Acute pulmonary embolism: assessment of helical CT for diagnosis.
OBJECTIVE
To determine the sensitivity and specificity of helical computed tomography (CT) for the diagnosis of acute pulmonary embolism.


METHODS
This prospective study included 47 patients who underwent pulmonary arteriography for evaluation for possible acute pulmonary embolism. Tailored helical CT and pulmonary arteriography were performed within 24 hours of each other. Each CT scan was interpreted by two chest radiologists, blinded to arteriographic results, at two institutions. CT scan interpretations were compared with findings on bilateral selective pulmonary arteriograms interpreted by two vascular radiologists at one institution.


RESULTS
Fifteen (32%) of 47 patients had angiographically proved pulmonary embolism. For the readers at the first institution, helical CT had 60% sensitivity, 81% specificity, 60% positive predictive value, 81% negative predictive value, and 75% overall accuracy. For the readers at the second institution, helical CT had 53% sensitivity, 97% specificity, 89% positive predictive value, 82% negative predictive value, and 83% accuracy.


CONCLUSIONS
Detection of pulmonary embolism with helical CT may be less accurate than previously reported. Given its high specificity but relatively low sensitivity, helical CT may not have the ideal attributes of a first-line imaging study for the diagnosis of pulmonary embolism.
Dept. of Radiology, Massachusetts General Hospital, Boston, MA 02114, USA.
E A
EA
Drucker
S M
SM
Rivitz
J A
JA
Shepard
P M
PM
Boiselle
B
B
Trotman-Dickenson
T J
TJ
Welch
T P
TP
Maus
S W
SW
Miller
J A
JA
Kaufman
A C
AC
Waltman
T C
TC
McLoud
C A
CA
Athanasoulis
D000208:Acute Disease; D000328:Adult; D000368:Aged; D000369:Aged, 80 and over; D003287:Contrast Media; D005260:Female; D006801:Humans; D008297:Male; D008875:Middle Aged; D015588:Observer Variation; D011379:Prognosis; D011446:Prospective Studies; D011651:Pulmonary Artery / Q000000981:diagnostic imaging; D011655:Pulmonary Embolism / Q000000981:diagnostic imaging*; D012680:Sensitivity and Specificity; D018709:Statistics, Nonparametric; D014057:Tomography, X-Ray Computed / Q000295:instrumentation / Q000379:methods* / Q000706:statistics & numerical data
D003287:Contrast Media