Top-Ten Tips for Dual-Energy CT in MSK Radiology

Dual-energy computed tomography (DECT) has the potential to detect musculoskeletal pathology with greater sensitivity than conventional CT alone at no additional radiation dose to the patient. It therefore has the potential to reduce the need for further diagnostic imaging or procedures (e.g., joint aspirations in the case of gout or magnetic resonance imaging to confirm undisplaced fractures).DECT is a well-established technique for the detection of gout arthropathy. Multiple newer applications have shown clinical potential including bone marrow edema detection and metal artifact reduction. Collagen analysis, bone marrow lesion detection, and iodine mapping in CT arthrography are areas of possible future application and development.This article outlines 10 tips on the use of DECT imaging of the musculoskeletal system, explaining the technique and indications with practical suggestions to help guide the radiologist.

Steam Sterilization of Equine Bone Block: Morphological and Collagen Analysis

Introduction. The use of equine bone blocks is widely reported for bone augmentation techniques. The block must be shaped according to the form of the defect that should be regenerated. The shaping could be performed by hand before or during the surgery, in a sterile ambient, or using a CNC milling machine that could not be sterile. The aim of our study was to evaluate if a steam sterilization could provide a medical grade sterilization of the blocks and to evaluate if bone microstructure and collagen structures change after different steam sterilization protocols provided by mainstream autoclave. Materials and Method. Two blocks of equine bone were divided into 16 samples. 1 sample was used as control and not submitted to any treatment. 15 samples were infected with a Streptococcus faecalis bacterial culture. The samples were singularly packed, randomly divided into 3 groups, and submitted to autoclave sterilization on the same device. The groups were submitted to a sterilization cycle (Gr. A: 121°C, 1,16 bar for 20′; Gr. B:134°C, 2,16 bar for 4′; Gr. C: 134°C, 2,16 bar for 3.30 min.). 2 samples for each group were evaluated for the sterility. 3 samples for each group were observed at SEM to notice the macro- and microstructure modification and to confocal microscope to observe the collagen. Results. All samples were sterile. The SEM evaluation showed, in all groups, a preserved morphological structure. Confocal microscope evaluation shows that the collagen structure appears to be more uniform and preserved in group C. Conclusion. Data show that autoclave steam sterilization could be reliable to obtain sterilization of equine bone blocks.

Avaliação da Exposição e da Interrupção da Nicotina Durante a Cicatrização em Ratos Wistar

As evidências clínicas e experimentais demonstram que o uso da nicotina tem efeitos deletéricos sobre a cicatrização. Entretanto, muitas dúvidas ainda existem entre cirurgiões e equipes de saúde em relação ao tempo de interrupção que antecede esses procedimentos. Nesta pesquisa, os ratos Wistar foram divididos em 3 grupos (G1, G2 e G3) que receberam doses diárias de 2 mg/kg de nicotina subcutânea durante 4 semanas. O G1 não interrompeu o uso por dez dias após a cirurgia de retirada de retalho cutâneo; o G2 interrompeu o uso da nicotina uma semana antes da cirurgia; e o G3 interrompeu por duas semanas antes da cirurgia, não fazendo mais uso durante os dez dias após esse procedimento. A análise dos parâmetros de cicatrização na fase proliferativa foi feita através de microscopia de luz e corados pelo H.E. e colorações especiais para análise de colágeno (Tricrômico de Masson e Verhoeff). Encontrou-se no G1 a presença de crosta fibrinoleucocitária, uma visível desorganização do colágeno e um deficiente tecido de granulação quando comparados aos G2 e G3. Dos escores médios dos três grupos obteve-se p=0,028 considerados significativos e no pós-teste Tukey-Kramer foram encontradas diferenças estatísticas significativas entre os G1 e G3 (p<0,05). Na análise do tecido de granulação (p=0,0008) e do colágeno (p=0,049) também se obteve diferença estatística significativa. Pode-se concluir que na interrupção por uma ou duas semanas obteve-se uma melhor e mais eficiente cicatrização, podendo, portanto, extrapolar esses resultados para orientação do pré e pós-cirúrgicos de pacientes tabagistas. Assessment of Exposure and Interruption of Nicotine During Wound Healing in Wistar Rats ABSTRACT: Clinical and experimental evidences show that the use of nicotine has deleterious effects on wound healing, although there are still many doubts among surgeons and health teams with regard to the interruption that should precede interventions. Wistar rats, divided into three groups (G1, G2 and G3), received daily subcutaneous doses of 2 mg/kg nicotine during 4 weeks. G1 did not interrupt use during 10 days after surgery; G2 interrupted nicotine use a week prior to surgery; G3 interrupted during two weeks before surgery and did not take nicotine during ten days after surgical procedure. Wound-healing parameters during the proliferation phase were analyzed by light microscopy and stained with HE and special stains for collagen analysis (Masson´s Trichromium and Verhoeff). A fibrin-leukocyte crust, a visible disorder of collagen and a granulation tissue deficiency occurred in G1 when compared to G2 and G3. Average scores of the three groups (p=0.028) were significant and significant statistical differences between G1 and G3 existed (p<0.05) by Tukey-Kramer´s post-test. Statistically significant difference existed in the granulation (p=0.0008) and collagen (p=0,049) tissues. Results show that a greater and more efficient wound-healing occurred when nicotine was interrupted for one or two weeks, which may be recommended for smoking patients in the pre- and post-surgery periods.