Date post: | 14-Apr-2017 |
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DAVID A. SCADUTO1, YUE-HOUNG HU2, YIHUAN LU3, HAILIANG HUANG1, JINGXUAN LIU4, KIM RINALDI1, GENE GINDI1, PAUL R. FISHER1, WEI ZHAO1
1Department of Radiology, Stony Brook Medicine, Stony Brook, New York 11794; 2Department of Radiation Oncology, Division of Medical Physics and Biophysics, Dana-Farber Cancer Institute and Harvard Medical School, Boston, Massachusetts 02115; 3Departments of Radiology and Biomedical Engineering, Yale University, New Haven, Connecticut 06520; 4Department of Pathology, Stony Brook Medicine, Stony Brook, New York 11794
Dependence of Contrast-Enhanced Lesion Detection in Contrast-Enhanced Digital Breast Tomosynthesis on Imaging Chain Design
BACKGROUND Contrast-enhanced digital breast tomosynthesis (CEDBT) may
reduce false-positives compared with CE digital mammography Reduces contrast signal integration/superposition inherent to CEDM CEDBT may differentiate true/false positives, like DCE-MRI, through
o characterization of stippled/non-mass enhancemento observation of contrast kinetics
3D localization in CEDBT may differentiate non-mass enhancement from background parenchymal enhancement
Reducing contrast superposition may improve relative contrast quantification
PURPOSE Investigate ability of CEDBT to
o identify small enhancements (stippled enhancement patterns)o accurately quantify relative iodine concentration (contrast kinetics)
Evaluate different imaging chain designs
METHODSExperimental System Siemens MAMMOMAT Inspiration DBT system Modified for DE imaging
o Low Energy: W/Rho High Energy: W/Cu or W/Ti 49 kVpo 300 μm a-Se detector
Phantom Imaging CIRS BR3D phantom Custom solid iodine insert
Patient Imaging IRB-approved clinical study Three patients, BI-RADS 4-5 1.5-2.0 ml Omnipaque 350 per kg body weight
Imaging Chain Design
SDNR Analysis Measured for each iodine object concentration, diameter in phantom
for each imaging chaino SDNR correlated to iodine concentration
Measured in each patient for each imaging chain
RESULTSSubtracted Reconstructions Six weighted subtractions produced for each dataset Weighting factor derived analytically and tuned empirically
RESULTS
SDNR Analysis
DISCUSSION Subtraction produces equivalent results in either projection or
reconstruction domains SART outperforms FBP, but judicious filter selection may improve
performance Scatter correcting projections improves SDNR for SART Strong correlation between iodine concentration and SDNR Future work: improve SDNR by further reducing residual structure
o Reduce misregistration due to patient motiono Improve reconstruction, scatter correction algorithms
ACKNOWLEDGMENTSWe gratefully acknowledge financial support from NIH (1 R01 CA148053 and 1 R01 EB002655) and Siemens Healthcare.
2 mm 8 mm 2 mm 8 mm 2 mm 8 mm 2 mm 8 mm1 mg/ml 2 mg/ml 3 mg/ml 5 mg/ml
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Phantom Imaging
Subtraction Scheme
A1 A2 A3 B1 B2 B3
SD
NR
Patient A Patient B Patient C0.0
0.5
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3.5Patient Imaging
SD
NR
Subtraction Scheme
A1 A2 A3 B1 B2 B3
Fig. 4. SDNR of embedded iodine inserts in phantom and iodinated lesions in patient cases. Subtraction in either domain gives essentially equivalent results. SART (A2-3/B2-3) generally outperforms FBP. Scatter correcting before SART improves SDNR. Data from Patient A could not be scatter corrected due to technical limitations of the algorithm.
Fig. 5. Measured SDNR of 8 mm iodine object from phantom for each subtraction scheme. Data were linearly fitted and Pearson correlation coefficients calculated; r > 0.98 was demonstrated for all cases. Subtraction schemes in corresponding subtraction domains (e.g., A1/B1) produced virtually identical SDNR and thus appear to overlap.
Fig. 3. Single slices from subtracted (top) phantom reconstructions and (bottom) patient reconstructions, according to imaging chain designs outlined in Fig. 2.
Fig. 1. (a) CIRS BR3D phantom with (b) custom iodine insert.
Fig. 2. Imaging chain designs. Images subtracted in either reconstruction or projection domain; reconstructed with FBP or SART; scatter corrected or uncorrected for SART.
0 1 2 3 4 5 6-2
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12 A1 r = 0.994A2 r = 0.986A3 r = 0.992B1 r = 0.985B2 r = 0.985B3 r = 0.992
SD
NR
Iodine Concentration (mg/ml)
LE/HE CEDBT Data
A1
A2
A3
B1
B2
B3
Reconstruction Domain Subtraction
Projection Domain Subtraction
SARTNo Scatter Correction
Scatter Corrected
FBP No Scatter Correction
SARTNo Scatter Correction
Scatter Corrected
FBP No Scatter Correction