Modal analysis for implant stability assessment: Sensitivity of this methodology for different implant designs

Publication date: Available online 8 June 2018
Source:Dental Materials
Author(s): Elisabetta Maria Zanetti, Stefano Ciaramella, Michele Calì, Giulia Pascoletti, Massimo Martorelli, Riccardo Asero, David C. Watts
ObjectiveTo investigate the influence of implant design on the change in the natural frequency of bone-implant system during osseointegration by means of a modal 3D finite element analysis.MethodsSix implants were considered. Solid models were obtained by means of reverse engineering techniques. The mandibular bone geometry was built-up from a CT scan dataset through image segmentation. Each implant was virtually implanted in the mandibular bone. Two different models have been considered, differing in the free length of the mandibular branch ('long branch' and 'short branch') in order to simulate the variability of boundary conditions when performing vibrometric analyses. Modal analyses were carried out for each model, and the first three resonance frequencies were assessed with the respective vibration modes.ResultsWith reference to the 'long branch' model, the first three modes of vibration are whole bone vibration with minimum displacement of the implant relative to bone, with the exception of the initial condition (1% bone maturation) where the implant is not osseointegrated. By contrast, implant displacements become relevant in the 'short branch' model, unless osseointegration level is beyond 20%. The difference between resonance frequency at whole bone maturation and resonance frequency at 1% bone maturation remained lower than 6.5% for all modes, with the exception of the third mode of vibration in the 'D' implant where this difference reached 9.7%. With reference to the 'short branch', considering the first mode of vibration, 61–68% of the frequency increase was achieved at 10% osseointegration; 72–79% was achieved at 20%; 89–93% was achieved at 50% osseointegration. The pattern of the natural frequency versus the osseointegration level is similar among different modes of vibration.SignificanceResonance frequencies and their trends towards osseointegration level may differ between implant designs, and in different boundary conditions that are related to implant position inside the mandible; tapered implants are the most sensitive to bone maturation levels, small implants have very little sensitivity. Resonance frequencies are less sensitive to bone maturation level beyond 50%.



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Bonding to caries affected dentine

Publication date: Available online 8 June 2018
Source:Dental Materials
Author(s): Naghmeh Meraji, Mohammad H. Nekoofar, Kazem Ashofteh Yazdi, Mohammad Reza Sharifian, Noushin Fakhari, Josette Camilleri
ObjectivesDentine replacement materials are often placed over caries affected dentine (CAD). The aim of this study was to compare the bonding characteristics and interactions of selected hydraulic calcium silicate-based dentine replacement materials to CAD and sound dentine.MethodsThree hydraulic calcium silicate-based dentine replacement materials were assessed: Retro MTA, Biodentine and Theracal LC. Material characterization was done by scanning electron microscopy and X-ray diffraction analyses. Blocks of sound and CAD were prepared and standardized by Vickers microhardness testing. Half of the affected and sound dentine blocks were pretreated with 5.25% NaOCl prior to material placement. The materials were stored either for 1 week or 24 weeks in 37°C in fully saturated conditions. Shear bond strength was assessed at both time periods. Radiopacity of the interfacial dentine was also evaluated to assess the remineralization potential of the dentine replacement materials.ResultsThe reaction of Theracal was slower than that of the water-based materials. The bond strengths of different materials did not differ after 1 week (P>0.05). The bond strength of Biodentine and Retro MTA increased over time but no change was observed for Theracal. NaOCl pre-treatment deteriorated the bond strength to sound dentine but improvement was observed in affected dentine. Radiopacity changes were observed after 24 weeks.SignificanceBiodentine and Retro MTA showed better bonding to CAD. Pretreatment with NaOCl improved the bond strength of dentine replacement materials to CAD.



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Principles and Practice of HDR Penile Brachytherapy: Planning and Delivery Techniques

Publication date: Available online 8 June 2018
Source:Practical Radiation Oncology
Author(s): Shireen Parsai, Sheen Cherian, Ryan K. Berglund, Byron Lee, Matthew Kolar, Nancy Nagle-Hernan, Allan Wilkinson, Jay Ciezki
ObjectivesTo allow for organ preservation, high dose rate brachytherapy may be used in the treatment of localized penile cancer. Penile cancer is a rare malignancy, accounting for less than one percent of cancers in men in the United States. The standard treatment for localized disease is partial amputation of the penis. However, patients with T1b or T2 disease, less than 4 cm in maximum dimension and confined to the glans penis may be treated with brachytherapy as an organ-sparing approach. Previous works have described the technique involved for low dose rate brachytherapy, whereas we detail the techniques involved with high dose rate brachytherapy.MethodsCircumcision should precede brachytherapy. Interstitial brachytherapy needles are placed in the operating room under general anesthesia with the goal of allowing appropriate target coverage. Target definition is done via CT-based simulation and planning. Radiation is delivered using a prescription dose of 3840 cGy in 12 fractions twice daily over a course of 6 days.ResultsAcute toxicities peak upon completion of radiation therapy and may include dermatitis, sterile urethritis and adhesions in the urethra. These are reversible, and generally take 2-3 months to heal. The two most common and significant late complications of radiation therapy for penile cancer are soft tissue necrosis and meatal stenosis. An increased risk of necrosis has been reported with T3 tumors and with higher-volume implants (>30 cc). Erectile function is generally maintained, as the erectile tissues including the penile shaft and corpora have not been irradiated.ConclusionsOrgan preservation is feasible using high dose rate brachytherapy with favorable acute and late toxicities.



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A review of factors impacting exposure to PM2.5, ultrafine particles and black carbon in Asian transport microenvironments

Publication date: August 2018
Source:Atmospheric Environment, Volume 187
Author(s): Prashant Kumar, Allison P. Patton, John L. Durant, H. Christopher Frey
The World Health Organization estimates 3.7 million deaths in 2012 in low- and middle-income Asian countries due to outdoor air pollution. However, these estimates do not account for the higher exposures of specific particulate matter (PM) components – including fine particles (PM2.5), ultrafine particles (UFP) and black carbon (BC) – typical of transport microenvironments (TMEs). With the rapidly growing number of on-road vehicles in Asia, human exposure to PM is an increasing concern. The aim of this review article is to comprehensively assess studies of PM2.5, UFP, and BC in Asian TMEs in order to better understand the extent of exposure, the underlying factors leading to exposure, and how Asian exposures compare to those found in Europe and the United States of America (USA). The health impacts of exposure to PM2.5, UFP, and BC are described and the key factors that influence personal exposure in TMEs (i.e., walk, cycle, car, and bus) are identified. Instrumentation and measurement methods, exposure modeling techniques, and regulation are reviewed for PM2.5, UFP, and BC. Relatively few studies have been carried out in urban Asian TMEs where PM2.5, UFP, and BC had generally higher concentrations compared to Europe and USA. Based on available data, PM2.5 concentrations while walking were 1.6 and 1.2 times higher in Asian cities (average 42 μg m⁻³) compared to cities in Europe (26 μg m⁻³) and the USA (35 μg m⁻³), respectively. Likewise, average PM2.5 concentrations in car (74 μg m⁻³) and bus (76 μg m⁻³) modes in Asian cities were approximately two to three times higher than in Europe and American cities. UFP exposures in Asian cities were twice as high for pedestrians and up to ∼9-times as high in cars than in cities in Europe or the USA. Asian pedestrians were exposed to ∼7-times higher BC concentrations compared with pedestrians in the USA. Stochastic population-based models have yet to be applied widely in Asia but can be used to quantify inter-individual and inter-regional variability in exposures and to assess the contribution of TMEs to total exposures for multiple pollutants. The review also highlights specific gaps in the Asian TME data set that need to be filled since UFP and BC studies were rare as were studies of pedestrian and cyclist exposure.

Graphical abstract

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Impact of heterogeneous uptake of nitrogen dioxide on the conversion of acetaldehyde on gamma-alumina in the absence and presence of simulated solar irradiation

Publication date: August 2018
Source:Atmospheric Environment, Volume 187
Author(s): Chengtian Du, Lingdong Kong, Assiya Zhanzakova, Songying Tong, Xin Yang, Lin Wang, Hongbo Fu, Tiantao Cheng, Jianmin Chen, Shicheng Zhang
Heterogeneous reactions of various atmospheric gaseous pollutants on particle surfaces are important pathways for the formation of secondary aerosols. However, these heterogeneous reactions are inevitable affected by each other in the real atmosphere. In this study, the impacts of the heterogeneous uptake of NO2 on the conversion of acetaldehyde on the particle surfaces in the absence and presence of simulated solar irradiation were investigated by using diffuse reflectance infrared spectroscopy (DRIFTS) at 298 K. It is found that in the absence of simulated solar irradiation the hydration reaction and subsequent polyoligomeric reaction as well as oligomeric reaction of CH3CHO are promoted by the pre-adsorption of NO2 for a short reaction time, but these reactions are significantly hindered, accompanied with the slightly enhanced formation of crotonaldehyde and adsorbed acetate by the pre-adsorption of NO2 for a longer time. In the presence of simulated solar irradiation, the occurrence of the aldol condensation and the oxidation of CH3CHO are promoted by the combined impacts of illumination, hydrogen bond (H-bond) catalysis, the enhanced surface acidity and the formed nitrite and nitrate, especially, the photolysis of the formed nitrite and nitrate, whereas the hydration reaction and subsequent polyoligomeric reaction as well as oligomeric reaction of CH3CHO molecules are suppressed. Meanwhile, the hydrogen bond catalysis for aldol condensation is significantly enhanced by light irradiation, showing a combined result of hydrogen bond catalysis and illumination. The heterogeneous reaction mechanism is proposed, and atmospheric implications based on these results are discussed in this study.

Graphical abstract

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Oxidative potential of size-segregated PM in an urban and an industrial area of Italy

Publication date: August 2018
Source:Atmospheric Environment, Volume 187
Author(s): Giulia Simonetti, Elena Conte, Cinzia Perrino, Silvia Canepari
This work is focused on the relationship between the size distribution of some source tracers of atmospheric particulate matter (PM) and the oxidative potential (OP) of each PM size fraction. Size-segregated PM samples were collected by a multistage impactor (cut-sizes: 0.18, 0.32, 0.56, 1.0, 1.8, 3.2, 5.6, 10 and 18 μm) in two geographical areas of Italy (Rome and Ferrara), characterized by different strength of the main PM sources. The samples were analysed by three different acellular OP methods: dithiothreitol (DTT), dichlorofluorescein diacetate (DCFH) and ascorbate (AA) assay.Elemental (Li, Be, B, Na, Mg, Al, Si, P, K, Ca, Ti, V, Cr, Mn, Fe, Co, Ni, Cu, Zn, Ga, As, Se, Rb, Sr, Zr, Nb, Mo, Cd, Sn, Sb, Te, Cs, Ba, La, Ce, W, Tl, Pb, Bi and U) and ionic (Cl⁻, NO3⁻, SO4²⁻, Na⁺, NH4⁺, K⁺, Mg²⁺, Ca²⁺) composition of the same samples was also determined, in order to trace the contribution of the main PM sources. The size distribution of the OP values was compared to the size distribution of some PM source tracers, with the aim of identifying the PM sources that mostly influence the oxidative properties of atmospheric dust.AA assay resulted to be more sensitive towards coarse particles and OP^AA showed a size distribution very similar to that of brake dust tracers. DTT and DCFH assays resulted instead more sensitive towards fine particles. OP^DTT and OP^DCFH values were comparable at the two sites; sources whose strength was very different in the two monitored areas (secondary contribution and, to a less extent, industrial sources) did not then contribute significantly to the measured OP values. The dimensional behaviour of OP^DTT and OP^DCFH was consistent with the contribution of biomass burning.



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High-dose intravenous methylprednisolone therapy in patients with Graves’ orbitopathy is associated with the increased activity of factor VIII

Abstract

Purpose

Venous thromboembolic events (VTE), with their life-threatening manifestation as pulmonary embolism, are potential adverse effects of intravenous methylprednisolone (IVMP) pulse therapy, partially due to a hypercoagulable state. The aim of the study was to analyze the influence of IVMP on selected hemostatic parameters in patients with moderate-to-severe Graves' orbitopathy (GO).

Methods

26 euthyroid patients with GO were treated with 12 pulses of IVMP (6 × 0.5, 6 × 0.25 g every week). Hemostatic variables [factor (F) II, FV, FVII, FVIII, fibrinogen, antithrombin, activated partial thromboplastin time (aPTT), prothrombin time, international normalized ratio of prothrombin time, platelets and D-dimer] were analysed before, 24 and 48 h after 1st, 6th and 12th pulse.

Results

A constant, transient trend in changes of some hemostatic variables was observed after all assessed pulses. We discovered an increase in median activity of FVIII 24 and 48 h after pulses, with a shortening of aPTT 24 h after each IVMP pulse (p < 0.00005). FVII decreased 24 h after each pulse (p < 0.0005 after 1st and 12th, p < 0.00005 after 6th). Fibrinogen level decreased 48 h after each pulse (P < 0.00005). We did not observe any statistically significant changes in hemostatic parameters in the long-term evaluation. Therapy was concluded in one patient after the 9th pulse due to pulmonary embolism.

Conclusions

The increase of FVIII activity is a consequence of treatment with IVMP and occurs after each pulse. In patients with additional risk factors of VTE, anticoagulation prophylaxis should be considered.

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Scholar : These new articles for Classroom Discourse are available online

The online platform for Taylor & Francis Online content New for Classroom Discourse and online now on Taylor & Francis Online: Original Articles Clarification requests as a method of pursuing understanding in CLIL physics lectures Leila Kääntä & Gabriele Kasper Pages: 1-22 | DOI: 10.1080/19463014.2018.1477608 To update which email alerts you receive, manage your alerts within the My Account area. Unsubscribe from new content alerts for this journal (both new issue and latest article notifications) with one click. If you need any further help, please contact us at support@tandfonline.com Please do not reply to this email. To ensure that you receive your alerts and information from Taylor & Francis Online, please add "alerts@tandfonline.com" and "info@tandfonline.com" to your safe senders list. Taylor & Francis, an Informa business. Taylor & Francis is a trading name of Informa UK Limited, registered in England under no. 1072954. Registered office: 5 Howick Place, London, SW1P 1WG.

Scholar : These new articles for American Review of Canadian Studies are available online

The online platform for Taylor & Francis Online content New for American Review of Canadian Studies and online now on Taylor & Francis Online: Original Articles Preventing the Parade: The Party Processions Acts in Ireland and Canada Annie Tock Morrisette Pages: 1-15 | DOI: 10.1080/02722011.2018.1470137 Do you have original research that relates to present-day Japan and its recent historical development? Contemporary Japan welcomes your submissions. To update which email alerts you receive, manage your alerts within the My Account area. Unsubscribe from new content alerts for this journal (both new issue and latest article notifications) with one click. If you need any further help, please contact us at support@tandfonline.com Please do not reply to this email. To ensure that you receive your alerts and information from Taylor & Francis Online, please add "alerts@tandfonline.com" and "info@tandfonline.com" to your safe senders list. Taylor & Francis, an Informa business. Taylor & Francis is a trading name of Informa UK Limited, registered in England under no. 1072954. Registered office: 5 Howick Place, London, SW1P 1WG.

Radionuclides in tea and their behaviour in the brewing process

Publication date: December 2018
Source:Journal of Environmental Radioactivity, Volume 192
Author(s): Markus Zehringer, Franziska Kammerer, Michael Wagmann
Tea plantations may be strongly affected by radioactive fallout. Tea plantations on the Turkish coast of the Black Sea were heavily contaminated by the fallout from the reactor fire at the Chernobyl nuclear power plant in 1986. Two years later, the contamination level was reduced by about 90%. When tea is brewed, the original contamination in the tea leaves is more or less leached into the tea water. While most of the radiocaesium (60–80%) is washed out by brewing, most of the radiostrontium remains in the leaves (70–80%). In food laws, a dilution factor of 40–50 is considered for tea brewing. Most laws only define limit values for radiocaesium. Radiostrontium is not specially regulated, even though its dose coefficients for ingestion are higher than the corresponding coefficients for radiocaesium. Radiostrontium in tea occurs primarily from global fallout (bomb tests from 1945-1965).



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Scholar : These new articles for Aphasiology are available online

The online platform for Taylor & Francis Online content New for Aphasiology and online now on Taylor & Francis Online: Original Articles "I definitely think it's a feasible and worthwhile option": perspectives of speech-language pathologists providing online aphasia group therapy Rachelle Pitt, Anne J. Hill, Deborah Theodoros & Trevor Russell Pages: 1-23 | DOI: 10.1080/02687038.2018.1482403 Reviews Reading comprehension treatment in aphasia: a systematic review Mary Purdy, Patrick Coppens, Elizabeth Brookshire Madden, Jennifer Mozeiko, Janet Patterson, Sarah E. Wallace & Donald Freed Pages: 1-23 | DOI: 10.1080/02687038.2018.1482405 Reporting interventions in communication partner training: a critical review and narrative synthesis of the literature Madeline Cruice, Monica Blom Johansson, Jytte Isaksen & Simon Horton Pages: 1-32 | DOI: 10.1080/02687038.2018.1482406 2018 Future Directions Forum JOIN US at the 2018 Future Directions Forum for Journal of Clinical Child & Adolescent Psychology - June 15-16, 2018 To update which email alerts you receive, manage your alerts within the My Account area. Unsubscribe from new content alerts for this journal (both new issue and latest article notifications) with one click. If you need any further help, please contact us at support@tandfonline.com Please do not reply to this email. To ensure that you receive your alerts and information from Taylor & Francis Online, please add "alerts@tandfonline.com" and "info@tandfonline.com" to your safe senders list. Taylor & Francis, an Informa business. Taylor & Francis is a trading name of Informa UK Limited, registered in England under no. 1072954. Registered office: 5 Howick Place, London, SW1P 1WG.

Scholar : These new articles for Aquatic Insects are available online

The online platform for Taylor & Francis Online content New for Aquatic Insects and online now on Taylor & Francis Online: From the Forthcoming Special Issue: Advances in Aquatic Insect Systematics and Biodiversity in the Neotropics The Naucoridae (Heteroptera: Nepomorpha) of Belize Robert W. Sites, Rachael H. Carrie & William D. Shepard Pages: 1-31 | DOI: 10.1080/01650424.2018.1450988 Hoping to have your article read by anyone, anywhere and at any time? Find out more about publishing open access with Ecosystem Health and Sustainability. To update which email alerts you receive, manage your alerts within the My Account area. Unsubscribe from new content alerts for this journal (both new issue and latest article notifications) with one click. If you need any further help, please contact us at support@tandfonline.com Please do not reply to this email. To ensure that you receive your alerts and information from Taylor & Francis Online, please add "alerts@tandfonline.com" and "info@tandfonline.com" to your safe senders list. Taylor & Francis, an Informa business. Taylor & Francis is a trading name of Informa UK Limited, registered in England under no. 1072954. Registered office: 5 Howick Place, London, SW1P 1WG.

Biomonitoring birds: the use of a micronuclei test as a tool to assess environmental pollutants on coffee farms in southeast Brazil

Abstract

Birds have often played an important role as environmental bioindicators, and different species can be useful due to their bioaccumulating capacity. The micronuclei test is a cytologic technique used for accessing DNA and is a biomarker for damage to DNA. This study analysed the Cerrado avian community, especially the efficiency of the blue-black grassquit (Volatinia jacarina) in responding to pesticide contamination in situ on different-sized coffee farms in southeast Brazil. The micronuclei test was used in erythrocytes of birds. Eighty-two individuals of 21 bird species belonging to 11 families that were found in all study areas were used to evaluate micronuclei (MN) frequency. Two hundred fifty-two MN were counted in every area of study. The MN average count was 3/10,000 erythrocytes, and 17.1% of all bird species exhibited no MN. The average MN was 1.29 ± 0.69 in small farms, 2.59 ± 1.65 in medium farms, and 5.41 ± 1.34 in large farms. Small farms accounted for 14.3% of MN frequency, medium farms 27.8%, and large farms 57.9%. V. jacarina was the most abundant species found and displayed a sensitive response to environmental contamination. Pesticides appear to induce MN formation in a dose-dependent way when farms are analysed according to their area. Therefore, biomonitoring birds remain an efficient means to detect environmental pollutants, especially pesticides. V. jacarina responds as a sensitive biomonitor, showing a dose-dependent response to pesticides used in coffee farms.

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Pharmacokinetics and disposition of miltefosine in healthy mice and hamsters experimentally infected with Leishmania infantum

Publication date: 30 August 2018
Source:European Journal of Pharmaceutical Sciences, Volume 121
Author(s): M. Dolores Jiménez-Antón, Estefanía García-Calvo, Cristina Gutiérrez, Mª.D. Escribano, Nour Kayali, José L. Luque-García, Ana Isabel Olías-Molero, María J. Corral, Maria P. Costi, Juan J. Torrado, José Mª. Alunda
Miltefosine is the only currently available oral drug for treatment of leishmaniasis. However, information on the pharmacokinetics (PK) of miltefosine is relatively scarce in animals. PK parameters and disposition of the molecule was determined in healthy NMRI mice and Syrian hamsters infected and treated with different miltefosine doses and regimens. Long half-life of the molecule was confirmed and differential pattern of accumulation of the drug was observed in analyzed organs in mice and hamster. Long treatment schedules produced miltefosine levels over IC50 value against L. infantum intracellular amastigotes for at least 24 days in spleen and liver of infected hamsters. The observed differential pattern of organ accumulation of the drug in mice and hamster supports the relevance of both species for translational research on chemotherapy of leishmaniasis.

Graphical abstract

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Stroke Mimics: The Quest for Leptomeningeal Anastomoses and Isolated Diffusion-Weigthed Mr Signal

Publication date: Available online 6 June 2018
Source:Seminars in Ultrasound, CT and MRI
Author(s): Humberto Morales, Marshall Kong
Stroke is caused by occlusion of a medium or large sized vessel in the brain. The treatment with either IV or IA thrombolysis is based on an accurate and time-sensitive diagnosis. On clinical and imaging grounds a number of entities – seizures, toxic-metabolic, infectious or demyelinating diseases - can mimic stroke. Identifying them is paramount as the treatment differs significantly. Prior imaging reviews have focused on the non-territorial distribution of these mimics. However, some important questions arise here. Are the vascular territories and their boundaries invariable in the human brain? Where should we draw the lines separating arterial territories? van der Zwan and colleagues addressed these questions decades ago. For him and others, the leptomeningeal anastomoses – a contentious concept for some but increasingly linked to collateral flow in stroke - is an important anatomic structure with significant variations in their distribution and pathophysiology. Variations in blood supply appear larger that traditionally taught. We revisit this concept and entertained their implications in cases of stroke mimics. For instance, the distribution of abnormalities in some toxic-metabolic processes appear to correlate with areas where rich leptomeningeal anastomoses are expected. We will also explore the concept of hyper intense signal on diffusion weighted-imaging (DWI) with no correlated changes on apparent diffusion coefficient (ADC) maps. We name this finding as "isolated DWI signal" and lay-out its importance in the recognition of many entities mimicking stroke. Taking together, the discussed anatomic and imaging concepts will help radiologists and clinicians to recognize not only the common but the unusual entities imitating stroke in the emergency room.



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Maging of Traumatic Injury to Neurovasculature

Publication date: Available online 16 April 2018
Source:Seminars in Ultrasound, CT and MRI
Author(s): David J. Choi, Evelyn S. Guerra, Sathish Dundamadappa
Trauma involving the vessels of the head and neck portends risk of hemorrhage, cerebral infarction, and death. Imaging is essential for the timely diagnosis of these injuries. This article will review diagnostic imaging findings and pitfalls as well as related pathophysiology, screening risk factors, management, and follow-up recommendations.



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Letter From the Guest Editor

Publication date: Available online 16 April 2018
Source:Seminars in Ultrasound, CT and MRI
Author(s): Hao S. Lo




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Soft Tissue Injuries of the Finger and Thumb

Publication date: Available online 16 April 2018
Source:Seminars in Ultrasound, CT and MRI
Author(s): Juliann Giese, Christopher Cerniglia
Soft tissue digital injury of the hand is a common presenting complaint in the emergency setting. Although initial work-up requires physical examination and radiographs, many of these entities may be radiographically occult and solely appreciated on ultrasound (US) or magnetic resonance imaging (MRI). If undiagnosed, these conditions may lead to sequela of untreated disease including early osteoarthritis, pain, permanent deformity, and immobility. Soft tissue finger injuries that may not be readily apparent without the use of MRI or US are discussed. The key imaging features of radiolucent foreign bodies in addition to tendon, collateral ligament, sagittal band, and pulley injuries on MRI and US are discussed.



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Imaging of Spine Fractures With Emphasis on the Craniocervical Junction

Publication date: Available online 16 April 2018
Source:Seminars in Ultrasound, CT and MRI
Author(s): Gabriela Santos-Nunez, Hao S. Lo, Hemang Kotecha, Joe Jose, Aly Abayazeed
Spinal cord injury often times is a catastrophic result of trauma. Delay in diagnosis may result in increased morbidity and mortality. Cross-sectional imaging is now increasingly used as a first-line diagnostic modality in the setting of trauma for recognition of spine fractures and ligamentous injuries that might be missed on routine radiographs. The learning objectives of this article are to review the anatomy of the spine and understand the mechanisms of injury in the cervical, thoracic, and lumbosacral column by applying easy and reproducible classification systems to guide clinical management.



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Pre-treatment functional MRI of breast cancer: T2* evaluation at 3 T and relationship to dynamic contrast-enhanced and diffusion-weighted imaging

Publication date: October 2018
Source:Magnetic Resonance Imaging, Volume 52
Author(s): Evanthia Kousi, Elizabeth A.M. O'Flynn, Marco Borri, Veronica A. Morgan, Nandita M. deSouza, Maria A. Schmidt
PurposeBaseline T2* relaxation time has been proposed as an imaging biomarker in cancer, in addition to Dynamic Contrast-Enhanced (DCE) MRI and diffusion-weighted imaging (DWI) parameters. The purpose of the current work is to investigate sources of error in T2* measurements and the relationship between T2* and DCE and DWI functional parameters in breast cancer.MethodsFive female volunteers and thirty-two women with biopsy proven breast cancer were scanned at 3 T, with Research Ethics Committee approval. T2* values of the normal breast were acquired from high-resolution, low-resolution and fat-suppressed gradient-echo sequences in volunteers, and compared. In breast cancer patients, pre-treatment T2*, DCE MRI and DWI were performed at baseline. Pathologically complete responders at surgery and non-responders were identified and compared. Principal component analysis (PCA) and cluster analysis (CA) were performed.ResultsThere were no significant differences between T2* values from high-resolution, low-resolution and fat-suppressed datasets (p > 0.05). There were not significant differences between baseline functional parameters in responders and non-responders (p > 0.05). However, there were differences in the relationship between T2* and contrast-agent uptake in responders and non-responders. Voxels of similar characteristics were grouped in 5 clusters, and large intra-tumoural variations of all parameters were demonstrated.ConclusionBreast T2* measurements at 3 T are robust, but spatial resolution should be carefully considered. T2* of breast tumours at baseline is unrelated to DCE and DWI parameters and contribute towards describing functional heterogeneity of breast tumours.



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