[Impact of an additional inspiration CT scan on the conventional protocol of the ¹⁸F-FDG PET-CT in the detection of small pulmonary nodes].
OBJECTIVE
To determine the impact of an additional inspiration CT scan on the conventional ¹⁸F-FDG PET-CT protocol in the detection of small pulmonary nodules.


METHODS
One hundred consecutive patients who presented with one or various nodules were studied. Whole-body PET-CT was performed using Gemini (Philips). CT acquisition parameters were 120 kV/25 mAs, the same as those for the transmission/fusion CT (mild expiration) and inspiratory CT.


RESULTS
A total of 188 nodules were detected in the inspiratory CT with sizes between 0.3-3 cm. Non-inspiratory CT did not show 20/188 nodules (10.6%) with sizes between 0.3-1cm, this corresponding to 17 patients. The most frequent localization of non-detectable nodules in non-inspiratory CT was the lower lobes. ¹⁸F-FDG uptake was detected by the PET in 83.9% and 72% of nodules with > 1 cm and between 0.7 and 1cm, respectively. However, only 10.5% of nodules <0.7 cm showed increased metabolic activity.


CONCLUSIONS
In selected patients, inspiratory CT added to conventional PET-CT significantly improves the detection of small nodules (10.6%), especially in those lesions located in the lower lobes, due to respiratory movements, and may have an impact on patient management.
García
J R
JR
CETIR Unidad PET, Esplugues de Llobregat, Barcelona, España. jrgarcia@cetir.es
Lozano
P
P
Soler
M
M
Alvarez Moro
F J
FJ
Fuertes
S
S
Arribas
C
C
Riera
E
E
Lomeña
F
F
D000328:Adult; D000368:Aged; D016477:Artifacts; D002277:Carcinoma / Q000000981:diagnostic imaging / Q000556:secondary; D005188:False Negative Reactions; D005260:Female; D005462:Fluorine Radioisotopes; D019788:Fluorodeoxyglucose F18; D006801:Humans; D001239:Inhalation; D008175:Lung Neoplasms / Q000000981:diagnostic imaging* / Q000556:secondary; D008297:Male; D008875:Middle Aged; D009068:Movement; D011446:Prospective Studies; D011877:Radionuclide Imaging; D019275:Radiopharmaceuticals; D012680:Sensitivity and Specificity; D003074:Solitary Pulmonary Nodule / Q000000981:diagnostic imaging; D014057:Tomography, X-Ray Computed / Q000379:methods*
D005462:Fluorine Radioisotopes; D019275:Radiopharmaceuticals; D019788:Fluorodeoxyglucose F18