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Extraintestinal manifestations are the cause of morbidity and affect the quality of life of patients with inflammatory bowel diseases (IBDs). Musculoskeletal manifestations, in particular, spondyloarthritis and osteoporosis, are the most frequent extraintestinal manifestation of IBDs. The diagnosis and management of the musculoskeletal manifestation of IBDs relies on imaging. Conventional radiography, magnetic resonance imaging, computed tomography, and ultrasound can help to detect pathological signs of spondyloarthritis, both peripheral and with axial involvement. Dual-energy X-ray absorptiometry is the gold standard for identifying the presence of osteoporosis, whereas conventional radiology and computed tomography can reveal occult vertebral fractures. The aim of this narrative review is to describe the imaging of musculoskeletal manifestations of IBDs.

The CoVID-19 pandemic has impacted in a lesser extent and intensity to patients younger than 15 years The role of different imaging studies of lung involvement has been extensively addressed, from the first cases of severe pneumonia and respiratory distress syndrome in adults There are fewer reports of the comparative usefulness of conventional radiology, ultrasound, and computed axial tomography in children Of those, ground glass opacities, crazy paving pattern and surrounding halo consolidation are the most characteristic Even though none of them allows diagnostic confirmation, their correct interpretation helps in decision flows Computed axial tomography is more accurate for defining the type and extent of lung parenchymal involvement The role of the ultrasound in early stages in the emergency department is clearer in adults than in children, in whom there is a good correlation with chest tomography This article addresses the different radiological patterns, their pathophysiological representation and differential diagnoses, in order to alert pediatricians of their interpretation, as well as the potential role of imaging diagnoses most frequently used in children with low acute respiratory infection La pandemia CoVID-19 ha impactado en una proporcion e intensidad menor a los pacientes menores de 15 anos El rol de los diferentes estudios por imagenes del compromiso pulmonar ha sido extensamente abordado, desde los primeros casos de neumonias graves y sindrome de distres respiratorio en adultos En ninos existen menos reportes de la utilidad de la radiologia convencional, ecografia y tomografia axial computarizada Sin embargo, los patrones mas caracteristicos observados en adultos se repiten en los ninos De ellos, el vidrio esmerilado, el patron en empedrado y la consolidacion con halo circundante son los mas caracteristicos Aun cuando ninguno de ellos permite confirmacion diagnostica, su correcta interpretacion ayuda en los flujos de decisiones La tomografia axial computarizada es mas certera para la definicion de tipo y extension del compromiso parenquimatoso pulmonar El rol en los estadios tempranos en el servicio de urgencia de la ecografia es mas claro en adultos que en ninos, donde existe buena correlacion con la tomografia de torax Este articulo aborda los diferentes patrones radiologicos, su representacion fisiopatologica y diagnosticos diferenciales, con el objeto de apoyar a los pediatras en su interpretacion, como tambien reconocer el rol de las tecnicas de imagenes diagnosticas mas frecuentemente utilizadas en ninos con infeccion respiratoria aguda baja

The accurate detection of lung lesions as well as the precise measurement of their sizes on Computed Tomography (CT) images is known to be crucial for the response to therapy assessment of cancer patients. The goal of this study is to investigate the feasibility of using mobile tele-radiology for this task in order to improve efficiency in radiology. Lung CT Images were obtained from The Cancer Imaging Archive (TCIA). The Bland-Altman analysis method was used to compare and assess conventional radiology and mobile radiology based lesion size measurements. Percentage of correctly detected lesions at the right image locations was also recorded. Sizes of 183 lung lesions between 5 and 52 mm in CT images were measured by two experienced radiologists. Bland-Altman plots were drawn, and limits of agreements (LOA) were determined as 0.025 and 0.975 percentiles (−1.00, 0.00), (−1.39, 0.00). For lesions of 10 mm and higher, these intervals were found to be much smaller than the decision interval (−30% and +20%) recommended by the RECIST 1.1 criteria. In average, observers accurately detected 98.2% of the total 271 lesions on the medical monitor, while they detected 92.8% of the nodules on the iPhone.

Chronic obstructive pulmonary disease (COPD) is an irrevocable disorder and has a high mortality rate. It can be diagnosed by using several methods, e.g., traditional radiology imaging, clinical details, and pulmonary function tests (PFTs). Conventional radiology detects the emphysema in its late phases when the disease has already damaged an enormous lung field region. So, high resolution computed tomography (HRCT) is used to precisely estimate the disease's severity. Early emphysema, typically less than 10 mm in diameter, often got missed during a visual assessment of HRCT scans. So an attempt has been made to target this issue. To the best of our knowledge, early emphysema regions' detection using HRCT images was not addressed. This paper proposes a novel method by incorporating details of low attenuation areas (LAA) into Fuzzy-C Mean (FCM) algorithm to identify the uncertain regions of early emphysema regions proficiently in HRCT images. Experimental results are authenticated by using ground truth marked by the expert radiologist. The investigational outcomes show that the proposed method gives results close to expert radiologist's manual demarcations.

Fracture healing is a complex physiologic process, relying on the crucial interplay between biological and mechanical factors. It is generally assessed using imaging modalities, including conventional radiology, CT, MRI and ultrasound (US), based on the fracture and patient features. Although these techniques are routinely used in orthopaedic clinical practice, unfortunately, they do not provide any information about the biomechanical status of the fracture site. Therefore, in recent years, several non-invasive techniques have been proposed to assess bone healing using ultrasonic wave propagation, changes in electrical properties of bones and callus stiffness measurement. Moreover, different research groups are currently developing smart orthopaedic implants (plates, intramedullary nails and external fixators), able to provide information about the fracture healing process. These devices could significantly improve orthopaedic and trauma clinical practice in the future and, at the same time, reduce patients' exposure to X-rays. This study aims to define the role of traditional imaging techniques and emerging technologies in the assessment of the fracture healing process.

BACKGROUND Among hospitalised patients, diagnostic radiation is possibly used least on pregnant patients due to the fear of ionising radiation on the fetus; however, what levels are currently being prescribed. AIMS To assess the cumulative levels of ionising radiation received by pregnant patients during a single admission to a tertiary hospital. MATERIALS AND METHODS A retrospective audit of pregnant patients admitted to Flinders Medical Centre, South Australia, Australia, between 2013 and 2017 inclusive was performed. All procedures utilising ionising radiation were collected including conventional radiology, computed tomography, fluoroscopy and nuclear medicine. Individual and cumulative effective doses for mother and fetus were calculated using patient dose reports and published conversion factors. RESULTS From 547 patients, the median cumulative effective dose was 0.02 mSv and only five patients received more than 10 mSv, with 19.07 mSv the highest dose received. The median fetal cumulative effective dose was 0.01 mSv but only three fetuses received more than 10 mSv, likely due to fetal exclusion in some procedural fields of view. Stays longer than ten days were associated with significantly higher cumulative effective dose, as did those with maternal cardiovascular related admission, for both maternal and fetal exposures. CONCLUSION These results suggest that pregnant patients are exposed to low doses of ionising radiation, in both individual procedures and cumulative doses. The detrimental risks associated with these levels of ionising radiation are not overt and so clinicians should question which risk is higher, the ionising radiation from the radiological procedures received or the lack of diagnostic information if avoided?

Background: Medical applications are the main source of exposure to ionizing radiation of human origin. Our objective was to determine the data on exposure to ionizing radiation of medical origin of the population of Ngaoundere in 2018. Methodology: It was a cross-sectional descriptive study conducted within a period of one year, in the different hospitals of Ngaoundere, with a functional medical imaging service. The variables studied were age, sex, type of examination, anatomical region and effective dose. The statistical analysis was performed using the Microsoft Office 2016 software, Sphinx V5; the effective dosage was calculated using the Internet Dose calculation Module. Results: In 2018, 4136 diagnostic acts using ionizing radiation were carried out; it concerned only conventional radiology with an average of 0.02 per capita. The total collective dose received by the population was 8300 mSv, and an average dose of 0.040 mSv per inhabitant. The proportion of the population that has actually benefited from a conventional radiology examination is 2.07%, an individual effective average dose of 2 mSv. The most frequent acts involved the thorax, limbs, spine and pelvis with respectively 53.9%; 19.6%; 14.3% and 6.7%. Acts involving the spine, pelvis and hip, skull and abdomen contributed to the majority of the collective effective dose respectively with 45.75%, 25.96%, 10.53% and 8.84%. The age group performing most exams in men is 25 to 49 and 25 to 54 in women; the number of acts is higher among men 2457 (59.4%) acts compared to women 1679 (40.6%) acts. The collective dose per sex is higher among women with 4487.22 mSv (54.06%) compared to men with 3812.98 mSv (45.94%). Conclusion: Only 2.07% of population of Ngaoundere benefited from a conventional radiology examination in 2018 with an individual effective average dose of 2 mSv. The annual per capita number of acts is 0.02 and annual per capita effective dose is 0.040 mSv in Ngaoundere in 2018.

From the development of X-ray imaging in the late 19th century, the field of medical imaging developed an impressive array of modalities. These can measure and image a variety of physical parameters from absorption coefficients to spin-spin relaxations. However, throughout most of the 20th century, the intrinsic biomechanical properties of tissues remained hidden from conventional radiology. This changed around 1990 when it was demonstrated that medical ultrasound systems with their fast pulse repetition rate and high sensitivity to motion could create images related to the stiffness of tissues and their shear wave properties. From there, vigorous development efforts towards imaging the elastic properties of tissues were launched across different modalities. These progressed from the research phase, through implementation on clinical scanners, through extensive clinical trials of selected diagnostic tasks, to government approvals, payer approvals, international standards statements, and into routine clinical practice around the globe. This review covers highlights of some major topics of the technical and clinical developments over the last 30 years with brief pointers to some of the remaining issues for the next decade of development.

Con el aumento progresivo de la incidencia de infección por virus de la inmunodeficiencia humana (VIH)/sida, la aparición de nuevas patologías, como las infecciones oportunistas o las infecciones por gérmenes poco comunes, ha llevado a que en la literatura mundial se mencionen con más frecuencia reportes de casos con nuevas formas de presentación o presentación inusual. En la literatura, hasta el momento, se han informado muy pocos casos de infección pulmonar por Salmonella y aún menos frecuente con formación de abscesos. Actualmente hay una serie de casos publicada en la revista Chest, en 1997, en la que se describe que la presencia de abscesos por Salmonella se relaciona directamente con la inmunosupresión por VIH/sida. En esta ocasión, describimos el caso de un paciente joven con antecedente de infección por VIH/sida, que presenta sintomatología respiratoria aguda, documentándose absceso pulmonar por Salmonella, con muy buena respuesta al manejo antibiótico y resolución de este confirmado por radiología convencional.

Introduction. In some cases C2 may suffer only rotational dislocation around its own axis (dens), causing no increase in the atlantodental interval (ADI), making it difficult to diagnose the instability in static radiographies. Objective. To report a case of atlanto-axial traumatic subluxation, without bony injury or displacement, in which the diagnosis cannot be achieved through conventional radiology and computed tomography, and discuss the types of transverse ligament injuries, its diagnosis, the instability and their treatment. Methods.A 61-year-old man, victim of head (occipital), complaining neck. Static radiographies and CT scan of cervical spine were performed, demonstrating no abnormalities. Flexion and extension cervical radiography revealed an increase of ADI in flexion, indicating instability and damage to the transverse atlantal ligament (TAL). The MRI of the cervical spine demonstrated the discontinuity of the TAL, configuring an injury to the structure of the ligament. The patient underwent to early surgery with C1-C2 fixation using the Goel-Harms’technique. Results. The diagnosis could be revealed only in dynamic radiographs or MRI study. The patient presented complete improvement of symptoms. Conclusions. The use of cervical dynamic radiography and / or magnetic resonance imaging allowed the diagnosis of instability and visualization of the TAL injury, avoiding the lack of diagnosis with its consequences. The MRI allows a direct view of the ligament injury, their classification and the prognostic evaluation of the injury, guiding the therapy, surgical or conservative.

Bone and muscle are two deeply interconnected organs and a strong relationship between them exists in their development and maintenance. The peak of both bone and muscle mass is achieved in early adulthood, followed by a progressive decline after the age of 40. The increase in life expectancy in developed countries resulted in an increase of degenerative diseases affecting the musculoskeletal system. Osteoporosis and sarcopenia represent a major cause of morbidity and mortality in the elderly population and are associated with a significant increase in healthcare costs. Several imaging techniques are currently available for the non-invasive investigation of bone and muscle mass and quality. Conventional radiology, dual energy X-ray absorptiometry (DXA), computed tomography (CT), magnetic resonance imaging (MRI) and ultrasound often play a complementary role in the study of osteoporosis and sarcopenia, depicting different aspects of the same pathology. This paper presents the different imaging modalities currently used for the investigation of bone and muscle mass and quality in osteoporosis and sarcopenia with special emphasis on the clinical applications and limitations of each technique and with the intent to provide interesting insights into recent advances in the field of conventional imaging, novel high-resolution techniques and fracture risk.

Schwannomas consist of benign tumors that arise from the nerves, however, they are not frequent in the breast. Our search criteria only found 28 cases described in Literature. We show the case about a 63 years old woman who underwent a breast magnetic resonance (MR) because of high risk for breast cancer, in which a lession on her left breast was found. Not only MR features seemed to be benign, but ultrasound and mamography features, too. The diagnosis of schwannoma was confirmed by ultrasound-guided biopsy. Findings in conventional radiology were correlated with those described in the reviewed literature. In our opinion, this case results valuable due to the inicial diagnosis by MR, which is not an imaging proof for bening tumors, innitially. According to the revised bibliography these features are pretty funny, as mamography and ultrasound, with histological findings, are the clues for the usual diagnosis.

In conventional radiology peer review practice, a small number of exams (routinely 5% of the total volume) is randomly selected, which may significantly underestimate the true error rate within a given radiology practice. An alternative and preferable approach would be to create a data-driven model which mathematically quantifies a peer review risk score for each individual exam and uses this data to identify high risk exams and readers, and selectively target these exams for peer review. An analogous model can also be created to assist in the assignment of these peer review cases in keeping with specific priorities of the service provider. An additional option to enhance the peer review process would be to assign the peer review cases in a truly blinded fashion. In addition to eliminating traditional peer review bias, this approach has the potential to better define exam-specific standard of care, particularly when multiple readers participate in the peer review process.

The coexistence of different bone diseases in the same patient involves a complex differential diagnosis. A patient is presented who was studied due to a renal mass that showed many sclerotic lesions in spine and limbs in conventional radiology and CT. These lesions were evaluated with 99mTC-HDP bone scintigraphy and 18F-FDG PET/CT, which helped to obtain the definitive pathological diagnosis of osteopoikilosis (OP) co-existing with gastric cancer bone metastases. Of the different imaging scans performed, bone scintigraphy was particularly relevant due to its ability to discriminate between benign and metastatic bone disease.

Inflammatory and infectious diseases include many different clinical conditions not often well-recognized and characterized with conventional radiology and biochemical tests. Radiological techniques (TC, MRI, US) show anatomical changes that usually occur in chronic stages of the disease leading to a delayed diagnosis and therapy. The possibility of nuclear medicine imaging to detect biological and biochemical changes in the earliest phases of diseases allow the clinician not only to promptly identify the infective or inflammatory focus, but also to establish the best therapeutic approach for the patient. The recent availability of different monoclonal antibodies and analogues of growth and signalling factors offer to physicians a wide spectrum of promising radiopharmaceuticals as markers for different pathological events. Therefore, NM may help in therapy decision-making, management and follow-up through the evaluation of the expression of these specific molecules, leading to the development of personalized therapies. The appeal to nuclear medicine imaging is becoming, indeed, more and more widespread not only for diagnostic purposes, but also for monitoring drug efficacy. Several advances have been observed in this field, and they seem to be very promising for a tailored medicine.

To the Editor: We appreciate the thoughtful comments of Drs. Zumblick and Mendes-Marcon regarding the use of point-of-care ultrasound (POCUS) as an alternative to conventional radiology. We are in complete agreement concerning both the efficacy and advantages of ultrasound for the detection of rib

The knee is a common site for bone tumors, whether clinically painful or not. Conventional radiology has been established as the first line of investigation in patients with knee pain and can reveal lesions that often generate questions not only for the generalist physician but also for the radiologist or general orthopedist. History, image examination, and histopathological analysis compose the essential tripod of the diagnosis of bone tumors, and conventional radiology is an essential diagnostic tool in patients with knee pain. This pictorial essay proposes to depict the main conventional radiography findings of the most common bone tumors around the knee, including benign and malignant tumors, as well as pseudo-tumors.O joelho é sede comum de apresentação de tumores ósseos, sejam eles clinicamente dolorosos ou não. A radiologia convencional consagra-se como exame de primeira linha para investigação inicial dos doentes com dor no joelho e pode revelar lesões que muitas vezes geram dúvidas tanto para o médico generalista quanto para o radiologista ou ortopedista geral. História, exame de imagem e estudo histopatológico compõem o tripé essencial do diagnóstico dos tumores ósseos, sendo a radiografia simples o instrumento essencial de investigação diagnóstica nesses casos. Este ensaio iconográfico propõe expor os principais achados dos mais frequentes tumores ósseos, benignos, malignos e pseudotumorais do joelho.

This study aimed to identify and give visibility to the main occupational hazards of radiology technicians, associated with the care of multiple trauma patient with a hospital department of conventional radiology. Exploratory and descriptive research with a qualitative approach. The data were collected through participant observation technique of calls made by radiology technicians in conventional radiology service of a general hospital in Florianopolis between May and September 2012. The observations that have characterized exposure to occupational risk were described in journal field subsequently estimated and compared with the theoretical framework contained in Decree No 25/1994. It was found that the occupational risks to which they are technicians exposed in radiology in the care of multiple traumas carrier are related to exposure to ionizing radiation, body fluids and ergonomic risks, neglects to personal protective equipment use and defects in equipment. The radiology technicians become more vulnerable to occupational risks when assisting polytrauma patients.

Background and objective The availability of digital X-ray detectors, together with the development of new robotized hardware and reconstruction algorithms, opens the opportunity to provide 3D capabilities with conventional radiology systems. This would be based on the acquisition of a limited number of projections with non-standard geometrical configurations. The versatility of these techniques is enormous, enabling the introduction of tomography in situations where a CT system is hardly available, such as during surgery or in an ICU, or in which a reduction of radiation dose is key, as in pediatrics. Computer simulations are a valuable tool to explore these possibilities before their actual implementation on real systems. Existing software tools generally simulate only standard acquisition protocols, such as cone-beam with circular trajectory, thus not allowing the users to evaluate more sophisticated projection geometries. The goal of this work is to design a simulation tool that enables the design of acquisition protocols with flexible projection geometries. Methods We present XAP-Lab, a software tool for the design of X-ray acquisition protocols with flexible trajectories. For a given projection geometry, defined through a graphical user interface, it allows the user to simulate projections using GPU-accelerated kernels, the visualization of the scanned field of view and the estimation of the total radiation dose. The complete acquisition protocol can then be exported with the appropriate format for its use on real systems. We tested the software by optimizing a tomosynthesis protocol and validating the results with real acquisitions using a SEDECAL NOVA FA radiography system and phantoms for quantitative and qualitative evaluation. Results Quantitative evaluation using a phantom showed a mean error under 4 mm for each position, below the ±5 mm tolerance of the system specified by the manufacturer. Visual evaluation on a thorax acquisition also showed a good geometrical agreement between simulated and real projections. Conclusions Results showed an excellent matching with simulations, supporting the usefulness of XAP-Lab for the design of new acquisition protocols with non-standard geometries.

Health care workers, including radiology technicians, are exposed to work burdens liable to cause exhaustion.To describe sources of exhaustion within the work process of technicians at a hospital department of conventional radiology in Santa Catarina, Brazil.Qualitative, descriptive and exploratory study in which data were collected from 12 radiology technicians by means of semi-structured interviews. The data were subjected to thematic analysis.Three sources of exhaustion stood out: musculoskeletal, represented by shoulder and back pain, mental, corresponding to stress and emotional and psychological overload, and respiratory, manifested as colds, pneumonia and rhinitis.The present study makes visible sources of exhaustion within the work process of radiology technicians, which are similar to those that affect other categories of health care workers.Os profissionais da saúde estão expostos a cargas de trabalho que interagem com o corpo e podem gerar desgastes. Entre esses profissionais, temos os das técnicas radiológicas.Descrever os desgastes presentes no processo de trabalho dos profissionais das técnicas radiológicas em serviço hospitalar de radiologia convencional no estado de Santa Catarina.Trata-se de uma pesquisa qualitativa, descritiva e exploratória. A técnica de coleta de dados foi entrevista semiestruturada, realizada com 12 profissionais técnicos em radiologia. A análise ocorreu por meio da análise temática.Destacaram-se três categorias de desgaste: os osteoarticulares, que foram manifestados por dores no ombro e na coluna vertebral; os psíquicos, que abordaram o estresse e o desgaste emocional e psicológico; e os do sistema respiratório, manifestando-se por meio de resfriado, pneumonia e rinite.A pesquisa permitiu dar visibilidade aos desgastes ocasionados pelo processo de trabalho dos profissionais das técnicas radiológicas em radiologia convencional. Evidenciou-se que esses desgastes são similares aos de outras categorias profissionais na área da saúde.

In this section, tables of normalized organ doses for conventional radiographs are listed that have been published thus far to the knowledge of the authors. The literature listings comprise tables and single publications to normalized organ doses in conventional radiology (Tables 29.1, 29.2, 29.3 and 29.4).

The main purpose of this study was to investigate patient dose in the chest (PA/AP/LAT) and skull (PA/AP/LAT) X‐ray examinations, as frequent procedures. The study was performed in eight public hospitals of Khuzestan province, Iran. Patient dosimetry was conducted on 567 standard patient X‐ray examinations (males: 61.2%, female: 38.2%). Dosimetry protocol in this study was indirect method, according to the International Atomic Energy Agency (IAEA) Technical Reports series No. 457. Patients weighing 70±10 kg were considered as standard. In the indirect dosimetry approach, exposure parameters such as kVp, mAs, focal film distance (FFD), and tube outputs recorded during data acquisition were used for calculating incident air kerma on the patient's skin, entrance surface air kerma (ESAK) that is recommended by the IAEA as the most appropriate patient dosimetry quantity in simple radiographic examinations. This survey reveals significant variations in the radiological practice. Results showed that the parameters set by radiologic technologists change in a wide range: mAs varied from 2 to 80 for skull PA, 2 to 202 for chest LAT, and FFD varied from 50 to 180 for skull LAT projection. The study showed that patient doses in three chest projections exceed the IAEA and European Commission dose reference levels (EC DRLs) — 1.0, 1.12, and 2.20 mGy for chest PA, chest AP, and chest LAT, respectively. Results also showed that mean ESAKs of patients in skull projections were generally lower than the IAEA and EC DRLs, 1.5, 1.72, and 2.25 for skull LAT, skull AP, and skull PA, respectively. This study provides evidence that dose reduction in the simple X‐ray examinations is feasible by updating clinical audits and implementation of systematic quality assurance (QA) and quality control (QC) programs. The authors recommend that DRLs obtained in this study can be used as local DRLs in Khuzestan area and dose surveys must be performed in all provinces to establish national dose reference levels (NDRLs) in Iran. PACS numbers: 87.53.Bn, 87.57.uq, 87.59.B

[Abstract] This article describes the case of a 40-year-old man who complained of pain in the posterior region of the right ankle that was exacerbated by plantar flexion without previous trauma. After a physical examination where tendinous and ligamentous injuries were ruled out, a conventional radiology test was requested with the finding of a Trigone Bone that was responsible for the clinic. In this case more tests were not required to establish the diagnosis and symptomatic relief was achieved with conservative measures [Resumen] En este artículo se presenta el caso de un varón de 40 años que se quejaba de dolor en la región posterior del tobillo derecho que se exacerbaba con la flexión plantar del tobillo sin traumatismo previo. Tras una exploración física donde se descartaron lesiones tendinosas y ligamentosas, se solicitó una prueba de radiología convencional con el hallazgo de un Hueso Trígono que era el responsable de la clínica. En este caso no se requirieron más pruebas para establecer el diagnóstico y se consiguió el alivio sintomático con medidas conservadoras

Los niveles de referencia en radiología sirven como guía para aplicar medidas que permitan asegurar las exposiciones de pacientes a radiación ionizante y mediante éstos iniciar procesos de optimización, con el objetivo de obtener una calidad de imagen aceptable para el diagnóstico. Parte fundamental para la determinación de los también llamados niveles orientativos, fue realizar el control de calidad de los equipos convencionales de rayos X, esto con el fin de garantizar la confiabilidad de las medidas. Se usaron dos métodos para medir la dosis de entrada en superficie; el primero mediante la utilización del rendimiento del tubo con parámetros propios por cada estudio incluyendo un factor de retrodispersión y el segundo método mediante dosímetros termoluminiscentes. Los niveles de referencia fueron determinados en el Hospital Universitario Nacional para el estudio de tórax por ser el de más alta frecuencia, columna lumbar por ser uno de los estudios que más implica dosis de radiación y abdomen, para cada uno de estos estudios, se realizó la evaluación clínica de la imagen en al menos una de sus proyecciones. Los resultados arrojan niveles de referencia inferiores a los niveles internacionales, lo que puede atribuirse a los avances de la radiología digital, sin embargo, se recomienda dar inicio al proceso de optimización del servicio, implementando el factor de rechazo y realizando el entrenamiento en el funcionamiento del control automático de exposición, como herramienta fundamental de disminución de dosis de radiación, con el fin de llegar a la estandarización de los protocolos de adquisición para la mayoría de estudios de radiografía convencional. Abstract: Reference levels in radiology work as a guide to apply actions which ensure doses of patients exposed to ionizing radiation and begin through them processes of optimization, with the aim to obtain an acceptable diagnosis image quality. A fundamental issue for determining the so called indicative levels was the development of the quality control of the X-ray conventional equipment in order to guarantee the reliability of measurements. Two methods were used to measure the surface entrance dose, the former through the use of the tube efficiency with specific parameters for each exam including a backscatter factor, the latter by using thermoluminescent dosimeters. The reference levels were established at the Hospital Universitario Nacional for thorax exam as it is the most frequent, lumbar spine since it involves greater radiation doses and abdomen. The clinical evaluation of the image was made for every exam at least on one of its projections. Results produced reference levels below the international levels, which can be explained by the advances in digital radiology. However, it is suggested that the process of optimization of the installation is started by introducing the scrap factor and training in the operation of the automatic exposure control as an essential tool to diminish radiation doses withthe purpose of reaching the standardization of the acquisition protocols of the majority of conventional radiography exams. Maestría

In clinical practice, the conventional radiography is still the radiologic method for the diagnosis of rheumatoid arthritis (RA). Moreover, it provides a quick overview of the symptomatic joints to narrow the differential diagnosis and to evaluate progression. RA is a polyarticular disease with bilateral and symmetric involvement of the peripheral joints, especially small joints, and less frequently, the cervical spine. The radiologic features are soft tissue swelling, periarticular osteoporosis, erosions, loss of joint space, and in advanced disease, osteolysis and typical subluxations or deformities, such as ulnar deviation.

Many gastro-enteropancreatic neuroendocrine tumours (GEP-NETs) secrete biologically active substances and can present with distinct clinical syndromes related to their oversecretion. In particular, carcinoid syndrome (CS) is a compendium of clinical manifestations including secretory diarrhoea, flushing and less commonly wheezing and dyspnoea secondary to overproduction of such compounds, mainly serotonin. Carcinoid syndrome is almost exclusively derived from small intestinal NETs that have metastasized to the liver and may also be associated with extensive fibrosis of heart valves and the mesenterium. Although the diagnosis is usually delayed due to the lack of tumour-specific symptoms, measurement of specific tumour metabolites such as 5-hydroxyindoloacetic acid facilitates the diagnosis. Conventional radiology and functioning imaging modalities using specific and occasionally non-specific tracers are used to identify the extent of disease and also provide information regarding prognosis and the application of specific treatment. The development though of diagnostic and predictive biomarkers that would allow for individualized workup and selection of specific treatments remains a priority in the field.

The availability of digital X-ray detectors, together with advances in reconstruction algorithms, creates an opportunity for bringing 3D capabilities to conventional radiology systems. The downside is that reconstruction algorithms for non-standard acquisition protocols are generally based on iterative approaches that involve a high computational burden. The development of new flexible X-ray systems could benefit from computer simulations, which may enable performance to be checked before expensive real systems are implemented. The development of simulation/reconstruction algorithms in this context poses three main difficulties. First, the algorithms deal with large data volumes and are computationally expensive, thus leading to the need for hardware and software optimizations. Second, these optimizations are limited by the high flexibility required to explore new scanning geometries, including fully configurable positioning of source and detector elements. And third, the evolution of the various hardware setups increases the effort required for maintaining and adapting the implementations to current and future programming models. Previous works lack support for completely flexible geometries and/or compatibility with multiple programming models and platforms. In this paper, we present FUX-Sim, a novel X-ray simulation/reconstruction framework that was designed to be flexible and fast. Optimized implementation for different families of GPUs (CUDA and OpenCL) and multi-core CPUs was achieved thanks to a modularized approach based on a layered architecture and parallel implementation of the algorithms for both architectures. A detailed performance evaluation demonstrates that for different system configurations and hardware platforms, FUX-Sim maximizes performance with the CUDA programming model (5 times faster than other state-of-the-art implementations). Furthermore, the CPU and OpenCL programming models allow FUX-Sim to be executed over a wide range of hardware platforms.