A cadaveric breast cancer tissue phantom for phase-contrast X-ray imaging applications

Background:As mammography X-ray imaging technologies advance and provide elevated contrast in soft tissues,a need has developed for reliable imaging phantoms for use in system design and component calibration.In advanced imaging modalities such as refraction-based methods,it is critical that developed phantoms capture the biological details seen in clinical precancerous and cancerous cases while minimizing artifacts that may be caused due to phantom production.This work presents the fabrication of a breast tissue imaging phantom from cadaveric breast tissue suitable for use in both transmission and refraction-enhanced imaging systems.Methods:Human cancer cell tumors were grown orthotopically in nude athymic mice and implanted into the fixed tissue while maintaining the native tumor/adipose tissue interface.Results:The resulting human–murine tissue hybrid phantom was mounted on a clear acrylic housing for absorption and refraction X-ray imaging.Digital breast tomosynthesis was also performed.Conclusion:Both attenuation-based imaging and refraction-based imaging of the phantom are presented to confirm the suitability of this phantom's use in both imaging modalities.

A novel and inexpensive ballistic gel phantom for ultrasound training

BACKGROUND: Ultrasonography use is increasing in emergency departments, and ultrasound education is now recommended in resident training. Ultrasound phantoms are used in many institutions for training purposes. The purpose of this study is to describe an inexpensive and simple method to create ultrasound-imaging models for the purpose of education and practice using clear ballistic gel.METHODS: Clear ballistic gel is used to simulate tissue for firing practice and other military evaluations.RESULTS: The transparent and durable ultrasound phantom we produced was clear and contained four vessel lumens. The images obtained using the phantom were of high quality and compared well to normal sonographic anatomy.CONCLUSIONS: The clear ballistic brand gel is unique because it is inexpensive, does not dry out, does not decay, is odorless, and is reusable. The ultrasound images obtained using the phantom are realistic and useful for ultrasound education.

Differentiation of white and red thrombus with magnetic resonance imaging： a phantom study

Background An early identification of the composition of arterial thrombus may have diagnostic, therapeutic, and prognostic implications. The variation of magnetic resonance （MR） signal intensity between white and red thrombi, especially in the susceptibility sensitive MR sequence, remains unknown. Our research was to evaluate the feasibility of MRI in differentiating of white and red thrombi with a phantom study. Methods A total of 12 red and 12 white thrombi were prepared with the venous blood. Examination of the phantom was completed using a 3.0T MR unit, including fluid attenuated inversion recovery （FLAIR） T1, T2-weighted imaging （T2WI）, FLAIR T2, T2＊ gradient echo （T2＊GRE） imaging, and susceptibility weighted angiography sequences （SWAN）. MR signal intensity patterns of the thrombi were objectively classified as hyperintensity, isointensity and hypointensity, compared with the background agar. The volume of thrombus was calculated and correlated with its signal intensity. Results For white thrombi, 11/12 clots showed hyperintensity and 1/12 showed isointensity in FLAIR T1 images. In T2WI, 6/12 clots showed hyperintensity, 3/12 isointensity, and 3/12 hypointensity. In FLAIR T2, 8/12 clots showed hyperintensity and 4/12 showed isointensity. In T2＊GRE, 3/12 clots showed hyperintensity and the remaining 9/12 clots showed isointensity. In SWAN, 5/12 clots demonstrated hyperintensity and 7/12 isointensity. For the red thrombus, 12/12 clots demonstrated hyperintensity in FLAIR T1, T2WI, and FLAIR T2 sequences. In T2＊GRE and SWAN sequences, 3/12 clots displayed hypointensity and the remaining 9/12 clots showed slight hyperintensity. Thrombi with hypointensity displayed in T2＊GRE and SWAN sequences were significantly larger than those with hyperintensity. Conclusions Differentiation of white and red thrombi with conventional MR sequence is unreliable, because both kinds of thrombi do not possess unique signal intensity features in these sequences. Red thrombus may or may not show hypointensity in the susceptibility sensitive MR sequences, depending on its size and time course.