Search

Background: Acute calcific tendinitis (ACT) of the longus colli muscle (LCM) is an inflammatory response due to deposition of calcium hydroxyapatite crystals. It is typically correlated with whiplash and overuse injuries. A common presentation of this inflammatory response is acute but progressive neck pain. It is a rare but important cause of neck pain that should be considered on a differential diagnosis when distinguishing between life-threatening conditions and non-life-threatening causes of neck pain., Case Report: A 51-year-old woman presented to the emergency department (ED) reporting a mild sore throat that progressed to acute neck pain and stiffness. She also reported fatigue, fever, myalgias, and nausea. In the ED, the patient was tachycardic, hypertensive, and mildly febrile with normal oxygen saturation. Examination revealed meningismus and was negative for lymphadenopathy, oropharyngeal findings, and neurologic deficits. Laboratory studies were significant for leukocytosis. Computed tomography (CT) neck was obtained and was notable for calcification of the superior left longus colli muscle with prevertebral and retropharyngeal space edema along the muscle body. WHY SHOULD AN EMERGENCY PHYSICIAN BE AWARE OF THIS?: ACT of the LCM is a benign, self-limited condition that can present with features overlapping emergent causes of acute neck pain. Correct diagnosis relies on characteristic radiographic findings on CT. Fortunately, patients may be discharged home with a short course of anti-inflammatories and corticosteroids with near-complete resolution of symptoms. Emergency physicians, therefore, can rule out life-threatening causes of neck pain, while also making a definitive diagnosis and initiating effective management for this pathology., Competing Interests: Declaration of Competing Interest The authors declare that they have no known competing financial interests or personal relationships that could have appeared to influence the work reported in this paper., (Copyright © 2023 Elsevier Inc. All rights reserved.)

The problem of the enormous amount of scattered radiation in kV CBCT (kilo voltage cone beam computer tomography) is addressed. Scatter causes undesirable streak- and cup-artifacts and results in a quantitative inaccuracy of reconstructed CT numbers, so that an accurate dose calculation might be impossible. Image contrast is also significantly reduced. Therefore we checked whether an appropriate implementation of the fast iterative scatter correction algorithm we have developed for MV (mega voltage) CBCT reduces the scatter contribution in a kV CBCT as well. This scatter correction method is based on a superposition of pre-calculated Monte Carlo generated pencil beam scatter kernels. The algorithm requires only a system calibration by measuring homogeneous slab phantoms with known water-equivalent thicknesses. In this study we compare scatter corrected CBCT images of several phantoms to the fan beam CT images acquired with a reduced cone angle (a slice-thickness of 14 mm in the isocenter) at the same system. Additional measurements at a different CBCT system were made (different energy spectrum and phantom-to-detector distance) and a first order approach of a fast beam hardening correction will be introduced. The observed image quality of the scatter corrected CBCT images is comparable concerning resolution, noise and contrast-to-noise ratio to the images acquired in fan beam geometry. Compared to the CBCT without any corrections the contrast of the contrast-and-resolution phantom with scatter correction and additional beam hardening correction is improved by a factor of about 1.5. The reconstructed attenuation coefficients and the CT numbers of the scatter corrected CBCT images are close to the values of the images acquired in fan beam geometry for the most pronounced tissue types. Only for extreme dense tissue types like cortical bone we see a difference in CT numbers of 5.2%, which can be improved to 4.4% with the additional beam hardening correction. Cupping is reduced from 20% to 4% with scatter correction and 3% with an additional beam hardening correction. After 3 iterations (small phantoms) and 6 to 7 iterations (large phantoms) the algorithm converges. Therefore the algorithm is very fast, that means 1.3 seconds per projection for 3 iterations on a standard PC.

To show the effects of different concentrations of contrast agent on signal time curves and image contrast of abdominal aorta, vena cava and portal vein in comparison to each other as well as liver and spleen. Imaging was carried out in a 1.0 Tesla clinical scanner. Sixty patients were prospectively included and divided into three contrast agent (Gd-DTPA) dosage groups (0.1 mmol/kg, 0.2 mmol/kg and 0.3 mmol/kg). All patients were scanned using a time-resolved 3D FLASH sequence (58 phases) with a 3.75 second acquisition time per phase. Signal time curves and image contrast levels were evaluated. No significant differences were found for the maximum signal enhancement between the groups in the investigated vessels. Image masking, the subtraction of the baseline images, resulted in a substantial improvement in image contrast. However, statistically significant differences between the contrast agent dosage groups could only be found for vena cava and liver. Vessel conspicuity is not significantly improved with an increase of contrast agent dose. However, an increase in contrast agent dosage increases vessel contrast. Our findings suggest that a single dose single station investigation seems to be sufficient for high quality abdominal MRA.