The utility of brain CT scan modality in the management of dizziness at the emergency department: A retrospective single-center study.

OBJECTIVES: This study examines the usefulness of computed tomography (CT) scans in evaluating patients with dizziness in the emergency department (ED). METHODS: Medical records of patients presented with complaints of dizziness or vertigo to the ED of a tertiary university hospital and underwent head CT scans from July 2015 to June 2018 were reviewed. The patients' demographic information, presenting symptoms, and final head CT scan and Magnetic resonance imaging (MRI) results were collected. Stepwise logistic regressions were used to analyze data. RESULTS: A total of 326 dizzy patients were included in this study. The majority of the patients (83.1%) were older than 44 years. Acute vertigo pattern of dizziness was detected among 50.6% of the patients and was more common among females than males (p < 0.001). Of these 326 patients who underwent head CT scans, 49 (15%) had abnormal findings with acute ischemic stroke was the most common one. A total of 191 patients underwent follow-up studies. MRI accounted for 70% of the follow-up studies. Of the 134 patients who received MRI of the brain, 36 (27%) had abnormal findings. A significant correlation of RBCs level, presence of other symptoms, and frequency of episodes with the presence of vertigo (p < 0.001) was found. CONCLUSION: The study's findings indicate low effectiveness of head CT scan compared to MRI for dizziness management. Future studies are suggested to provide more insights into the cost-effectiveness and utility of head CT scans and MRI in providing valuable findings.

Chemical Items Used for Preparing Tissue-Mimicking Material of Wall-Less Flow Phantom for Doppler Ultrasound Imaging.

The wall-less flow phantoms with recognized acoustic features (attenuation and speed of sound), interior properties, and dimensions of tissue were prepared, calibrated, and characterized of Doppler ultrasound scanning demands tissue-mimicking materials (TMMs). TMM phantoms are commercially available and ready-made for medical ultrasound applications. Furthermore, the commercial TMM phantoms are proper for ultrasound purpose or estimation of diagnostic imaging techniques according to the chemical materials used for its preparation. However, preparing a desirable TMM for wall-less flow phantom using a specific chemical material according to the specific applications is required for different flow. In this review, TMM and wall-less flow phantoms prepared using different chemical materials and methods were described. The chemical materials used in Doppler ultrasound TMM and wall-less flow phantoms fabricated over the previous decades were of high interest in this review.

A New Scatter Particle and Mixture Fluid for Preparing Blood Mimicking Fluid for Wall-Less Flow Phantom.

BACKGROUND: To examine the blood flow and detection of the issues related to it by medical ultrasound, it is extremely important to have suitable blood mimicking fluid (BMF) to be used in vitro and to have a movable or portable Doppler flow phantom to use it as a standardizing tool. As known, the main drawbacks of the currently commercial BMF used in the research studies are high in cost and the long time needed for preparation, which is at least 5-7 h. Moreover, there are only two common scatter particles using in BMF as suspension materials such as nylon (Orgasol) and polystyrene. Thus, we need to prepare BMF with both a new mixture fluid and new scatter particle to be as a reflecting factor of ultrasonic waves, for evaluating the speed of sound of the blood flow in the same method like in the research study of ultrasound with relatively low-cost and less consuming time of preparation. However, both the acoustical and physical features of the Doppler flow phantom components (BMF and tissue mimicking material) must correspond the features of the human tissues to make the examination significance. In addition, the BMF must also represent the hemodynamic features of real human blood. METHODS: In this experiment, a new adequate ternary mixture liquid for preparation of BMF applied and suspended with a new scatter particle material, this scatter particle material called poly (4-methylstyrene), it used to be adequate with the mixture density and for saving neutrally buoyant. This BMF was prepared for use in the test objects or Doppler flow phantom. The poly (4-methylstyrene) particles were applied for suspension in a mixture liquid or fluid based on three items, which were distilled water, propylene glycol (PG), and polyethylene glycol (PEG) (200 Mw). The diameter of poly (4-methylstyrene) particles is 3-8 µm, which determined by specific sieve in a unit of µm, and the density is 1.040 g/ml. RESULTS: Speed of sound, viscosity, density, Backscatter power and attenuation features of mixture fluid or liquid which used for preparing a BMF were measured, discussed, and agreed with draft International Electrotechnical Commission values. CONCLUSIONS: There are three various types of ternary items of mixture fluid (water, PG, and PEG [200 Mw]), and a new type of scatter particle material poly (4-methylstyrene) was utilized for preparing the BMF. The scatter particles and mixture fluid prepared and measured at a temperature that simulates the body temperature 37°C. Moreover, one of the advantages of this new blood that is being cheaper than the commercially available BMF products because the PG and the polyethylene glycol (200 Mw) are much cheaper and more available than glycerol and the Dextran that used usually. In addition, new BMF needs less time for preparation compared to the commercial one.

A Review of Medical Doppler Ultrasonography of Blood Flow in General and Especially in Common Carotid Artery.

Medical Doppler ultrasound is usually utilized in the clinical adjusting to evaluate and estimate blood flow in both the major (large) and the minor (tiny) vessels of the body. The normal and abnormal sign waveforms can be shown by spectral Doppler technique. The sign waveform is individual to each vessel. Thus, it is significant for the operator and the clinicians to understand the normal and abnormal diagnostic in a spectral Doppler show. The aim of this review is to explain the physical principles behind the medical Doppler ultrasound, also, to use some of the mathematical formulas utilized in the medical Doppler ultrasound examination. Furthermore, we discussed the color and spectral flow model of Doppler ultrasound. Finally, we explained spectral Doppler sign waveforms to show both the normal and abnormal signs waveforms that are individual to the common carotid artery, because these signs are important for both the radiologist and sonographer to perceive both the normal and abnormal in a spectral Doppler show.

A Review of Suspension-Scattered Particles Used in Blood-Mimicking Fluid for Doppler Ultrasound Imaging.

Doppler ultrasound imaging system description and calibration need blood-mimicking fluids (BMFs) for the test target of medical ultrasound diagnostic tools, with known interior features and acoustic and physical properties of this fluid (BMF). Physical and acoustical properties determined in the International Electrotechnical Commission (IEC) standard are specified as constant values, the materials used in the BMF preparation should have values similar to the IEC standard values. However, BMF is ready-made commercially from a field of medical usage, which may not be appropriate in the layout of ultrasound system or for an estimate of novel imaging mechanism. It is often eligible to have the capability to make sound properties and mimic blood arrangement for specific applications. In this review, sufficient BMF materials, liquids, and measures are described which have been generated by utilizing diverse operation mechanism and materials that have sculptured a range of biological systems.