A new breast tomosynthesis imaging method: Continuous Sync-and-Shoot - technical feasibility and initial experience

Background Digital breast tomosynthesis (DBT) is gaining popularity in breast imaging. There are several different technical approaches for conducting DBT imaging. Purpose To determine optimal imaging parameters, test patient friendliness, evaluate the initial diagnostic performance, and describe diagnostic advances possible with the new Continuous Sync-and-Shoot method. Material and Methods Thirty-six surgical breast specimens were imaged with digital mammography (DM) and a prototype of a DBT system (Planmed Oy, Helsinki, Finland). We tested the patient friendliness of the sync-and-shoot movement without radiation exposure in eight volunteers. Different imaging parameters were tested with 20 specimens to identify the optimal combination: angular range 30 degrees, 40 degrees, and 60 degrees; pixel binning; Rhodium (Rh) and Silver (Ag) filtrations; and different kV and mAs values. Two breast radiologists evaluated 16 DM and DBT image pairs and rated six different image properties. Imaging modalities were compared with paired t-test. Results The Continuous Sync-and-Shoot method produced diagnostically valid images. Five out of eight volunteers felt no/minimal discomfort, three experienced mild discomfort from the tilting movement of the detector, with the motion being barely recognized. The combination of 30 degrees, Ag filtering, and 2 x 2 pixel binning produced the best image quality at an acceptable dose level. DBT was significantly better in all six evaluated properties (P < 0.05). Mean Dose(DBT)/Dose(DM) ratio was 1.22 (SD = 0.42). Conclusion The evaluated imaging method is feasible for imaging and analysing surgical breast specimens and DBT is significantly better than DM in image evaluation

Classification of findings in mammography screening--a method to minimise recall anxiety?

STUDY OBJECTIVE--The aim was to find out if it is possible, by classifying screening mammograms according to the likelihood of malignancy, to divide the recalled women to a group in which there is high suspicion of malignancy, most having breast cancers, and a group with more obscure findings. DESIGN--Screening mammograms of recalled women were classified according to the likelihood of malignancy. 0 = technically insufficient, 1 = normal, 2 = benign tumour, 3 = malignancy cannot be excluded, 4 = strongly suspicious for malignancy, 5 = malignant. SETTING--This study was a population based survey of mammography screening in Helsinki and surroundings in Finland. PATIENTS--21,417 women (aged 50-59 years) were invited to be screened, 18,012 (84.10%) participated. Of these 579 (3.21% of those screened) were recalled for further studies; 124 of these were referred for surgical biopsy and 82 had breast cancer. MEASUREMENTS AND MAIN RESULTS--All cases classified as 5, 60% of the cases classified as 4, 6.5% of the cases classified as 3, 0% of the cases classified as 2 or 1, and 1.2% of the cases classified as 0 proved to have breast cancers. However classification 5 represented 5.9% of all recalled women and 41.5% of all screening detected breast cancers; classification 4, 6.0% of all recalled women and 25.6% of all screening detected breast cancers; classification 3, 68.9% of all recalled women and 31.7% of all screening detected breast cancers; classification 2, 11.7% and classification 1, 2.9% of all recalled women. No breast cancers were detected with these classifications. Classification 0 represented 4.5% of all recalled women and 1.2% of all screening detected breast cancers. Classifications 5 and 4 represented only 11.9% of all recalled women but 67.1% of all screening detected breast cancers. CONCLUSIONS--By classifying screening mammograms according to the likelihood of malignancy, recalled women can be divided into two groups: (1) a quite small subgroup in which everyone or almost everyone will be shown to have breast cancer; and (2) a much larger subgroup in which only a few will be proven to have breast cancer. The invitation procedure for the further studies should be improved on this basis of minimising anxiety among recalled women