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.

Background: We evaluated the risk of lateral circumflex femoral artery (LCFA) injury during ultrasound-guided intra-articular hip injections. Methods: This study was divided into three parts. (1) Four ultrasound-guided hip injections were performed on human cadavers. With needles in place, tissues were dissected to expose the LCFA. (2) Ultrasound-trained rheumatologists marked a planned needle trajectory from skin to hip joint on live human ultrasound images during an Observed Structured Clinical Examination (OSCE). Doppler was subsequently activated to locate the LCFA, and the distance between trajectory and arterial signal was recorded. (3) Rheumatologists certified in musculoskeletal ultrasound were surveyed about joint injection vascular complications. Results:(1) In one of the four cadaveric dissections, the needle made direct contact with the LCFA. (2) Of 27 OSCE participants, only two activated Doppler before marking simulated hip injection trajectories. Trajectories passed through LCFA Doppler signal in six (22%) cases. Mean minimal distance from trajectory to arterial signal was 4 mm (range, 0–11 mm). (3) Of 62 survey respondents, 24% stated that they did not use Doppler routinely. While none reported bleeding injuries with their patients, 16% knew of a hip injection-related vascular complication performed by another provider. Conclusion: There is a risk of LCFA injury during ultrasound-guided hip joint injection. Routine use of Doppler should be considered in standard hip injection protocols.

Background: Shear-wave elastography of the kidney has emerged as a potential clinical application of this novel imaging tool. However, normal velocity values for shear-wave elastography involving the cortex of healthy kidneys have not been definitively established, and both inter- and intraobserver reliability has yet to be comprehensively evaluated. Methods: This prospective study involved ultrasound examination of 11 healthy adults. Shear-wave velocity values were obtained at the renal cortex in the longitudinal and transverse planes by both junior (fellow) and senior (attending) radiologists. Results: The mean shear-wave velocity values ranged between 2.82 and 2.9 m/s, which did not vary significantly between observers (junior vs. senior) or method of measurement (longitudinal vs. transverse planes), P = 0.533. However, there was a wide variation for these measurements (0.51–4.99 m/s). Separate analysis of the measurement depth demonstrated no statistically significant association with the shear-wave velocity values, P = 0.477. Conclusion: Our results agree with previous publications and help establish normal shear-wave velocity values and their range for the renal cortex in adults.

Objective: High-resolution ultrasonography (HRUS) has been used recently to characterize median and ulnar nerves but is seldom used to characterize the lower extremity nerves. The reference standard for normal the lower extremity nerves has not been established. Thus, this study measured the cross-sectional areas (CSAs) of the sciatic nerve of 200 healthy male or female volunteers, aged 18–80 using HRUS. These data provide basic clinical data for the use of high-resolution ultrasound for the future diagnosis, treatment, and prognostic evaluation of peripheral neuropathies. Methods: Two hundred healthy volunteers with 400 lower extremities were studied with HRUS. According to their age, the subjects were assigned to young group (18-30 years, n = 75), middle group. (31-60 years, n = 70), and old group(61-80 year, n = 55).Age, sex, height, weight were recorded and CSAs of sciatic nerve were obtained at every predetermined sites. Results: The mean CSAs of sciatic nerves at GS and MGPF were 0.527 ± 0.028 cm² and 0.444 ± 0.026 cm² respectively. Pearson's correlation analysis showed that the mean CSAs were correlated with height and weight. There was no difference in mean CSAs among the three groups (P > 0.05). Women had smaller CSAs of the normal Sciatic nerves than men in two measuring sites (GS, MGPF) (P < 0.05). Conclusion: Peripheral nerve ultrasonography is a reliable and reproducible diagnostic method in the hands of experienced examiners. Normal values for the sciatic nerve nerves are provided by our study. Thus, reference values of Sciatic nerve CSA of the lower extremity can facilitate the analysis of abnormal nerve conditions.

Introduction: Ultrasound (USG) can be a good screening tool to identify high-risk nodule requiring fine-needle aspiration cytology (FNAC). The study aimed to assess the association of USG characteristic of thyroid nodule with malignancy. Methods: A cross-sectional study was performed from August 2011 to July 2012 at Tribhuvan University Teaching Hospital. Patients referred for USG of the neck with thyroid nodule more than 10 mm were offered FNAC and included in the study after taking informed consent. USG characteristics were compared with histopathologic diagnosis of benign or malignant nodule. Results: USG characteristics significantly (P < 0.05) associated with malignancy were as follows: size of thyroid nodule more than 30 mm, ill-defined margin, solid echotexture, hypoechoic lesion, microcalcification, and any form of increased vascularity. High sensitivity was seen in microcalcification, hypoechoic echogenicity, and ill-defined margin and high specificity was seen in ill-defined margin and solid echotexture. Relatively high sensitivity and specificity was found in ill-defined margin. Conclusions: Texture, size, margin, echogenicity, and vascularity are important factors for discriminating benign from malignant nodule. Hypoechogenicity, vascularity of any type, ill-defined margin, and microcalcification were independent predictors of malignancy. None of the characteristics were sensitive and specific to be used independently as screening tool to identify high risk of malignancy.

Background: In normal knees, quadriceps contraction changes the shape of the prefemoral fat pad (PFP). However, in persons with knee osteoarthritis (OA), the functional or morphological changes of the PFP are unclear. This study aimed to clarify the morphological changes in the PFP in individuals with knee OA through ultrasonography. Materials and Methods: Participants were divided into the OA (36 knees; mean age, 74 years), elderly (31 knees; mean age, 70 years), and young (26 knees; mean age, 21 years) groups. The anteroposterior (AP) length of the PFP before and during isometric quadriceps contraction at 0°, 30°, 60°, and 90° knee flexion was measured ultrasonographically. The difference between the maximum and minimum length values, change in length, was also measured. These parameters were compared among the three groups. In the OA group, correlations between the parameters and clinical features (knee pain; visual analog scale, knee range of motion [ROM], Kellgren and Lawrence (K/L) grade, and intercondylar distance) were examined by Spearman and Pearson's correlation coefficient tests. Results: The AP lengths of the PFP before contraction were significantly lower in the OA group than in elderly group and young group at 30° (6.9 ± 2.5 vs. 12.0 ± 3.6 or 11.1 ± 2.7 mm, respectively; in order P = 0.014, P = 0.006) and 60° (6.5 ± 2.0 vs. 9.7 ± 2.5 or 9.1 ± 2.7 mm, respectively; both P < 0.001). The AP lengths of the PFP during contraction were significantly lower in the OA group than in elderly group and young group at 0° (6.7 ± 2.3 vs. 8.8 ± 3.7 or 9.1 ± 1.6 mm, respectively; both P < 0.001), 30° (7.9 ± 2.6 vs. 12.9 ± 3.7 or 13.0 ± 2.6 mm, respectively; both P < 0.001), and 60° (7.1 ± 2.5 vs. 13.5 ± 2.6 or 13.6 ± 3.0 mm, respectively; both P < 0.001). The change in length before maximum isometric quadriceps contraction was significantly lower in the knee OA group than in both elderly and young groups (3.3 ± 1.9 vs. 8.4 ± 2.5 or 6.8 ± 3.0 mm, respectively; both P < 0.001). The change in length during contraction was also significantly lower in the knee OA group than in both the elderly and young groups (3.9 ± 2.3 vs. 8.7 ± 2.3 or 8.9 ± 2.0 mm, respectively; both P < 0.001). In the OA group, change in length during contraction was significantly associated with knee pain (r = −0.476, P = 0.007), knee ROM (r = 0.388, P = 0.019), and Kellgren and Lawrence grade (r = −0.357, P = 0.045). Conclusions: In knee OA, movement of PFP was decreased more than healthy participants. In the knee OA group, the decrease of the morphological change of the PFP showed the relationship between VAS score, knee extension ROM, intercondylar distance (ICD), and K/L grade. An evaluation to the PFP may be required in individuals with knee OA.

We developed a simplified three-dimensional ultrasonic device that can scan a wide area and performed measurements in the scanned area. The system is more compact than magnetic resonance imaging (MRI) systems and can measure random cross sections by acquiring volume data over a wide range through freehand scanning with a magnetic sensor unit that detects the transducer position. The system was applied successfully to a case with a huge myoma. Our system, in ways similar to computed tomography or MRI systems, can support both the objective understanding of the pathology of huge tumors and follow-up determinations of tumor diameters at arbitrary cross sections in the volume data.

Biliary sludge (or very thick bile) is mainly comprised of calcium bilirubinate granules and lesser amounts of cholesterol crystals, and it can produce a layer of low amplitude of echoes in the most dependent part of the gallbladder (GB). In tumefactive biliary sludge, low-amplitude echoes do not form a fluid–fluid level but instead tend to give the appearance of a polypoid mass that is bounded by a smooth margin, round, and lobulated. Differential diagnoses for an echogenic mass in the GB lumen include GB carcinoma, tumefactive sludge, and gangrenous cholecystitis. In this case report, we describe a rare case in which biliary sludge did not form a fluid–fluid level but tended to accumulate and appear as a polypoid mass within the lumen of the GB. The lesion was finally identified as being tumefactive sludge mimicking neoplasm of the GB.

We present a case of acute abdominal pain due to partial torsion of spleen located in its own normal anatomical position in a 20-year-old woman, diagnosed by ultrasound and confirmed on computed tomography and treated laparoscopically.