Journal of Medical Ultrasonics最新文献

Purpose: Knee pain is a characteristic symptom of early-stage knee osteoarthritis. Recently, the association between knee symptoms and infrapatellar fat pad (IFP) degeneration has garnered attention. This study aimed to clarify the association between ultrasound-derived size and echo intensity (EI) in the IFP and knee symptoms.

Methods: A total of 163 community-dwelling older individuals (women, n = 106; age, 75.1 ± 7.0 years) participated. An ultrasound imaging device was used to assess the area and EI of the superficial and deep parts of the central, medial, and lateral IFP and presence of medial meniscal extrusion (MME) and medial tibial osteophytes. Based on the 2011 version of the Knee Society Knee Scoring System (KSS) symptoms category, the participants were classified into a symptomatic (KSS symptom score < 23, n = 74) or asymptomatic (KSS symptom score ≧23, n = 89) group. Logistic regression analyses were performed with groups as dependent variables and EI and area of the IFP as independent variables.

Results: EI of the superficial part of the medial IFP was significantly associated with knee symptoms, adjusting for age, sex, body mass index, MME, and medial osteophytes (p < 0.05). MME was also significantly associated with knee symptoms (p < 0.05). EI of the other parts, area of any parts, and medial osteophytes were not associated with knee symptoms.

Conclusion: These findings suggested the utility of evaluating EI on the superficial part of the medial IFP and MME as the articular structures associated with knee symptoms.

Purpose: Parathyroid lipoadenomas are difficult to recognize preoperatively; hence, they may remain undetected. Difficulty in recognition is thought to be due to the adipocytes present in the tumor. This study aimed to clarify the impact of adipocytes as a component of parathyroid adenomas on ultrasound evaluation.

Methods: Eighteen parathyroid adenoma cases, in which the adipose tissue accounted for more than 10% of the tumors, were included in this study. Of these, five were consistent with lipoadenomas. Twenty-five consecutive patients with parathyroid adenoma without adipocytes were used as controls.

Results: Ultrasonography revealed a lipoadenoma detection rate of 20.0%. This increased to 80.0% at re-examinations performed after obtaining information from other imaging modalities. Compared with parathyroid adenoma cases with no adipocytes or few adipocytes, the frequencies of ill-defined margins, iso- and/or hyperechogenicity, heterogeneous consistency with a two-tone pattern, poor vascular flow, no polar artery, and no hyperechoic line were significantly higher in parathyroid lipoadenoma cases. The hyperechoic and isoechoic areas in tumors with a two-tone pattern correspond to adipocyte- and parathyroid cell-rich areas, respectively. The lipoadenoma tumor sizes measured using ultrasound tended to be smaller than the actual sizes.

Conclusions: The characteristic ultrasound findings of lipoadenomas were clearly different from those of parathyroid adenomas with or without adipocytes. We believe that our findings may contribute to an increased detection rate of lipoadenomas and allow us to consider them in the differential diagnosis.

Purpose: Early detection and quantitative evaluation of liver steatosis are crucial. Therefore, this study investigated a method for classifying ultrasound images to fatty liver grades based on echo-envelope statistics (ES) and convolutional neural network (CNN) analyses.

Methods: Three fatty liver grades, i.e., normal, mild, and moderate-to-severe, were defined using the thresholds of the magnetic resonance imaging-derived proton density fat fraction (MRI-PDFF). There were 10 cases of each grade, totaling 30 cases. To visualize the texture information affected by the deposition of fat droplets within the liver, the maps of first- and fourth-order moments and the heat maps formed from both moments were employed as parametric images derived from the ES. Several dozen to hundreds of regions of interest (ROIs) were extracted from the liver region in each parametric image. A total of 7680 ROIs were utilized for the transfer learning of a pretrained VGG-16 and classified using the transfer-learned VGG-16.

Results: The classification accuracies of the ROIs in all types of the parametric images were approximately 46%. The fatty liver grade for each case was determined by hard voting on the classified ROIs within the case. In the case of the fourth-order moment maps, the classification accuracy of the cases through hard voting mostly increased to approximately 63%.

Conclusions: The formation of parametric images derived from the ES and the CNN classification of the parametric images were proposed for the quantitative diagnosis of liver steatosis. In more than 60% of the cases, the fatty liver grade could be estimated solely using ultrasound images.

Purpose: This retrospective study aimed to investigate the role of an additional high mechanical index (MI) setting scan during the post-vascular phase (PVP) in detecting deep-seated hepatocellular carcinoma (HCC) lesions.

Methods: A total of 805 confirmed HCCs, which underwent Sonazoid-based contrast-enhanced ultrasound (CEUS) between January 2014 and October 2021, were included. Low MI scan was initially employed for lesion detection during the PVP, followed by high MI scan. Propensity score matching (PSM) was utilized to address confounding variables.

Results: Of the 805 study lesions, 668 were detected as perfusion defects at the initial low MI setting, while 137 remained undetected. Among these 137 undetected lesions, 77 were identified at the subsequent high MI setting, whereas 60 remained undetected. Lesions that were larger (18.69 ± 11.27 mm vs. 16.55 ± 7.42 mm, p = 0.006), more superficial (6.06 ± 2.41 cm vs. 7.40 ± 2.74 cm, p < 0.001), and hypoechoic (482/668 vs. 62/137, p < 0.001) were detectable at the initial low MI setting. Male patients benefited more from the additional high MI scan (63/97 vs. 14/40, p < 0.001). Lesions identified with additional high MI were larger (18.30 ± 8.76 mm vs. 14.30 ± 4.34 mm, p < 0.001) and deeper than undetected ones (8.48 ± 2.48 cm vs. 6.02 ± 2.43 cm, p < 0.001). After PSM, depth was shown to be an independent predictor in multivariate analysis (odds ratio: 1.557, 95% confidence interval: 1.249-1.941). The depth cutoff was 7.75 cm, with a sensitivity of 0.681, specificity of 0.851, and area under the curve of 0.774.

Conclusions: The additional high MI setting scan during the PVP of Sonazoid-based CEUS leads to enhanced detection of deep-seated HCCs.

Purpose: Acoustic radiation force impulse (ARFI) elastography and contrast-enhanced ultrasonography (CEUS) are emerging techniques that are becoming common in ultrasound examinations. We previously reported that ARFI (push pulse) induced lung hemorrhage in rabbits, indicating that greater risks are associated with ARFI than with conventional ultrasound. In this study, we assessed the risk of lung hemorrhage under a combination of ARFI elastography and CEUS, considering potential exacerbation of ARFI-induced lung hemorrhage as a result of the ultrasound contrast agent (UCA) used in CEUS.

Methods: Twenty-three rabbits were divided into non-UCA and UCA groups. ARFI exposure parameters were set at six mechanical index (MI) levels (0.29, 0.45, 0.60, 0.88, 1.0, 1.39) in non-UCA groups and five MI levels (0.29, 0.66, 0.88, 0.97, 1.25) in UCA groups. Lung exposure was performed bilaterally through the intercostal space in each rabbit. Lung damage was assessed through macroscopic and microscopic observation post euthanasia.

Results: Lung hemorrhage was detected at MI_0.3 levels of 0.88 or higher. Logistic regression analyses showed that MI_0.3 was a statistically significant factor for occurrence of lung hemorrhage in both non-UCA and UCA groups, and the MI_0.3 threshold (ED₀₅) for inducing lung hemorrhage was 0.68 and 0.71, respectively. However, multivariate logistic regression and linear regression analyses across all samples indicated that UCA did not significantly affect the occurrence or area of lung hemorrhage.

Conclusion: This study demonstrates that UCA does not significantly worsen ARFI-induced lung hemorrhage in terms of occurrence or severity. However, risks and benefits of ARFI elastography on the lung should be considered, irrespective of UCA administration.

Purpose: Most studies on the performance of first-trimester cardiac screening have concentrated on comparing the detection rate between different protocols and not on the actual reason for false-negative results. Herein, we report the performance of first-trimester congenital heart disease (CHD) screening and factors that may affect the detection rate of CHDs.

Methods: This retrospective observational study included patients who underwent first-trimester screening and subsequently gave birth at our facility. We analyzed the performance of first-trimester screening for CHD and major CHD (CHD requiring cardiac surgery or interventional catheterization within 12 months of birth).

Results: Of the 6614 fetuses included, 53 had CHD and 35 had major CHD. For the prenatal diagnosis of CHD, the detection rate, specificity, positive predictive value, negative predictive value, and first-trimester detection rate for CHD were 64.1%, 99.9%, 94.4%, 99.7%, and 82.9%, respectively; the respective values for major CHD were 85.7%, 99.96%, 93.75%, 99.92%, and 85.7%. The detection rate was not significantly different when classified by crown-rump length or number of fetuses. A weak correlation was observed between low detection rate of major CHD and lower maternal body mass index (BMI) (correlation ratio: 0.17). The detection rate was significantly higher when the fetus was scanned with its spine at the 5-7 o'clock position (posterior spine) than at other positions (odds ratio: 3.82, 95% confidence interval: 1.16-12.5, p = 0.02).

Conclusion: Posterior spine contributes to an improved diagnostic rate in first-trimester CHD screening. In addition, sonographers must recognize that low maternal BMI is a risk factor of false-negative results.

Ultrasound (US) has high specificity and sensitivity, and it should be performed first for patients with suspicion of biliary tract cancer. However, the complicated anatomy in addition to the gas images makes it difficult to delineate the entire extrahepatic bile duct (EHBD). The keys to depiction of EHBD are the "J" shape manipulation in the left lateral decubitus position and the use of magnified images with high-frequency transducers. Furthermore, indirect findings such as gallbladder (GB) distension, BD dilatation, and debris echo in the GB and BD are also important for detecting occult lesions, particularly in the ampullary region of Vater. For the differential diagnosis of BD wall thickening, the spreading pattern in the long and short axial directions should be assessed first. Then, the characteristics of the innermost hyperechoic layer (IHL) and outermost hyperechoic layer (OHL) should be evaluated. Asymmetrical wall thickening, absence of IHL, and presence of irregularity or discontinuity in OHL are characteristic patterns of cholangiocarcinoma (CCA). Because CCA is the most common BD polypoid lesion, it is important to diagnose tumor extension and depth invasion in addition to differential diagnosis. Nodular-type CCA is usually hypoechoic and more likely to invade vertically. In contrast, papillary-type CCA is often hyperechoic and extends laterally. Contrast‑enhanced US may be useful for evaluating these findings. However, if the possibility of CCA cannot be ruled out or a definitive diagnosis is needed, a transpapillary biopsy or endoscopic US-guided tissue acquisition should be considered.