Software Volumetric Evaluation of Doubling Times for Differentiating Benign Versus Malignant Pulmonary Nodules
Marie-Pierre Revel1,2,3,
Aurelie Merlin1,2,3,
Severine Peyrard1,4,
Rached Triki1,2,3,
Sophie Couchon1,2,3,
Gilles Chatellier1,2,5 and
Guy Frija1,2,3
1 Département de Radiologie, Assistance Publique des Hôpitaux de
Paris, 20 rue Leblanc, Paris, F-75015 France.
2 Université Paris-Descartes, Faculté de Médecine, Paris,
F-75015 France.
3 Département de Radiologie, Hôpital Européen Georges
Pompidou, Paris, F-75015 France.
4 Centre d'Investigations Cliniques, Hôpital Européen George
Pompidou, Paris, F-75015 France.
5 Unité de Recherché Clinique, Hôpital Européen
George Pompidou, Paris, F-75015 France.
View larger version (117K):
[in a new window]
|
Fig. 1A —Malignant pulmonary nodule in 54-year-old woman who is not a
smoker. Unenhanced axial transverse CT image shows 9-mm round nodule with
smooth margins in right upper lobe. Patient had history of ovarian malignancy.
No prior CT examination was available.
|
|
View larger version (124K):
[in a new window]
|
Fig. 1B —Malignant pulmonary nodule in 54-year-old woman who is not a
smoker. On second CT examination, 2 months after A, size of nodule has
not changed on visual estimation. Measured diameter variation is only 0.9 mm,
which is a nonsignificant change.
|
|
View larger version (72K):
[in a new window]
|
Fig. 1C —Malignant pulmonary nodule in 54-year-old woman who is not a
smoker. Volume of nodule on follow-up CT, 2 months after A, is 547
mm3. Relative volume variation is thus 41%, and calculated doubling
time is 117 days, suggesting malignancy. Nodule was surgically removed and was
found to be pulmonary metastasis expressing same hormone receptors as primary
ovarian tumor.
|
|
View larger version (117K):
[in a new window]
|
Fig. 2A —Malignant pulmonary nodule in 65-year-old man who is a
smoker. Unenhanced axial transverse CT image shows 11-mm lobulated nodule in
right upper lobe, which is likely to be malignant given patient's age and
smoking status and size and lobulated contours of nodule. Nodule was detected
on routine chest radiograph with patient being asymptomatic.
|
|
View larger version (119K):
[in a new window]
|
Fig. 2B —Malignant pulmonary nodule in 65-year-old man who is a
smoker. No obvious change in nodule size is apparent on second CT examination,
which was performed preoperatively. Diameter variation measured with manually
positioned electronic calipers is 0.8 mm.
|
|
View larger version (45K):
[in a new window]
|
Fig. 2C —Malignant pulmonary nodule in 65-year-old man who is a
smoker. Software-measured volume on second CT examination is 993
mm3, representing 29% increase. Software-estimated doubling time is
296 days, suggesting malignancy. Pathologic examination after surgical
resection showed stage I poorly differentiated large cell carcinoma.
|
|
View larger version (83K):
[in a new window]
|
Fig. 3A —Benign nodule in 50-year-old man who is a smoker. Unenhanced
CT scan obtained to confirm chest radiographic findings shows 10-mm
noncalcified nodule in right upper lobe. Centrilobular emphysema is also
present.
|
|
View larger version (58K):
[in a new window]
|
Fig. 3B —Benign nodule in 50-year-old man who is a smoker.
Three-dimensional surface-rendering view of nodule segmentation on first CT
follow-up. Volume variation at 6 weeks is only 1%, giving estimated doubling
time of more than 11 years.
|
|
View larger version (65K):
[in a new window]
|
Fig. 3C —Benign nodule in 50-year-old man who is a smoker. Nodule
segmentation on CT scan obtained 6 months after A. Volume variation
remains very small (2%), and software-estimated doubling time is more than 17
years. This nodule had remained unchanged at 3 years.
|
|
View larger version (147K):
[in a new window]
|
Fig. 4A —Benign nodule in 44-year-old man who is a smoker. Unenhanced
CT axial transverse image shows 6-mm perifissural opacity. This nodule is
likely to be intrapulmonary lymph node.
|
|
View larger version (58K):
[in a new window]
|
Fig. 4B —Benign nodule in 44-year-old man who is a smoker.
Segmentation of nodule on CT scan obtained 10 months after A.
Three-dimensional surface-rendering view of segmented nodule shows its
triangular shape. Nodule morphology and shape are better analyzed on
volumetric than on 2D CT images. This nodule is likely to be intrapulmonary
lymph node. Relative volume variation is 6%, and estimated nodule doubling
time is 593 days. Nodule remained unchanged at 28 months.
|
|
View larger version (8K):
[in a new window]
|
Fig. 5A —Volume variation of benign nodules according to their initial
size. Plot of relative volume variation against initial nodule size. No
correlation was found (p = 0.84, F test).
|
|
View larger version (9K):
[in a new window]
|
Fig. 5B —Volume variation of benign nodules according to their initial
size. Nodule size distribution in benign group A (absolute volume variation,
< 10%) and benign group B (absolute volume variation,  10%). Mean
nodule size and nodule size distribution were similar in groups A and B
(p = 0.82, Student's t test).
|
|
View larger version (9K):
[in a new window]
|
Fig. 6 —Volume variation of benign nodules according to nodule type.
Plot of relative volume variation against nodule type. No correlation was
found (p = 0.2, F test).
|
|
View larger version (9K):
[in a new window]
|
Fig. 7 —Volume variation of benign nodules according to differences
in tube current (mAs) exposure between two successive CT scans. Relative
volume variation of nodules scanned with less than 50-mAs difference and
nodules scanned with more than 50-mAs difference between two CT scans.
Distribution and mean relative volume variation were not different between two
groups.
|
|
CiteULike 
Complore 
Connotea 
Del.icio.us 
Digg 
Reddit 
Technorati What's this?
Copyright © 2006 by the American Roentgen Ray Society.
