Undergraduate radiodiagnostic professors.

The international literature on university teaching, has insisted on the need to combine a double component in the professional profile of teachers: content knowledge and pedagogical content knowledge. Regarding the content, the area of knowledge of radiology and physical medicine is made up of different medical specialties, among which are radiodiagnosis, nuclear medicine, radiation oncology, physical medicine and rehabilitation. On the other hand, the pedagogical content knowledge is framed by framework that the Bologna Declaration (1999). Focusing on radiodiagnosis, the ideal candidates must be professionals in this medical specialty, vocational teachers and people who find in the undergraduate teaching process an opportunity to transmit their knowledge, experiences and values in an entertaining and understandable way for students who are incorporated into medical knowledge.

Los profesores de radiodiagnóstico en pregrado / Undergraduate Radiodiagnostic professors

La literatura internacional plantea un doble componente en el perfil profesional del profesor universitario: el conocimiento del contenido (content knowledge) y el conocimiento didáctico del contenido (pedagogical content knowledge). En cuanto al contenido, el área de conocimiento de radiología y medicina física está compuesta por diferentes especialidades médicas entre las que se encuentran radiodiagnóstico, medicina nuclear, oncología radioterápica, medicina física y rehabilitación. Por su parte, el conocimiento didáctico del contenido está enmarcado por todo lo que ha significado la Declaración de Bolonia (1999). Centrándonos en el radiodiagnóstico, los candidatos idóneos deben ser profesionales de esta especialidad médica, vocacionales y que hallen en el proceso docente de pregrado una oportunidad de transmitir sus conocimientos, experiencias y valores de una forma amena y comprensible para alumnos que se incorporan al conocimiento médico.(AU)

The international literature on university teaching, has insisted on the need to combine a double component in the professional profile of teachers: content knowledge and pedagogical content knowledge. Regarding the content, the area of knowledge of Radiology and Physical Medicine is made up of different medical specialties, among which are Radiodiagnosis, Nuclear Medicine, Radiation Oncology, Physical Medicine and Rehabilitation. On the other hand, the pedagogical content knowledge is framed by framework that the Bologna Declaration (1999). Focusing on Radiodiagnosis, the ideal candidates must be professionals in this medical specialty, vocational teachers and people who find in the undergraduate teaching process an opportunity to transmit their knowledge, experiences and values in an entertaining and understandable way for students who are incorporated into medical knowledge.(AU)

Análisis de la función ventricular derecha en resonancia magnética cardíaca. Comparación de la cuantificación en los planos eje corto y 4 cámaras / Cardiac magnetic resonance analysis of right ventricular function: comparison of quantification in the short-axis and 4-chamber planes

Objetivo. Comparar los métodos de segmentación del ventrículo derecho en los planos eje corto y 4 cámaras, en los estudios de resonancia magnética cardíaca, y realizar una correlación con el método ecocardiográfico tricuspid annular plane systolic excursion (TAPSE). Material y métodos. Se estudiaron 26 pacientes con diversas enfermedades cardiovasculares con un equipo de resonancia magnética de 1,5 T. Se adquirieron en todos los estudios imágenes en modo cine en eje corto y en 4 cámaras (steady-state free precession, 6 mm de grosor de corte, desde la base al ápex ventricular). En todos los pacientes se cuantificaron los volúmenes telediastólico, telesistólico y la fracción de eyección del ventrículo derecho. A 14 pacientes se les practicó también una ecocardiografía y se calculó la función ventricular derecha (TAPSE), el mismo día que se realizó el estudio de resonancia magnética cardíaca. Resultados. No hubo diferencias estadísticamente significativas en los volúmenes y la función del ventrículo derecho determinados con los 2 métodos de segmentación. La correlación al estimar los volúmenes fue excelente (r > 0,95) y disminuyó levemente para la fracción de eyección (r > 0,84). La correlación entre fracción de eyección del ventrículo derecho y TAPSE fue muy baja (r = 0,2; p < 0,01). Conclusión. Ambos métodos de segmentación ventricular cuantifican adecuadamente la función del ventrículo derecho. La correlación con el método ecocardiográfico es discreta (AU)

Objective. To compare the methods of right ventricle segmentation in the short-axis and 4-chamber planes in cardiac magnetic resonance imaging and to correlate the findings with those of the tricuspid annular plane systolic excursion (TAPSE) method in echocardiography. Material and methods. We used a 1.5 T MRI scanner to study 26 patients with diverse cardiovascular diseases. In all MRI studies, we obtained cine-mode images from the base to the apex in both the short-axis and 4-chamber planes using steady-state free precession sequences and 6 mm thick slices. In all patients, we quantified the end-diastolic volume, end-systolic volume, and the ejection fraction of the right ventricle. On the same day as the cardiac magnetic resonance imaging study, 14 patients also underwent echocardiography with TAPSE calculation of right ventricular function. Results. No statistically significant differences were found in the volumes and function of the right ventricle calculated using the 2 segmentation methods. The correlation between the volume estimations by the two segmentation methods was excellent (r = 0,95); the correlation for the ejection fraction was slightly lower (r = 0,8). The correlation between the cardiac magnetic resonance imaging estimate of right ventricular ejection fraction and TAPSE was very low (r = 0,2, P < .01). Conclusion. Both ventricular segmentation methods quantify right ventricular function adequately. The correlation with the echocardiographic method is low (AU)

Cardiac magnetic resonance analysis of right ventricular function: comparison of quantification in the short-axis and 4-chamber planes.

OBJECTIVE: To compare the methods of right ventricle segmentation in the short-axis and 4-chamber planes in cardiac magnetic resonance imaging and to correlate the findings with those of the tricuspid annular plane systolic excursion (TAPSE) method in echocardiography. MATERIAL AND METHODS: We used a 1.5T MRI scanner to study 26 patients with diverse cardiovascular diseases. In all MRI studies, we obtained cine-mode images from the base to the apex in both the short-axis and 4-chamber planes using steady-state free precession sequences and 6mm thick slices. In all patients, we quantified the end-diastolic volume, end-systolic volume, and the ejection fraction of the right ventricle. On the same day as the cardiac magnetic resonance imaging study, 14 patients also underwent echocardiography with TAPSE calculation of right ventricular function. RESULTS: No statistically significant differences were found in the volumes and function of the right ventricle calculated using the 2 segmentation methods. The correlation between the volume estimations by the two segmentation methods was excellent (r=0,95); the correlation for the ejection fraction was slightly lower (r=0,8). The correlation between the cardiac magnetic resonance imaging estimate of right ventricular ejection fraction and TAPSE was very low (r=0,2, P<.01). CONCLUSION: Both ventricular segmentation methods quantify right ventricular function adequately. The correlation with the echocardiographic method is low.

Maximal curvature-based segmentation of 3D vessel contours.

The segmentation of three-dimensional vascular trees is an important topic in medical image processing. Although it may seem to be an easy task, many different techniques have been proposed in the literature during the last decade and many difficulties remain. One can wonder why the human eye is usually able to understand the connectivity and the topology of the different structures while most algorithms fail to do so. In this paper, we propose an original approach that classifies the different contours by applying a geodesic distance transform on the contours of the vessels, where the evolution speed depends directly on the maximal curvature of the contours. This proposition comes from the observation that the maximal curvature on a standard vessel is usually positive and almost constant while it approaches zero or becomes negative on the contour at the contact with other structures. We describe our method in details and present promising results on synthetic and real images, where the method has been able to detect complex vascular structures without leaking into bones or mixing different vascular networks.

[Percutaneous placement of covered stents for treatment of post discectomy arterial rupture]. / Rotura arterial posdiscectomía. Tratamiento mediante implante percutáneo de una endoprótesis cubierta.

INTRODUCTION: Vascular lesions produced as a consequence of surgical spinal treatment are rare, but serious. Fast diagnosis and treatment are essential in lesions that produce massive blood loss. Following the use of non covered stents in the treatment of peripheral vascular stenotic obstructive pathologies, the appearance of covered stents allowed aneurysms, pseudo aneurysms, fistulas or bleedings to be treated. Being able to graft a stent in serious patients, during diagnosis itself, with a minimum amount of aggression and local anaesthesia affords this technique huge advantages over others. CASE REPORT: In this work we report the case of an arterial rupture which came about as a complication of a discectomy. After the surgical intervention, there was an important haematocrit reduction within a short space of time. The patient s quickly becoming anaemic and the existence of a retroperitoneal mass of heterogeneous echogenicity pointed towards a postoperative haemorrhage. This was confirmed by arteriography, which revealed an important contrast extravasation. A covered stent was placed at the same time and, in the post graft follow up, it was confirmed that there was no bleeding. At 12 hours after the operation the patient was moved from the postoperative recovery unit to a hospital ward and, 5 days later, was discharged. In a check up carried out in the Neurosurgery unit 2 months after being sent home, the patient was found to be asymptomatic. CONCLUSION: The placement of covered stents is a valid therapeutic option for treating postoperative haemorrhagic lesions. It can be performed at the same time as diagnosis and does not require general anaesthesia. In the case we have described, the patient recovered quickly and ambulatory check ups showed he continued to be asymptomatic

[Percutaneous treatment of peripheral vascular malformations]. / Tratamiento percutáneo de las malformaciones vasculares periféricas.

OBJECTIVE: Vascular malformations are uncommon pathologic entities in which surgery is usually not possible or is inefficient. Our experience with the percutaneous treatment of peripheral vascular malformations, by means of transarterial embolization or direct puncture is here reported. MATERIAL AND METHODS: During the 1993-1997 period a total of 35 patient, 20 females (57%) and 15 males (43%) aged 11 to 75 years, were treated at our Unit. Sixteen vascular malformations were hemodynamically active (45.7%) and 19 hemodynamically inactive (54.3%). A total of 126 embolizations (mean 3.6) were performed. Malformations were studied by means of doppler-echography, magnetic resonance, arteriography and direct puncture angiography. Considering location, size and hemodynamic characteristics a specific approach and therapy was performed in each case. In two cases (5.7%) a surgical exeresis after embolization was performed. RESULTS: A technical success, defined as the possibility of embolizing the malformation, was achieved in 100% of cases. No technical complications during the procedure occurred. The mean follow-up time was 23 months (6-69). All patients but one improved both objectively and subjectively and all but one have recovered their daily activities in the following days. The exception was one patient who developed a severe complication--cutaneous necrosis--a few days after the procedure which required repairing surgery. All patient had edema, pain and increased functional impairment after the embolization which subsided with medical treatment. CONCLUSIONS: Percutaneous embolization of vascular malformations is an effective method associated with a low complication rate. Our results are encouraging although more extensive investigation are required to draw definite conclusions.

[Wallstent endoprostheses implanted by fluoroscopic guidance in the palliative treatment of malignant esophageal obstructions and esophago-tracheal fistulas]. / Endoprótesis de Wallstent implantadas bajo control fluoroscópico en el tratamiento paliativo de las obstrucciones esofágicas malignas y fístulas esófago-traqueales.

PURPOSE: The objective of this study was to present our experience with metallic stents (Wallstent) for palliation of dysphagia due to malignant esophageal obstruction and esophagotracheal fistula. PATIENTS AND METHODS: From August 1994 to July 1996 20 uncovered and 6 covered stents were inserted in 16 consecutive patients with dysphagia grade 3 (n = 4) or grade 4 (n = 12) caused by incurable malignant obstructions. The obstruction was in the proximal (n = 4), in the middle (n = 3) and the distal (n = 9) third of the esophagus. Five patients presented with esophagotracheal fistula. The stent insertion was performed under fluoroscopic control. RESULTS: Exact positioning of the stent with reduction of the dysphagia was obtained in all patients. There were no complications related with the procedure. Esophagotracheal fistula was solved in those patients treated with covered stents. Six patients had recurrent dysphagia due to tumor ingrowth or overgrowth. In these patients an additional overlapping stent was placed. In latest evaluation 2 patients presented dysphagia grade I, 5 grade III, and 4 grade IV. CONCLUSION: Implantation of stents proved to be an effective and safe method of palliating dysphagia and occluding esofagotracheal fistula. Placement of stents was feasible without major procedure-related complications.

[Percutaneous implant of Hickman catheters and reservoirs. Long-term experience]. / Implante percutáneo de catéteres de Hickman y reservorios. Experiencia a largo plazo.

OBJECTIVE: To report our experience with long term external catheters and implantable ports in the last 8 years. MATERIAL AND METHODS: From December 1987 to August 1995 a total of 617 central venous catheters were implanted in 541 patients in our Interventionist Vascular Radiology Unit, 265 men (49%) and 276 women (51%), with a mean age of 46 years. A total of 335 (54%) were partially implantable external catheters and 241 (39%) implantable ports in chest and 41 (7%) in the forearm. RESULTS: A technical success--defined as the possibility of implanting the catheter--was achieved in 98% of cases. Immediate complications included 5 pneumothorax (0.8%), 11 accidental carotid artery puncture (2%) with no clinical relevance, 18 catheter misplacement (3%), and 8 vein spasm (1%). Fifty-two catheters (8%) were removed on account of infectious complications. Currently, 71 catheters are still in use (12%), 433 (70%) have been removed or the catheter was patent until patients's death. CONCLUSIONS: Partially implantable central venous catheters and totally implantable ports are a safe alternative in patients requiring a central venous access for prolonged treatments. The low number of immediate complications renders the Interventionist Vascular Radiology Unit the proper place where to perform these procedures.