Effect of Slice Thickness and Primary 2D Versus 3D Virtual Dissection on Colorectal Lesion Detection at CT Colonography in 452 Asymptomatic Adults
C. Daniel Johnson1,
Joel G. Fletcher1,
Robert L. MacCarty1,
Jay N. Mandrekar2,
William S. Harmsen2,
Paul J. Limburg3 and
Lynn A. Wilson1
1 Department of Radiology, Mayo Clinic, 200 First St., SW, Rochester, MN
55905.
2 Department of Biostatistics, Mayo Clinic, Rochester, MN.
3 Division of Gastroenterology, Mayo Clinic, Rochester, MN.
View larger version (63K):
[in this window]
[in a new window]
[as a PowerPoint slide]
|
Fig. 1A —Correlation of 3D endoluminal virtual dissection display with
traditional images at CT colonography in sigmoid colon of 70-year-old man.
Typical 3D endoluminal virtual dissection display of 15-cm colonic segment.
Diverticulum (arrow) and prominent fold (arrowhead) are
correlated with 2D multiplanar and perspective, volume-rendered images for
diagnosis.
|
|
View larger version (144K):
[in this window]
[in a new window]
[as a PowerPoint slide]
|
Fig. 1B —Correlation of 3D endoluminal virtual dissection display with
traditional images at CT colonography in sigmoid colon of 70-year-old man.
Transverse image shows diverticulum (arrow) displayed in
A.
|
|
View larger version (142K):
[in this window]
[in a new window]
[as a PowerPoint slide]
|
Fig. 1C —Correlation of 3D endoluminal virtual dissection display with
traditional images at CT colonography in sigmoid colon of 70-year-old man.
Traditional perspective. Volume-rendered 3D endoluminal display shows that
suspicious abnormality on virtual dissection image (arrowhead in
A) is flexural fold (arrowhead).
|
|
View larger version (129K):
[in this window]
[in a new window]
[as a PowerPoint slide]
|
Fig. 1D —Correlation of 3D endoluminal virtual dissection display with
traditional images at CT colonography in sigmoid colon of 70-year-old man.
Two-dimensional coronal reformation shows same colonic fold (arrow)
seen in A (arrowhead, A) and C.
|
|
View larger version (14K):
[in this window]
[in a new window]
[as a PowerPoint slide]
|
Fig. 2 —Flowchart shows randomization scheme for image
interpretation. Each case was interpreted by two (radiologists A and B) of
three radiologists using different slice thicknesses (1.25 vs 2.5 mm) and
using 3D virtual dissection and primary 2D display with 3D problem solving.
Same randomization scheme was used for radiologists A and C (151 patients) and
for radiologists B and C (151 patients). Std = standard 2.5-mm slice thickness
at 1.25-mm intervals, high = 1.25-mm slice thickness at 1.25-mm intervals, C =
conventional viewing platform (2D with 3D problem solving), VP = virtual
pathology viewing platform (3D with virtual dissection), 1st and 2nd = first
and second reviews.
|
|
View larger version (126K):
[in this window]
[in a new window]
[as a PowerPoint slide]
|
Fig. 3A —Missed cancers at index endoscopy. Prone axial CT
colonography image in 65-year-old man shows large polyp in sigmoid colon
(arrow) that was detected by both reviewers using every combination
of slice thickness and primary search method. Histopathology showed 1.3-cm
invasive adenocarcinoma invading submucosa but not muscularis propria with
positive lymph nodes.
|
|
View larger version (110K):
[in this window]
[in a new window]
[as a PowerPoint slide]
|
Fig. 3B —Missed cancers at index endoscopy. Prone axial CT
colonography image in 70-year-old man shows large flat lesion
(arrows) laterally in ascending colon. Lesion was detected by both
reviewers using every combination of slice thickness and primary search
method. Surgical specimen revealed 4-cm tubulovillous adenoma with focus of
invasive adenocarcinoma.
|
|
View larger version (128K):
[in this window]
[in a new window]
[as a PowerPoint slide]
|
Fig. 3C —Missed cancers at index endoscopy. Coronal 2D multiplanar
reformation image in 65-year-old man shows large lobulated polyp
(arrow) at rectosigmoid junction. Lesion was identified at three of
four interpretations and missed by one reviewer using primary 2D search and
2.5-mm slice thickness. Surgical specimen revealed 3.2-cm invasive
adenocarcinoma extending into pericolic fat.
|
|
View larger version (82K):
[in this window]
[in a new window]
[as a PowerPoint slide]
|
Fig. 3D —Missed cancers at index endoscopy. Three-dimensional
endoluminal virtual pathology image in 81-year-old man shows ileocecal valve
(arrowhead) and cecal polyp (arrow). Polyp was detected at
three of four interpretations and was missed using primary 3D search with
virtual pathology and 1.25-mm slices. Histopathology results showed invasive
adenocarcinoma invading pericolic fat.
|
|
CiteULike 
Complore 
Connotea 
Del.icio.us 
Digg 
Reddit 
Technorati What's this?
Copyright © 2007 by the American Roentgen Ray Society.
