Ultrasonography最新文献

Purpose: This study compared the imaging performance of low-mechanical-index phase-inversion harmonic imaging (low-MI PIHI) with conventional contrast-enhanced ultrasonography (CEUS) during the Kupffer phase (KP) of Sonazoid-enhanced imaging for visualizing hepatic lesions, focusing on lesion conspicuity and overall image quality.

Methods: This prospective study was approved by the Institutional Review Board and included 71 patients with 72 focal liver lesions examined between February 2023 and January 2024. All patients underwent Sonazoid-enhanced CEUS. Three image sets were acquired for each lesion: baseline B-mode imaging, conventional KP imaging, and low-MI PIHI KP imaging. Two independent radiologists, blinded to clinical information, independently evaluated lesion conspicuity, border delineation, and overall image quality using a 5-point Likert scale.

Results: Baseline B-mode imaging demonstrated the lowest lesion conspicuity scores, which improved with conventional KP imaging and were highest with low-MI PIHI KP imaging (all P<0.001). Compared with conventional KP imaging, low-MI PIHI KP imaging provided significantly higher lesion conspicuity for both reviewers (P<0.001), with the most pronounced improvement observed in hepatocellular carcinomas within cirrhotic livers, where conspicuity scores nearly doubled (P<0.001). Lesion border delineation also improved significantly for both reviewers (P<0.001). Overall image quality was consistently superior with low-MI PIHI KP imaging (P≤0.003). These advantages were particularly evident for small lesions (≤2 cm) and in cirrhotic liver backgrounds.

Conclusion: Low-MI PIHI KP imaging significantly enhances hepatic lesion conspicuity and margin delineation compared with conventional CEUS harmonic imaging, while also improving overall image quality. These improvements may support more confident lesion detection and facilitate image-guided procedures.

Ultrasound (US)-guided ablation has evolved from early ethanol injection into a cornerstone curative strategy for hepatocellular carcinoma. This review traces the technological advancement of US guidance from early pioneering efforts to present standardized techniques and future innovations. It discusses how modern tools-fusion imaging, contrast-enhanced US, and artificial fluid techniques-overcome challenges in tumor visibility and accessibility, emphasizing technique optimization rather than energy modality selection. The review also explores future horizons, including artificial intelligence-driven planning, histotripsy, and immuno-ablation. Ultimately, the authors advocate for a philosophy of "optimized ablation," prioritizing technical mastery of evolving US technologies to maximize therapeutic efficacy and patient safety beyond simple expansion of treatment territory.

Purpose: This study aimed to evaluate the clinical utility of transabdominal ultrasound (TAUS) for pancreatic cyst surveillance by assessing its concordance with follow-up computed tomography (CT) and magnetic resonance imaging (MRI) findings and the associated risk of malignancy.

Methods: This retrospective study included 523 patients who underwent TAUS for pancreatic cysts (≥1 cm), followed by contrast-enhanced CT or MRI within a 1-year interval between 2021 and 2022. Cysts were classified as high-risk if they exhibited any high-risk stigmata or worrisome features, and as low-risk otherwise, based on the 2024 international consensus guidelines. TAUS classifications were compared with those from CT/MRI. In a subset of 164 patients with reference standards, malignancy rates were compared between high- and low-risk cysts on TAUS.

Results: The overall cyst identification rate on TAUS was 88.7% (464/523), with identification rates higher in patients with lower body mass index (23.8±3.3 kg/m2 vs. 29.2±3.3 kg/m2, P=0.003) and in those with non-tail cyst locations (92.7% [406/438] vs. 68.2% [58/85] for tail lesions, P<0.001). Among identified cysts, 86 (18.5%) were classified as high-risk and 378 (81.5%) as low-risk. TAUS-based risk classification demonstrated significant correlation with CT/MRI classification (P<0.001). The likelihood of a high-risk cyst on CT/MRI increased with the number of high-risk or worrisome features identified on TAUS. Malignancy rates were significantly higher in high-risk cysts than in low-risk cysts based on TAUS assessment (12.5% [4/32] vs. 1.5% [2/132], P=0.014).

Conclusion: TAUS may serve as a useful noninvasive imaging modality for pancreatic cyst surveillance, particularly in patients with favorable visualization conditions. TAUS features correlated well with CT/MRI findings in identifying high-risk pancreatic cysts, and the presence of multiple worrisome features on TAUS was associated with an increased likelihood of high-risk classification on subsequent cross-sectional imaging.

Purpose: This study was performed to examine the association between preoperative thyroid ultrasound (US) features and the risk of developing hypothyroidism after hemithyroidectomy.

Methods: Patients who underwent hemithyroidectomy between March 2020 and June 2023 were retrospectively included. Postoperative hypothyroidism was defined as a continued need for thyroxine 2 years after surgery. To assess US features suggestive of diffuse thyroid disease, two radiologists evaluated the echogenicity, echotexture, and vascularity of the thyroid parenchyma on preoperative thyroid US images. A US thyroid parenchymal score was defined by summing the scores for these parameters, and a weighted score was also developed using β-coefficients from a multivariable logistic regression model. Model performance was evaluated using the area under the receiver operating characteristic curve (AUC) and integrated discrimination improvement (IDI).

Results: Overall, 398 patients were included, of whom 191 (47.9%) developed postoperative hypothyroidism. Preoperative thyroid-stimulating hormone (TSH), body surface area-adjusted remnant thyroid volume, histologic evidence of thyroiditis, and both unweighted and weighted US thyroid parenchymal scores were identified as significant predictors of postoperative hypothyroidism. The unweighted and weighted US scores were statistically significant predictors in the multivariable analysis (unweighted: odds ratio [OR], 1.36 [95% confidence interval (CI), 1.04 to 1.78]; weighted: OR, 3.05 [95% CI, 1.22 to 7.62]). Although adding US scores did not significantly improve the AUC, it led to significant improvements in IDI (P=0.04 and P=0.03, respectively).

Conclusion: US assessment of the thyroid parenchyma served as an independent predictor of postoperative hypothyroidism and improved discrimination of predicted probabilities based on preoperative TSH.

Purpose: The utility of platelet transfusion for preventing post-biopsy bleeding in patients with cirrhosis and thrombocytopenia remains a topic of debate. This study investigated whether prophylactic transfusion reduces this risk.

Methods: This retrospective study included patients with cirrhosis and thrombocytopenia who underwent ultrasound-guided percutaneous liver biopsy (March 2018-October 2024) at a tertiary institution. Bleeding events were defined as major (requiring intervention or resulting in death) or minor (non-interventional hematoma). Pre- and post-transfusion platelet counts were compared, and bleeding incidence was examined by transfusion status. Logistic regression was used to identify factors associated with bleeding events. Propensity score matching (PSM) and inverse probability of treatment weighting (IPTW) were applied to assess bleeding incidence by transfusion status.

Results: This study analyzed 526 biopsies from 497 patients (mean age, 62.1±10.6 years; 365 men [73.4%]), of whom 42 (8.0%) received prophylactic platelet transfusion. While platelet counts increased after transfusion (from 54.5×109/L to 72.5×109/L, P<0.001), no significant difference was observed in bleeding incidence between the transfused and non-transfused groups (31.0% vs. 20.9%, P=0.128). Multivariate analysis indicated that platelet transfusion was not associated with all bleeding (odds ratio [OR], 1.318; P=0.449) or major bleeding (OR, 1.754; P=0.420). PSM and IPTW analyses similarly revealed no association between transfusion and all bleeding (PSM: OR, 1.173; P=0.739; IPTW: OR, 0.907; P=0.807) or major bleeding (PSM: OR, 0.658, P=0.716; IPTW: OR, 0.863; P=0.876).

Conclusion: Prophylactic platelet transfusion may not provide a universal benefit in patients with cirrhosis and thrombocytopenia, warranting a more tailored approach based on individual risk assessment.

Purpose: This study analyzed the malignancy rate of lymph nodes (LNs) according to the concordance of ultrasound (US) and computed tomography (CT) imaging features in patients with thyroid cancer.

Methods: A retrospective analysis was performed of 277 cytopathologically confirmed cervical LNs (53.1% malignant) from 228 patients with thyroid cancer who underwent US-guided biopsy and preoperative US and CT. Malignancy rates were calculated according to the concordance of US and CT imaging features by matching cortical hyperechogenicity or abnormal vascularity on US (US-echo-vascularity) with strong or heterogeneous enhancement on CT (CT-enhancement), cystic changes on US (US-cystic) with cystic changes on CT (CT-cystic), and echogenic foci on US (US-EF) with calcifications on CT (CT-calcification).

Results: Malignancy rates were significantly higher in positively concordant cases across all imaging features compared to negatively concordant cases (US-echo-vascularity/CT-enhancement: 93.5% vs. 8.2%, P<0.001; US-cystic/CT-cystic: 94.4% vs. 41.3%, P<0.001; and US-EF/CT-calcification: 84.4% vs. 34.5%, P<0.001). Discordance in US-cystic/CT-cystic (96.3% vs. 94.4%, P=0.735) or US-EF/CT-calcification (86.0% vs. 84.4%, P=0.873) findings showed malignancy rates comparable to those for positively concordant cases. However, discordance in US-echo-vascularity/CT-enhancement resulted in a significantly lower malignancy rate than in positively concordant cases (66.8% vs. 93.5%, P<0.001). In this discordant group, CT demonstrated a higher diagnostic odds ratio (3.896 vs. 0.257, P=0.002) and higher sensitivity (81.1% vs. 18.9%, P<0.001) than US.

Conclusion: Positive US/CT concordance across all imaging features, as well as discordance in US-cystic/CT-cystic or US-EF/CT-calcification, strongly suggested LN metastasis. CT-enhancement was particularly reliable when discordant with US-echo-vascularity.

Purpose: Needle tip localization during ultrasound-guided procedures is challenging when the needle is poorly visualized. This study aimed to develop and evaluate a handheld ultrasound system with magnetic needle navigation (HUMaN) that integrates ultrasound imaging and real-time three-dimensional magnetic tracking within a compact form factor.

Methods: HUMaN was designed using a dual-board architecture that incorporates an ultrasound probe, a real-time imaging system, and a magnetic needle guidance module that detects magnetic field disturbances to estimate needle position and orientation. The tracked needle trajectory is superimposed onto ultrasound images, and an active cooling mechanism with optimized airflow was implemented to maintain thermal stability. In vivo imaging feasibility was assessed under institutional review board approval. Needle localization accuracy was evaluated using a custom jig at multiple depths, and surface temperatures were continuously monitored during extended operation.

Results: The system achieved sub-millimeter needle localization accuracy, with a mean bias within 0.1 mm and a precision within 0.3 mm at both 10-mm and 20-mm depths. In vivo ultrasound imaging was successfully demonstrated. Thermal evaluations showed that the device surface temperature remained well below the IEC 60601-1 safety limit (39°C) during 80 minutes of continuous operation.

Conclusion: HUMaN provides accurate needle localization together with fully integrated ultrasound imaging in a handheld, bracket-free design. These findings suggest that the system is well-suited for point-of-care ultrasound procedures that require portability and ease of use.

Purpose: This study aimed to enhance the noninvasive identification of hepatocellular carcinoma (HCC) by modifying the Sonazoid-based contrast-enhanced ultrasound (CEUS) Liver Imaging Reporting and Data System (LI-RADS) through integration of Kupffer-phase (KP) imaging and optimization of washout timing criteria.

Methods: This retrospective two-center study enrolled 558 patients with solitary liver nodules who underwent Sonazoid-based CEUS between August 2022 and September 2024. CEUS features were assessed according to LI-RADS v2017 using predefined washout time windows (2, 5, and 10 minutes). A modified LI-RADS algorithm incorporating KP hypoenhancement was developed. Interobserver agreement was evaluated using the Cohen kappa. Diagnostic performance metrics (area under the curve [AUC], sensitivity, specificity, and positive predictive value) were compared between the modified CEUS LI-RADS algorithms and the Japan Society of Hepatology (JSH) and Korean Liver Cancer Association (KLCA) guidelines using the McNemar and DeLong tests.

Results: For key CEUS features, interobserver agreement was moderate to almost perfect (κ=0.580-0.815). The modified CEUS LI-RADS-10min algorithm demonstrated superior performance over the other algorithms. By reclassifying LR-M nodules with early washout and mild KP hypoenhancement as LR-5, the modified CEUS LI-RADS-10min algorithm achieved the highest diagnostic performance for HCC (AUC, 0.782), improving sensitivity while maintaining specificity (73.7%). Its performance was comparable to that of the KLCA guideline. The JSH guidelines showed the highest sensitivity (91.7%) but the lowest specificity (53.9%).

Conclusion: Integrating KP hypoenhancement with a 10-minute washout window improves the sensitivity of Sonazoid-based CEUS LI-RADS for diagnosing HCC while preserving specificity, providing feasible refinement aligned with established guidelines and promoting standardization.