Pulmonary edema is one of the most common complications of left ventricular failure. It is typically suggested by symptoms like dyspnea and diagnosed by auscultation of the chest or radiography. It is frequently relatively far advanced before it can be reliably detected. Radiographically, it is difficult to distinguish from inflammatory or other pulmonary infiltrates and in many patients the discrimination of pulmonary edema from infection can be difficult and pivotal for the choice of therapy. The nuclear magnetic resonance T1 and T2 relaxation times are sensitive to the total free tissue water and should be independent of the spin density per unit volume. If so, they can be used for measuring lung water. Edema fluid is an ultrafiltrate of plasma with a sodium ion concentration similar to plasma. Therefore, increased extracellular water should be measurable as an increase in sodium signal intensity. By using a paramagnetic agent that is confined to the vascular compartment and measuring the blood T1 and the total T1, it will be possible to compute the T1 of the extravascular compartment in physiologic situations where diffusion between compartments is """"""""fast."""""""" Edema tends to be patchy, frequently occupying the dependent portions of the lungs preferentially. An advantage of an imaging method for measurement is that it can account for the nonhomogeneous distribution of edema. Regional measurements made from images will be compared directly to gravimetric measurements to determine the accuracy of the method. This will be studied in a 1.4 Tesla animal imaging system using animal models for atelectasis permeability edema and hemodynamic edema.

Agency
National Institute of Health (NIH)
Institute
National Heart, Lung, and Blood Institute (NHLBI)
Type
Research Project (R01)
Project #
1R01HL033950-01A1
Application #
3346365
Study Section
Diagnostic Radiology Study Section (RNM)
Project Start
1986-07-01
Project End
1989-06-30
Budget Start
1986-07-01
Budget End
1987-06-30
Support Year
1
Fiscal Year
1986
Total Cost
Indirect Cost
Name
University of Pennsylvania
Department
Type
Schools of Medicine
DUNS #
042250712
City
Philadelphia
State
PA
Country
United States
Zip Code
19104
Summers, R M; Joseph, P M; Kundel, H L (1991) Sodium nuclear magnetic resonance imaging of neuroblastoma in the nude mouse. Invest Radiol 26:233-41
Lancaster, L; Bogdan, A R; Kundel, H L et al. (1991) Sodium MRI with coated magnetite: measurement of extravascular lung water in rats. Magn Reson Med 19:96-104
Summers, R M; Joseph, P M; Renshaw, P F et al. (1988) Dextran-magnetite: a contrast agent for sodium-23 MRI. Magn Reson Med 8:427-39
Kundel, H L; Shetty, A; Joseph, P M et al. (1988) Sodium NMR imaging of lung water in rats. Magn Reson Med 6:381-9