title: Application of MOSFET detectors for dosimetry in small animal radiography using short exposure times.
abstract: Digital subtraction angiography (DSA) X-ray imaging for small animals can be used for functional phenotyping given its ability to capture rapid physiological changes at high spatial and temporal resolution. The higher temporal and spatial requirements for small-animal imaging drive the need for short, high-flux X-ray pulses. However, high doses of ionizing radiation can affect the physiology. The purpose of this study was to verify and apply metal oxide semiconductor field effect transistor (MOSFET) technology to dosimetry for small-animal diagnostic imaging. A tungsten anode X-ray source was used to expose a tissue-equivalent mouse phantom. Dose measurements were made on the phantom surface and interior. The MOSFETs were verified with thermoluminescence dosimeters (TLDs). Bland-Altman analysis showed that the MOSFET results agreed with the TLD results (bias, 0.0625). Using typical small animal DSA scan parameters, the dose ranged from 0.7 to 2.2 cGy. Application of the MOSFETs in the small animal environment provided two main benefits: (1) the availability of results in near real-time instead of the hours needed for TLD processes and (2) the ability to support multiple exposures with different X-ray techniques (various of kVp, mA and ms) using the same MOSFET. This MOSFET technology has proven to be a fast, reliable small animal dosimetry method for DSA imaging and is a good system for dose monitoring for serial and gene expression studies.
authors.affiliation: Center for In Vivo Microscopy, Department of Biomedical Engineering, Duke University, Durham, NC 27710, USA.
authors.forename: Ming
authors.initials: M
authors.lastname: De Lin
authors.forename: Greta
authors.initials: G
authors.lastname: Toncheva
authors.forename: Giao
authors.initials: G
authors.lastname: Nguyen
authors.forename: Sangroh
authors.initials: S
authors.lastname: Kim
authors.forename: Colin
authors.initials: C
authors.lastname: Anderson-Evans
authors.forename: G Allan
authors.initials: GA
authors.lastname: Johnson
authors.forename: Terry T
authors.initials: TT
authors.lastname: Yoshizumi
mesh_terms: D004867:Equipment Design; D019544:Equipment Failure Analysis; D011829:Radiation Dosage; D011856:Radiographic Image Enhancement / Q000295:instrumentation* / Q000379:methods; D011874:Radiometry / Q000295:instrumentation* / Q000379:methods; D012680:Sensitivity and Specificity; D014159:Transducers; D014173:Transistors, Electronic