A new cephalic reference plane for use with magnetic resonance imaging: the chiasmato-commissural plane

Summary A cephalic reference plane is described through the chiasmatic notch and the posterior commissure, which is easily identified on mid-sagittal cuts using magnetic resonance imaging. The horizontal cuts so obtained are almost parallel to the lateral fissure and are perpendicular to the axis of the brain stem.This work was published in part in C R Acad Sci Paris, t. 311, série III, p. 115–121, 1990     

Human heart: tagging with MR imaging--a method for noninvasive assessment of myocardial motion

Specified regions of the myocardium can be labeled in magnetic resonance (MR) imaging to serve as markers during contraction. The technique is based on locally perturbing the magnetization of the myocardium with selective radio-frequency (RF) saturation of multiple, thin tag planes during diastole followed by conventional, orthogonal-plane imaging during systole. The technique was implemented on a 0.38-T imager and tested on phantoms and volunteers. In humans, tags could be seen 60-450 msec after RF saturation, thus permitting sampling of the entire contractile phase of the cardiac cycle. Tagged regions appear as hypointense stripes, and their patterns of displacement reflect intervening cardiac motion. In addition to simple translation and rotation, complex motions such as cardiac twist can be demonstrated. The effects of RF pulse angle, relaxation times, and heart rate on depiction of the tagged region are discussed.     

Juvenile papillomatosis of the breast: sonographic appearance

Three patients with juvenile papillomatosis of the breast are described. The lesions were apparent clinically as a palpable mass. At mammography, juvenile papillomatosis was not depicted in two patients and was seen as a poorly defined mass in one case. In all patients, high-frequency ultrasound examination showed an ill-defined, inhomogeneous mass with one or several small (up to 0.4 cm), rounded, relatively echo-free areas, which were seen mainly or exclusively near the borders of the lesion.     

Carotid bifurcation disease: prediction of ulceration with B-mode US

The presence of carotid ulceration was assessed by two readers for 55 B-mode ultrasound (US) studies. Intact surgical specimens were available for comparison. Ulceration was considered present if the following criteria were obtained: a continuous contour showing focal depression, a well-defined break in the surface 1 mm or more across, a well-defined back wall at the base of the depression, and an anechoic area within the plaque which extended to the surface and was 1 mm or more deep. Using these criteria, the two readers agreed on the diagnosis for 47 studies. When the surgical specimen was used as a reference standard, the accuracy of B-mode US was 60%, its sensitivity was 39%, and its specificity was 72%. Since the impact of scan quality was ruled out by using only scans on which the two readers agreed, the poor results must be attributed to the lack of definitive US criteria. A second review of the scans, with the readers looking only for a heterogeneous echo pattern, revealed that appearance had no higher correlation with ulceration at surgery than any of the original criteria had.