Carcinoma of the breast: detection with MR imaging versus xeromammography

Detectability of breast cancer with magnetic resonance (MR) imaging versus xeromammography was quantitatively compared. MR images were obtained of breasts of 120 women who underwent xeromammography. T1 values were determined for masses larger than 2 cm. Cancer was histologically confirmed in 39 breasts and was considered excluded from 81 due to results of biopsy, cyst aspiration, or sonography or absence of change in xeromammographic findings over time. Images were blindly interpreted by three observers, and results were expressed as receiver operating characteristic curves. Detectability of breast cancer was substantially better with xeromammography than with MR imaging for all observers (P less than .03, 10(-6), and .001). On MR images, spiculation of a mass, distorted architecture, skin thickening, and nipple or skin retraction were specific but relatively insensitive indicators of cancer. Masses with smooth, distinct margins and signal intensity greater than that of fat on T2-weighted images were always benign. Other findings and T1 values were not diagnostically useful. The authors conclude that xeromammography is superior to MR imaging in detection of breast cancer.     

Acute myocardial ischemia: MR imaging with Mn-TP

Cardiac-gated magnetic resonance (MR) imaging was performed in rats to determine the effects of manganese ethylenediaminetetraphosphonate (TP). Ten normal rats received Mn-TP in a dose of 50 mumol/kg through a tail-vein injection. Spin-echo MR images were obtained before and every 10 minutes after Mn-TP injection for 1 hour. Cardiac signal intensity (SI) increased more than 70% after Mn-TP injection and remained nearly unchanged 1 hour after injection. Myocardial T1 was 517 +/- 49 msec in eight control rats and 282 +/- 61 msec (P less than .001) in six rats 81 +/- 0 minutes after injection. Nine rats underwent occlusion of the left anterior descending coronary artery prior to MR imaging. Images were obtained before and 15, 30, and 60 minutes after Mn-TP injection. In normal myocardium, SI increased up to 82% and remained elevated for 1 hour. In ischemic myocardium, SI rose 11%, leading to a marked contrast between the two tissue zones. T1 was also different in the two regions: In normal tissue, it was 206 msec +/- 54; in ischemic tissue, 338 +/- 82 (P less than .001). With T1-weighted MR imaging, Mn-TP showed a potential for delineating the jeopardized area after acute myocardial ischemia.     

The combination of guanethidine 3% and adrenaline 0.5% in 1 eyedrop (GA) in glaucoma treatment.

During a 7-month period 33 patients (20 with primary open-angle glaucoma and 13 with suspected glaucoma) were treated with guanethidine 3% and adrenaline 0.5% in 1 eyedrop twice daily. The previous therapy was discontinued and the aim of the trial was to treat the patients with GA alone. There was an average decrease in intraocular pressure of 10.8 mmHg or 37.5% for the whole group (including 5 patients with additional therapy). In eyes with an average IOP in a day-curve without medication equal to or higher than 28 mmHg we found a decrease of 44.6% or 14.4 mmHg, and in eyes with an average IOP without medication between 21 and 28 mmHg a decrease of 30.4% or 7.6 mmHg. With GA alone the IOP was 3.3 to 3.9 mmHg lower than on the previous therapy (P less than 0.05); 46% of the eyes without additional therapy had all IOPs lower than 22 mmHg and 74% of the eyes had IOPs lower than 22 mmHg except 1 with a peak lower or equal to 25 mmHg 3 hours after application. This peak 3 hours after application indicates that GA has a biphasic action and was significant at the 0.5% level. Red eyes and slight ptosis were no problem for most patients. Patients found it very convenient to administer GA only twice daily.     

A double-blind short-term trial of guanethidine 3 % and adrenaline 0.5 % combined in one eye drop

Summary A double-blind short-term trial was done to test the effect of guanethidine 3% — adrenaline 0.5% (G-A) in a combined eye drop in 18 patients with open-angle glaucoma and one patient with narrow-angle glaucoma. In 9 of the 19 patients we expected an IOP lowering agent. There was one false-negative result. The mean fall in IOP due to G-A was 10.1 mm Hg (range 3 to 23) and 8.7 mm Hg (range –1 to 26) 6 and 8 h after application respectively. There was no effect on IOP in the 9 eyes that received the placebo.     

Blood flow imaging with MR: spin-phase phenomena

Blood flow phenomena occurring when flow is within the magnetic resonance (MR) imaging plane were analyzed. In this situation, the signal intensity of vascular lumina is predominantly determined by spin-phase change phenomena, and section transition effects of moving spins can be neglected. In this paper, we develop the concepts of in-plane flow, with emphasis on the notion that the spatial variations in velocity and acceleration of blood, which mainly occur along vessel walls, are important determinants of intravascular signal loss in MR images. Flow patterns in the large mediastinal arteries were qualitatively and quantitatively analyzed in six healthy subjects and 14 patients with hemodynamic abnormalities using multiple electrocardiograph-gated image acquisition; ungated studies of 30 patients were analyzed for venous flow effects. Intraluminal signal was strongly dependent on the phase of the cardiac cycle and the echo number. Signal loss was found to occur along vessel walls, in vascular bends, and at bifurcations.