[Low-dose CT in neutropenic patients with fever of unknown origin].
OBJECTIVE
To define the value of low-dose multislice CT in a clinical setting for early detection of pneumonia in neutropenic patients with fever of unknown origin.


METHODS
Thirty-five neutropenic patients suffering from fever of unknown origin with normal chest X-ray underwent unenhanced low-dose CT of the chest (120 kV, 10 eff. mAs, collimation 4 x 1 mm) using a multislice CT scanner. Axial und frontal slices with a thickness of 5 mm were calculated. If no pneumonia was found, standard antibiotics were given and a repeated examination was performed if fever continued. In case of pneumonia, antimycotic therapy was added and a follow-up CT was performed within one week. Regression or progression of pneumonia at follow-up served as evidence of pneumonia; lowering of fever within 48 h or inconspicuous follow-up CT was regarded as absence of pneumonia.


RESULTS
Ten of 35 patients had pneumonic infiltration, which decreased or increased on follow-up CT in 3 and 6 patients, respectively. One patient revealed leucemic infiltration by bronchoalveolar lavage. Twenty-five of 35 patients had no evidence of pneumonia. Twenty of these patients were free of fever within 48 h under antibiotics; one patient died due to his basic illness. Out of 4 patients with persisting fever, 3 patients had no pneumonia on repeated examination; one patient showed disseminated micronodular infiltration. Frontal reconstructions helped to differentiate infiltration from atelectasis in 4 patients. Sensitivity and specificity for the detection of pneumonia at the first examination were 90 % and 96 %, negative predictive value was 96 %.


CONCLUSIONS
Low-dose multislice CT should be performed in neutropenic patients having a fever of unknown origin and normal chest X-ray.
Wendel
F
F
Institut für Röntgendiagnostik der Universität Würzburg. wendel@roentgen.uni-wuerzburg.de
Jenett
M
M
Geib
A
A
Hahn
D
D
Sandstede
J
J
D000328:Adult; D000368:Aged; D005260:Female; D005335:Fever of Unknown Origin / Q000175:diagnosis* / Q000209:etiology*; D006801:Humans; D008297:Male; D008875:Middle Aged; D009503:Neutropenia / Q000150:complications* / Q000000981:diagnostic imaging*; D011014:Pneumonia / Q000000981:diagnostic imaging* / Q000209:etiology*; D011379:Prognosis; D011829:Radiation Dosage; D015203:Reproducibility of Results; D012680:Sensitivity and Specificity; D036542:Tomography, Spiral Computed / Q000379:methods*