ABSTRACT
I. Introduction 211
II. Magnetic Resonance Angiography 212
A. Techniques 212
B. Hardware and Software Requirements 213
C. Clinical Applications 215
III. Direct Thrombus Imaging 217
IV. Conclusions 220
References 220
I. Introduction
Pulmonary embolism (PE) is proved in approximately 0.5 per 1000 population
annually, with an estimated 600,000 cases in the United States alone (1,2). Of
these, 90% of patients will reach hospital to allow a diagnosis to be made.
Recently, it has been proposed to classify PE as massive, submassive, or non-
massive PE, according to clinical severity at the time of presentation (3). Less
than 5% of patients will suffer from massive PE and these patients benefit
from rapid (thrombolytic) intervention using echocardiography as (bed-side)
diagnostic test (3). A small subgroup of patients will present with submassive
PE, that is, those with echocardiographic signs of right ventricular dysfunction.
There is some evidence that more aggressive therapy may be indicated in these
patients (4-6), but further studies are required. However, the vast majority of
cases will have nonmassive (hemodynamically stable) PE and can undergo stan-
dard diagnostic tests.
