DETECTION OF NODULAR LESIONS IN THE LUNG USING HELICAL COMPUTED-TOMOGRAPHY - COMPARISON OF FAST COUCH SPEED TECHNIQUE WITH CONVENTIONAL COMPUTED-TOMOGRAPHY
K. Mori et al., DETECTION OF NODULAR LESIONS IN THE LUNG USING HELICAL COMPUTED-TOMOGRAPHY - COMPARISON OF FAST COUCH SPEED TECHNIQUE WITH CONVENTIONAL COMPUTED-TOMOGRAPHY, Japanese Journal of Clinical Oncology, 24(5), 1994, pp. 252-257
The present study assessed the ability of helical CT performed at fast
couch speeds (20 mm or 25 mm/sec), sufficient to cover the entire lun
g field during a single breath hold, compared with conventional CT for
detecting pulmonary nodules in patients with metastatic lung disease.
The subjects were seven consecutive patients with metastatic lung tum
ors in whom 152 lesions were detected by conventional CT. The average
diameter of the nodules was 8.3 (range 2-23 mm). To scan the entire lu
ng, we first employed conventional CT (10-mm slice thickness, 10 mm co
uchtop slide). We then used helical CT with couchtop speeds of 20 and
25 mm/sec, permitting easy scanning of the entire lung field during a
single breath hold (images of reconstruction intervals; 25, 20, 12.5 a
nd 10 mm). We assessed each image to compare detection capabilities in
the lung. The detection capabilities for each reconstruction interval
were 78, 83, 91 and 97%, respectively. The detection of nodules was s
uperior for 12.5 and 10 mm images than for 25 and 20 mm images (P < 0.
01). In 25 and 20 mm images, the detection capability was significantl
y lower in the apical area than in the middle area (P<0.01). For nodul
es 5 mm in diameter, 10 mm images permitted complete detection. Helica
l CT fast couch speeds (20 or 25 mm/sec), which allow imaging of the e
ntire lung during a single breath hold, may be useful in detecting met
astic pulmonary nodules, and helical CT is expected to be a useful met
hod for lung screening.