John Michael Boone PhD, Presenter: Research Consultant, Varian Medical Systems, Inc Speaker, General Electric Company Speaker, Imaging Diagnostic Systems, Inc

Karen K. Lindfors MD, Abstract Co-Author: Nothing to Disclose

Kai Yang, Abstract Co-Author: Nothing to Disclose

George W. Burkett, Abstract Co-Author: Nothing to Disclose

Nathan Packard, Abstract Co-Author: Nothing to Disclose

Shih-Ying Huang, Abstract Co-Author: Nothing to Disclose

Katherine G. Metheany, Abstract Co-Author: Nothing to Disclose

Thomas Roy Nelson PhD, Abstract Co-Author: Consultant, Koninklijke Philips Electronics NV Equipment support, Koninklijke Philips Electronics NV

et al, Abstract Co-Author: Nothing to Disclose

et al, Abstract Co-Author: Nothing to Disclose

While mammography is the primary modality for breast cancer screening, breast imaging using true computed tomography methods may prove useful in the screening, diagnostic, and diagnostic arenas.

Two breast CT prototypes were built and tested at our institution. These systems scan one breast at a time with the women prone, and use cone beam CT geometry with a flat panel detector system. Radiation dose levels are equivalent to two view mammography. Images from each breast comprise 300 to 500 images, each with 512 x 512 voxels measuring about 0.30 mm isotropically. Image quality was measured using the MTF, RMS noise and NPS parameters. A Phase I study involving 10 healthy volunteers, and a Phase II study which has currently enrolled 103 BIRADS 4 and 5 patients, were performed, including several with contrast agent injection.

The measured MTF is superior (Fc about 2 cycles/mm) to conventional whole body CT, while the NPS shows slightly higher noise levels than conventional scanners, The noise in the breast images is nevertheless acceptable and can be modulated with appropriate choice of section thickness. Women prefer the comfort of breast CT over mammography (p<0.01), due likely to the lack of breast compression. Subjective comparisons of breast CT images with mammograms suggest improved mass conspicuity (p < 0.05) but reduced microcalcification detection (p < 0.05). A number of selected breast CT images are illustrated, with comparisons to mammographic, ultrasound, and MRI images. Breast CT images of DCIS, IDC, LCIC, fibroadenoma are shown, and contrast enhanced breast CT is also demonstrated.

Breast CT is an emerging breast imaging technology, however its exact role in breast cancer imaging is currently unproven. Nevertheless, initial clinical experience on over 100 Phase II patients has demonstrated that the ability to visualize the three dimensional breast volume using coronal, sagittal, and axial images is a powerful diagnostic adjunct to mammography.

This preliminary investigation of breast CT performance shows excellent image quality – the detail that is visible suggests that breast CT will have some role to play in breast imaging.

Boone, J, Lindfors, K, Yang, K, Burkett, G, Packard, N, Huang, S, Metheany, K, Nelson, T, et al, , et al, , A Dedicated CT Scanner for Breast Imaging: Technical Evaluation and Preliminary Images Selected from Scans of 113 Women.  Radiological Society of North America 2007 Scientific Assembly and Annual Meeting, November 25 - November 30, 2007 ,Chicago IL. http://archive.rsna.org/2007/5011929.html