Handheld dermatoscope versus digital camera for hair counts in laser facial hair removal.

The lack of uniform and objective techniques to evaluate treatment efficacy in photo-epilation studies leads to contradictory results. Thus, there is an urgent need to explore commonly accepted assessment tools. One of the most common methods uses hair counts via digital photography. However, macrophotography may not be able to depict the vellus-like hair induced by photo-epilation. On the other hand, handheld dermatoscopy is practical, affordable and offers high-quality magnification. Hair counts from a handheld dermatoscope and a digital camera were compared in 73 women who underwent 6 sessions with the Alexandrite 755 nm laser. Significantly more hairs were counted using the dermatoscope than using the digital camera (76.9 ± 41.3 vs. 58.6 ± 31.4, p < .005), independently of hair thickness and hair density. The difference in hair counts between the two instruments was inversely related to hair thickness and directly related to hair density. The handheld dermatoscope may be a more effective tool than the widely used digital camera in evaluating the response to laser hair removal treatment.

On the Response of a Micro Non-Destructive Testing X-ray Detector.

Certain imaging performance metrics are examined for a state-of-the-art 20 µm pixel pitch CMOS sensor (RadEye HR), coupled to a Gd2O2S:Tb scintillator screen. The signal transfer property (STP), the modulation transfer function (MTF), the normalized noise power spectrum (NNPS) and the detective quantum efficiency (DQE) were estimated according to the IEC 62220-1-1:2015 standard. The detector exhibits excellent linearity (coefficient of determination of the STP linear regression fit, R2 was 0.9978), while its DQE peaks at 33% and reaches 10% at a spatial frequency of 3 cycles/mm, for the measured with a Piranha RTI dosimeter (coefficient of variation CV = 0.03%) exposure value of 28.1 µGy DAK (detector Air Kerma). The resolution capabilities of the X-ray detector under investigation were compared to other commercial CMOS sensors, and were found in every case higher, except from the previous RadEye HR model (CMOS-Gd2O2S:Tb screen pair with 22.5 µm pixel pitch) version which had slightly better MTF. The present digital imager is designed for industrial inspection applications, nonetheless its applicability to medical imaging, as well as dual-energy is considered and certain approaches are discussed in this respect.

Improvement of image quality using BLADE sequences in brain MR imaging.

The purpose of this study is to compare two types of sequences in brain magnetic resonance (MR) examinations of uncooperative and cooperative patients. For each group of patients, the pairs of sequences that were compared were two T2-weighted (T2-W) fluid attenuated inversion recovery sequences with different k-space trajectories (conventional Cartesian and BLADE) and two T2-TSE weighted with different k-space trajectories (conventional Cartesian and BLADE). Twenty-three consecutive uncooperative patients and 44 cooperative patients, who routinely underwent brain MR imaging examination, participated in the study. Both qualitative and quantitative analyses were performed based on the signal-to-noise ratio, contrast-to-noise ratio (CNR), and relative contrast (ReCon) measures of normal anatomic structures. The qualitative analysis was performed by experienced radiologists. Also, the presence of motion, other (e.g., Gibbs, susceptibility artifacts, phase encoding from vessels) artifacts and pulsatile flow artifacts was evaluated. In the uncooperative group of patients, BLADE sequences were superior to the corresponding conventional sequences in all the cases. Furthermore, the differences were found to be statistically significant in almost all the cases. In the cooperative group of patients, BLADE sequences were superior to the conventional sequences with the differences of the CNR and ReCon values in nine cases being statistically significant. Furthermore, BLADE sequences eliminated motion and other artifacts and T2 FLAIR BLADE sequences eliminated pulsatile flow artifacts. BLADE sequences (T2-TSE and T2 FLAIR) should be used in brain MR examinations of uncooperative patients. In cooperative patients, T2-TSE BLADE sequences may be used as part of the routine protocol and orbital examinations. T2 FLAIR BLADE sequences may be used optionally in examinations of AVM, orbits, haemorrhages, ventricular lesions, lesions in the frontal lobe, periventricular lesions, lesions in regions close to artifacts and lesions in posterior fossa.