Properties of SiCN Films Relevant to Dental Implant Applications.

The application of surface coatings is a popular technique to improve the performance of materials used for medical and dental implants. Ternary silicon carbon nitride (SiCN), obtained by introducing nitrogen into SiC, has attracted significant interest due to its potential advantages. This study investigated the properties of SiCN films deposited via PECVD for dental implant coatings. Chemical composition, optical, and tribological properties were analyzed by adjusting the gas flow rates of NH3, CH4, and SiH4. The results indicated that an increase in the NH3 flow rate led to higher deposition rates, scaling from 5.7 nm/min at an NH3 flow rate of 2 sccm to 7 nm/min at an NH3 flow rate of 8 sccm. Concurrently, the formation of N-Si bonds was observed. The films with a higher nitrogen content exhibited lower refractive indices, diminishing from 2.5 to 2.3 as the NH3 flow rate increased from 2 sccm to 8 sccm. The contact angle of SiCN films had minimal differences, while the corrosion rate was dependent on the pH of the environment. These findings contribute to a better understanding of the properties and potential applications of SiCN films for use in dental implants.

Percutaneous stenting of the portal vein prior to biliary bypass in a patient with chronic pancreatitis and portal biliopathy.

Chronic pancreatitis (CP) often leads to obstruction of one or all the components of the spleno-mesenterico-portal (SMP) axis. This is often due to the ongoing inflammatory process which may lead to thrombosis of the surrounding veins. However, the inflammation also leads to progressive fibrosis and occlusion of the veins without thrombosis. This fibrosis is also responsible for the duodenal obstruction and biliary strictures associated with CP. These patients, with simple occlusion or encasement of one or a combination of components of the SMP axis, can be treated with venous stenting. Here, we present the case of a 58-year-old gentleman with portal vein occlusion and portal biliopathy secondary to CP. This patient was successfully treated with percutaneous transhepatic portal vein stenting and a subsequent surgical biliary bypass. In conclusion, portal venous obstruction in CP may be just due to local fibrosis and is amenable to treatment with a percutaneously placed portal venous stent.

Cerebral hyperperfusion syndrome after endovascular reconstruction of carotid artery in high-flow carotid-jugular fistula.

We describe the occurrence of cerebral hyperperfusion syndrome (CHS) in a case of long-standing carotid-jugular fistula (CJF) treated by endovascular reconstruction of the carotid artery. A 43-year-old male with a high-flow CJF between the internal carotid artery (ICA) and internal jugular vein underwent endovascular reconstruction of the carotid artery using a stent graft. After treatment, the patient developed CHS. The patient succumbed to a large intracranial bleed in the left external capsule and parietal lobe on the fifth postoperative day. CHS following endovascular reconstruction of carotid artery is rare. We present the first reported case of CHS following endovascular reconstruction of ICA. A review of literature for patients treated by endovascular rerouting of blood flow to the cerebral parenchyma associated with hyperperfusion syndrome has been performed.

The role of squash cytology in rapid on-site adequacy checking and rapid diagnosis in image-guided gun biopsy at a tertiary cancer center.

OBJECTIVE: To evaluate the role of squash cytology in rapid on-site adequacy checking (ROSAC) of image-guided gun biopsy and to determine its diagnostic accuracy at a tertiary cancer center. STUDY DESIGN: This was a prospective study on 183 patients undergoing image-guided biopsy. Squash smears were prepared from biopsy cores and checked for adequacy by cytotechnologists. When adequate, more cores were sampled from the same area for histopathology. If inadequate, the procedure was repeated at the same sitting on a different area. The squash smears were reported by cytopathologists within 4 h after staining with conventional Papanicoloau stain. The results were compared with the final histopathology report. RESULTS: The sampling was representative in 95.6% cases with concordance for adequacy in 97.3% cases. The sensitivity, specificity, positive predictive value and negative predictive value of squash cytology for diagnosis of the lesion were 99.4, 92.7, 97.7 and 97.4%, respectively. CONCLUSIONS: Squash cytology is an ideal and cost-effective technique for ROSAC of image-guided biopsies, which ensures adequacy, avoids repeat procedures and prevents delay in diagnosis. It can be effectively performed by trained cytotechnologists in radiology clinics. Squash cytology is also a cost-effective tool offering rapid diagnosis which expedites planning of treatment.

18F-FDG PET/CT-directed biopsy: does it offer incremental benefit?

PURPOSE: To study whether the metabolic information provided by a prior PET/computed tomography (CT) scan can add valuable information and an incremental benefit while performing image-guided biopsies. METHODS: Fluorine-18 fluorodeoxyglucose (F-FDG) PET/CT findings of 112 patients were available before biopsy and were considered for analysis. Biopsies were performed using standard techniques only after the needle tip was confirmed to be in the portion of the lesion corresponding to the hypermetabolic area seen on PET. This was achieved by visual coregistration and also by software registration algorithms that registered the intraprocedural CT images with the preselected PET/CT data. Only those biopsies for which a definitive histopathological diagnosis could be made were considered 'diagnostic'. Cases in which PET/CT added an incremental value were divided into three categories. RESULTS: A total of 112 patients (66 male and 46 female, age range 16-74 years) underwent a biopsy based on PET findings. The biopsy sites were as follows: lung, 54; lymph nodes, 27; bone, 12; and soft-tissue masses/deposits, 19. Out of the 112 biopsies, an incremental benefit was seen overall in 53 patients (47.3%): in 40.7% (22/54) of patients who underwent lung biopsies, 44.4% (12/27) of those who underwent lymph node biopsies, 66.6% (8/12) of those who underwent bone biopsies and 57.8% (11/19) of those who underwent soft-tissue biopsies. Out of the cases that showed an incremental benefit, the highest number (30) belonged to the category in which the biopsy sample was obtained from the focal hypermetabolic portion of the apparently larger morphological lesion seen on CT. CONCLUSION: PET/CT data coregistered with intraprocedural CT images can guide needle placement in the viable portion of the lesion, thus increasing the chances of achieving a definitive diagnosis. This approach can offer a significant incremental benefit while performing image-guided biopsies.

Ultrasound-guided botulinum toxin injection: A simple in-office technique to improve tracheoesophageal speech in postlaryngectomy patients.

BACKGROUND: Pharyngoesophageal spasm is a known entity to cause hypertonic/failed tracheoesophageal speech and is successfully treated by botulinum toxin A injection. However, success of botulinum toxin treatment is based on the accurate localization of the pharyngoesophageal segment. METHODS: A 65-year-old man who had a laryngectomy using voice prosthesis with hypertonic speech underwent ultrasonographic localization of the hypertonic pharyngoesophageal segment. The ultrasound findings were confirmed using videofluoroscopy. Under ultrasound guidance, botulinum toxin was injected into the hypertonic pharyngoesophageal segment and subsequently voice outcomes were evaluated by a speech language pathologist and the pharyngoesophageal segment was assessed by using an ultrasound scan. RESULTS: The patient had improvement in his postinjection tracheoesophageal puncture speech. Ultrasound scan assessment of the pharyngoesophageal segment showed adequate dilation as compared to the pre-botulinum toxin injection treatment. CONCLUSION: Ultrasonographic localization of the hypertonic pharyngoesophageal segment and ultrasound-guided botulinum toxin injection is a simple, quick, and relatively cheap method to be used in routine practice.

Therapeutic response to radiofrequency ablation of neoplastic lesions: FDG PET/CT findings.

Ablation of neoplastic lesions by using radiofrequency energy is gaining popularity in clinical practice because of the minimally invasive nature of radiofrequency ablation (RFA). Primary and secondary tumors of the liver and lung are treated with RFA when surgery is precluded because of comorbidity. Benign bone tumors are also treated with RFA to relieve pain and prevent further tumor growth. Differentiation between postablation tissue changes and residual disease is difficult with morphologic imaging modalities such as ultrasonography, computed tomography (CT), and magnetic resonance (MR) imaging, thus limiting the use of these modalities to detection of residual disease early after RFA. Fluorine 18 fluorodeoxyglucose (FDG) positron emission tomography (PET) is a functional imaging modality that can be used to study the effects and efficacy of RFA. Lesions that show increased FDG uptake at PET become completely photopenic immediately after RFA, a finding that is suggestive of the completeness of ablation. Focal areas of increased FDG uptake within the ablated zone are suggestive of residual disease. Reactive tissue changes such as inflammation are depicted in the periphery of the ablated lesion and show a uniform low-grade FDG uptake, which can be differentiated from the focal, nodular intense uptake in areas of residual disease. Use of combined FDG PET/CT to detect residual disease early after RFA allows ablation to be repeated, if necessary, to obtain the maximum therapeutic benefit. Note that FDG uptake in the complications sometimes associated with RFA can be a cause of potential false-positive PET results.