[en] The authors discuss the concept of symmetry and defect of symmetry in radiological imaging and recall the definition of asymmetry (congenital or constitutional) and dissymmetry (acquired). They then describe a rule designed for the cognitive method of automatic evaluation of shape recognition data and propose the use of reversal symmetry

[en] Study of spinal deformities in 82 cases of nephroblastoma treated surgically or by chemotherapy and high-energy radiotherapy. This paper stresses the high incidence of radiation induced scoliosis which was observed in all patients who had reached adulthood. On the basis of a detailed analysis of the relations between the height of the vertebral body and of the intervertebral space, the authors propose a theory of a compensation of the reduction in vertebral height by displacement the nucleus pulposus towards the irradiated side. This phenomenon prevents the development of scoliosis in subjects under the age of 11 years, despite an already well established deformity of the vertebral bodies. The compensation decreases with increasing age and the degree od scoliosis. This explains partly the increased degree of scoliotic deformity during puberty. Orthopaedic treatment therefore needs to be started relatively early

[en] We report a case of arteriovenous fistula due to spontaneous rupture of an aortic aneurysm into the inferior vena cava. This is a rare complication of atheromatous aneurysm, often difficult to diagnose as the clinical presentation may be obscure. Although aortography is the reference diagnostic investigation, spiral CT acquisition with 3D and 2D reformation allowed visualization of the arteriovenous communication and provided an accurate diagnosis. (authors)

[en] Angio-CT is a minimally invasive diagnostic method for the evaluation of diseases of the carotid bifurcation. Necessary technical conditions are: spiral scans with a 2-3 mm/sec table speed, 2 mm beam collimation, 1 mm reconstruction and IV iodinated contrast material injected at 2.5 ml/sec. information is provided y axial images, shaded surface display (SSD), multiplanar curved reformations and maximum intensity projection (MIP). Multiplanar curved reconstructions are particularly useful for CT-density plaque characterization. Angio-CT is multiplanar and allows characterization of plaques with respect to calcification, fatty content, fibrosis, ulceration, and size that cannot be obtained with conventional angiography. The assessment of CT-plaque density is quantitative but quantitative texture analysis of CT-angiographic defined plaques has still to be done and to be correlated with clinical risk. CT angiography can visualize angiographically defined ulcerations of more than 1 mm size, but fails to visualize fine (<1 mm) intimal ruptures. Comparing low invasive methods, angio-MRI is very sensitive for the detection of fat, but has low sensitivity for calcifications (contrary to CT); with respect to a combination of Doppler and B-ultrasound, angio-CT has probably a lesser sensitivity for the identification of fresh thrombi, but shows the 3D aspect of plaques. We need still more data on comparison between different imaging modalities with respect to plaque characterization and associated risks, but angio-CT and ultrasound can be used in most cases for exploration of carotid bifurcation. (authors)

[en] Vertebral artery dissection is the first diagnosis that must be suspected by a 40 years old patient with posterior fossa ischemic signs. CT datas from six cases of spontaneous or post-traumatic vertebral artery dissections are reviewed. Cervical CT is performed after contrast medium injection from C7 to CO with 1.5 mm thick slices and a 2 mm gap or with a spiral mod including millimetric reconstruction. The enhancement of the vascular wall, the hypodense hematoma surrounding a stenotic and eccentric lumen, and the enhancement of the artery are typical for a vertebral artery dissection. CT findings were correlated with angiography that is still considered to be the gold standard for this diagnosis. Among noninvasive technics including MRI, duplex scanning and CT, the latter appears very accurate to diagnose vertebral artery dissection. (authors). 13 refs., 4 figs., 2 tabs

[en] Until now little attention has been paid to the potential of MR imaging in congenital heart disease of the newborn. ECG-gated MRI was therefore performed at 0.5 tesla in 23 newborns with suspected congenital heart disease. Two newborns were controlled after surgery. All had undergone prior evaluation by two-dimensional Doppler echocardiogrpahy. MR imaging was of a satisfying quality in all but one newborn. The aim of this study was to assess complementary information provided by MRI in comparison to 2-D DE. Pre-operatively MRI missed some abnormalities shown by 2-D DE: one coartaction, one ductus arteriosus and one ulmonary atresia. MRI demonstrated lesions that echocardiography had either failed to visualize or found inconclusive, inlcuding double aortic arch, muscular ventricular septum defect and severe ductus arteriosus. In one of the two patients with a ventricular septum defect, angiography was avoided and in the other patient is merely confirmed the MRI results. Post-operatively, MRI demonstrated information complementary to that obtained from to 2-D DE: (1) clearly visualizing the reinsertion of the coronary arteries in the 'switched' transposition of the great vessels, (2) appreciating the diameter and patency of the palliative shunt in the Blalock-Taussig procedure. (author). 25 refs.; 9 figs.; 1 tab