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Thyroid ultrasound with gray-scale and color Doppler is the most helpful imaging modality to differentiate normal thyroid parenchyma from diffuse or nodular thyroid disease by evaluating glandular size, echogenicity, echotexture, margins, and vascularity. The various causes of diffuse thyroid disease often have overlapping sonographic imaging features. Thyroid nodules may be hyperplastic or neoplastic, with most due to benign hyperplastic changes in architecture and benign follicular adenomas; only a small percentage are malignant. A systematic approach to nodule morphology that includes evaluation of composition, echogenicity, margin, shape, and any echogenic foci can guide decision to biopsy or follow nodules., Competing Interests: Disclosure The authors have nothing to disclose., (Copyright © 2020 Elsevier Inc. All rights reserved.)

Objective: For ultrasound, a wide variation is often observed among the number and sequence of images acquired for a particular examination type. Scanner-based protocols are preset pathways in the ultrasound machine that guide a sonographer through the required study images. These protocols can streamline image acquisition by improving consistency and efficiency of ultrasound examinations. This study evaluated whether implementation of scanner-based protocol-driven ultrasound improves efficiency by decreasing the scanning duration and number of images acquired., Materials and Methods: Retrospective evaluation of 437 carotid Doppler examinations, 395 complete abdominal ultrasound examinations with Doppler imaging, and 413 bilateral lower extremity venous Doppler examinations for deep venous thrombosis (DVT) performed by five sonographers before and after implementation of scanner-based protocol-driven ultrasound was performed. The scanning duration and number of images acquired for each study were recorded. Statistical analysis compared the scanning duration and number of images acquired before and after implementation of protocol-driven ultrasound. A p value of < 0.05 was considered significant., Results: A significant decrease in scanning duration occurred for both carotid Doppler ultrasound examinations (decrease by 12.4% [2.7 minutes], p < 0.0001) and complete abdominal ultrasound examinations with Doppler imaging (decrease by 7.5% [2.0 minutes], p = 0.0054) after implementation of protocol-driven ultrasound. The decrease in scanning duration was not significant for lower extremity DVT Doppler examinations (p = 0.4192). In addition, there was a significant decrease in the overall number of images obtained for all three types of studies., Conclusion: Scanner-based protocol-driven ultrasound is an effective method that streamlines image acquisition and significantly improves efficiency in an ultrasound department while ensuring consistency and adherence to accreditation guidelines.

Objective: Volumetric flow measurement with Doppler ultrasound is useful in assessing blood flow as part of an evaluation of arteriovenous fistula maturity in patients undergoing hemodialysis. In this study, we assessed both accuracy and variability in volumetric flow measurements obtained using modern and commercially available ultrasound systems and an in vitro experimental setup., Methods: Volumetric flow measurements using duplex ultrasound were obtained by 3 users operating 5 different systems for randomized flow in the range of 100 to 1000 mL/min. Users performed 3 consecutive measurements at a given flow rate. Data were analyzed using statistical techniques to assess measurement accuracy and variability., Results: Over the span of flow rates studied, the root mean square error (RMSE) for the 5 ultrasound systems ranged from 38.8 to 79.7, 36.8 to 52.0, 73.0 to 85.3, 26.7 to 44.6, and 43.9 to 93.5 mL/min. Corresponding average RMSE values were 60.3, 42.7, 81.1, 37.2, and 64.4 mL/min, respectively. A linear regression analysis of mean interobserver measurements revealed an excellent correlation for all ultrasound systems (r(2) > 99.1%). Assessment of intraobserver measurements revealed no statistically significant differences for any ultrasound system evaluated (P > .94). Comparison of interobserver measurements indicates no statistically significant differences between any of the 5 systems (P > .14)., Conclusions: Modern ultrasound systems are reasonably accurate in blood flow measurement in an experimental setup mimicking clinically relevant blood flow ranges in a hemodialysis fistula. Users need adequate training and experience to perform multiple measurements and use appropriate techniques to minimize errors in flow measurement.

Sonographic evaluation of the genitourinary system is a fast, safe, and effective means to detect renal disease. In conjunction with other modalities, Doppler can depict a variety of abnormalities. However, optimization of Doppler techniques and a solid understanding of Doppler threshold criteria are critical for success, whether in the native or transplanted kidney.

Ultrasound is the initial imaging modality of choice when evaluating the upper extremity venous system. When sonographic findings are equivocal or nondiagnostic, particularly in evaluating the central deep veins, MR venography or catheter venography correlation may be helpful. Ultrasound provides an accurate, rapid, low-cost, portable, noninvasive method for screening, mapping, and surveillance of the upper extremity venous system.

Purpose: To compare various objective ultrasonographic (US) criteria for native arteriovenous fistula (AVF) maturation with subsequent fistula outcomes and clinical evaluation by experienced dialysis nurses., Materials and Methods: US fistula evaluation results were analyzed retrospectively in 69 patients within 4 months after AVF placement; adequacy for dialysis was known in 54. Measurements included minimum venous diameter and blood flow rate. Experienced dialysis nurses examined 30 fistulas clinically. Predictors of fistula adequacy were analyzed with univariate and multivariate logistic regression. Mean fistula diameters and blood flow rates were compared by using analysis of variance or unpaired Student t tests., Results: Fistula adequacy for dialysis doubled if the minimum venous diameter was 0.4 cm or greater (89% [24 of 27]) versus less than 0.4 cm (44% [12 of 27]; P <.001). Fistula adequacy for dialysis was nearly doubled if flow volume was 500 mL/min or greater (84% [26 of 31]) versus less than 500 mL/min (43% [nine of 21]; P =.002). Combining venous diameter and flow volume increased fistula adequacy predictive value: minimum venous diameter of 0.4 cm or greater and flow volume of 500 mL/min or greater (95% [19 of 20]) versus neither criterion met (33% [five of 15]; P =.002). Women were less likely to have an adequate fistula diameter of 0.4 cm or greater: 40% (12 of 30) of women versus 69% (27 of 39; P =.015) of men. No significant differences in blood flow or minimum venous diameter were found during 2-4 postoperative months. Experienced dialysis nurses' accuracy in predicting eventual fistula maturity was 80% (24 of 30)., Conclusion: US measurements of AVF at 2-4 months in patients undergoing hemodialysis are highly predictive of fistula maturation and adequacy for dialysis.

Purpose: To prospectively assess the effect of preoperative ultrasonographic (US) mapping on surgical selection, placement of arteriovenous fistulas (AVFs) and grafts, and negative surgical exploration rates., Materials and Methods: US assessment of the upper extremity arterial and venous anatomy was performed in 70 patients with chronic renal failure before surgical evaluation. The surgeon documented the planned access procedure, which was based on physical examination results, and then reviewed the US preoperative mapping report. The surgical procedure and outcome were recorded., Results: Fifty-two of the 70 patients who underwent mapping had vascular access placement. Preoperative US mapping resulted in a change in the planned surgical procedure in 16 (31%) of the 52 patients. An AVF rather than the planned graft was placed in eight (15%) patients. The AVF placement rate increased from 32% (126 of 395 patients) to 58% (30 of 52 patients). Unsuccessful surgical explorations decreased from 11% (28 of 256) to 0%., Conclusion: Preoperative US mapping before hemodialysis access placement can result in a change in surgical management, with an increased number of AVFs placed and an improved likelihood of selecting the most functional vessels preoperatively. Further study is needed to determine longer term outcomes.

Purpose: To prospectively evaluate the sensitivity of ultrasonography (US) in diagnosing stenosis of hemodialysis access grafts and their drainage veins in patients clinically suspected of having graft dysfunction., Materials and Methods: Thirty-eight patients in whom dysfunction of their hemodialysis access grafts was suspected underwent both Doppler US and angiography. Gray-scale and color US were combined with spectral analysis of the graft, anastomoses, and venous outflow. Flow velocity at anastomoses and suspected stenotic areas was measured. The volume of flow in the graft was also measured. The prospective US criterion for diagnosis of stenosis was a focal twofold or higher elevation of peak systolic velocity (PSV) compared with the PSV immediately upstream. A blinded angiographic evaluation of the graft and drainage veins followed US. Angiographic diagnosis of stenosis required at least 50% narrowing in luminal diameter. US and angiographic results were then compared., Results: Angiography allowed diagnosis of 43 stenoses in 34 patients. US depicted 92% (37 of 40) of these stenoses, with a 94% positive predictive value for any individual patient. Focal 2- to 2.9-times PSV elevation was associated with 75% or greater stenosis. Graft flow volume and resistive index change did not correlate with stenosis., Conclusion: US reliably depicts stenoses of hemodialysis access grafts and drainage veins in a clinically selected population when PSV criteria are used.