Accuracy of CT colonography in the preoperative staging of colon cancer: a prospective study of 217 patients.

AIM: The purpose of the present study was to evaluate the accuracy of computed tomography colonography (CTC) in the preoperative localization and TN staging of colon cancer. CTC can be an effective technique for preoperative evaluation of colon cancer and could facilitate the selection of high-risk patients who may benefit from neoadjuvant chemotherapy. METHOD: This was a prospective observational study conducted at a single tertiary-care centre. It involved 217 patients (225 tumours) who had colon cancer and underwent preoperative CTC and elective colectomy. The radiologist determined the TNM stage using postprocessing software with multiplanar images and virtual colonoscopy. The following criteria were analysed for every colon tumour: location, size and signs of direct colon wall invasion. The histopathological findings of the surgical colectomy specimens served as the reference standard for local staging. RESULTS: CTC detected all tumours and achieved an exact location in 208 cases (92.4%). CTC findings changed the surgical plan in 31 patients (14.3%) following colonoscopy. The accuracy in differentiating T3/T4 vs T1/T2 tumours was 87.1%, with a sensitivity and specificity of 88.5% and 84.1%, respectively (kappa = 0.71). For high-risk tumours (T3 ≥ 5 mm and T4), CTC showed an accuracy, sensitivity and specificity of 82.7%, 86% and 80%, respectively (kappa = 0.65). The accuracy of N-stage evaluation was 69.3%, the sensitivity 74% and the specificity 67.1% (kappa = 0.37). CONCLUSION: CTC provides accurate information for the assessment of tumour localization and T staging, allowing better surgical planning and also allows the selection of locally advanced tumours that may benefit from new treatments such as neoadjuvant chemotherapy.

Accuracy of magnetic resonance enterography in the preoperative assessment of patients with Crohn's disease of the small bowel.

AIM: To assess the accuracy of magnetic resonance enterography in predicting the extension, location and characteristics of the small bowel segments affected by Crohn's disease. METHOD: This is a prospective study including a consecutive series of 38 patients with Crohn's disease of the small bowel who underwent surgery at a specialized colorectal unit of a tertiary hospital. Preoperative magnetic resonance enterography was performed in all patients, following a homogeneous protocol, within the 3 months prior to surgery. A thorough exploration of the small bowel was performed during the surgical procedure; calibration spheres were used according to the discretion of the surgeon. The accuracy of magnetic resonance enterography in detecting areas affected by Crohn's disease in the small bowel was assessed. The findings of magnetic resonance enterography were compared with surgical and pathological findings. RESULTS: Thirty-eight patients with 81 lesions were included in the study. During surgery, 12 lesions (14.8%) that were not described on magnetic resonance enterography were found. Seven of these were detected exclusively by the use of calibration spheres, passing unnoticed at surgical exploration. Magnetic resonance enterography had 90% accuracy in detecting the location of the stenosis (75.0% sensitivity, 95.7% specificity). Magnetic resonance enterography did not precisely diagnose the presence of an inflammatory phlegmon (accuracy 46.2%), but it was more accurate in detecting abscesses or fistulas (accuracy 89.9% and 98.6%, respectively). CONCLUSION: Magnetic resonance enterography is a useful tool in the preoperative assessment of patients with Crohn's disease. However, a thorough intra-operative exploration of the entire small bowel is still necessary.

Reacciones adversas y contraindicaciones de los contrastes ecográficos. Respuesta del autor / Ultrasound contrast agents: Adverse reactions and contraindications. Author reply

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[Iodinated contrast agents used in Radiology]. / Contrastes yodados de utilización en Radiología.

Iodinated contrast media are widely used in Radiology practices with a very low rate of adverse effects, being contrast-induced nephropathy the most serious one. In the majority of cases it is temporary and reversible, even though it can increase the inhospital morbidity and mortality in patients with risk factors. We will describe the various measures of prevention, being hydration and use of non-ionic contrast low osmolality those which have demonstrated greater effectiveness. Precautions to be taken in some risk situations, as patients treated with metformin or with impaired renal function, are also discussed.

Contraindicaciones y reacciones adversas a los medios de contraste intravenosos / Contraindications and adverse reactions to intravenous contrast media

No disponible

Contrastes yodados de utilización en Radiología / Iodinated contrast agents used in Radiology

Los medios de contraste yodados son ampliamente utilizados en los Servicios de Radiología con muy baja tasa de efectos adversos. La nefropatía inducida por el contraste es la reacción adversa más importante. En la mayoría de los casos es transitoria y reversible, aunque provoca un aumento de la morbimortalidad intrahospitalaria en pacientes con factores de riesgo. Describiremos las diferentes medidas de prevención, siendo la hidratación y la utilización de contrastes no iónicos de baja osmolalidad las que han demostrado mayor efectividad. También trataremos en este artículo, las precauciones que se deben adoptar en algunas situaciones de riesgo como pacientes tratados con metformina y con deterioro de su función renal (AU)

Iodinated contrast media are widely used in Radiology practices with a very low rate of adverse effects, being contrast-induced nephropathy the most serious one. In the majority of cases it is temporary and reversible, even though it can increase the inhospital morbidity and mortality in patients with risk factors. We will describe the various measures of prevention, being hydration and use of non-ionic contrast low osmolality those which have demonstrated greater effectiveness. Precautions to be taken in some risk situations, as patients treated with metformin or with impaired renal function, are also discussed (AU)

[Multislice CT arteriography in the pre-surgical evaluation of patients with ureteropelvic junction stenosis]. / La arteriografía por tomografía computarizada multicorte en la valoración prequirúrgica de pacientes con estenosis de la unión pieloureteral.

INTRODUCTION: The current treatment of choice for ureteropelvic stenosis is endopyelotomy, but the presence of vessels in contact with the stenotic area of the ureteropelvic junction reduces the success of these interventions and increases vascular and hemorrhagic complications. The aim of our study was to use multislice CT arteriography to evaluate patients prior to surgery for ureteropelvic junction stenosis. PATIENTS AND METHODS: 16 patients with ureteropelvic junction stenosis underwent multislice CT arteriography; multidirectional images and three-dimensional reconstructions were used to identify and characterize vessels in contact with the stenotic area of the ureteropelvic junction. RESULTS: A total of eight vessels (four arteries and four veins) in six (38%) patients were found in contact with or passing within 2 mm of the ureteropelvic junction. The vessels were located anterior to the junction in four cases; it was posterior in one case, and anteromedial in the other. Endopyelotomy was contraindicated in the six patients in whom vessels were found in contact with the ureteropelvic junction. The presence of the vessels was confirmed during surgery in five of these patients; the remaining patient did not undergo surgery). CONCLUSION: Multislice CT arteriography allows adequate presurgical evaluation of ureteropelvic junction stenosis, detecting the presence of crossing vessels and facilitating the planning of the surgical approach in these patients.

La arteriografía por tomografía computarizada multicorte en la valoración prequirúrgica de pacientes con estenosis de la unión pieloureteral / Multislice CT arteriography in the pre-surgical evaluation of patients with ureteropelvic junction stenosis

Introducción. El tratamiento de elección de la estenosis de la unión pieloureteral (UPU) es actualmente la pielotomía endoscópica, pero la presencia de vasos en contacto con el área estenótica de la UPU disminuye el éxito de estas intervenciones y aumenta las complicaciones hemorrágicas y vasculares. El objetivo de nuestro estudio es realizar una valoración prequirúrgica de los pacientes con estenosis de la UPU mediante arteriografía por tomografía computarizada (TC), utilizando la TC multicorte. Pacientes y métodos. Estudiamos 16 pacientes con estenosis de la UPU, mediante arteriografía por TC multicorte. Los estudios se valoraron con imágenes multidireccionales y reconstrucciones tridimensionales para identificar y caracterizar vasos en contacto con la UPU. Resultados. En 6 pacientes (38%) se encontraron 8 vasos en contacto con la UPU (o con una separación inferior a 2 mm). Cuatro de estos vasos eran arterias y el resto eran vasos venosos. La localización de los vasos fue en cuatro pacientes anterior a la UPU, en un caso el vaso era posterior y en el otro anteromedial. La presencia de vasos en contacto con la UPU contraindicó la pielotomía endoscópica en 6 pacientes. En 5 de estos pacientes se confirmó la presencia del vaso en la intervención quirúrgica (1 caso no fue intervenido). Conclusión. La arteriografía por TC multicorte permite una adecuada valoración prequirúrgica de las estenosis de la UPU, detectando la presencia de cruces vasculares y facilitando el planteamiento quirúrgico de estos pacientes

Introduction. The current treatment of choice for ureteropelvic stenosis is endopyelotomy, but the presence of vessels in contact with the stenotic area of the ureteropelvic junction reduces the success of these interventions and increases vascular and hemorrhagic complications. The aim of our study was to use multislice CT arteriography to evaluate patients prior to surgery for ureteropelvic junction stenosis. Patients and methods. 16 patients with ureteropelvic junction stenosis underwent multislice CT arteriography; multidirectional images and three-dimensional reconstructions were used to identify and characterize vessels in contact with the stenotic area of the ureteropelvic junction. Results. A total of eight vessels (four arteries and four veins) in six (38%) patients were found in contact with or passing within 2 mm of the ureteropelvic junction. The vessels were located anterior to the junction in four cases; it was posterior in one case, and anteromedial in the other. Endopyelotomy was contraindicated in the six patients in whom vessels were found in contact with the ureteropelvic junction. The presence of the vessels was confirmed during surgery in five of these patients; the remaining patient did not undergo surgery). Conclusion. Multislice CT arteriography allows adequate presurgical evaluation of ureteropelvic junction stenosis, detecting the presence of crossing vessels and facilitating the planning of the surgical approach in these patients