Unpaired low-dose computed tomography image denoising using a progressive cyclical convolutional neural network.

BACKGROUND: Reducing the radiation dose from computed tomography (CT) can significantly reduce the radiation risk to patients. However, low-dose CT (LDCT) suffers from severe and complex noise interference that affects subsequent diagnosis and analysis. Recently, deep learning-based methods have shown superior performance in LDCT image-denoising tasks. However, most methods require many normal-dose and low-dose CT image pairs, which are difficult to obtain in clinical applications. Unsupervised methods, on the other hand, are more general. PURPOSE: Deep learning methods based on GAN networks have been widely used for unsupervised LDCT denoising, but the additional memory requirements of the model also hinder its further clinical application. To this end, we propose a simpler multi-stage denoising framework trained using unpaired data, the progressive cyclical convolutional neural network (PCCNN), which can remove the noise from CT images in latent space. METHODS: Our proposed PCCNN introduces a noise transfer model that transfers noise from LDCT to normal-dose CT (NDCT), denoised CT images generated from unpaired CT images, and noisy CT images. The denoising framework also contains a progressive module that effectively removes noise through multi-stage wavelet transforms without sacrificing high-frequency components such as edges and details. RESULTS: Compared with seven LDCT denoising algorithms, we perform a quantitative and qualitative evaluation of the experimental results and perform ablation experiments on each network module and loss function. On the AAPM dataset, compared with the contrasted unsupervised methods, our denoising framework has excellent denoising performance increasing the peak signal-to-noise ratio (PSNR) from 29.622 to 30.671, and the structural similarity index (SSIM) was increased from 0.8544 to 0.9199. The PCCNN denoising results were relatively optimal and statistically significant. In the qualitative result comparison, PCCNN without introducing additional blurring and artifacts, the resulting image has higher resolution and complete detail preservation, and the overall structural texture of the image is closer to NDCT. In visual assessments, PCCNN achieves a relatively balanced result in noise suppression, contrast retention, and lesion discrimination. CONCLUSIONS: Extensive experimental validation shows that our scheme achieves reconstruction results comparable to supervised learning methods and has performed well in image quality and medical diagnostic acceptability.

A cascade-based dual-domain data correction network for sparse view CT image reconstruction.

Computed tomography (CT) provides non-invasive anatomical structures of the human body and is also widely used for clinical diagnosis, but excessive ionizing radiation in X-rays can cause harm to the human body. Therefore, the researchers obtained sparse sinograms reconstructed sparse view CT images (SVCT) by reducing the amount of X-ray projection, thereby reducing the radiological effects caused by radiation. This paper proposes a cascade-based dual-domain data correction network (CDDCN), which can effectively combine the complementary information contained in the sinogram domain and the image domain to reconstruct high-quality CT images from sparse view sinograms. Specifically, several encoder-decoder subnets are cascaded in the sinogram domain to reconstruct artifact-free and noise-free CT images. In the encoder-decoder subnets, spatial-channel domain learning is designed to achieve efficient feature fusion through a group merging structure, providing continuous and elaborate pixel-level features and improving feature extraction efficiency. At the same time, to ensure that the original sinogram data collected can be retained, a sinogram data consistency layer is proposed to ensure the fidelity of the sinogram data. To further maintain the consistency between the reconstructed image and the reference image, a multi-level composite loss function is designed for regularization to compensate for excessive smoothing and distortion of the image caused by pixel loss and preserve image details and texture. Quantitative and qualitative analysis shows that CDDCN achieves competitive results in artifact removal, edge preservation, detail restoration, and visual improvement for sparsely sampled data under different views.

Impact of Imatinib on the Fertility of Male Patients with Chronic Myelogenous Leukaemia in the Chronic Phase.

BACKGROUND: Imatinib is a first-line tyrosine kinase inhibitor for treating chronic myelogenous leukaemia (CML) and has greatly improved the prognosis of this disease. An increasing number of CML patients of reproductive age are diagnosed each year, and the impact of imatinib on fertility is a major concern. Providing useful advice to these patients regarding the choice of their therapeutic treatment is very important. OBJECTIVE: This study examined the impact of imatinib on the fertility of male patients with CML in the chronic phase. PATIENTS AND METHODS: We performed a study of 48 adult male CML patients in the chronic phase (CML-CP), 50 healthy control subjects, and 10 male patients with infertility. Imatinib levels in semen and plasma were measured using high-performance liquid chromatography/mass spectrometry. We examined the effects of imatinib on sperm parameters and the male reproductive system using a computer-assisted sperm assay and ultrasound, respectively. We analysed sex hormone levels in the sera of CML-CP patients using an enzyme-linked immunosorbent assay. RESULTS: Imatinib levels in semen were comparable to plasma levels in CML-CP patients. CML-CP patients treated with imatinib exhibited reduced sperm density, counts, survival rates, and activity. Ultrasound demonstrated that the shape and size of the testis and epididymis in CML-CP patients undergoing imatinib treatment were normal. However, 19 of these patients exhibited a hydrocele in their tunica vaginalis, with a large dark area of effusion (0.7-2.9 cm in width). Sex hormone levels in the sera of the CML-CP patients were normal. CONCLUSIONS: These results suggest that imatinib crosses the blood-testis barrier and reduces sperm density, sperm count, survival rates, and activity in CML-CP patients. However, imatinib did not affect the structure of reproductive organs or sex hormone levels.

[Study on composing prescription laws of treating aplastic anemia by Chinese medicine using applying data mining technique].

OBJECTIVE: To explore composing prescription laws of treating aplastic anemia (AA) by Chinese medicine (CM). METHODS: The literatures on treating AA by CM were recruited from various medical periodicals at home from 1979 to 2009 including China National Knowledge Infrastructure (CNKI), VIP information network, and Wangfang data knowledge service platform. The database correlated to CM features was established using the technique of computer data bank. The data mining (DM) technique was applied to analyze drugs sorts, frequency of drug application, and association degree. RESULTS: Three hundred and eleven pertinent literatures including 677 prescriptions and 254 Chinese herbs (CHs) were screened. There were 69 CHs for invigorating deficiency, 42 for heat clearing, 20 for promoting blood circulation and removing blood stasis, 16 for arresting bleeding, and 16 for relieving exterior syndrome, which occupied the top 5. The frequency of drug application of 254 CHs amounted to 7 547, in which the frequency of drug application of Mongolian milkvetch root, Rehmannia root, Suberect spatholobus stem, Hairyvein agrimonia herb, and Chinese thorowax root were 379, 248, 167, 85, and 13 respectively, and they occupied the first place of CHs for invigorating deficiency, heat clearing, promoting blood circulation and removing blood stasis, arresting bleeding, and relieving exterior syndrome, respectively. The number of the prescriptions containing 12, 10, and 11 CHs was occupied the top 3. The coverage rate of the prescription including Mongolian milkvetch root and Chinese angelica was 60%, and thus 4 core drugs groups were established covering invigorating qi and enriching the blood, reinforcing Shen and supporting yang, replenishing yin to tonify Shen, tonifying Shen to replenish essence, and invigorating qi and enriching blood respectively. Summarized were six potential composing prescription laws covering invigorating qi and enriching blood, reinforcing Shen and supporting yang, replenishing yin to tonify Shen, strengthening Pi and harmonizing Wei, tonifying the blood and promoting blood circulation, clearing away heat and toxic materials, and removing heat from the blood to stop bleeding. CONCLUSIONS: Applying DM technique, the fundamental core drugs groups consisting of Mongolian milkvetch root and Chinese angelica were discovered. The 4 core drugs groups established were in accordance with the realization of modern CM for the pathomechanism of AA. The 6 composing prescription laws summarized revealed the rules of drug application.

[Photochemotherapy with psoralen and ultraviolet A induced apoptosis of NB4 cells and its effects on caspase-8 and caspase-8 protein expressions].

OBJECTIVE: To study the regulatory effects of psoralen (PSO) plus ultraviolet A (UVA), which is PUVA, on cell apoptosis of human leukemia cell line NB4 and signal pathway of cell apoptosis. METHODS: Human leukemia cell line NB4 was cultured in vitro. The NB4 cells were treated with PSO extracted from Chinese medicine psoralea fruits at different concentrations (0, 5, 10, 20 and 40 microL) plus UVA of wave length 360 nm at different irradiation time points (0 and 5 min). The apoptosis ratio was detected by flow cytometry (FCM). The ultrastructure changes were observed using transmission electron microscope (TEM). The expressions of Caspase-8 and Caspase-8 protein were detected by immunocytochemical method (ICC). RESULTS: After treatment of PSO at different concentrations with a 0 and 5-min exposure of UVA, the apoptosis rate of NB4 cells increased dose-and time-dependently, and was up to peak after treatment of PSO at 40 microg/mL with 5-min exposure of UVA. An interaction was shown between the two factors (P <0. 01). There were obvious morphological apoptosis of NB4 cells under TEM after treated with PUVA. The expressions of Caspase-3 and Caspase-8 protein were up-regulated by PSO, UVA, and PUVA, but the effects of PUVA on Caspase-3 protein were stronger than PSO and UVA at 12 h time-dependently (P <0.01).An interaction was shown between the concentration of PSO and time of UVA (P <0.01). CONCLUSIONS: The optimal combination of PUVA was PSO in 40 microg/mL and 5-min exposure of UVA. PUVA could induce the apoptosis of NB4 cells and in vitro activate Caspase-3 and Caspase-8 genes.

A novel computer-assisted drill guide template for thoracic pedicle screw placement: a cadaveric study.

INTRODUCTION: The objective of this study was to develop a novel, patient-specific, navigational template for thoracic pedicle screw placement. METHODS: Twenty thoracic cadaver specimens were randomly divided into two groups of 10: the navigational template group and the free-hand group. A volumetric CT scan was performed on each thoracic vertebra, and a three-dimensional reconstruction model was generated. A drill template was designed with a surface that was the inverse of the posterior vertebral surface. Each drill template and its corresponding vertebra were manufactured using a rapid prototyping technique and tested for violation. Two hundred and forty screws were implanted into the thoracic spines and the positions of the screws were evaluated. RESULTS: Two hundred and forty thoracic screws were inserted using either the navigational template method or the free-hand method. The accuracy rate and incidence of risk for setting thoracic pedicle screws differed statistically between the two methods (P < 0.05): The navigational template method had a higher accuracy rate and a lower incidence of risk than the free-hand method. Moreover, the free-hand method had a significant learning curve, whereas a learning curve for the navigational template method was not obvious. CONCLUSION: We have developed a novel, patient-specific, navigational template for thoracic pedicle screw placement with good applicability and high accuracy.

[Effect of post-remission therapy mainly with compound huangdai tablet on long-term survival of patients with acute promyelocytic leukemia].

OBJECTIVE: To investigate the effect of post-remission therapy mainly with Compound Huangdai Tablet (CHDT) on long-term survival of patients with acute promyelocytic leukemia (APL). METHODS: One hundred and twelve APL patients were treated after remission mainly with CHDT administered alternately with chemotherapeutic projects such as HACP, HAOP, HAEP and HAMP. The relapse rate and relapse-free survival (RFS) rate in them were estimated by bone marrow examination. RESULTS: The total relapse rate was 14.29% (16/112), and the median time of relapse was 12.5 (4-67) months. Patients were followed up for 1-72 months, the median follow-up time being 59 months. The actual RFS rate of 1-, 2-, 3-, 4-, 5- and 6-year was 92.86%, 89.29%, 88.39%, 87.50%, 86.61% and 85.71%, respectively, while the estimated RFS rate (%) of corresponding year was 92.45 +/- 2.57, 88.25 +/- 3.20, 87.09 +/- 3.36, 85.89 +/- 3.52, 84.44 +/- 3.75 and 82.78 +/- 4.03 respectively; the relapse rate in patients who received treatment after complete response for <10 courses group was 34.29%, while in those treated for > or = 10 courses was 5.19%; and the RFS rate in them was 65.71% and 94.81% respectively, the difference between groups was statistically significant (P<0.01). CONCLUSION: The post-remission therapy mainly with CHDT is an effective and feasible program for the treatment of APL.

[Compound huangdai tablet as induction therapy for 193 patients with acute promyelocytic leukemia].

OBJECTIVE: To report the results of curative and adverse effects of compound huangdai tablet (CHDT) as induction therapy for 193 patients with acute promyelocytic leukemia (APL). METHODS: CHDT was administered 1.25 g orally three times a day after meal for three days, then the dosage was gradually increased to 7.5 g/d. RESULTS: One hundred and ninety-three patients achieved complete remission (CR), 78.8% of whom in 30 to 60 days with an average time of 44.3 d. No serious infection, bleeding or DIC occurred during the treatment course. The major adverse effects were gastrointestinal symptoms. There was no change in lanine transaminase, urea, creatinine or electrocardiographic QTc interval in 110 APL patients observed before and after the treatment. CONCLUSION: CHDT therapy is a modality of higher CR rate, good safety and tolerance without bone marrow suppression for APL patients.