Linda Moy MD, Presenter: Nothing to Disclose

Fabio Ponzo, Abstract Co-Author: Nothing to Disclose

Marilyn E. Noz PhD, Abstract Co-Author: Nothing to Disclose

Antoinette Murphy_Walcott, Abstract Co-Author: Nothing to Disclose

Abby Deans, Abstract Co-Author: Nothing to Disclose

Elissa Lipcon Kramer MD, Abstract Co-Author: Nothing to Disclose

Investigate if PET/CT, when reviewed side-by-side and fused with MR, can improve the specificity of MRI.

We designed an apparatus for the PET/CT scanner which allows images of the breast to be acquired prone. Patients’ were included in this study if MRI detected a mass which was not seen on mammography or US. The PET and MRI studies were matched twice by two observers. Two blinded radiologist evaluated the value of PET by comparing side-by-side images and fused PET/MRI images. Findings were correlated with histology.

Twenty-one women had both exams to stage their cancer, 6 for problem solving. All 27 fusion volume sets (two observers, 54 fusions in all) were judged to be visually acceptable. Multivariate analysis showed that the registration methodology between observers and across patients was not significantly different (p < .05). Sixty-one enhancing masses were seen, mean 1.8 cm. PET identified 28(61%) foci of uptake which matched the MRI finding. Twenty-seven of 28 (96.4%) foci of activity were cancers, mean 2.2cm. One false positive focus is due to uptake in a lumpectomy scar. Thirty three of 61(54%) masses had no uptake on PET. Seven of 33 (21%) enhancing masses not seen on PET were cancers, mean 1.2 cm, 2 DCIS, 5 invasive ductal carcinoma. Twenty-six of 33 (79%) are biopsy proven to be benign (19/26). Seven of 26 lesions are being followed with mammography, US, and MRI (mean 14 months, range 9 – 32 mons). The PET/MRI images have a sensitivity of 80% and a specificity of 96.3%. Fusion images were more helpful in women with multicentric disease and non-anatomic findings (e.g. post-surgical scar).

PET may increases the specificity of MRI. PET/MRI fusion was more helpful than side-by side evaluation because lesions were better localized.

The additional metabolic information provided by PET may increase the specificity of breast MRI.

Moy, L, Ponzo, F, Noz, M, Murphy_Walcott, A, Deans, A, Kramer, E, Improving the Specificity of Breast Magnetic Resonance Imaging (MRI) by Fusing MRI with FDG-Positron Emission Tomography (FDG-PET/CT) 3D-Data-Sets.  Radiological Society of North America 2006 Scientific Assembly and Annual Meeting, November 26 - December 1, 2006 ,Chicago IL. http://archive.rsna.org/2006/4438993.html