Dependence of Contrast-Enhanced Lesion Detection in Contrast-Enhanced Digital Breast Tomosynthesis...

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

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3.5Patient Imaging

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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.

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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

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Iodine Concentration (mg/ml)

LE/HE CEDBT Data

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Reconstruction Domain Subtraction

Projection Domain Subtraction

SARTNo Scatter Correction

Scatter Corrected

FBP No Scatter Correction

SARTNo Scatter Correction

Scatter Corrected

FBP No Scatter Correction