In this review, the flow phantoms and 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 by Doppler ultrasound (US) scanning which demands tissue-mimicking materials (TMMs). TMM phantoms are commercially available and readymade for medical US applications. Furthermore, the commercial TMM phantoms are proper for US purpose or estimation of diagnostic imaging techniques according to the chemical materials used for its preparation.

Background: Mural lesions of gallbladder on ultrasound (US) are often difficult to characterize as benign or malignant. Purpose: The aim of the study was to evaluate the role of contrast-enhanced US (CEUS) in characterization of gallbladder (GB) wall lesions and making distinction between benign wall thickening and GB adenocarcinoma, utilizing both quantitative and qualitative parameters. Methods: A total of 26 patients with GB wall lesions detected on sonography underwent CEUS. Lesions were evaluated on the basis of morphological imaging features, enhancement pattern, dynamic real-time contrast uptake, and intralesional vascularity. Results: Overall, 19 patients had final diagnosis of GB adenocarcinoma, whereas seven patients had benign etiology. CEUS has enabled the differentiation of nonenhancing tumefactive sludge from enhancing mural lesions, thus improving the accuracy of morphological assessment of lesions. The intactness of outer wall was better assessed on CEUS. The dynamic postcontrast assessment showed that carcinoma showed early washout of contrast compared to benign thickening (P = 0.002). Nonlayered mural enhancement or thick enhancing inner layer with nonenhancing thin outer layer was associated with adenocarcinoma. The classification of intralesional vascularity on CEUS was not helpful in distinguishing benign lesions and adenocarcinoma. Conclusion: CEUS can increase the diagnostic confidence in differentiation between benign mural lesions and adenocarcinoma of GB.

Background: This study evaluated the ultrasonographic and clinical findings of two groups with rhabdomyolysis, who showed abnormal or normal ultrasonographic findings of kidneys. Methods: Two groups (n = 78) of abnormal (A) and normal (B) renal ultrasonographic findings were included. Multiple laboratory findings were assessed within 2 days before or after ultrasonography. Student's t-test or Mann–Whitney U-test was used for statistical analysis. Results: The variable causes of rhabdomyolysis were intense exercise, burn, operation, shivering, and drug intoxication, etc. Group A (n = 26; M:F = 19:7) showed enlarged both kidneys, increased parenchymal thickness, and increased (n = 23, 88.5%) or decreased (n = 3, 11.5%) cortical echogenicity. Group A also showed elevated blood urea nitrogen (BUN), creatinine, potassium, and prolonged activated partial thromboplastin time (aPTT), compared with those in Group B (n = 52; M:F = 36:16), and these results were statistically significant (P < 0.01). The myoglobin in serum and urine, creatine kinase, prothrombin time, dark urine, and microscopic hematuria were not statistically different between the two groups. Conclusion: Patients with elevated BUN, creatinine, potassium, and prolonged aPTT showed the ultrasonographic findings of acute kidney injury, but other parameters were not statistically different between the two groups.

Background: Color Doppler ultrasonography of intrarenal arterial Resistive Index (RI), performed early after kidney transplant, has proven to reliably predict short-term allograft function. The aim of this study was to assess whether early Doppler assessment could correlate with long-term renal function. Methods: This was a retrospective study of intrarenal RI using ultrasound in 41 stable kidney transplant patients who underwent RI assessment within 1 month after the transplant. Color Doppler ultrasonography was done to calculate the intrarenal RI within the first 4 weeks after transplant. The mean values of the intrarenal RI of the interlobar arteries of the allograft kidneys were measured and recorded. The data were analyzed with the aid of computer-based SPSS 20.0 software for windows (IBM, International Business Machines Corporation, Company, Armonk, New York, USA). Results: Older recipient age, active smoking, and proteinuria were associated with a higher intrarenal RI. Multivariate analyses showed that renal RI and donor age were independent predictors of allograft outcome. Kaplan–Meier estimates of cumulative graft survival were significantly worse in patients who had the values of the RI of 0.7 or more than they were in patients who had the values of the RI of <0.7. Conclusion: This study reveals that renal RI determined within the 1^st month after renal transplant correlates with long-term allograft function in kidney transplant recipients.

Background: The objective of this study was to determine the feasibility of assessing tendon quality as quantified by histology through changes in quantitative ultrasound measures. Methods: Eight cadaveric shoulders (four with a small supraspinatus tendon tear) were examined using conventional B-mode ultrasound in the transverse plane by internally rotating and hyperextending the humerus. Quantitative ultrasound measures (skewness, kurtosis, variance, and echogenicity) were calculated based on the grayscale distribution of the ultrasound image taken of the supraspinatus tendon near the insertion site. The specimens were then dissected to the supraspinatus tendon where tendon biopsies were taken near the insertion site, mid-substance, and myotendinous junction. Through histology, tendon quality was evaluated based on collagen fiber organization, fatty infiltration, nuclei shape, and cellularity. Correlations between quantitative ultrasound measures and histological grades of tendon quality were determined through Pearson or Spearman's rho correlations. Results: A total of three significant correlations between quantitative ultrasound measures and histological parameters of tendon quality were found. Significant correlations between kurtosis and cellularity at the insertion site (r = 0.724) (P < 0.05) as well as variance and fatty infiltration at the myotendinous junction (ρ = −0.843) (P < 0.05) and for the whole tendon (ρ = −0.826) (P < 0.05) were found. Conclusion: The results show the potential for quantitative ultrasound measures to assess factors of tendon quality that can only be determined through histology. With further development of the methodology that utilizes quantitative ultrasound measures, clinicians might be able to evaluate the tendon quality noninvasively in future.

Background: The purpose of this retrospective study is to investigate the association of qualitative and semiquantitative strain elastography (SE) features with factors such as lesion size, skin-to-lesion distance, and patient's age in fibroadenomas and to discuss false-positive results. Methods: A total of 120 lesions that were performed SE with histopathologically confirmed fibroadenoma were included in the study. All images were reviewed from the archiving system with a consensus of two radiologists. Tsukuba elasticity score was used for color scoring (from 1 to 5). Lesions with strain ratio (SR) ≥2.27 and color scale score of 4 or 5 were considered as false positive. The patients were divided into two groups according to the age: <50 and ≥50 years old. Regard of the size, lesions were divided into two groups: <15 mm and ≥15 mm. The distances of the lesions to the skin were also divided into two groups: <5 mm and ≥5 mm. Statistical analysis to identify associations between these groups and SR was carried out with Pearson Chi-square test and Fisher's exact test. The false-positive rates were calculated. Results: There was no statistically significant difference between patients' age, lesion size, skin-to-lesion distance, and SR values. The false-positive rate was 21.66% for SR, while it was 3.33% for color scale. Conclusion: SR values of the fibroadenomas were not affected by factors such as age, lesion size, and depth. In addition, false-positive rates significantly decrease when color scale scores are evaluated for fibroadenomas.

Background: The purpose of this study was to evaluate the diagnostic value of transrectal real- time strain elastography (RTE) in identifying prostatic carcinoma (PCa). Methods: 60 patients suspected of having PCa based on abnormal digital rectal examination and raised prostate specific antigen levels underwent transrectal ultrasound (TRUS), color Doppler (CD) and RTE. Elastograms were scored on a five point scale based on distribution of strain in relation to hypoechoic area on TRUS. Twelve core systematic biopsy as well as targeted biopsy was performed from suspicious areas on TRUS and RTE. Diagnostic performance of sonoelastography was evaluated using histopathology as reference standard. Results: Histopathology revealed cancer in 28 out of 60 patients (47%) studied. Gleason score ranged from 6 to 9. The sensitivity, specificity, positive predictive value (PPV), and negative predictive value (NPV) of TRUS in detecting prostate cancer were 78.57%, 81.25%, 78.57%, and 81.25%, respectively. On CD evaluation 87.5% (n = 28) of benign lesions showed symmetric, radial flow compared to 14.3% (n = 4) of malignant lesions (P < 0.0001). The sensitivity and specificity of RTE was 89.29% and 56.25% with PPV and NPV being 58.13% and 82.35%, respectively. Higher elastography score was found to be significantly associated with malignant histopathology (P = 0.004). Cancer detection rate with RTE was greater for tumors with higher Gleason score. Conclusion: RTE was found to have better sensitivity than TRUS as well as combination of TRUS and CD. Although less specific, RTE can be an effective adjuvant tool to TRUS for guidance of biopsy and improve detection rate of PCa.

The “snowstorm” sign refers to the ultrasound appearance of motile hyperechoic specks within synovial fluid and has been reported to have a high specificity for gout. We describe three additional etiologies commonly encountered in the rheumatology clinic that can produce a snowstorm: calcium pyrophosphate deposition disease, fibrin collections/rice bodies, and gas bubbles in viscous synovial fluid.

Background: Intervention under ultrasonography (US) guidance has become increasingly prevalent in recent years. This study aimed to assess the treatment response to US-guided musculoskeletal interventions in daily practice. Methods: This retrospective study sought to identify the treatment response to US-guided interventions in different tissues conducted between January 2017 and December 2018. The treatment response to various US-guided interventions in different tissues was recorded. The response was further classified into positive response and negative response according to the improvement of symptoms or satisfaction of the treatment. Results: Among the 605 interventions included for data analysis, a positive response rate of 81% was observed in this study for all US-guided interventions, ranging from 70% to 88% in different categories. Conclusion: This real-world analysis demonstrated the effectiveness of various US-guided interventions without serious complications. We recommend US as a useful guidance for a variety of injections.

There is a constant quest for a regional anesthetic technique that would provide anesthesia adequately for shoulder surgeries but lacks the complications of an interscalene block, such as phrenic nerve palsy. The nerves to be blocked for a surgery can be analyzed and tailored. We discuss the precise blockade of the superior and middle trunk of the brachial plexus along with superficial cervical plexus block using ultrasound for performing three different shoulder surgeries exclusively under regional anesthesia, in high-risk patients without any clinically observed complications.

Pigmented villonodular synovitis (PVNS) is a rare synovial proliferative disease featuring hemosiderin deposits. Calcium pyrophosphate deposition (CPPD) is a crystal-induced inflammatory arthritis common in the elderly. We reported the case of a 78-year-old male who was under stroke rehabilitation when acute inflammatory and hemorrhagic knee arthritis of his paretic lower limb occurred. CPPD was proven by synovial analysis. Ultrasonography showed widespread synovial nodular lesions in the affected knee and helped guiding difficult arthrocentesis. These led to a rapid diagnosis of PVNS with magnetic resonance imaging. In elderly stroke patients, knee pain, being a common complaint, warrants a careful diagnosis including adequate imaging. This case demonstrates that ultrasonography is an accessible and useful diagnostic tool.