Sacral tumours on MRI : a pictorial essay

Tumours of the sacrum can be primary or secondary. Since the sacrum is rich in haematopoietic bone marrow, bone metastases are the most frequent aetiologies. However, tumours can arise from all components of the sacrum and primary bone tumours should be considered in case of a solitary lesion and absence of oncologic history. As the clinical signs are usually non-specific, magnetic resonance imaging has become an indispensable tool in narrowing the differential diagnosis and determining the therapeutic approach. This pictorial essay illustrates specific features of the most common sacral tumours on magnetic resonance (MR) imaging

Sacral Fractures and Associated Injuries.

STUDY DESIGN: Literature review. OBJECTIVE: The aim of this review is to describe the injuries associated with sacral fractures and to analyze their impact on patient outcome. METHODS: A comprehensive narrative review of the literature was performed to identify the injuries associated with sacral fractures. RESULTS: Sacral fractures are uncommon injuries that result from high-energy trauma, and that, due to their rarity, are frequently underdiagnosed and mistreated. Only 5% of sacral fractures occur in isolation. Injuries most often associated with sacral fractures include neurologic injuries (present in up to 50% of sacral fractures), pelvic ring disruptions, hip and lumbar spine fractures, active pelvic/ abdominal bleeding and the presence of an open fracture or significant soft tissue injury. Diagnosis of pelvic ring fractures and fractures extending to the lumbar spine are key factors for the appropriate management of sacral fractures. Importantly, associated systemic (cranial, thoracic, and abdominopelvic) or musculoskeletal injuries should be promptly assessed and addressed. These associated injuries often dictate the management and eventual outcome of sacral fractures and, therefore, any treatment algorithm should take them into consideration. CONCLUSIONS: Sacral fractures are complex in nature and often associated with other often-missed injuries. This review summarizes the most relevant associated injuries in sacral fractures and discusses on their appropriate management

Narrative and Notice in Livy's Fourth Decade: The Case of Scipio Africanus

This paper argues for the importance of Livy's annalistic notices in structuring the author's aims and the reader's reception of the history, as against the standard conception of the notices as archaic memoranda. Taking the later career of Scipio Africanus the Elder as a test case, the paper demonstrates the tension between the formal features of the narrative and the actual content of the notices. As summarized in the eulogy for Africanus (38.53.9-11), Livy constructs a narrative of Scipio's decline emphasizing his peripeteia after the Hannibalic war. This narrative finds corroboration in the confinement of Africanus' subsequent actions chiefly to the annalistic notices. The notices themselves, however, provide a counter-narrative to the main text, albeit in fragmentary and marginal form. Through the interaction of narrative center and periphery the notices thus offer a space for Livy, and the reader, to explore alternative visions of Roman history.Classic

MicroRNA-155 expression is independently predictive of outcome in chordoma.

BackgroundChordoma pathogenesis remains poorly understood. In this study, we aimed to evaluate the relationships between microRNA-155 (miR-155) expression and the clinicopathological features of chordoma patients, and to evaluate the functional role of miR-155 in chordoma.MethodsThe miRNA expression profiles were analyzed using miRNA microarray assays. Regulatory activity of miR-155 was assessed using bioinformatic tools. miR-155 expression levels were validated by reverse transcription-polymerase chain reaction. The relationships between miR-155 expression and the clinicopathological features of chordoma patients were analyzed. Proliferative, migratory and invasive activities were assessed by MTT, wound healing, and Matrigel invasion assays, respectively.ResultsThe miRNA microarray assay revealed miR-155 to be highly expressed and biologically active in chordoma. miR-155 expression in chordoma tissues was significantly elevated, and this expression correlated significantly with disease stage (p = 0.036) and the presence of metastasis (p = 0.035). miR-155 expression also correlated significantly with poor outcomes for chordoma patients (hazard ratio, 5.32; p = 0.045). Inhibition of miR-155 expression suppressed proliferation, and the migratory and invasive activities of chordoma cells.ConclusionsWe have shown miR-155 expression to independently affect prognosis in chordoma. These results collectively indicate that miR-155 expression may serve not only as a prognostic marker, but also as a potential therapeutic target in chordoma

Is a low sacral ratio associated with primary vesicoureteral reflux in children?

Introduction: The association of sacral anomalies with fecal incontinence and lower urinary tract dysfunction is known. The sacral ratio is proposed as a tool for evaluation of sacral development. The aim of this cross-sectional study was to evaluate the prevalence and severity of vesicoureteral reflux in children with a low sacral ratio. Materials and Methods: Six hundred and sixty nine children who were referred to a radiology clinic for a standard (fluoroscopic) VCUG to detect vesicoureteral reflux and other anomalies of the lower urinary tract after an episode of urinary tract infection were included in the study and their sacral ratios were measured. Results: All children were younger than 14 years of age (mean 3.44±3.20). Of 669 children, 593 (88.6%) had normal sacral ratios out of whom 423 (71.3%) did not have VUR and 170 (28.7%) had VUR. Seventy-six (11.3%) children out of 669 cases had low sacral ratios; 49 (64.5%) of them had no VUR and 27 (35.5%) had VUR. There was no significant difference in the prevalence of VUR between children with and without a low sacral ratio (p value=0.217). Also, there was no significant difference or trend between a low sacral ratio and the severity of reflux (Chi2 for trend). Conclusions: Although sacral anomalies may be related to some cases of VUR by producing lower urinary tract dysfunction, the sacral ratio is not associated with VUR

Bone marrow edema in sacroiliitis : detection with dual-energy CT

Objectives: To evaluate the feasibility and diagnostic accuracy of dual-energy computed tomography (DECT) for the detection of bone marrow edema (BME) in patients suspected for sacroiliitis. Methods: Patients aged 18-55 years with clinical suspicion for sacroiliitis were enrolled. All patients underwent DECT and 3.0 T MRI of the sacroiliac joints on the same day. Virtual non-calcium (VNCa) images were calculated from DECT images for demonstration of BME. VNCa images were scored by two readers independently using a binary system (0 = normal bone marrow, 1 = BME). Diagnostic performance was assessed with fluid-sensitive MRI as the reference standard. ROIs were placed on VNCa images, and CT numbers were displayed. Cutoff values for BME detection were determined based on ROC curves. Results: Forty patients (16 men, 24 women, mean age 37.1 years +/- 9.6 years) were included. Overall inter-reader agreement for visual image reading of BME on VNCa images was good (kappa = 0.70). The sensitivity and specificity of BME detection by DECT were 65.4% and 94.2% on the quadrant level and 81.3% and 91.7% on the patient level. ROC analyses revealed AUCs of 0.90 and 0.87 for CT numbers in the ilium and sacrum, respectively. Cutoff values of - 44.4 HU (for iliac quadrants) and - 40.8 HU (for sacral quadrants) yielded sensitivities of 76.9% and 76.7% and specificities of 91.5% and 87.5%, respectively. Conclusions: Inflammatory sacroiliac BME can be detected by VNCa images calculated from DECT, with a good interobserver agreement, moderate sensitivity, and high specificity

Outcomes of Fusions From the Cervical Spine to the Pelvis.

Study designRetrospective cohort study.ObjectiveDetermine the indications, complications, and clinical outcomes in patients requiring fusions from the cervical spine to the pelvis. Several investigators have examined fusions from the thoracic spine to the sacrum, but no similar study has been performed for cervical-to-pelvis fusions.MethodsPatients from 2003 to 2014 with an upper instrumented vertebrae (UIV) in the cervical spine (any level) and a lower instrumented vertebrae (LIV) in the sacrum or pelvis were included in the study. Those with infectious or acute trauma-related deformities were excluded. Patient demographics, medical history, diagnosis, operative procedure, and health-related quality of life measures were analyzed. Student's t test, Kruskal-Wallis test, and χ2 test were used as appropriate; significance was set at P < .05 for all tests.ResultsFifty-five patients met inclusion criteria for the study. Average follow-up was 2.8 years. Proximal junctional kyphosis was the most common indication for cervical-to-pelvis fusions (36%). The most common UIV was C2 (29%) followed by C7 (24%). There was an average 31° correction in maximum kyphosis and a 3.3 cm improvement in sagittal vertical axis. In adults, the rate of complication was 71.4%, with a major complication rate of 39.3% and reoperation rate of 53.6%. There was significant improvement in the Scoliosis Research Society (SRS-22r) score (3.0 to 3.5; P < .01).ConclusionProximal junctional kyphosis is the most common indication for patients requiring fusion to the cervical spine. Adult patients incur a significant risk of major complications and reoperations. However, significant improvement in SRS-22r outcomes are noted in these patients

Is Sacral Extension a Risk Factor for Early Proximal Junctional Kyphosis in Adult Spinal Deformity Surgery?

Study designRetrospective cohort study.PurposeTo investigate the role of sacral extension (SE) for the development of proximal junctional kyphosis (PJK) in adult spinal deformity (ASD) surgery.Overview of literatureThe development of PJK is multifactorial and different risk factors have been identified. Of these, there is some evidence that SE also affects the development of PJK, but data are insufficient.MethodsUsing a combined database comprising two propensity-matched groups of fusions following ASD surgery, one with fixation to S1 or S1 and the ilium (SE) and one without SE but with a lower instrumented vertebra of L5 or higher (lumbar fixation, LF), PJK and the role of further parameters were analyzed. The propensity-matched variables included age, the upper-most instrumented vertebra (UIV), preoperative sagittal alignment, and the baseline to one year change of the sagittal alignment.ResultsPropensity matching led to two groups of 89 patients each. The UIV, pelvic incidence minus lumbar lordosis, sagittal vertical axis, pelvic tilt, age, and body mass index were similar in both groups (p >0.05). The incidence of PJK at postoperative one year was similar for SE (30.3%) and LF (22.5%) groups (p =0.207). The PJK angle was comparable (p =0.963) with a change of -8.2° (SE) and -8.3° (LF) from the preoperative measures (p =0.954). A higher rate of PJK after SE (p =0.026) was found only in the subgroup of patients with UIV levels between T9 and T12.ConclusionsInstrumentation to the sacrum with or without iliac extension did not increase the overall risk of PJK. However, an increased risk for PJK was found after SE with UIV levels between T9 and T12

DeepWalking: Enabling Smartphone-based Walking Speed Estimation Using Deep Learning

Walking speed estimation is an essential component of mobile apps in various fields such as fitness, transportation, navigation, and health-care. Most existing solutions are focused on specialized medical applications that utilize body-worn motion sensors. These approaches do not serve effectively the general use case of numerous apps where the user holding a smartphone tries to find his or her walking speed solely based on smartphone sensors. However, existing smartphone-based approaches fail to provide acceptable precision for walking speed estimation. This leads to a question: is it possible to achieve comparable speed estimation accuracy using a smartphone over wearable sensor based obtrusive solutions? We find the answer from advanced neural networks. In this paper, we present DeepWalking, the first deep learning-based walking speed estimation scheme for smartphone. A deep convolutional neural network (DCNN) is applied to automatically identify and extract the most effective features from the accelerometer and gyroscope data of smartphone and to train the network model for accurate speed estimation. Experiments are performed with 10 participants using a treadmill. The average root-mean-squared-error (RMSE) of estimated walking speed is 0.16m/s which is comparable to the results obtained by state-of-the-art approaches based on a number of body-worn sensors (i.e., RMSE of 0.11m/s). The results indicate that a smartphone can be a strong tool for walking speed estimation if the sensor data are effectively calibrated and supported by advanced deep learning techniques.Comment: 6 pages, 9 figures, published in IEEE Global Communications Conference (GLOBECOM