MicroDose

MicroDose is a trademark owned by Philips. It refers to a line of mammography equipment advertising a very low radiation dose. This equipment is based on a photon-counting detector for capturing the x-ray image.

History

The MicroDose brand was originally created by Sectra Mamea AB, a subsidiary of Sectra AB formed from the purchase of Mamea Imaging AB in 2004.^[1] In 2011 the Sectra mammography division was sold off to Philips.^[2]

List of MicroDose products

• Sectra MicroDose D20
• Sectra MicroDose D40
• Sectra MicroDose L30 - Introduced a more compact and efficient detector system^[3]
• Philips MicroDose SI (L50) - Introduced an energy-resolved detector for spectral imaging (SI)^[4]

Photon-counting detector

A photon-counting detector utilizes the discrete nature of X-rays, as it counts individual photons when they are captured in a detector medium. This is in contrast to “pseudo-digital” detectors that integrates photon energy over time, thus in practice measuring an analog signal that in turn is digitized. While the conversion steps from analog to digital signal in a traditional detector introduces thermal noise, quantization errors and loss of information during signal processing, a truly digital detector suffers from none of these weaknesses. A photon-counting detector is capable of capturing close to all information in the signal. This way it is possible to lower the radiation dose to a minimum while preserving or even improving image quality.

Uses

There are today very few commercially available MicroDose modalities. The brand consists of mammography systems, mainly targeted for intense breast screening programs where the significance of low dose is high as large parts of a population are targeted. Breast examinations is one of the most demanding with respect to image quality, early detection of cancerous changes includes finding micro-calcifications in the breast tissue. These tiny structures can be perceived by a trained eye, but only as far as the image quality allows.

See also

• Mammography
• Medical Imaging
• X-ray
• Semiconductor detector
• Scintillation counter

References

• M. Lundqvist, B. Cederström,V. Chmill, M. Danielsson and B. Hasegawa, “Evaluation of a photon-counting x-ray imaging system”, IEEE Transactions on Nuclear Science, Vol 48 (4), pp. 1524–1529, 2001
• M. Danielsson, H. Bornefalk, B. Cederström, V. Chmill, B. Hasegawa, M. Lundqvist, D. Nygren and T. Tabár, “Dose-efficient system for digital mammography”, Proc. SPIE, Physics of Medical Imaging, vol. 3977, pp. 239–249 San Diego, 2000
• M. Lundqvist, M. Danielsson, B. Cederström, V. Chmill, A. Chuntonov, and M. Åslund, “Measurements on a full-field digital mammography system with a photon counting crystalline silicon detector”, Proc. SPIE, Physics of Medical Imaging, vol. 5030, pp. 547–552, San Diego, 2003
• B. Hemdal, L. Herrnsdorf, I. Andersson, G. Bengtsson, B. Heddson, M. Olsson, “Average glandular dose in routine mammography screening using a Sectra MicroDose Mammography unit”, PMID 15933152, PubMed, 2005