In cone beam breast computed tomography (CT), scattered radiation leads to nonuniform biasing of CT numbers known as a cupping artifact. Besides being visual distractions, cupping artifacts appear as background nonuniformities, which impair efficient gray scale windowing and pose a problem in threshold based volume visualization/segmentation. To overcome this problem, we have developed a background nonuniformity correction method specifically designed for cone beam breast CT. With this technique, the cupping artifact is modeled as an additive background signal profile in the reconstructed breast images. Due to the largely circularly symmetric shape of a typical breast, the additive background signal profile was also assumed to be circularly symmetric. The radial variation of the background signals was estimated by measuring the spatial variation of adipose tissue signals in front view breast images. To extract adipose tissue signals in an automated manner, a signal sampling scheme in polar coordinates and a background trend fitting algorithm were implemented. The background fits compared with targeted adipose tissue signal value (constant throughout the breast volume) to get an additive correction value for each tissue voxel. To test the accuracy, we applied the technique to cone beam CT images of mastectomy specimens. After correction, the images demonstrated significantly improved signal uniformity in both front and side view slices. The reduction of both intraslice and interslice variations in adipose tissue CT numbers supported our observations.

Accurate and fast projector/back‐projector (PBP) is the key to successful simulation and iterative reconstruction of tomosynthesis and cone beam CT. In this study, the accuracy and computation speed of a ray‐driven PBP operator were investigated. To simulate x‐ray tomography imaging, a ray‐driven projector was developed and implemented on a 64 computing node PC Cluster. Each x‐ray path is represented by sampling points in the object. Their μ values are summed up to compute the integral attenuation along the path. To evaluate the accuracy of the reprojection algorithm as the function of sampling ratio (Sampling length / voxel length), reprojections obtained with a significantly smaller sampling ratio were used as reference. To minimize the additional loss of accuracy from pixelization, the pixel size of the projection images was selected to be one third of the voxel size projected back to the image plane. Error images were formed by subtracting the re‐projection from the reference re‐projection and used to compute the percentage errors. SART were implemented for image reconstruction in tomosynthesis and CBCT imaging. To evaluate its accuracy, CBCT images reconstructed with 300 projection views over 360 degree were compared to the original CBCT images. Errors were computed from the subtraction images and plotted together the computing time as the function of the sampling ratio. With reduced sampling ratio, the accuracies of both the re‐projection and SART algorithms were improved at the expense of longer computing time. The improvement was accelerated with smaller sampling ratios. Aliasing artifacts were visible when the sampling ratios were greater than 0.5. We have demonstrated that the accuracy of the re‐projection and SART reconstructions improved with reduced the sampling ratio at the expense of longer computing time for a ray‐driven PBP. The tradeoff between accuracy and computing time should be determined by the imaging requirement.

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Background Diabetic mastopathy is a rare breast condition that occurs in women with poorly controlled diabetes and is characterized by hardening of the breast tissue. The purpose of this case report is to provide an overview of the clinical characteristics and therapeutic principles of this rare disease to support front-line physicians in their crucial activity of case identification. Case presentation A 64-year-old Asian female patient with a history of type II diabetes mellitus was referred to our clinic for an evaluation of a newly discovered breast mass. The patient had been diagnosed with diabetes more than 20 years prior and was being managed with oral hypoglycemic agents. Her past medical history was otherwise unremarkable. Physical examination of the breast revealed a palpable, mobile, and firm mass measuring 6 × 4 cm in the upper quadrant of the right breast. Ultrasound images showed an uneven hypoechoic nodule, BI-RADS 4B. Mammography showed the compact and flaky nature of the two breasts and the heterogeneity of the substantive density increases. The patient’s clinical manifestations and imaging findings suggest the possibility of breast cancer. The patient opted for surgical excision of the mass. Through surgery, the mass was completely excised with negative margins. Pathological examination of the mass revealed a proliferation of fibroblastic cells, with an increased nuclear/cytoplasmic ratio, consistent with a diagnosis of diabetic mastopathy. Conclusions This case report serves to highlight the importance of recognizing diabetic mastopathy as a possible differential diagnosis of a breast mass in patients with diabetes mellitus. In our patient, early diagnosis and treatment with lumpectomy resulted in a favorable outcome, emphasizing the importance of prompt medical and surgical management. In addition, more research is needed to mine the diagnostic marker of diabetic mastopathy and provide data related to its prognosis.

Purpose: To compare the visibility of micro‐calcifications in cone‐beam breast CT with that in conventional CT. Material and method: Calcium Carbonate grains (ranging from 180–200 to 250–280 microns) were used to simulate calcifications. Two bowl shaped plastic containers filled with paraffin were used to simulate a breast. The phantom was scanned with a bench‐top experimental CBCT system, configured for breast imaging. The system consists of a conventional tungsten target x‐ray tube (G‐1592) and an a‐Si:H/CsI flat panel detector (Paxscan 4030CB). The source to image and source to iso‐center distances are 100 and 75 cm, corresponding to a magnification factor of 1.33 at the iso‐center. A conventional CT system (GE Discovery STE PET/CT Scanner) was used to scan one phantom by itself and with two phantoms on an anthropomorphic chest phantom. Result: The visibility of the calcifications in CBCT images was found to be significantly better than that in the conventional CT images. Calcifications as small as 180–200μm were visible in the CBCT images. While calcifications of 212–224μm were visible in the conventional CT images when only breast phantom was scanned. None of the calcifications studied (280 μm or smaller) were visible when the two breast phantoms were placed on the anthropomorphic chest phantom for scan. Conclusion: Our results indicated that CBCT is capable of imaging calcifications as small as 180 μm. This is due to the intrinsic high spatial resolution of the detector used and the pendant geometry used which allowed the breast to be scanned and imaged by itself. The conventional CT is intrinsically lower in spatial resolution. An important disadvantage is the inclusion of the entire chest in the scan which results in degraded spatial resolution as well as overall higher radiation dose to the patient.