Changes in choroidal imaging parameters following adalimumab therapy for refractory noninfectious uveitis.

PURPOSE: To evaluate the short-term change in choroidal structure following adalimumab (ADA) treatment in refractory noninfectious uveitis. METHODS: This was a retrospective study of 33 eyes from 18 patients with refractory noninfectious uveitis. Subfoveal choroidal thickness (SFCT), the choroidal stromal index (CSI) defined as the proportion of stromal area to the total choroidal area were used as choroidal imaging parameters and were evaluated by enhanced depth imaging optical coherence tomography (EDI-OCT). The change in these parameters in the 2 months following initiation of ADA was analysed. A linear mixed-effect model was used to assess the effect of ADA treatment. RESULTS: The causes of uveitis were Vogt-Koyanagi-Harada disease (VKHD) (42.4%), presumed autoimmune retinopathy (15.2%), others (12.1%) and unclassified (30.3%). In the analysis of all eyes, the SFCT was 309.7 ± 113.1 µm at baseline, 295.7 ± 114.5 µm at 1 month and 275.2 ± 98.8 µm at 2 months after ADA initiation (P < 0.001). The CSI was 0.275 ± 0.050 at baseline, 0.273 ± 0.068 at 1 month and 0.273 ± 0.046 at 2 months (P = 0.785). In the subgroup analysis, the SFCT decreased significantly from baseline to 2 months in VKHD eyes (P = 0.007) and unclassified eyes (P = 0.034). There was no significant change in CSI in either subgroup. CONCLUSIONS: In the assessment of short-term response to ADA treatment in uveitic eyes, using EDI-OCT, the SFCT appears to be more effective as a choroidal imaging biomarker than the CSI, especially in VKHD eyes.

Performance of mobile digital X-ray fluoroscopy using a novel flat panel detector for intraoperative use.

BACKGROUND: Technologies employing digital X-ray devices are developed for mobile settings. OBJECTIVE: To develop a mobile digital X-ray fluoroscopy (MDF) for intraoperative guidance, using a novel flat panel detector to focus on diagnostics in outpatient clinics, operating and emergency rooms. METHODS: An MDF for small-scale field diagnostics was configured using an X-ray source and a novel flat panel detector. The imager enabled frame rates reaching 30 fps in full resolution fluoroscopy with maximal running time of 5 minutes. Signal-to-noise (SNR), contrast-to-noise (CNR), and spatial resolution were analyzed. Stray radiation, exposure radiation dose, and effective absorption dose were measured for patients. RESULTS: The system was suitable for small-scale field diagnostics. SNR and CNR were 62.4 and 72.0. Performance at 10% of MTF was 9.6 lp/mm (53 µ m) in the no binned mode. Stray radiation at 100 cm and 150 cm from the source was below 0.2 µ Gy and 0.1 µ Gy. Exposure radiation in radiography and fluoroscopy (5 min) was 10.2 µ Gy and 82.6 mGy. The effective doses during 5-min-long fluoroscopy were 0.26 mSv (wrist), 0.28 mSv (elbow), 0.29 mSv (ankle), and 0.31 mSv (knee). CONCLUSIONS: The proposed MDF is suitable for imaging in operating rooms.

Dedicated mobile volumetric cone-beam computed tomography for human brain imaging: A phantom study.

BACKGROUND: Mobile computed tomography (CT) with a cone-beam source is increasingly used in the clinical field. Mobile cone-beam CT (CBCT) has great merits; however, its clinical utility for brain imaging has been limited due to problems including scan time and image quality. OBJECTIVE: The aim of this study was to develop a dedicated mobile volumetric CBCT for obtaining brain images, and to optimize the imaging protocol using a brain phantom. METHODS: The mobile volumetric CBCT system was evaluated with regards to scan time and image quality, measured as signal-to-noise-ratio (SNR), contrast-to-noise-ratio (CNR), spatial resolution (10% MTF), and effective dose. Brain images were obtained using a CT phantom. RESULTS: The CT scan took 5.14 s at 360 projection views. SNR and CNR were 5.67 and 14.5 at 120 kV/10 mA. SNR and CNR values showed slight improvement as the x-ray voltage and current increased (p < 0.001). Effective dose and 10% MTF were 0.92 mSv and 360 µ m at 120 kV/10 mA. Various intracranial structures were clearly visible in the brain phantom images. CONCLUSIONS: Using this CBCT under optimal imaging acquisition conditions, it is possible to obtain human brain images with low radiation dose, reproducible image quality, and fast scan time.

Development of a mini-mobile digital radiography system by using wireless smart devices.

The current technologies that trend in digital radiology (DR) are toward systems using portable smart mobile as patient-centered care. We aimed to develop a mini-mobile DR system by using smart devices for wireless connection into medical information systems. We developed a mini-mobile DR system consisting of an X-ray source and a Complementary Metal-Oxide Semiconductor (CMOS) sensor based on a flat panel detector for small-field diagnostics in patients. It is used instead of the systems that are difficult to perform with a fixed traditional device. We also designed a method for embedded systems in the development of portable DR systems. The external interface used the fast and stable IEEE 802.11n wireless protocol, and we adapted the device for connections with Picture Archiving and Communication System (PACS) and smart devices. The smart device could display images on an external monitor other than the monitor in the DR system. The communication modules, main control board, and external interface supporting smart devices were implemented. Further, a smart viewer based on the external interface was developed to display image files on various smart devices. In addition, the advantage of operators is to reduce radiation dose when using remote smart devices. It is integrated with smart devices that can provide X-ray imaging services anywhere. With this technology, it can permit image observation on a smart device from a remote location by connecting to the external interface. We evaluated the response time of the mini-mobile DR system to compare to mobile PACS. The experimental results show that our system outperforms conventional mobile PACS in this regard.

Compact soft x-ray transmission microscopy with sub-50 nm spatial resolution.

In this paper, the development of compact transmission soft x-ray microscopy (XM) with sub-50 nm spatial resolution for biomedical applications is described. The compact transmission soft x-ray microscope operates at lambda = 2.88 nm (430 eV) and is based on a tabletop regenerative x-ray source in combination with a tandem ellipsoidal condenser mirror for sample illumination, an objective micro zone plate and a thinned back-illuminated charge coupled device to record an x-ray image. The new, compact x-ray microscope system requires the fabrication of proper x-ray optical devices in order to obtain high-quality images. For an application-oriented microscope, the alignment procedure is fully automated via computer control through a graphic user interface. In imaging studies using our compact XM system, a gold mesh image was obtained with 45 nm resolution at x580 magnification and 1 min exposure. Images of a biological sample (Coscinodiscus oculoides) were recorded.