Comparison of the Radiation Dose from Cone Beam Computed Tomography and Multidetector Computed Tomography in Examinations of the Hand.

PURPOSE: Comparison of radiation dose of cone beam computed tomography (CBCT) and multidetector computed tomography (MDCT) in examinations of the hand. MATERIALS AND METHODS: Dose calculations were carried out by means of Monte Carlo simulations in MDCT and CBCT. A corpse hand was examined in a 320-row MDCT scanner and a dedicated extremities CBCT scanner with standard protocols and multiple low-dose protocols. The image quality of the examinations was evaluated by 5 investigators using a Likert scale from 1 (very good) to 5 (very poor) regarding depiction of cortical bone, cancellous bone, joint surfaces, soft tissues and artifacts. For a sum of ratings of all structures < 50 a good overall image quality was expected. The studies with at least good overall image quality were compared with respect to the dose. RESULTS: The dose of the standard examination was 13.21 (12.96 to 13.46 CI) mGy in MDCT and 7.15 (6.99 to 7.30 CI) mGy in CBCT. The lowest dose in a study with good overall image quality was 4.54 (4.43 to 4.64 CI) mGy in MDCT and 5.72 (5.59 to 5.85 CI) mGy in CBCT. CONCLUSION: Although the dose of the standard protocols in the CBCT is lower than in the MDCT, the MDCT can realize a good overall image quality at a lower dose than the CBCT. Dose optimization of CT examination protocols for the hand is useful in both modalities, the MDCT has an even greater potential for optimization. KEY POINTS: • Low dose examinations of the hand are feasible in CBCT and MDCT.• In default settings CBCT has a lower dose than MDCT.• MDCT enables a good image quality at a lower dose than CBCT. Citation Format: • Neubauer J, Neubauer C, Gerstmair A et al. Comparison of the Radiation Dose from Cone Beam Computed Tomography and Multidetector Computed Tomography in Examinations of the Hand. Fortschr Röntgenstr 2016; 188: 488 - 493.

[Why radiologists should be concerned with semantics]. / Warum Radiologen sich mit Semantik befassen sollten.

Radiological image and data archives contain huge amounts of data which are barely utilized by current technologies. In the future semantic technologies currently under development will enable analysis of the contents not only on the level of individual patients but also along entire data collections thereby resulting in new applications that will benefit routine clinical practice, teaching activities and research. As a prerequisite the development of software for semantic analysis of image and report contents is necessary, i.e. an "understanding" of the contents by the software. Based on specific ontologies, standardized protocols and semantic image annotation new systems will be developed that make the content of these data archives accessible and support diagnosis, quality assurance, innovative research applications and last not least, the merging of data of different medical disciplines, such as radiology, pathology and clinical chemistry.