RESUMO
INTRODUCTION: Metal artifacts may negatively affect radiologic assessment in the oral cavity. The aim of this study was to evaluate different metal artifact reduction techniques for metal artifacts induced by dental hardware in CT scans of the oral cavity. METHODS: Clinical image quality was assessed using a Thiel-embalmed cadaver. A Catphan phantom and a polymethylmethacrylate (PMMA) phantom were used to evaluate physical-technical image quality parameters such as artifact area, artifact index (AI), and contrast detail (IQFinv). Metal cylinders were inserted in each phantom to create metal artifacts. CT images of both phantoms and the Thiel-embalmed cadaver were acquired on a multislice CT scanner using 80, 100, 120, and 140 kVp; model-based iterative reconstruction (Veo); and synthesized monochromatic keV images with and without metal artifact reduction software (MARs). Four radiologists assessed the clinical image quality, using an image criteria score (ICS). RESULTS: Significant influence of increasing kVp and the use of Veo was found on clinical image quality (p = 0.007 and p = 0.014, respectively). Application of MARs resulted in a smaller artifact area (p < 0.05). However, MARs reconstructed images resulted in lower ICS. CONCLUSION: Of all investigated techniques, Veo shows to be most promising, with a significant improvement of both the clinical and physical-technical image quality without adversely affecting contrast detail. MARs reconstruction in CT images of the oral cavity to reduce dental hardware metallic artifacts is not sufficient and may even adversely influence the image quality.
Assuntos
Artefatos , Implantes Dentários , Metais , Boca/diagnóstico por imagem , Radiografia Dentária/métodos , Imagem Radiográfica a Partir de Emissão de Duplo Fóton/métodos , Cadáver , Humanos , Imagens de Fantasmas , Doses de Radiação , Radiografia Dentária/instrumentação , Imagem Radiográfica a Partir de Emissão de Duplo Fóton/instrumentação , Reprodutibilidade dos Testes , Sensibilidade e Especificidade , Tomografia Computadorizada por Raios X/instrumentação , Tomografia Computadorizada por Raios X/métodosRESUMO
Infectious spondylodiscitis (IS) is defined as the pathogenic invasion of the vertebrae and intervertebral disks. It is a serious condition that can lead to many complications such as chronic pain, permanent neurological deficits, and even death. Vertebral surgical procedures, invasive urinary tract manipulations, and central line-associated bloodstream infection are the primary methods by which microorganisms reach the vertebrae and intervertebral disks. Hemodialysis (HD) patients are regularly exposed to bloodstream infections due to long-term catheter utilization or repeated vascular puncturing in patients with arteriovenous fistula. Due to the high risk of blood stream infections, HD patients have a higher risk of developing IS. Despite advanced diagnostic methods, diagnosis of spondylodiscitis is often delayed due to insidious and nonspecific symptoms, allowing dissemination of the infection, which explains the high level of mortality due to spondylodiscitis in HD patients. The infectious process typically occurs in the thoracic or lumbar region, although cervical IS does occur. We herein report the case of a 67-year-old man on HD who developed infectious cervical spondylodiscitis. The diagnosis was established a few days after symptom onset, but the issue was unfortunately fatal despite a well-conducted antibiotic treatment.
RESUMO
Posttraumatic pseudoaneurysms of the lower limb are increasingly recognized due to the development of cross-sectional imaging. Two cases of anterior tibial artery pseudoaneurysm after blunt trauma are presented. The diagnostic technique of choice is Doppler ultrasound (US). In some cases, computed tomography angiography (CTA) or magnetic resonance angiography (MRA) is needed to identify the feeding vessel. The treatment of choice is not yet determined. Ultrasound-guided thrombin injection is widely used as first-line treatment, but some cases are refractory to this treatment. Further investigation and optimization of therapeutic technique to definitely exclude the pseudoaneurysm from the circulation may result in faster and more cost-effective treatment than US-guided thrombin injection.