Madeleine R. Fisher

Gynecologic masses: Value of magnetic resonance imaging

Forty-two women with gynecologic abnormalities were studied with the use of magnetic resonance imaging. Magnetic resonance imaging correctly assessed the origin of the pelvic mass in all patients. In the evaluation of leiomyoma, magnetic resonance imaging accurately depicted the number, size, and location of the lesion. In the evaluation of endometrial carcinoma, magnetic resonance imaging depicted the location of the lesion, the presence of cervical extension, and the depth of myometrial penetration in the majority of the cases. In the analysis of adnexal cysts, magnetic resonance imaging was sensitive in localizing the lesion and was able to distinguish serous from hemorrhagic fluid. This preliminary report indicates that magnetic resonance imaging may become a valuable imaging modality in the diagnosis of gynecologic abnormalities.

Pathologic Blood Flow in Pulmonary Vascular Disease as Shown by Gated Magnetic Resonance Imaging

Axial, dual spin-echo magnetic resonance (MR) images, taken at the level of the pulmonary arteries and gated to the cardiac cycle, were qualitatively and quantitatively evaluated in nine patients with primary pulmonary arterial hypertension and six controls. In controls and patients, intravascular signal intensity was higher during diastole than during systole when fast flow conditions exist in the arteries; however, patients with severe pulmonary arterial hypertension showed significantly higher signals in the pulmonary arteries than did controls. A correlation between pulmonary vascular resistance and the MR signal in the right pulmonary artery in early systole (r = 0.89) showed the ability of MR images to provide information on blood flow and suggests a role for magnetic resonance in assessing the severity of this disease noninvasively. Flow-related cardiosynchronous variations in the lung parenchyma of controls were also observed; with further development, magnetic resonance may become useful to measure tissue perfusion and provide both pathoanatomic and pathophysiologic information. Furthermore, there was a significant difference between the MR signal intensity of dorsal and ventral lung regions.

Magnetic resonance imaging of the normal and pathologic muscular system

Abstract Evaluation of the muscular system with magnetic resonance (MR) was conducted: (1) to assess the capability of MR to depict muscular abnormalities; (2) to evaluate the ability of MR to discriminate between various types of muscular pathologies based on relaxation parameters; and (3) to determine the optimal spin echo (SE) sequence that produced optimal contrast. Retrospective analysis was performed on 59 consecutive patients with a variety of muscular abnormalities. MR muscle analysis included visual inspection of contour and size; muscle intensity changes in relation to various TR TE combinations; measurement of T1 and T2 relaxation and spin density; and calculation of percent contrast variation with different SE imaging combinations. Contour and size abnormalities were not reliable for detection of muscular pathology. For each individual subject intensity and relaxation times of all muscles involved by pathology differed from normal muscle. Although all pathologies caused increase in signal intensity of muscle, the alterations in relaxation times were variable. Fatty atrophy caused a decrease in T1 and increase in T2; while post-surgical changes, infection, acute intramuscular hemorrhage, and tumor invasion caused an increase in both T1 and T2. Percent contrast indicated that the optimum sequence for evaluation of fatty atrophy was a short (0.5 sec) repetition time (TR) and echo delay time (TE) of 56 msec, while for demonstration of the remaining muscular abnormalities, including post-surgical changes, infection, acute intramuscular hemorrhage, and tumor invasion, a long TR (TR = 2.0 sec) and TE (56 msec) was optimal. Differentiation between various benign and malignant muscular abnormalities (excluding fatty atrophy) was not possible using either quantitative intensity values or relaxation times.

Magnetic Resonance Imaging of Congenital Heart Disease

Magnetic resonance (MR) imaging is an entirely noninvasive technique for the visualization of cardiovascular anatomy, and it is well suited for the evaluation of congenital heart disease. Clinical MR uses high-strength static magnetic fields, low-strength changing magnetic fields, and radiofrequency pulses to generate images of the body with high soft-tissue contrast. However, to visualize cardiac anatomy, an electrocardiographic (ECG)-gated technique is necessary for synchronization of the MR pulse sequences to specific phases of the cardiac cycle. This technique greatly improves cardiac image quality and provides excellent differentiation of the internal cardiac structures.