinopelvic dissociation were identified at a mean age of 31.6 ± 11.6 years and an injury severity score of 23.1 ± 3.8 between 1969 and 2018. Most cases were related to fall from heights (55.7%), followed by road accidents (28.5%). Two hundred fifty-eight patients (68.1%) showed neurologic impairment at initial presentation, which improved in 65.1% after surgery. The treatment of choice was surgery in 93.1% of cases with triangular fixation in 68.8%. Regardless of the technique, the healing/fusion rate was 100% with a complication rate of 29.9% (n = 96/321). CONCLUSION Spinopelvic dissociation is a rare type of injury with limited data in the literature. Based on our review, it is possible that a streamlined, evidence-based algorithm may improve care for these difficult patients. LEVEL OF EVIDENCE II STUDY DESIGN:: Systematic Review.

Background Our aims were to determine if features derived from texture analysis (TA) can distinguish normal, benign, and malignant tissue on automated breast ultrasound (ABUS); to evaluate whether machine learning (ML) applied to TA can categorise ABUS findings; and to compare ML to the analysis of single texture features for lesion classification. Methods This ethically approved retrospective pilot study included 54 women with benign (n = 38) and malignant (n = 32) solid breast lesions who underwent ABUS. After manual region of interest placement along the lesions’ margin as well as the surrounding fat and glandular breast tissue, 47 texture features (TFs) were calculated for each category. Statistical analysis (ANOVA) and a support vector machine (SVM) algorithm were applied to the texture feature to evaluate the accuracy in distinguishing (i) lesions versus normal tissue and (ii) benign versus malignant lesions. Results Skewness and kurtosis were the only TF significantly different among all the four categories (p < 0.000001). In subsets (i) and (ii), a maximum area under the curve of 0.86 (95% confidence interval [CI] 0.82–0.88) for energy and 0.86 (95% CI 0.82–0.89) for entropy were obtained. Using the SVM algorithm, a maximum area under the curve of 0.98 for both subsets was obtained with a maximum accuracy of 94.4% in subset (i) and 90.7% in subset (ii). Conclusions TA in combination with ML might represent a useful diagnostic tool in the evaluation of breast imaging findings in ABUS. Applying ML techniques to TFs might be superior compared to the analysis of single TF.

Objective Sheep are used as a large animal model for intervertebral disc research. However, for the ovine ventral surgical approach to the cervical disc, limited descriptions exist. We, therefore, give a detailed in vivo anatomical description of this approach in sheep for the use in intervertebral disc regeneration and degeneration models to increase the reproducibility of such interventions. Materials and Methods Eighteen female Swiss white alpine sheep, with an age range of 2 to 4 years, were used. A ventral surgical access was performed to establish defined intervertebral disc punch defect from cervical levels C3/4 to C5/6. Cervical levels C2/3 and C6/7 were used as negative controls. Intraoperative findings, radiographical controls and postoperative clinical follow-up were documented and collected for this clinical report. Results All sheep recovered rapidly from the surgical intervention. Two sheep developed wound seroma, which resorbed spontaneously. Two further sheep showed wound dehiscence within 3 days after surgery, which had to be revised. No clinical wound infections occurred and all sheep healed well and did not show any side effects related to the surgical procedure. Conclusion The ventral surgical access to the ovine cervical spine is a safe and reliable procedure. The advantage of the cervical intervertebral disc is the easier surgical access and the increased disc height compared to the sheep lumbar spine. Since the ovine cervical intervertebral disc shows a high grade of similarities (e.g. molecular characteristics) compared to human discs, it is a promising degeneration and regeneration model for disc diseases.

Objective To develop an analysis method that is sensitive to non-model-conform responses often encountered in ultra-high field presurgical planning fMRI. Using the consistency of time courses over a number of experiment repetitions, it should exclude low quality runs and generate activation maps that reflect the reliability of responses. Materials and methods 7 T fMRI data were acquired from six healthy volunteers: three performing purely motor tasks and three a visuomotor task. These were analysed with the proposed approach (UNBIASED) and the GLM. Results UNBIASED results were generally less affected by false positive results than the GLM. Runs that were identified as being of low quality were confirmed to contain little or no activation. In two cases, regions were identified as activated in UNBIASED but not GLM results. Signal changes in these areas were time-locked to the task, but were delayed or transient. Conclusion UNBIASED is shown to be a reliable means of identifying consistent task-related signal changes regardless of response timing. In presurgical planning, UNBIASED could be used to rapidly generate reliable maps of the consistency with which eloquent brain regions are activated without recourse to task timing and despite modified hemodynamics. Electronic supplementary material The online version of this article (doi:10.1007/s10334-016-0533-8) contains supplementary material, which is available to authorized users.

Intravoxel incoherent motion (IVIM) analysis of diffusion imaging data provides biomarkers of true passive water diffusion and perfusion properties. A new IVIM algorithm with variable adjustment of the b-value threshold separating diffusion and perfusion effects was applied for cerebral tissue characterization in healthy volunteers, computation of test-retest reliability, correlation with arterial spin labeling, and assessment of applicability in a small cohort of patients with malignant intracranial masses. The main results of this study are threefold: (i) accounting for regional differences in the separation of the perfusion and the diffusion components improves the reliability of the model parameters; (ii) if differences in the b-value threshold are not accounted for, a significant tissue-dependent systematic bias of the IVIM parameters occurs; (iii) accounting for voxel-wise differences in the b-value threshold improves the correlation with CBF measurements in healthy volunteers and patients. The proposed algorithm provides a robust characterization of regional micro-vascularization and cellularity without a priori assumptions on tissue diffusion properties. The glioblastoma multiforme with its inherently high variability of tumor vascularization and tumor cell density may benefit from a non-invasive clinical characterization of diffusion and perfusion properties., NeuroImage: Clinical, 11, ISSN:2213-1582

The aim of this study was to assess the interreader agreement and diagnostic accuracy of morphologic magnetic resonance imaging (MRI) analysis and quantitative MRI-based texture analysis (TA) for grading of cartilaginous bone tumors.This retrospective study was approved by our local ethics committee. Magnetic resonance imaging scans of 116 cartilaginous bone neoplasms were included (53 chondromas, 26 low-grade chondrosarcomas, 37 high-grade chondrosarcomas). Two musculoskeletal radiologists blinded to patient data separately analyzed 14 morphologic MRI features consisting of tumor and peritumoral characteristics. In addition, 2 different musculoskeletal radiologists separately performed TA including 19 quantitative TA parameters in a similar fashion. Interreader reliability, univariate, multivariate, and receiver operating characteristics analyses were performed for MRI and TA parameters separately and for combined models to determine independent predictors and diagnostic accuracy for grading of cartilaginous neoplasms. P values of 0.05 and less were considered statistically significant.Between both readers, MRI and TA features showed a mean kappa value of 0.49 (range, 0.08-0.82) and a mean intraclass correlation coefficient of 0.79 (range, 0.43-0.99), respectively. Independent morphological MRI predictors for grading of cartilaginous neoplasms were bone marrow edema, soft tissue mass, maximum tumor extent, and active periostitis, whereas TA predictors consisted of short-run high gray-level emphasis, skewness, and gray-level and run-length nonuniformity. Diagnostic accuracies for differentiation of benign from malignant as well as for benign from low-grade cartilaginous lesions were 87.0% and 77.4% using MRI predictors exclusively, 89.8% and 89.5% using TA predictors exclusively, and 92.9% and 91.2% using a combined model of MRI and TA predictors, respectively. For differentiation of low-grade from high-grade chondrosarcoma, no statistically significant independent TA predictors existed, whereas a model containing MRI predictors exclusively had a diagnostic accuracy of 84.8%.Texture analysis improves diagnostic accuracy for differentiation of benign and malignant as well as for benign and low-grade cartilaginous lesions when compared with morphologic MRI analysis.

Background The purpose of this study was to investigate whether any texture features show a correlation with intrahepatic tumor growth before the metastasis is visible to the human eye. Methods Eight male C57BL6 mice (age 8–10 weeks) were injected intraportally with syngeneic MC-38 colon cancer cells and two mice were injected with phosphate-buffered saline (sham controls). Small animal magnetic resonance imaging (MRI) at 4.7 T was performed at baseline and days 4, 8, 12, 16, and 20 after injection applying a T2-weighted spin-echo sequence. Texture analysis was performed on the images yielding 32 texture features derived from histogram, gray-level co-occurrence matrix, gray-level run-length matrix, and gray-level size-zone matrix. The features were examined with a linear regression model/Pearson correlation test and hierarchical cluster analysis. From each cluster, the feature with the lowest variance was selected. Results Tumors were visible on MRI after 20 days. Eighteen features from histogram and the gray-level-matrices exhibited statistically significant correlations before day 20 in the experiment group, but not in the control animals. Cluster analysis revealed three distinct clusters of independent features. The features with the lowest variance were Energy, Short Run Emphasis, and Gray Level Non-Uniformity. Conclusions Texture features may quantitatively detect liver metastases before they become visually detectable by the radiologist.

Purpose: To evaluate the accuracy of a deep learning software (DLS) in the discrimination between phyllodes tumors (PT) and fibroadenomas (FA). Methods: In this IRB-approved, retrospective, single-center study, we collected all ultrasound images of histologically secured PT (n = 11, 36 images) and a random control group with FA (n = 15, 50 images). The images were analyzed with a DLS designed for industrial grade image analysis, with 33 images withheld from training for validation purposes. The lesions were also interpreted by four radiologists. Diagnostic performance was assessed by the area under the receiver operating characteristic curve (AUC). Sensitivity, specificity, negative and positive predictive values were calculated at the optimal cut-off (Youden Index). Results: The DLS was able to differentiate between PT and FA with good diagnostic accuracy (AUC = 0.73) and high negative predictive value (NPV = 100%). Radiologists showed comparable accuracy (AUC 0.60–0.77) at lower NPV (64–80%). When performing the readout together with the DLS recommendation, the radiologist’s accuracy showed a non-significant tendency to improve (AUC 0.75–0.87, p = 0.07). Conclusion: Deep learning based image analysis may be able to exclude PT with a high negative predictive value. Integration into the clinical workflow may enable radiologists to more confidently exclude PT, thereby reducing the number of unnecessary biopsies. Keywords: Breast imaging, Ultrasound, Phyllodes, Fibroadenoma, Deep learning, Computer assisted diagnosis

Posthepatectomy liver failure (PHLF) remains challenging to diagnose and difficult to treat. The extent of transient regeneration-associated steatosis (TRAS) differs between successful liver regeneration and PHLF. This study aims to quantify TRAS by magnetic resonance imaging (MRI) after hepatectomy in mice.Mice (C57BL/6) underwent either extended hepatectomy (EH) or standard hepatectomy (SH). Serial MRI on postoperative days 1-7 was used to compare TRAS and liver remnant growth between groups. Survival was also assessed.EH was associated with decreased survival and impaired proliferation when compared to SH (p = 0.02 and p = 0.03). MRI showed increased TRAS 48 h after EH compared to SH (11.8 ± 6% vs. 4.3 ± 2%, p 0.001). Compared to EH survivors, death after EH was associated with increased TRAS 48 h postoperatively (16.4 ± 6% vs. 9.2 ± 5%, p = 0.02).EH is associated with increased TRAS and inferior outcomes when compared to SH. MRI may help to predict PHLF after hepatectomy.

Background Chronic airway fibrosis (CAF) is the most prevalent complication in human lung transplant recipients. The aim of the study is to evaluate magnetisation transfer (MT) as a biomarker of developing CAF of lung transplants in a mouse model. Methods Lung transplantation was performed in 48 mice, applying major or minor histocompatibility mismatches between strains for the induction of CAF. MT measurements were performed in vivo with systematic variation of off-resonance frequencies and flip angle of the MT prepulse. MT ratios (MTRs) were compared for lungs showing CAF and without CAF. Results Seven out of 24 animals (29%) showed a pattern of CAF at histology. All mice developing CAF also showed signs of acute rejection, whereas none of the lungs showed signs of other post-transplant complications. After lung transplantation, pulmonary infiltration was a frequent finding (14 out of 24) exhibiting a higher MTR (24.8% ± 4.5%) compared to well-ventilated lungs (12.3% ± 6.9%, p = 0.001) at 8000 Hz off-resonance frequency, 3000° flip angle. In infiltrated lung tissue exhibiting CAF, lower MTR values (21.8% ± 5.7%) were found compared to infiltrated lungs showing signs of acute rejection alone (26.5% ± 2.9%, p = 0.028), at 8000 Hz, 3000° flip angle. The highest MTR values were observed at 3000° flip angle, using a 1000 Hz off-resonance frequency. Conclusion MTR might serve as a tool for the detection of CAF in infiltrated lung tissue.

This study aimed to monitor the course of liver regeneration by multiparametric magnetic-resonance imaging (MRI) after partial liver resection characterizing Small-for-Size Syndrome (SFSS), which frequently leads to fatal post-hepatectomy liver failure (PLF). Twenty-two C57BL/6 mice underwent either conventional 70% partial hepatectomy (cPH), extended 86% partial hepatectomy (ePH) or SHAM operation. Subsequent MRI scans on days 0, 1, 2, 3, 5 and 7 in a 4.7T MR Scanner quantified longitudinal and transverse relaxation times, apparent diffusion coefficient (ADC) and the magnetization-transfer ratio (MTR) of the regenerating liver parenchyma. Histological examination was performed by hematoxylin-eosin staining. After hepatectomy, an increase of T1 time was detected being larger for ePH on day 1: 18% for cPH vs. 40% for ePH and on day 2: 24% for cPH vs. 49% for ePH. An increase in T2 time, again greater in ePH was most pronounced on day 5: 21% for cPH vs. 41% for ePH. ADC and MTR showed a decrease on day 1: 21% for ePH vs. 13% for cPH for ADC, 15% for ePH vs. 11% for cPH for MTR. Subsequently, all MR parameters converged towards initial values in surviving animals. Dying PLF animals exhibited the strongest increase of T1 relaxation time and most prominent decreases of ADC and MTR. The retrieved MRI biomarkers indicate SFSS and potentially developing PLF at an early stage, likely reflecting cellular hypertrophy with extended water content and concomitantly diluted cellular components as features of liver regeneration, appearing more intense in ePH as compared to cPH.

Background Texture analysis in oncological magnetic resonance imaging (MRI) may yield surrogate markers for tumor differentiation and staging, both of which are important factors in the treatment planning for cervical cancer. Purpose To identify texture features which may predict tumor differentiation and nodal status in diffusion-weighted imaging (DWI) of cervical carcinoma Material and Methods Twenty-three patients were enrolled in this prospective, institutional review board (IRB)-approved study. Pelvic MRI was performed at 3-T including a DWI echo-planar sequence with b-values 40, 300, and 800 s/mm2. Apparent diffusion coefficient (ADC) maps were used for region of interest (ROI)-based texture analysis (32 texture features) of tumor, muscle, and fat based on histogram and gray-level matrices (GLM). All features confounded by the ROI size (linear model) were excluded. The remaining features were examined for correlations with histological differentiation (Spearman) and nodal status (Kruskal–Wallis). Hierarchical cluster analysis was used to identify correlations between features. A P value Results Mean age was 55 years (range = 37–78 years). Biopsy revealed two well-differentiated, eight moderately differentiated, two moderately to poorly differentiated tumors, and five poorly differentiated tumors. Six tumors could not be graded. Lymph nodes were involved in 11 patients. Three GLM features correlated with the differentiation: LRHGE (ϱ = 0.53, P = 0.03), ZP (ϱ = –0.49, P Conclusion We identified potentially predictive GLM features for histological tumor differentiation and histogram features for nodal cancer stage.

PURPOSE: For diffusion data sets including low and high b-values, the intravoxel incoherent motion model is commonly applied to characterize tissue. The aim of the present study was to show that machine learning allows a model-free approach to determine tissue type without a priori assumptions on the underlying physiology. MATERIALS AND METHODS: In 8 healthy volunteers, diffusion data sets were acquired using an echo-planar imaging sequence with 16 b-values in the range between 0 and 1000 s/mm. Using the k-nearest neighbors technique, the machine learning algorithm was trained to distinguish abdominal organs (liver, kidney, spleen, muscle) using the signal intensities at different b-values as training features. For systematic variation of model complexity (number of neighbors), performance was assessed by calculation of the accuracy and the kappa coefficient (κ). Most important b-values for tissue discrimination were determined by principal component analysis. RESULTS: The optimal trade-off between model complexity and overfitting was found in the range between K = 11 to 13. On "real-world" data not previously applied to optimize the algorithm, the k-nearest neighbors algorithm was capable to accurately distinguish tissue types with best accuracy of 94.5% and κ = 0.92 reached for intermediate model complexity (K = 11). The principal component analysis showed that most important b-values are (with decreasing importance): b = 1000 s/mm, b = 970 s/mm, b = 750 s/mm, b = 20 s/mm, b = 620 s/mm, and b = 40 s/mm. Applying a reduced set of 6 most important b-values, still a similar accuracy was achieved on the real-world data set with an average accuracy of 93.7% and a κ coefficient of 0.91. CONCLUSIONS: Machine learning allows for a model-free determination of tissue type using intra voxel incoherent motion signal decay curves as features. The technique may be useful for segmentation of abdominal organs or distinction between healthy and pathological tissues.

The aim of this study was to evaluate the diagnostic accuracy of a multipurpose image analysis software based on deep learning with artificial neural networks for the detection of breast cancer in an independent, dual-center mammography data set.In this retrospective, Health Insurance Portability and Accountability Act-compliant study, all patients undergoing mammography in 2012 at our institution were reviewed (n = 3228). All of their prior and follow-up mammographies from a time span of 7 years (2008-2015) were considered as a reference for clinical diagnosis. After applying exclusion criteria (missing reference standard, prior procedures or therapies), patients with the first diagnosis of a malignoma or borderline lesion were selected (n = 143). Histology or clinical long-term follow-up served as reference standard. In a first step, a breast density-and age-matched control cohort was selected (n = 143) from the remaining patients with more than 2 years follow-up (n = 1003). The neural network was trained with this data set. From the publicly available Breast Cancer Digital Repository data set, patients with cancer and a matched control cohort were selected (n = 35 × 2). The performance of the trained neural network was also tested with this external data set. Three radiologists (3, 5, and 10 years of experience) evaluated the test data set. In a second step, the neural network was trained with all cases from January to September and tested with cases from October to December 2012 (screening-like cohort). The radiologists also evaluated this second test data set. The areas under the receiver operating characteristic curve between readers and the neural network were compared. A Bonferroni-corrected P value of less than 0.016 was considered statistically significant.Mean age of patients with lesion was 59.6 years (range, 35-88 years) and in controls, 59.1 years (35-83 years). Breast density distribution (A/B/C/D) was 21/59/42/21 and 22/60/41/20, respectively. Histologic diagnoses were invasive ductal carcinoma in 90, ductal in situ carcinoma in 13, invasive lobular carcinoma in 13, mucinous carcinoma in 3, and borderline lesion in 12 patients. In the first step, the area under the receiver operating characteristic curve of the trained neural network was 0.81 and comparable on the test cases 0.79 (P = 0.63). One of the radiologists showed almost equal performance (0.83, P = 0.17), whereas 2 were significantly better (0.91 and 0.94, P0.016). In the second step, performance of the neural network (0.82) was not significantly different from the human performance (0.77-0.87, P0.016); however, radiologists were consistently less sensitive and more specific than the neural network.Current state-of-the-art artificial neural networks for general image analysis are able to detect cancer in mammographies with similar accuracy to radiologists, even in a screening-like cohort with low breast cancer prevalence.

PURPOSE: The purposes of this study were to demonstrate the feasibility and accuracy of single-source dual-energy (DE) computed tomography (CT) with sequential data acquisition and a coregistration motion correction algorithm for urinary stone characterization and to evaluate the value of iterative reconstructions (IRs) in DE imaging. MATERIALS AND METHODS: Thirty-five urinary stones were placed in cylindrical phantoms with diameters of 30 and 40 cm. The phantoms were scanned on a 64-section CT machine with a single-source DE protocol consisting of 2 sequential acquisitions at 80 and 140 kilovolt (peak). The phantom was moved between the 80- and 140-kilovolt (peak) scans. Images were reconstructed with weighted filtered back projection (FBP) and with IR, and data were coregistered. Two independent and blinded readers assessed data sets for stone detection, overall image quality, and visibility of stones. Image noise and Hounsfield unit values of the stones were measured, and the DE index was calculated. In addition, the data sets were analyzed on color-coded images using the standard postprocessing software for differentiating uric acid- (UA) from non-UA-containing stones. RESULTS: The motion correction algorithm achieved a good coregistration of the 2 scans with different energy levels. Both readers detected all stones on all data sets with both reconstruction types. The overall image quality was rated significantly higher in IR images in the 40-cm phantom as compared with that in FBP images (P < 0.05), whereas no significant difference was found for the 30-cm phantom. Visibility of stones was rated significantly higher for both the 30- and 40-cm phantoms on IR as compared with that on FBP images, an effect that was pronounced for UA stones (P < 0.05). Noise was significantly reduced by up to 31% in the 40-cm phantom when using IR as compared with FBP (P < 0.001). The DE index was similar in the FBP and IR data sets for the 30- (P = 0.116) and 40-cm phantoms (P = 0.544), being significantly different between UA-containing stones, cystine, and struvite stones as well as stones of other compositions (P < 0.001). The postprocessing software classified all stones correctly as UA- or non-UA-containing stones on color-coded images. In the 40-cm phantom, false-positively colored voxels were found in the FBP data sets, which were not seen when using IR instead. CONCLUSIONS: Our study indicates that single-source dual-energy CT with sequential acquisitions at different energy levels and a coregistration motion correction algorithm is feasible and accurate for characterizing urinary stone composition on the basis of phantom evaluation. As compared with reconstructions with FBP, the use of IR in dual-energy CT reduces noise, improves overall image quality and visibility of stones particularly in large phantoms, and helps to avoid false classifications of urinary stones.

Several investigations have shown limitations of fMRI reliability with the current standard field strengths. Improvement is expected from ultra highfield systems but studies on possible benefits for cognitive networks are lacking. Here we provide an initial investigation on a prominent and clinically highly-relevant cognitive function: language processing in individual brains. 26 patients evaluated for presurgical language localization were investigated with a standardized overt language fMRI paradigm on both 3 T and 7 T MR scanners. During data acquisition and analysis we made particular efforts to minimize effects not related to static magnetic field strength differences. Six measures relevant for functional activation showed a large dissociation between essential language network nodes: although in Wernicke's area 5/6 measures indicated a benefit of ultra highfield, in Broca's area no comparison was significant. The most important reason for this discrepancy was identified as being an increase in susceptibility-related artifacts in inferior frontal brain areas at ultra high field. We conclude that functional UHF benefits are evident, however these depend crucially on the brain region investigated and the ability to control local artifacts., Highlights • First investigation about possible ultra highfield MR benefits for studying cognitive networks • Ultra highfield benefits for cognitive Network activations depend on the brain area. • High field (3 T) and ultra high field (7 T) first hand comparison