CT attenuation values of blood and myocardium: rationale for accurate coronary artery calcifications detection with multi-detector CT.

OBJECTIVES: To determine inter-session and intra/inter-individual variations of the attenuations of aortic blood/myocardium with MDCT in the context of calcium scoring. To evaluate whether these variations are dependent on patients' characteristics. METHODS: Fifty-four volunteers were evaluated with calcium scoring non-enhanced CT. We measured attenuations (inter-individual variation) and standard deviations (SD, intra-individual variation) of the blood in the ascending aorta and of the myocardium of left ventricle. Every volunteer was examined twice to study the inter-session variation. The fat pad thickness at the sternum and noise (SD of air) were measured too. These values were correlated with the measured aortic/ventricular attenuations and their SDs (Pearson). Historically fixed thresholds (90 and 130 HU) were tested against different models based on attenuations of blood/ventricle. RESULTS: The mean attenuation was 46 HU (range, 17-84 HU) with mean SD 23 HU for the blood, and 39 HU (10-82 HU) with mean SD 18 HU for the myocardium. The attenuation/SD of the blood were significantly higher than those of the myocardium (p < 0.01). The inter-session variation was not significant. There was a poor correlation between SD of aortic blood/ventricle with fat thickness/noise. Based on existing models, 90 HU threshold offers a confidence interval of approximately 95% and 130 HU more than 99%. CONCLUSIONS: Historical thresholds offer high confidence intervals for exclusion of aortic blood/myocardium and by the way for detecting calcifications. Nevertheless, considering the large variations of blood/myocardium CT values and the influence of patient's characteristics, a better approach might be an adaptive threshold.

Impulse oscillometry identifies peripheral airway dysfunction in children with adenosine deaminase deficiency.

Adenosine deaminase-deficient severe combined immunodeficiency (ADA-SCID) is characterized by impaired T-, B- and NK-cell function. Affected children, in addition to early onset of infections, manifest non-immunologic symptoms including pulmonary dysfunction likely attributable to elevated systemic adenosine levels. Lung disease assessment has primarily employed repetitive radiography and effort-dependent functional studies. Through impulse oscillometry (IOS), which is effort-independent, we prospectively obtained objective measures of lung dysfunction in 10 children with ADA-SCID. These results support the use of IOS in the identification and monitoring of lung function abnormalities in children with primary immunodeficiencies.

Intraosseous lipoma: radiological findings

OBJECTIVE: Intraosseous lipomas may be less rare lesions than previously suggested in the literature. They have frequently been misdiagnosed as other benign bone lesions. A combination of computed tomography, magnetic resonance imaging and radiography is essential for decreasing misdiagnosis rates. MATERIALS AND METHODS: This retrospective study presents ten cases of intraosseous lipoma. The patients' ages ranged from 25 to 80 years, and six of them were female. Six patients presented with bone pain, whereas four patients were asymptomatic with incidentally discovered lesions. The involved bones were: femur (four patients), tibia (two patients), calcaneus (one patient), sacrum (one patient), iliac bone (one patient), navicular bone (one patient). All of the patients were assessed by means of conventional radiography, computed tomography and magnetic resonance imaging of the affected region. RESULTS: In all of the cases, plain films revealed well-defined lytic lesions. Both computed tomography and magnetic resonance imaging were quite useful in demonstrating fat within the femur. The histologic pattern of all tumors was that of mature adipose tissue. CONCLUSION: Intraosseous lipoma is a well-defined entity that may develop with varying presentations. Plain radiographs alone cannot establish the diagnosis of this lesion. However, both computed tomography and magnetic resonance imaging are quite useful methods in these cases.

QualIM®: software para treinamento na interpretação de imagens médicas digitais

OBJETIVO: Foi desenvolvido um software denominado QualIM® - Qualificação de Imagens Médicas para treinamento de profissionais na interpretação de exames digitais de mamografias utilizando ferramentas de manipulação de imagens, em monitores específicos, classificadas em BI-RADS®. MATERIAIS E MÉTODOS: O sistema, desenvolvido em Delphi 7, armazena as respostas da interpretação de imagens mamográficas durante o treinamento e compara aos dados inseridos denominados "padrão-ouro". O sistema contém imagens de computed radiography, direct radiography e digitalizadas. O software converte as imagens do computed radiography e direct radiography para o formato TIFF, mantendo as resoluções espacial e de contraste originais. Profissionais em treinamento manipulam o realce da imagem utilizando ferramentas de software (zoom, inversão, réguas digitais, outras). Dependendo da complexidade, são apresentadas até oito incidências mamográficas, seis imagens de ultra-som e duas de anatomopatológico. RESULTADOS: O treinamento iniciou em 2007 e atualmente faz parte do programa de residência em radiologia. O software compõe o texto, de forma automática, das informações inseridas pelo profissional, baseado nas categorias BI-RADS, e compara com a base de dados. CONCLUSÃO: O software QualIM é uma ferramenta digital de ensino que auxilia profissionais no reconhecimento de padrões visuais de uma imagem mamográfica, bem como na interpretação de exames mamográficos, utilizando a classificação BI-RADS.

Right ventricular rupture due to recurrent mediastinal infection with a closed chest.

Right ventricular (RV) rupture in cases of mediastinitis following cardiac surgery is a rare and dangerous complication. Bleeding from the right ventricle occurs mainly after sternal reopening, due to either iatrogenic manipulation (wire removal, lesions due to wiring maneuvers) or mechanical shearing forces, producing direct injury. We present a case of RV wall perforation due to infection in a recurrent postoperative mediastinitis with a closed chest. The current literature on treatment of postoperative mediastinitis is also reviewed.

Estudio de los tumores óseos mediante el tratamiento de imágenes digitalizadas

Aquest informe tècnic mostra la classificació, incidència, característiques i diagnòstic dels tumors ossis primaris i secundaris metastàsics més freqüents a partir de 145 radiografies digitalitzades

Trabecular bone score in type 1 diabetes--a cross-sectional study.

UNLABELLED: Trabecular bone score (TBS) seems to provide additive value on BMD to identify individuals with prevalent fractures in T1D. TBS did not significantly differ between T1D patients and healthy controls, but TBS and HbA1c were independently associated with prevalent fractures in T1D. A TBS cutoff <1.42 reflected prevalent fractures with 91.7 % sensitivity and 43.2 % specificity. INTRODUCTION: Type 1 diabetes (T1D) increases the risk of osteoporotic fractures. TBS was recently proposed as an indirect measure of bone microarchitecture. This study aimed at investigating the TBS in T1D patients and healthy controls. Associations with prevalent fractures were tested. METHODS: One hundred nineteen T1D patients (59 males, 60 premenopausal females; mean age 43.4 ± 8.9 years) and 68 healthy controls matched for gender, age, and body mass index (BMI) were analyzed. The TBS was calculated in the lumbar region, based on two-dimensional (2D) projections of DXA assessments. RESULTS: TBS was 1.357 ± 0.129 in T1D patients and 1.389 ± 0.085 in controls (p = 0.075). T1D patients with prevalent fractures (n = 24) had a significantly lower TBS than T1D patients without fractures (1.309 ± 0.125 versus 1.370 ± 0.127, p = 0.04). The presence of fractures in T1D was associated with lower TBS (odds ratio = 0.024, 95 % confidence interval (CI) = 0.001-0.875; p = 0.042) but not with age or BMI. TBS and HbA1c were independently associated with fractures. The area-under-the curve (AUC) of TBS was similar to that of total hip BMD in discriminating T1D patients with or without prevalent fractures. In this set-up, a TBS cutoff <1.42 discriminated the presence of fractures with a sensitivity of 91.7 % and a specificity of 43.2 %. CONCLUSIONS: TBS values are lower in T1D patients with prevalent fractures, suggesting an alteration of bone strength in this subgroup of patients. Reliable TBS cutoffs for the prediction of fracture risk in T1D need to be determined in larger prospective studies.

Acurácia na reprodutibilidade do posicionamento diário de pacientes submetidos a radioterapia conformada (RT3D) para câncer de próstata

OBJETIVO: Avaliar a reprodutibilidade do posicionamento de pacientes com diagnóstico de câncer de próstata submetidos a radioterapia conformada. MATERIAIS E MÉTODOS: Foram avaliados 960 (posições anterior e lateral) filmes radiológicos, de um total de 120 pacientes que receberam radioterapia conformada na próstata com técnica isocêntrica. As imagens foram obtidas em acelerador linear de partículas 6 MV. Aplicou-se protocolo específico para planejamento e tratamento da próstata, com o paciente em posição supina, mãos colocadas sobre o tórax, pés apoiados em suporte apropriado. Diariamente, os pacientes foram posicionados conforme demarcações na pele, coincidentes com os lasers da sala. Os filmes radiológicos foram comparados com as radiografias reconstruídas digitalmente (digitally reconstructed radiography - DRR) em sistema de planejamento computadorizado Eclipse, a partir das tomografias. As radiografias de posicionamento foram realizadas no primeiro dia e após, semanalmente, até o término do tratamento. RESULTADOS: As médias dos deslocamentos observados foram de 1,99 ± 1,25 mm no sentido crânio-caudal, 1,37 ± 0,84 mm no látero-lateral e 1,94 ± 1,10 mm no ântero-posterior. CONCLUSÃO: O uso de protocolos específicos para posicionamento dos pacientes é possível na prática clínica, possibilita reprodutibilidade adequada e rápida correção dos possíveis erros.

Furosemide stimulation of parathormone in humans: role of the calcium-sensing receptor and the renin-angiotensin system

Les interactions entre les systèmes de régulation du sodium et du calcium sont encore mal comprises et leur importance clinique mérite d'être étudiée plus en détail. Les études chez l'animal ont montré qu'il existe des relations entre le taux plasmatique d'hormone parathyroïdienne (PTH) et l'aldostérone ou l'activité de la rénine. Par ailleurs, il a été démontré chez l'animal et chez l'homme que le taux sanguin de PTH augmente rapidement après une injection de furosémide, un diurétique de l'anse ce qui fait penser qu'il existe un lien entre l'effet du furosémide sur le rein et la sécrétion de PTH. Toutefois, à ce jour, le(s) mécanisme(s) impliqués dans ce lien reste(nt) encore inconnu(s). Des résultats plus récents suggèrent que l'effet du furosemide est amoindri par l'administration préalable d'un calcimimétique agissant au niveau du récepteur sensible au calcium (calcium sensing receptor). Pour explorer chez l'homme, les mécanismes possibles du lien entre PTH et effet du furosemide sur le rein, nous avons planifié une étude randomisée croisée contre placebo réalisée chez 18 volontaires sains masculins. Le but principal était d'investiguer le rôle du système rénine-angiotensine et des calcium sensing receptors. L'étude s'est donc réalisée en 2 phases pour chaque sujet. Les participants ont ainsi reçu soit du cinacalcet (60mg) soit un placebo dans une première phase et le placebo ou du cinacalcet dans la 2° phase. Dans chaque phase d'évaluation, une injection de 20 mg de furosemide a été administrée par voie intraveineuse à l'équilibre soit 3 heures après la prise du placebo ou du cinacalcet. Des échantillons de plasma ont été prélevés toutes les 15 minutes pendant 1 heure puis toutes les heures pour le dosage de PTH intacte, calcium, sodium, potassium, magnésium, phosphate, activité de la rénine plasmatique et aldostérone jusqu'à 6h après l'injection de furosémide. L'excrétion urinaire de ces mêmes électrolytes a été mesurée aux mêmes intervalles.

A comprehensive model for quantum noise characterization in digital mammography.

NlmCategory="UNASSIGNED">A version of cascaded systems analysis was developed specifically with the aim of studying quantum noise propagation in x-ray detectors. Signal and quantum noise propagation was then modelled in four types of x-ray detectors used for digital mammography: four flat panel systems, one computed radiography and one slot-scan silicon wafer based photon counting device. As required inputs to the model, the two dimensional (2D) modulation transfer function (MTF), noise power spectra (NPS) and detective quantum efficiency (DQE) were measured for six mammography systems that utilized these different detectors. A new method to reconstruct anisotropic 2D presampling MTF matrices from 1D radial MTFs measured along different angular directions across the detector is described; an image of a sharp, circular disc was used for this purpose. The effective pixel fill factor for the FP systems was determined from the axial 1D presampling MTFs measured with a square sharp edge along the two orthogonal directions of the pixel lattice. Expectation MTFs were then calculated by averaging the radial MTFs over all possible phases and the 2D EMTF formed with the same reconstruction technique used for the 2D presampling MTF. The quantum NPS was then established by noise decomposition from homogenous images acquired as a function of detector air kerma. This was further decomposed into the correlated and uncorrelated quantum components by fitting the radially averaged quantum NPS with the radially averaged EMTF(2). This whole procedure allowed a detailed analysis of the influence of aliasing, signal and noise decorrelation, x-ray capture efficiency and global secondary gain on NPS and detector DQE. The influence of noise statistics, pixel fill factor and additional electronic and fixed pattern noises on the DQE was also studied. The 2D cascaded model and decompositions performed on the acquired images also enlightened the observed quantum NPS and DQE anisotropy.

Susceptibilidad antibiótica de las bacterias causantes de infecciones odontogénicas

Objetivos: Identificar la flora bacteriana y su susceptibilidad a varios antibióticos utilizados en infecciones odontogénicas de localización periapical y en las pericoronaritis del tercer molar inferior, para poder adaptar convenientemente el tratamiento antibiótico a las exigencias de tales infecciones, y evitar así los efectos secundarios y los sobretratamientos con antibióticos. Material y métodos: Se han seleccionado con unos criterios de inclusión y de exclusión a 64 pacientes que presentaban una infección odontogénica. Se recogieron muestras de las lesiones en condiciones de máxima asepsia, evitando la contaminación por flora saprófita bucal. Las muestras se sembraron en medios de cultivo apropiados y se incubaron en condiciones aeróbicas y anaeróbicas; finalmente se procedió a la identificación de los microorganismos aislados y a la determinación de su susceptibilidad antibiótica, los resultados se analizaron estadísticamente mediante la prueba t-Student (para muestras aparejadas y para una muestra). Resultados: Se aislaron un total de 184 cepas bacterianas, incluyendo cocos Gram positivo anaerobios facultativos (68%), bacilos Gram negativo anaerobios estrictos (30%), y bacilos Gram positivo anaerobios facultativos (2%). Independientemente del origen de la infección odontogénica los antibióticos que obtuvieron los mejores resultados en cuanto a mayor sensibilidad y menor resistencia estadísticamente significativos fueron respectivamente la amoxicilina/clavulánico y la amoxicilina (p<0,05). Discusión: Cada vez hay más estudios que indican el alto índice de resistencias a antibióticos en poblaciones bacterianas patógenas que producen infecciones en territorios no bucodentales. A pesar de ello, los niveles de resistencia a los antibióticos en las infecciones odontogénicas no han seguido la misma tendencia, aunque se ha detectado para ciertos antibióticos un alto índice de resistencia. En nuestro trabajo hemos encontrado que los antibióticos de uso común que han obtenido mayor sensibilidad y menor resistencia han sido la amoxicilina en combinación con ácido clavulánico seguido de la amoxicilina.

The knowledge about diagnostic imaging methods among primary care and medical emergency physicians

Objective To evaluate the knowledge about diagnostic imaging methods among primary care and medical emergency physicians. Materials and Methods Study developed with 119 primary care and medical emergency physicians in Montes Claros, MG, Brazil, by means of a structured questionnaire about general knowledge and indications of imaging methods in common clinical settings. A rate of correct responses corresponding to ≥ 80% was considered as satisfactory. The Poisson regression (PR) model was utilized in the data analysis. Results Among the 81 individuals who responded the questionnaire, 65% (n = 53) demonstrated to have satisfactory general knowledge and 44% (n = 36) gave correct responses regarding indications of imaging methods. Respectively, 65% (n = 53) and 51% (n = 41) of the respondents consider that radiography and computed tomography do not use ionizing radiation. The prevalence of a satisfactory general knowledge about imaging methods was associated with medical residency in the respondents' work field (PR = 4.55; IC 95%: 1.18-16.67; p-value: 0.03), while the prevalence of correct responses regarding indication of imaging methods was associated with the professional practice in primary health care (PR = 1.79; IC 95%: 1.16-2.70; p-value: 0.01). Conclusion Major deficiencies were observed as regards the knowledge about imaging methods among physicians, with better results obtained by those involved in primary health care and by residents.

Synovial chondromatosis of the shoulder: imaging findings

Synovial chondromatosis is a benign condition characterized by synovial proliferation and metaplasia, with development of cartilaginous or osteocartilaginous nodules within a joint, bursa or tendon sheath. In the shoulder, synovial osteochondromatosis may occur within the glenohumeral joint and its recesses (including the tendon sheath of the biceps long head), and in the subacromial-deltoid bursa. Such condition can be identified either by radiography, ultrasonography or magnetic resonance imaging, showing typical features according to each method. Radiography commonly shows ring-shaped calcified cartilages and periarticular soft tissues swelling with erosion of joint margins. Ultrasonography demonstrates hypoechogenic cartilaginous nodules with progressive increase in echogenicity as they become calcified, with development of posterior acoustic shadow in case of ossification. Besides identifying cartilaginous nodules, magnetic resonance imaging can also demonstrate the degree of synovial proliferation. The present study is aimed at describing the imaging findings of this entity in the shoulder.

Presence of air in the hepatic portal system in association with umbilical venous catheter malposition

The authors report a case of umbilical venous catheter malposition with air in the portal venous system in a preterm neonate. Initially, the hypothesis of necrotizing enterocolitis was considered, but the newborn progressed with no finding of disease and the air disappeared at follow-up radiography. The differential diagnosis of such a finding can avoid unnecessary clinical treatments.

Radiographic adenoid evaluation: proposal of an objective parameter

Objective The objective of the present study was to evaluate current radiographic parameters designed to investigate adenoid hypertrophy and nasopharyngeal obstruction, and to present an alternative radiographic assessment method. Materials and Methods In order to do so, children (4 to14 years old) who presented with nasal obstruction or oral breathing complaints were submitted to cavum radiographic examination. One hundred and twenty records were evaluated according to quantitative radiographic parameters, and data were correlated with a gold-standard videonasopharyngoscopic study, in relation to the percentage of choanal obstruction. Subsequently, a regression analysis was performed in order to create an original model so the percentage of the choanal obstruction could be predicted. Results The quantitative parameters demonstrated moderate, if not weak correlation with the real percentage of choanal obstruction. The regression model (110.119*A/N) demonstrated a satisfactory ability to “predict” the actual percentage of choanal obstruction. Conclusion Since current adenoid quantitative radiographic parameters present limitations, the model presented by the present study might be considered as an alternative assessment method in cases where videonasopharyngoscopic evaluation is unavailable.