Comparison of microvascular flow imaging and contrast-enhanced ultrasound for blood flow analysis of cervical lymph node lesions

Effectiveness of microvascular flow imaging for radiofrequency ablation in recurrent thyroid cancer: comparison with power Doppler imaging

OBJECTIVES

To compare microvascular flow imaging (MVFI) and power Doppler ultrasonography imaging (PDUS) for detecting intratumoral vascularity in recurrent thyroid cancer both before and after radiofrequency ablation (RFA).

METHODS

This retrospective study included 80 patients (age, 57 ± 12 years; 54 women) with 110 recurrent tumors who underwent RFA between January 2021 and June 2023. A total of 151 PDUS and MVFI image sets were analyzed (85 pre-RFA, 66 post-RFA). Two readers assessed vascularity on the images using a four-point scale with a 2-week interval between PDUS and MVFI to estimate inter-reader agreement. Intra-reader agreement was determined by reinterpreting images in reverse order (MVFI-PDUS) after a 1-month gap. Additionally, diagnostic performance for identifying viable tumors after RFA was assessed in 44 lesions using thyroid-protocol CT as a reference standard.

RESULTS

MVFI demonstrated higher vascular grades than PDUS, both before (reader 1: 3.04 ± 1.15 vs. 1.93 ± 1.07, p < 0.001; reader 2: 3.20 ± 0.96 vs. 2.12 ± 1.07, p < 0.001) and after RFA (reader 1: 2.44 ± 1.28 vs. 1.67 ± 1.06, p < 0.001; reader 2: 2.62 ± 1.23 vs. 1.83 ± 0.99, p < 0.001). Inter-reader agreement was substantial (κ = 0.743) and intra-reader agreement was almost perfect (κ = 0.840). MVFI showed higher sensitivity (81.5%-88.9%) and accuracy (84.1%-86.4%) than PDUS (sensitivity: 51.9%, p < 0.01; accuracy: 63.6-70.5%, p < 0.04), without sacrificing specificity.

CONCLUSION

MVFI was superior to PDUS for assessing intratumoral vascularity and showed good inter- and intra-reader agreement, highlighting its clinical value for assessing pre-RFA vascularity and accurately identifying post-RFA viable tumors in recurrent thyroid cancer.

CLINICAL RELEVANCE STATEMENT

Microvascular flow imaging (MVFI) is superior to power-Doppler US for assessing intratumoral vascularity; therefore, MVFI can be a valuable tool for assessing vascularity before radiofrequency ablation (RFA) and for identifying viable tumors after RFA in patients with recurrent thyroid cancer.

KEY POINTS

The value of microvascular flow imaging (MVFI) for evaluating intratumoral vascularity is unexplored. MVFI demonstrated higher vascular grades than power Doppler US before and after ablation. Microvascular flow imaging showed higher sensitivity and accuracy than power Doppler US without sacrificing specificity.

Smart scanning: automatic detection of superficially located lymph nodes using ultrasound - initial results

Over the last few years, there has been an increasing focus on integrating artificial intelligence (AI) into existing imaging systems. This also applies to ultrasound. There are already applications for thyroid and breast lesions that enable AI-assisted sonography directly on the device. However, this is not yet the case for lymph nodes.The aim was to test whether already established programs for AI-assisted sonography of breast lesions and thyroid nodules are also suitable for identifying and measuring superficial lymph nodes. For this purpose, the two programs were used as a supplement to routine ultrasound examinations of superficial lymph nodes. The accuracy of detection by AI was then evaluated using a previously defined score. If available, a comparison was made with cross-sectional imaging.The programs that were used are able to adequately detect lymph nodes in the majority of cases (78.6%). Problems were caused in particular by a high proportion of echo-rich fat, blurred differentiation from the surrounding tissues and the occurrence of lymph node conglomerates. The available cross-sectional images did not contradict the classification of the lesion as a lymph node in any case.In the majority of cases, the tested programs are already able to detect and measure superficial lymph nodes. Further improvement can be expected through specific training of the software. Further developments and studies are required to assess risk of malignancy. · The inclusion of AI in imaging is increasingly becoming a scientific focus.. · The detection of lymph nodes is already possible using device-integrated AI software.. · Malignancy assessment of the detected lymph nodes is not yet possible.. · Rink M, Künzel J, Stroszczynski C et al. Smart scanning: automatic detection of superficially located lymph nodes using ultrasound - initial results. Fortschr Röntgenstr 2024; DOI 10.1055/a-2331-0951.

Efficacy and safety of percutaneous ultrasound-guided thermal ablation in the treatment of cervical metastatic lymph nodes from papillary thyroid carcinoma

OBJECTIVE

To evaluate the efficacy and safety of percutaneous ultrasound-guided thermal ablation in the treatment of cervical metastatic lymph nodes (LNs) from papillary thyroid carcinoma (PTC).

MATERIALS AND METHODS

A total of 77 patients with 79 LNs ablated by microwave ablation (MWA) or radiofrequency ablation (RFA) between September 2018 and October 2022 were enrolled in this study. After treatment, patients were followed up with measurement of diameters of LNs and serum thyroglobulin (s-Tg) at 1, 3, 6, and 12 months and annually thereafter. The paired t-test was used to compare the changes of s-Tg level, diameters of LNs before and after ablation.

RESULTS

There were no serious complications related to ablation while one case of incomplete ablation in MWA was found during follow-up. The mean longest and shortest diameter of the ablated LNs reduced from 11.6 ± 4.3 mm to 5.0 ± 4.1 mm (p < 0.001), and from 6.1 ± 1.9 mm to 3.0 ± 2.5 mm (p < 0.001) at the last follow-up visit. Besides, the final volume reduction rate (VRR) was 61.8 ± 56.4% (range, -67.0 -100%). The complete disappearance rate was 46.8%, but there were 4 (5.1%) LNs becoming bigger than before. The average s-Tg level was 9.2 ± 26.6 ng/mL, a data significantly decreased to 3.7 ± 7.0 ng/mL at the last follow-up, but no statistical difference was shown.

CONCLUSION

Thermal ablation is an effective and safe modality for the treatment of metastatic LNs from PTC.

An observational study of microcirculation among healthy individuals by age and sex

OBJECTIVE

This study measured normal ranges of microcirculatory parameters in healthy individuals and investigated differences in parameters by age and sex.

METHODS

Participants were enrolled into three groups with equal numbers of male and female: young (20-39 years), middle-aged (40-59 years), and elderly (60-79 years). Sublingual microcirculation images were obtained using the incident dark field (IDF).

RESULTS

A total of 75 female and 75 male healthy individuals were enrolled. The elderly group had a higher TVD (26.5 [2] vs. 25.2 [1.8]; p = 0.019) and a lower PPV (97 [2] vs. 98 [3]; p = 0.03) than did the young group. In the elderly group, systolic blood pressure (SBP) and mean arterial pressure (MAP) were moderately and positively correlated with MFI score (r = 0.407, p < 0.05, and r = 0.403, p < 0.05, respectively). The female participants had a lower MFI score than did the male participants (2.9 [2.8-3] vs. 3.0 [2.9-3]; p = 0.015).

CONCLUSIONS

This study revealed the range of microcirculatory parameters between different ages and sexes in healthy individuals. We found that blood pressure levels were correlated with microcirculatory parameters, especially in elders and female.