Inter-Gender Pelvic Shape Variations as a Cause of DDH Overdiagnosis.

OBJECTIVE: Developmental dysplasia of the hip (DDH) is an abnormal relationship between the acetabulum and the head of the femur. Plain x-ray of both hips at the age of 3 months is still in use in some countries. On plain films, classic lines and angles are evaluated to meet current guidelines for positive DDH. Among these is the acetabular angle (AA), which most did not exceed 30° in normal pelvis regardless of gender. A flat promontory gives the impression of a high AA angle, whereas a sharp promontory gives the impression of a low AA angle. MATERIALS AND METHODS: All anteroposterior (AP) pelvic digital x-ray studies performed to rule out DDH were collected from the PACS systems. A novel angle was measured between a line parallel to the lateral aspect of the region of the inferior iliac spines and a line that extends along the acetabular roof to quantify the roundness of the iliac promontory. We called the former line the Miral line and the formed angle the iliac promontory angle. RESULTS: We show that the promontory shape is significantly different between genders, and therefore it is mistaken to generalize an upper AA limit for males and females. In addition, we show that the current guideline of the upper limit of AA did not predict the incidence of DDH. CONCLUSION: We suggest that the current practice is introducing a high rate of false positive, especially among females, and the current guidelines on AA should be reviewed and assigned separately for males and females. This is more important for countries that did not utilize the ultrasonographic assessment for DDH.

Career caseload predicts interobserver agreement on the final classification of a mammogram.

INTRODUCTION: Differences in radiologists' experience can potentially introduce interobserver variability in reading mammograms. This work investigated the effect of radiologists' experience on agreement on mammographic final classification. METHODS: This was a cross-sectional study. Seventeen radiologists were asked to provide their final impression on 60 mammogram cases. Experience parameters included breast subspecialty, years reading mammograms, cases read per year and career caseload. Career caseload was calculated by multiplying years reading mammograms by the average number of cases read per year. The interobserver agreement was calculated using Cohen kappa (κ). The difference in κ between radiologists' groups was compared using the independent-sample t-test and analysis of variance. RESULTS: The average interobserver agreement was 0.25 (fair). A small difference was found in favour of breast radiologists against general radiologists (κ = 0.21 and 0.29, respectively, P = 0.019). Years reading mammograms and cases read per year did not seem to significantly affect the interobserver agreement (P = 0.056 and 0.273 respectively). Radiologist who had career caseload of at least 2500 cases showed significantly higher consistency than those who read less. κ for radiologists who had career caseload of 2500-4000 cases and >4000 cases was 0.33 and 0.28, respectively, whereas for <2500 κ was 0.17 (P = 0.001). CONCLUSION: A fair level of interobserver agreement on the final classification of a mammogram was demonstrated. Career caseload was the most important experience parameter to associate with the interobserver agreement. Training strategies aiming to increase radiologists' career caseload may be beneficial.

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.

Compliance With Radiation Protection Practices Among Radiologists.

BACKGROUND: Radiologists are at higher risk of adverse health effects due to their occupational radiation exposure; therefore, applying protection techniques is imperative. Studies on radiologists' compliance in this regard are scarce. We aimed to assess compliance with radiation safety practices among radiologists. METHODS: Questionnaires were distributed to radiologists in tertiary hospitals. The questionnaire was designed to assess compliance in three domains: using personal protective devices, using exposure-reduction techniques during fluoroscopic exposures, and using personal dose-monitoring devices. Descriptive analysis of the compliance was performed. RESULTS: Sixty-two radiologists were included in the analysis. Use of leaded aprons and thyroid shields was commonplace, whereas only 3.2% ever use leaded eyeglasses. About half of the radiologists always considered reducing the time of exposure and avoided exposure by the primary beam, and the other half did that sometimes. Most of the radiologists (66.1%) always complied with reducing the number of unnecessary exposures, and the rest only complied sometimes. Most of the radiologists (93.5%) always used single personal dose-monitoring devices, most commonly at the neck level over the collar. There was no difference in compliance between different sexes, position descriptions, hospital types, hospital sizes, or years of experience. CONCLUSION: Future compliance improvement strategies for radiologists should focus on use of thyroid shields and leaded eyeglasses and use of exposure-reduction techniques during fluoroscopic operations.

High-frequency ultrasound for in vivo measurement of colon wall thickness in mice.

Mouse models are becoming increasingly important in the study of molecular mechanisms of colorectal disease and in the development of novel therapeutics. To enhance this phase of preclinical research, cost-effective, easy to use noninvasive imaging is required to detect and monitor changes in the colon wall associated with disease pathology. This study investigated the feasibility of using 40-MHz (high frequency) B-mode ultrasound (HF-US) to image the normal mouse colon and measure its thickness in vivo by establishing a robust imaging protocol and conducting a blinded comparison of colon wall thickness (CWT) measurement between and within operators. The in vivo and ex vivo appearance of mouse colon under HF-US revealed distinct patterns. Colon wall thickness was reproducibly and accurately measured using HF-US compared with histology measurement. The technique was more sensitive in detecting changes in CWT in distal than proximal colon as it showed the highest level of inter- and intraoperator reproducibility. Using the protocol described, it is possible to detect changes in thickness of 0.09 mm and 0.25 mm in distal and proximal colon, respectively. In conclusion, HF-US provides an easy to use and noninvasive method to perform anatomical investigations of mouse colon and to monitor changes in CWT.