Cáncer de esófago: particularidades anatómicas,estadificación y técnicas de imagen

Cancer of the esophagus is a tumor with aggressive behavior that is usually diagnosed in advanced stages. The absence of serosa allows it to spread quickly to neighboring mediastinal structures, and an extensive lymphatic drainage network facilitates tumor spread even in early stages. The current TNM classification, harmonized with the classification for gastric cancer, provides new definitions for the anatomic classification, adds non-anatomic characteristics of the tumor, and includes tumors of the gastroesophageal junction. Combining endoscopic ultrasound, computed tomography, positron emission tomography, and magnetic resonance imaging provides greater accuracy in determining the initial clinical stage, and these imaging techniques play an essential role in the selection, planning, and evaluation of treatment. In this article, we review some particularities that explain the behavior of this tumor and we describe the current TNM staging system; furthermore, we discuss the different imaging tests available for its evaluation and include a diagnostic algorithm.     

Resonancia magnética de próstata: utilidad de la secuencia de difusión en la detección de isquemia postembolización en pacientes con hiperplasia prostática benigna

ObjectiveTo analyze the usefulness of diffusion magnetic resonance (MR) sequences before and after prostatic artery embolization (PAE) in patients with benign prostatic hyperplasia (BPH).Material and methodsWe analyzed MR studies done before (7-10 days) and after (30 days) PAE in 19 patients with BPH treated with PAE between June 2012 and December 2013. We used 1.5 Tesla scanners with body surface coils. In pre-PAE MR studies, we recorded mean b40 values and minimum (min) and maximum (max) apparent diffusion coefficient (ADC) values. In post-PAE MR studies, we recorded b40, b400, and b1000 values and min, mean, and max ADC values. We compared diffusion behavior/ADC before and after PAE and areas without ischemia. We correlated these with decreased prostatic volume (PV).ResultsWe identified ischemia with contrast in 8 (42.1%) patients. No significant difference was found in mean b40 (p= 0.1650) or in the b40 ratio (p= 0.8868) between patients with ischemia and those without before PAE. Min b40, b40 ratio, and min ADC values differed significantly between ischemic areas and nonischemic areas within patients [p= 0.048 (b40 min and ratio) and p= 0.002 (min ADC)]. No significant correlation was found between the percentage decrease in PV and mean b40 (p= 0.8490) or b40 ratio (p = 0.8573).ConclusionPost-PAE ischemia generates objective changes in diffusion and ADC values that enable ischemic sectors to be differentiated from nonischemic sectors. Future studies should analyze whether it is possible to subjectively differentiate between these areas through the visualization of nonischemic sectors and the feasibility of replacing them with contrast to detect ischemia.     

Aplicaciones de la técnica de difusión por resonancia magnética en el manejo de la patología tumoral osteomuscular

Magnetic resonance imaging (MRI) is the technique of choice in the diagnosis, staging, and follow-up of musculoskeletal tumors. Diffusion imaging is a new functional MRI technique that provides information that is complementary to that obtained in conventional MRI sequences. Diffusion imaging has proven useful in different clinical situations like the characterization of disease involving the bone marrow (bone metastases, benign fractures, or hematological disease), the evaluation of tumors of the bones and soft tissues, and the monitoring of the response to treatment in patients with tumors. The aim of this article is to review the diffusion technique in MRI and its current clinical applications in the management of musculoskeletal tumors.     

Resonancia magnética en la valoración de las conexiones venosas pulmonares anómalas

ObjectiveTo illustrate the morphological and functional magnetic resonance findings for total and partial anomalous pulmonary venous connections as well as of the most common complications after surgery.ConclusionThe magnetic resonance findings are fundamental in defining the type of anomalous connection, deciding on the treatment, planning the surgery, and detecting postsurgical complications.     

Variante interhemisférica media de holoprosencefalia: diagnóstico mediante resonancia magnética fetal

Congenital anomalies of the central nervous system comprise a wide spectrum of malformations associated with a wide variety of genetic syndromes and chromosomal anomalies, and they are among the principal causes of morbidity and mortality in infants. Among these anomalies, holoprosencephaly arises from the complete or partial failure of the brain to divide into the cerebral hemispheres. Imaging tests are fundamental for the prenatal diagnosis of holoprosencephaly; the diagnostic process usually starts with sonography and then the findings are refined with fetal MRI. Radiologists need to be familiar with the possible findings because the prognosis varies.     

Comparación de la calidad de imagen y dosis de radiación en angio-tomografía computarizada de arterias periféricas con 80 y 100 kV

ObjectiveTo compare the image quality and dose of radiation in two groups of patients undergoing CT angiography of the lower limbs, one with tube voltage of 80 kV and the other with tube voltage of 100 kV.Material and methodsWe performed CT angiography of the lower limbs in 60 patients with suspected peripheral arterial disease. Patients were randomly assigned to one of two groups; in one group, CT angiography was performed using a tube voltage of 80 kV, whereas in the other it was performed using 100 kV. The remaining acquisition parameters were the same in both groups. The images were analyzed by quantifying vascular density (VD) and noise (N) and by calculating the quotients density/noise (QVDN) and contrast/noise (QCN). Two radiologists working independently evaluated the subjective quality of the images. We calculated the estimated effective dose (EED) based on the dose-length product (DLP).ResultsIn the group studied at 80 kV, VD was significantly higher (462.5 UH ± 95.6 vs. 372 UH ± 100.9; P <. 001), QVDN was significantly higher (241.9 ± 48.1 vs. 194.3 ± 49.6; P < .001), and there were trends toward higher N (21.3 UH ± 13 vs. 16.3 UH ± 3.5; P = .098) and toward higher QCN (21.4 ± 12.1 vs. 22.9 ± 9.1; P = .15). No significant differences were found in the subjective quality of the images. The EED was significantly lower in the group studied at 80 kV (4.73 mSv ± 1.1 vs. 9.6 mSv ± 2.2; P <. 001).ConclusionUsing 80 kV instead of 100 kV for CT angiography of the lower limbs reduces the dose of radiation without affecting the diagnostic efficacy of the study.     

Variación de tamaño de la hiperplasia nodular focal mediante resonancia magnética

ObjectiveTo evaluate the changes in the size of focal nodular hyperplasia (FNH) during long-term magnetic resonance imaging (MRI) follow-up.Material and methodsWe reviewed 44 FNHs in 30 patients studied with MRI with at least two MRI studies at least 12 months apart. We measured the largest diameter of the lesion (in mm) in contrast-enhanced axial images and calculated the percentage of variation as the difference between the maximum diameter in the follow-up and the maximum diameter in the initial study. We defined significant variation in size as variation greater than 20%. We also analyzed predisposing hormonal factors.ResultsThe mean interval between the two imaging studies was 35 ± 2 months (range: 12-94). Most lesions (80%) remained stable during follow-up. Only 9 of the 44 lesions (20%) showed a significant variation in diameter: 7 (16%) decreased in size and 2 (4%) increased, with variations that reached the double of the initial size. The change in size was not related to pregnancy, menopause, or the use of birth control pills or corticoids.ConclusionChanges in the size of FNHs during follow-up are relatively common and should not lead to a change in the diagnosis. These variations in size seem to be independent of hormonal factors that are considered to predispose.     

Valoración del grado de resección de los macroadenomas hipofisarios en la resonancia magnética posquirúrgica inmediata

Objective

To evaluate if it is possible to determine the extent of pituitary macroadenomas resection in the immediate postoperative pituitary magnetic resonance imaging (MRI).

El nuevo formato de los documentos de evaluación de la formación sanitaria especializada: una revolución inadvertida

The recent publication of the resolution through which the basic directives about the contents of the documents to accredit the assessments of specialists in training maintains the model but incorporates new elements that enable important changes in the assessment.The resolution has errors and is confusing because the rules are hidden in the instructions for filling out the forms and in footnotes. Nevertheless, the resolution is more than a simple change in the forms: it is a step toward a more current assessment based on the evaluation of residents’ competence. The most significant changes are a stronger role for collaborating teachers, an increase in the number of possible reasons for negative assessments, and the establishment of the rotation as the basic unit of analysis.     

Imagen por resonancia magnética en la estadificación y planificación del tratamiento del cáncer de cérvix

ObjectiveTo review the key points that are essential for the correct staging of cervical cancer by magnetic resonance imaging.ConclusionMagnetic resonance imaging is the method of choice for locoregional staging of cervical cancer. Thorough evaluation of prognostic factors such as tumor size, invasion of adjacent structures, and the presence of lymph node metastases is fundamental for planning appropriate treatment.     

Esclerosis hipocampal: evaluación volumétrica de las subestructuras del hipocampo utilizando resonancia magnética

Objective

The pathological classification of hippocampal sclerosis is based on the loss of neurons in the substructures of the hippocampus. This study aimed to evaluate these substructures in patients with hippocampal sclerosis by magnetic resonance imaging and to compare the usefulness of this morphological analysis compared to that of volumetric analysis of the entire hippocampus.

Imagerie de la trachée de l'adulte

Imaging of normal and pathologic trachea at the thoracic and cervical levels is described extensively. Beside congenital abnormalities discovered in adulthood, acquired tracheal abnormalities are artificially divided in two subgroups. One group consists of diffuse abnormalities, with all but one diseases associated with a diffuse narrowing of the tracheal lumen. The other group comprises focal abnormalities that lead to tracheal stenoses of various lengths, with a postintubation stenosis as probably the most frequent cause, followed by tumours. The main modality for tracheal imaging is now multidetector-row spiral CT. This technique allows for faster volume coverage and higher spatial and temporal resolution. The improved spatial resolution impacts on both axial images and all reconstructions techniques that have become indispensable for interpretation of a vertical structure such as the trachea. Chest X-ray is no longer the frontline imaging technique. MRI has not yet reached all its potential as compared to CT.     

Resonancia magnética en la planificación de la braquiterapia intracavitaria para el tratamiento del cáncer de cérvix localmente avanzado

Cervical cancer is the third most common gynecological cancer. Its treatment depends on tumor staging at the time of diagnosis, and a combination of chemotherapy and radiotherapy is the treatment of choice in locally advanced cervical cancers. The combined use of external beam radiotherapy and brachytherapy increases survival in these patients. Brachytherapy enables a larger dose of radiation to be delivered to the tumor with less toxicity for neighboring tissues with less toxicity for neighboring tissues compared to the use of external beam radiotherapy alone. For years, brachytherapy was planned exclusively using computed tomography (CT). The recent incorporation of magnetic resonance imaging (MRI) provides essential information about the tumor and neighboring structures making possible to better define the target volumes. Nevertheless, MRI has limitations, some of which can be compensated for by fusing CT and MRI. Fusing the images from the two techniques ensures optimal planning by combining the advantages of each technique.     

Une nouvelle méthode de lecture de la réaction précipitante en Médecine Légale

Sans résuméVortrag, gelegentlich der Tagung der Deutschen Gesellschaft für gerichtliche und soziale Medizin in München 1952.