A novel region-based level set method initialized with mean shift clustering for automated medical image segmentation

Appropriate initialization and stable evolution are desirable criteria to satisfy in level set methods. In this study, a novel region-based level set method utilizing both global and local image information complementarily is proposed. The global image information is extracted from mean shift clustering without any prior knowledge. Appropriate initial contours are obtained by regulating the clustering results. The local image information, as extracted by a data fitting energy, is employed to maintain a stable evolution of the zero level set curves. The advantages of the proposed method are as follows. First, the controlling parameters of the evolution can be easily estimated by the clustering results. Second, the automaticity of the model increases because of a reduction in computational cost and manual intervention. Experimental results confirm the efficiency and accuracy of the proposed method for medical image segmentation.     

局部皮瓣在眼周美容整形中的应用分析

目的：探究局部皮瓣在眼周美容整形中的应用并分析。方法选择自2013年1月-2014年1月间来我院就诊的眼周皮肤受损患者41例。采取局部皮瓣疗法，根据创面的大小，部位等情况规划出一个完整的方案，最大程度的使辅助切口适应面部轮廓，尽量隐藏切口线[1]。结果本组一共有41例患者，术后皮瓣全部存活，且在术后随访几个月期间，无畸形产生，没有影响眼功能，患者很满意。结论局部皮瓣在眼周美容中能够获得效果显著的美容修复作用，值得在临床上大面积推广应用。     

Accompanying DCIS in breast cancer patients with invasive ductal carcinoma is predictive of improved local recurrence-free survival

BackgroundDuctal carcinoma in situ (DCIS) often accompanies invasive ductal carcinoma (IDC). The presence of co-existing DCIS is postulated to present as a less aggressive phenotype than IDC alone.Patients and methodsPatients diagnosed with hormone receptor-positive breast cancer receiving mastectomy were evaluated. Only patients without adjuvant radio- and chemotherapy were included to decrease treatment bias on local recurrence (LR).ResultsOf 2239 breast cancer patients, 198 fulfilled the inclusion criteria. The overall LR rate was 11.6%. Tumor stage (p = 0.002), nodal status (pN2 vs. pN0, p = 0.023) and pure IDC compared with IDC-DCIS (p = 0.029) were multivariate independent factors for increased LR risk. Patients with IDC-DCIS were significantly younger (p < 0.001), had smaller tumors (p = 0.001), less lymph node involvement (p = 0.012). The LR rate was significantly increased in patients with pure IDC (p = 0.012). The time to distant metastases was decreased in patients with pure IDC compared with that observed in patients with IDC-DCIS (log rank = 0.030).ConclusionInvasive ductal carcinoma accompanied by DCIS is associated with lower LR. The prognostic value of co-existing DCIS in the adjuvant decision-making process may be considered a new independent prognostic marker. This finding needs further studies to evaluate its usefulness in premenopausal women.     

Local release of magnesium from mesoporous TiO2 coatings stimulates the peri-implant expression of osteogenic markers and improves osteoconductivity in vivo

Local release of Mg ions from titanium implant surfaces has been shown to enhance implant retention and integration. To clarify the biological events that lead to this positive outcome, threaded implants coated with mesoporous TiO₂ thin films were loaded with Mg-ions and placed in the tibia of rabbits for 3 weeks, after surface characterization. Non-loaded mesoporous coated implants were used as controls. Peri-implant gene expression of a set of osteogenic and inflammatory assays was quantified by means of real-time quantitative polymerase chain reaction. The expression of three osteogenic markers (OC, RUNX-2 and IGF-1) was significantly more pronounced in the test specimens, suggesting that the release of Mg ions directly at the implant sites may stimulate an osteogenic environment. Furthermore, bone healing around implants was evaluated on histological slides and by diffraction-enhanced imaging (DEI), using synchrotron radiation. The histological analysis demonstrated new bone formation around all implants, without negative responses, with a significant increase in the number of threads filled with new bone for test surfaces. DEI analysis attested the high mineral content of the newly formed bone. Improved surface osteoconductivity and increased expression of genes involved in the bone regeneration were found for magnesium-incorporation of mesoporous TiO₂ coatings.     

Teaching medical students and residents how to inject local anesthesia almost painlessly

The objective of the present study was to determine whether it is possible to consistently and reliably teach medical students and resident learners how to administer local anesthetics in an almost painless manner. Using the published technique, 25 consecutive medical students and residents were taught how to inject local anesthetics for carpal tunnel release by watching the senior author perform the technique once. The learner then independently administered the anesthesia to the next patient who then scored the learner’s ability to inject the local anesthetic from a pain perspective. The teaching technique is demonstrated in an accompanying online video. The learners were consistently capable of administering local anesthetics with minimal pain. During the injection process, the patients only felt pain once (‘hole-in-one’) 76% of the time. This pain was attributed to the first 27-gauge needle poke. The other 24% of the time, patients felt pain twice (eagle) during the 5 min injection process. All 25 patients rated the entire pain experience to be less than 2/10. Eighty-four per cent of the patients indicated that the experience was better than local anesthetic given at the dentist’s office. Medical students and residents can quickly and reliably learn how to administer local anesthesia for carpal tunnel release with minimal pain to the patient.     

Metastatic Lymph Node Ratio of Central Neck Compartment Has Predictive Values for Locoregional Recurrence in Papillary Thyroid Microcarcinoma

ObjectivesThis study aimed to evaluate the significance of metastatic lymph node ratio (the ratio between the metastatic lymph node and the harvested lymph nodes; MLNR) in the central neck for the prediction of locoregional recurrence in patients with papillary thyroid microcarcinoma.MethodsAfter reviewing medical records of papillary thyroid microcarcinoma patients who received total thyroidectomy with central neck node dissection, 573 consecutive adult patients were enrolled in this study, with a follow-up period of more than 36 months. Regarding the risk of recurrence, multivariate analyses were performed with the following variables; sex, age, multiplicity of the primary tumor, presence of pathological extrathyroidal extension, the level of postoperative stimulated serum thyroglobulin, the number of harvested lymph nodes, the number of lymph node metastasis and MLNR.ResultsThe MLNR showed a predictive significance for the locoregional recurrence (P<0.05). Most recurrences were occurred in the lateral neck (n=12, 80%) with a median interval of 20 months. The lowest cutoff value of the MLNR for a meaningful separation of disease recurrence was 0.44 (hazard ratio, 8.86; 95% confidence interval, 1.49 to 52.58; P=0.001).ConclusionWhen the MLNR is higher than 0.44, there is an increased risk of locoregional recurrence mostly in the lateral neck. Therefore, MLNR of the central neck in a permanent or frozen biopsy may be helpful in decision making in the extent of thyroidectomy and/or the need for contralateral central neck lymph nodes dissection.