Ultra-low-dose CBCT: new cornerstone of paranasal sinus imaging.

BACKGROUND: This study evaluates the clinical image quality (IQ) and usability of a sinonasal ultra-low-dose (ULD) cone-beam computed tomography (CBCT) scan. The results are compared to those of a high resolution (HR) CBCT scan to identify the strengths and weaknesses of a ULD CBCT protocol. METHODOLOGY: Sixty-six anatomical sites in 33 subjects were imaged twice using two imaging modalities: HR CBCT (Scanora 3Dx scanner; Soredex, Tuusula, Finland) and ULD CBCT (Promax 3D Mid scanner; Plandent, Helsinki, Finland). IQ, opacification and obstruction, structural features and operative usability were assessed. RESULTS: The overall IQ in subjects with 'no or minor opacification' was excellent: 100% (HR CBCT) and 99% (ULD CBCT) of ratings were evaluated as sufficient for every structure. Increased opacification reduced the quality of both imaging modalities, resulting conchtoethmoidectomy, frontal sinusotomy, sphenotomy and posterior ethmoidectomy in cases with greater opacification. CONCLUSIONS: IQ of paranasal ULD CBCT is sufficient for clinical diagnostics and should be considered for surgical planning. We recommend it as the primary imaging protocol for all patients who meet imaging criteria due to recurrent or chronic nasal symptoms. Additional or conventional imaging might be needed for patients with extensive chronic rhinosinusitis and/or indications of frontal sinus involvement.

Periapical infection may affect birth outcomes via systemic inflammation.

OBJECTIVES: Maternal dental periapical infections are associated with preterm birth and intrauterine growth restriction. This study investigates whether the association is mediated through bacterial spread from periapical lesions to placenta (direct pathway) or systemic inflammatory reaction (indirect pathway). MATERIALS AND METHODS: We compared birth outcomes in Malawian mothers with and without periapical infection. As markers of a direct pathway, we identified placental bacteria using a 16S rDNA approach and assessed histological evidence of inflammation in the placenta and amniotic membranes. We measured C-reactive protein, alpha-1-acid glycoprotein, and salivary cortisol as markers of an indirect pathway. We used regression models to associate the predictor variables with duration of pregnancy and newborn size. RESULTS: Of 1,024 women, 23.5% had periapical infection. There was no association of periapical infection with either bacterial DNA or histological inflammation in placenta or membranes. Periapical infection was associated with C-reactive protein, alpha-1-acid glycoprotein, and cortisol concentrations in a dose-dependent manner at 36 weeks. Addition of alpha-1-acid glycoprotein or cortisol concentration into regression models attenuated the association between periapical infection and pregnancy outcomes. CONCLUSION: There was no evidence of direct spread of periapical bacteria to the placenta. Periapical infections and adverse pregnancy outcomes are in part mediated through systemic inflammation.

Assessment of the effective dose in supine, prone, and oblique positions in the maxillofacial region using a novel combined extremity and maxillofacial cone beam computed tomography scanner.

OBJECTIVE: The objectives of this study were to assess the organ and effective doses (International Commission on Radiological Protection [ICRP] 103 standard) resulting from supine, prone, and oblique phantom positions in the maxillofacial region using a novel cone beam computed tomography (CBCT) device and to compare the results with conventional dental CBCT and multislice computed tomography (MSCT) devices. STUDY DESIGN: Measurements were performed using an anthropomorphic RANDO head phantom (Radiation Analogue Dosimetry System) with 20 MOSFET (metal-oxide-semiconductor field-effect transistor) dosimeters placed in the most radiosensitive maxillofacial organs. Effective doses were measured in 3 phantom positions using a combined extremity and maxillofacial CBCT device: the Planmed Verity CBCT scanner. Reference values were measured in the upright position with 2 CBCT devices and in the prone position with one MSCT scanner. RESULTS: The Planmed Verity CBCT scanner effective doses were 247 µSv in supine, 192 µSv in prone, and 134 µSv in oblique position. The effective dose with ProMax 3D MAX CBCT was 168 µSv; with i-CAT Next Generation, 170 µSv; and with Philips Brilliance 64 MSCT, 781 µSv. CONCLUSIONS: Head positioning has an important effect on the organ and effective doses. The Planmed Verity CBCT scanner effective dose results were comparable with those attained on 2 conventional CBCT devices and were considerably lower than the MSCT scanner results.

A texture analysis method for MR images of airway dilator muscles: a feasibility study.

OBJECTIVES: Airway dilator muscles play an important role in the analysis of breathing-related symptoms, such as obstructive sleep apnoea. Texture analysis (TA) provides a new non-invasive method for analysing airway dilator muscles. In this study, we propose a TA methodology for airway dilator muscles and prove the robustness of this method. METHODS: 15 orthognathic surgery patients underwent 3-T MRI. Computerized TA was performed on 20 regions of interest (ROIs) in the patients' airway dilator muscles. 53 texture parameters were calculated for all ROIs. The robustness of the TA method was analysed by altering the locations, sizes and shapes of the ROIs. RESULTS: Our study shows that there is significant difference in TA results as the size or shape of ROI changes. The change of location of the ROI inside the studied muscle does not affect the TA results. CONCLUSIONS: The TA method is valid for airway dilator muscles. We propose a methodology in which the number of co-occurrence parameters is reduced by using mean values from four different directions (0°, 45°, 90° and 135°) with pixel spacing of 1 pixel.

Trauma induced eagle syndrome.

Eagle syndrome is characterized by secondary calcification and elongation of the styloid process. Eagle syndrome is often associated with sharp, intermittent pain along the path of the glossopharyngeal nerve located in the hypopharynx and at the base of the tongue. In some cases, the stylohyoid apparatus can compress the internal and/or the external carotid arteries and their perivascular sympathetic fibres, resulting in a persistent pain radiating throughout the carotid territory. The pathogenesis of the syndrome is not understood. The authors report the case of a 52-year-old woman with post traumatic Eagle syndrome-like pain and pseudoarthrosis of the stylohyoid ligament.