Super-Resolution Reconstruction of CT Images Based on Multi-scale Information Fused Generative Adversarial Networks.

The popularization and widespread use of computed tomography (CT) in the field of medicine evocated public attention to the potential radiation exposure endured by patients. Reducing the radiation dose may lead to scattering noise and low resolution, which can adversely affect the radiologists' judgment. Hence, this paper introduces a new network called PANet-UP-ESRGAN (PAUP-ESRGAN), specifically designed to obtain low-dose CT (LDCT) images with high peak signal-to-noise ratio (PSNR) and high resolution (HR). The model was trained on synthetic medical image data based on a Generative Adversarial Network (GAN). A degradation modeling process was introduced to accurately represent realistic degradation complexities. To reconstruct image edge textures, a pyramidal attention model call PANet was added before the middle of the multiple residual dense blocks (MRDB) in the generator to focus on high-frequency image information. The U-Net discriminator with spectral normalization was also designed to improve its efficiency and stabilize the training dynamics. The proposed PAUP-ESRGAN model was evaluated on the abdomen and lung image datasets, which demonstrated a significant improvement in terms of robustness of model and LDCT image detail reconstruction, compared to the latest real-esrgan network. Results showed that the mean PSNR increated by 19.1%, 25.05%, and 21.25%, the mean SSIM increated by 0.4%, 0.4%, and 0.4%, and the mean NRMSE decreated by 0.25%, 0.25%, and 0.35% at 2[Formula: see text], 4[Formula: see text], and 8[Formula: see text] super-resolution scales, respectively. Experimental results demonstrate that our method outperforms the state-of-the-art super-resolution methods on restoring CT images with respect to peak signal-to-noise ratio (PSNR), structural similarity (SSIM) and normalized root-mean-square error (NRMSE) indices.

Two-dimensional biomechanical finite element modeling of the pelvic floor and prolapse.

We developed the pelvic floor model in physiological and pathological states to understand the changes of biomechanical axis and support that may occur from the normal physiological state to the prolapse pathological state of the pelvic floor. Based on the physiological state model of the pelvic floor, we model the uterus to the pathological state position by balancing intra-abdominal pressure (IAP) and uterine pathological position load. Under combined impairments, we compared the patterns of changes in pelvic floor biomechanics that may be induced by different uterine morphological characteristic positions under different IAP. The orientation of the uterine orifice gradually changes from the sacrococcygeal direction to the vertical downward of vaginal orifice, and a large downward prolapse displacement occurs, and the posterior vaginal wall shows "kneeling" profile with posterior wall bulging prolapse. When the abdominal pressure value was 148.1 cmH2O, the descent displacement of the cervix in the normal and pathological pelvic floor system was 11.94, 20, 21.83 and 19.06 mm in the healthy state, and 13.63, 21.67, 22.94 and 19.38 mm in the combined impairment, respectively. The above suggests a maximum cervical descent displacement of the uterus in the anomalous 90° position, with possible cervical-uterine prolapse as well as prolapse of the posterior vaginal wall. The combined forces of the pelvic floor point in the direction of vertical downward prolapse of the vaginal orifice, and the biomechanical support of the bladder and sacrococcygeal bone gradually diminishes, which may exacerbate the soft tissue impairments and biomechanical imbalances of the pelvic floor to occur of POP disease.

A 2D equivalent mechanical model of the whole pelvic floor and impairment simulation.

We developed a complete 2D equivalent mechanical model of the pelvic floor based on magnetic resonance imaging (MRI) images of a 35-year-old healthy woman. This model can simulate anterior vaginal prolapse (AVP) due to soft tissue impairment. Thus, we can study the mechanism of prolapse formation from a mechanical perspective and improve the assessment and treatment of the condition in clinical practice. Based on 2D MRI image parameter measurements and computer-aided design methods, the 2D equivalent mechanical model of the whole pelvic floor in the sagittal plane was accurately reconstructed, which includes all necessary tissues of the pelvic floor system. Material parameters were mainly from the literature. We simulated the impairment by reducing the tissue's mechanical properties, and numerical simulations predicted the mechanical response and morphological changes of the healthy and impaired pelvic floor in different states. In six intra-abdominal pressure (IAP) states (8.4-208.9 cmH2 O), the maximum cervical descent in the impaired pelvic floor was 0.3-18.521 mm, which was much greater than that in the healthy pelvic floor (0.14-6.55 mm). Once the impairment occurred (0%-25%), there was a significant increase in maximum displacement, stress, and cervical descent (30.9-36.5 mm, 0.56-1.12 MPa, 4.6-12.1 mm), and a clinically similar prolapse shape occurred. Simple supine and standing will not cause prolapse. The formation of prolapse is closely related to vaginal tissue impairment. In the standing position, the main forces on the healthy pelvic floor system are distributed horizontally posteriorly and inferiorly, reducing the burden in the vertically downward direction.

The influence of the combined impairments and apical mesh surgery on the biomechanical behavior of the pelvic floor system.

Objective: The prolapse mechanism of multifactorial impairment of the female pelvic floor system and the mechanics of the pelvic floor after apical suspension surgery are not yet understood, so we developed biomechanical models of the pelvic floor for the normal physiological state (0°) and 90° pathological state. Methods: Under different types and levels of the impairments and uterosacral suspensions, the possible changes in the morphometric characteristics and the mechanical characteristics of suspension and support functions were simulated based on the biomechanical models of the pelvic floor. Results: After the combined impairments, the descending displacement of the pelvic floor cervix and the stress and displacement of the perineal body reached maximum values. After surgical mesh implantation, the stresses of the normal pelvic floor were concentrated on the uterine fundus, cervix, and top of the bladder and the stresses of the 90° pathological state pelvic floor were concentrated on the uterine fundus, uterine body, cervix, middle of the posterior vaginal wall, and bottom of the perineal body. Conclusion: After the combined impairments, the biomechanical support of the bladder and sacrococcyx in the anterior (0°) and 90° pathological state pelvic floor system is diminished, the anterior vaginal wall dislodges from the external vaginal opening, and the posterior vaginal wall forms "kneeling" profiles. The pelvic floor system may evolve with a tendency toward the cervical prolapse with anterior and posterior vaginal wall prolapse and eventually prolapse. After surgical mesh implantation, the cervical position can be better restored; however, the load of combined impairment of the pelvic floor is mainly borne by the surgical mesh suspension, the biomechanical support function of pelvic floor organs and sacrococcyx was not repaired by the physiological structure, and the results of uterosacral suspension alone may be poor.

Surgical Effect Observation and Treatment Strategy Analysis of Pseudo Urgency Syndrome.

Background and Objectives: pseudo urgency syndrome among patients with mixed incontinence (MUI) causes and the corresponding treatment strategies is explored. Materials and Methods: A total of 40 patients with MUI are treated with transobturator tape (TOT) and/or solifenacin succinate. Further, 30 patients with simple stress urinary incontinence (SUI) that were treated with transobturator tape (TOT) from the period of December 2018 to August 2020 are retrospectively analyzed; then, their clinical characteristics and therapeutic effects were summarized and analyzed. Results: The effective rates of SUI symptoms in MUI and simple SUI groups were 85% and 90%, respectively; further, the difference was noted as not statistically significant (P > 0.05). Among the 40 patients with MUI, 12 patients had unstable bladder contraction, and the other 28 patients showed normal bladder compliance. The treatment effectiveness rates of SUI symptoms in patients with unstable bladder contraction and normal bladder compliance were 83.3% and 85.7%, respectively; further, no significant difference was noted (P > 0.05). However, the effective rates of urge urinary incontinence (UUI) were 50% and 85.7%, respectively, however the difference was noted as statistically significant (P < 0.05). Conclusions: Most of the UUI symptoms in MUI patients may be "pseudo urgency syndrome" caused by the worry about the leakage of urine, rather than a real sense of UUI that is caused by excessive bladder excitement. Direct surgical treatment in patients with MUI can improve the symptoms of urinary incontinence, and the effect is more obvious in patients with urinary frequency who have normal bladder compliance according to urodynamics.