EMC - Radiologie最新文献

Erectile dysfunction has a wide range of aetiologies. Among organic disorders, vascular origin is by far the most common type; it may be either a veno-occlusive dysfunction or an arterial insufficiency by reduction of flux in atherosclerosis. These two subtypes are frequently associated and present in numerous diseases. Ultrasonography with Doppler analysis after intracavernous injection of a vasoactive substance is a major first-line investigation for initial diagnosis. The strict technical procedure makes this examination able to establish a definite and accurate diagnosis for arterial insufficiency and to suspect veno-occlusive dysfunction. Invasive methods have been replaced progressively by Doppler examination. The reason may be the availability of new efficient drugs and also the variable results obtained from surgery and vascular interventional radiology. Other techniques such as CT or MRI, today under clinical evaluation, are promising.

Combined B mode and Doppler ultrasound techniques is now considered the preferential method for investigating lower limb venous network. It allows direct examination of the vessels and provides anatomic and physiologic information. This non-invasive method has two major clinical indications: the diagnosis of vein-thrombosis and the assessment of chronic venous disease. Detection of lower-limb deep-vein thrombosis has been assessed mainly in three situations: in patients with clinically suspected deep-vein thrombosis or with clinically suspected pulmonary embolism, and in those at high risk of venous thrombo-embolism in screening. Lower-limb venous ultrasound was compared with a reference standard or with clinical outcome. Various diagnostic managements have been recommended combining clinical assessment and D- dimer plasma measurement in venous thrombosis as well as also helical computed tomography in pulmonary embolism. Before they can be used in clinical practice, diagnostic strategies need to be compared in term of cost-effectiveness. Feasibility as well as availability of equipment and expertise must also be taken into consideration. Lower-limb venous ultrasound remains also highly useful as a complementary tool to the clinical assessment for determining the aetiology, the anatomy and the pathophysiology of chronic venous disease.

Hepatic neoplasms are infrequent in children; they constitute only 1-2 % of all paediatric tumours. Of them, 2/ 3 are malignant. Clinical examination, biology, and imaging have a major role in establishing the diagnosis. Ultrasonography with colour-Doppler which is usually the first investigation performed has to answer the following questions: Is-it a hepatic mass? What is the aspect of the lesion (cystic, solid, calcifications)? Is there one or several tumours? Are the bile ducts dilated? Is there an underlying chronic liver disease (tyrosinemia, glycogen storage disease, cirrhosis…)? Are there associated visceral abnormalities (Pepper syndrome, tyrosinemia, lymphoma…)? Which segment of the liver is involved? MRI and CT with contrast enhancement also provide sufficient information for diagnosis and treatment. Percutaneous biopsy is carried out in some cases, subsequently.

Chest X-ray constitutes the basic investigation of lungs and mediastinum in children. Precise knowledge of the anatomy is necessary for a relevant interpretation. Reading the AP-view consists in the successive analysis of bones, soft tissues, mediastinum, and lung fields. The exposition of lateral view is not systematic and must be made after analysing the AP-view. The various aspects in relation with the thymus have also to be known, in particular in the first 2 years of life.

The number of abdominal biopsies has dramatically increased in the past few years. This can be attributed to the progresses made in biopsy devices, guidance techniques (computed tomography and ultrasonography), management of biopsy samples in pathology department, and an improvement in radiologists' skills. Therefore, many lesions, which were considered unreachable in the past, now fully benefit from image-guided biopsy. Whenever a lesion appears difficult to biopsy, several tricks allow making biopsy possible and safe. The aim of this article is to present the state of the art in the field of abdominal biopsy, with emphasis on tricks of the trade which make things easier. Expected results, as a function of target lesions and diseases will be reminded. Lastly, contraindications and complications of image-guided biopsies will be presented.

Diseases of the oesophagus in children can be distributed into 2 groups: malformative abnormalities and acquired disorders. The principal deformations are the oesophageal atresia, the tracheo-oesophageal fistula and the congenital stenosis. Oesophageal duplications and compressions due to abnormal vascular ring are also reviewed in this chapter. Gastroesophageal reflux and abnormalities of the œsogastric junction are the acquired pathology the most frequently encountered among children. Infectious or inflammatory lesions are much rarer, idiopathic achalasia and tumours are exceptional. Lesions in relation with the ingestion of a foreign body or a caustic substance are also to be known. Imaging, as primary or complementary technique, still consists in conventional radiology while sonography, CT or MRI provide useful information in more specific diseases.

Main diseases of the wrist including normal variants, articular, ligament, tendinous and tumoural disorders are considered in this chapter. Pictorial findings of CT scanning and MRI are described with emphasis put on the advantages and disadvantages of each technique.

Stress fractures are common lesions that occur without trauma neither focal abnormality. They include fatigue fractures which are caused by the application of abnormal stress or torque to a bone that has normal resistance, and insufficiency fractures which occur when normal activity stresses a bone that is deficient in resistance. Such fractures seem to occur more frequently, this being due to both increased sport participation and improved identification by imaging techniques. Following a review of the pathophysiology, aetiology and clinical features, imaging features are presented: bone scintigraphy, radiography, computed tomography, magnetic resonance imaging (MRI) and ultrasound; the findings are presented according to bone shape and to the site of the fracture. Diagnosis of stress fractures is based on the patient's history of physical activity, early abnormalities on the bone scintigraphy and delay on x-ray features. Earlier diagnosis may be done by performing CT scanning and MRI since these techniques are able to detect a fracture even in difficult cases.

The indications for Doppler ultrasonography in urinary tract imaging have been diversified during the past decade. This technique can be used for the diagnosis of vascular disorders involving the renal pedicle or the intrarenal vascular bed, the diagnosis of some nephropathies, in the evaluation of renal tumours and several urinary tract disorders including lithiases, acute obstruction or vesico-ureteral reflux. It benefits from some recent technical improvements and the development of ultrasound contrast agents.