Risk factors for unresectable pancreatic cancer following high-intensity focused ultrasound treatment.

PURPOSE: Pancreatic cancer is one of the most aggressive malignant tumors with poor prognosis. High-intensity focused ultrasound (HIFU) is an effective and safe treatment option for advanced pancreatic cancer, however, the survival time of patients after the treatment was different. So, the purpose of this study was to evaluate the relationship between the high-risk characteristics and prognosis of unresectable pancreatic cancer after HIFU treatment. PATIENTS AND METHODS: This prospective study included 30 patients with unresectable pancreatic cancer who received HIFU at Beijing Friendship Hospital. Data on patients' tumor size, pain scores, peripheral blood lymphocyte subsets, CA19-9 and contrast enhanced ultrasound (CEUS) features were collected to assess the relationship with overall survival (OS) after HIFU. RESULTS: The median OS from the start of HIFU treatment was 159 days, 95% confidence interval (95% CI): 108-210. The levels of pain were determined by visual analogue scale (VAS) score, and the quartile of the score decreased from 6 (2, 7) to 4 (2, 5) immediately after one session of the treatment (p = 0.001). The diagnostic model showed that high post VAS score and decreasing of peripheral CD4+ T cells were significantly correlated with poor prognosis (p < 0.05), and showed good discrimination ability (AUC = 0.848, 95% CI = 0.709-0.987). CONCLUSION: HIFU can effectively relieve pain in patients with unresectable pancreatic cancer. Post treatment VAS and change of peripheral CD4+ T cells are independent risk factors affecting the prognosis in patients with unresectable pancreatic cancer after HIFU treatment.

Contrast-enhanced ultrasound for evaluating response to pulsed-wave high-intensity focused ultrasound therapy in advanced pancreatic cancer.

OBJECTIVE: To examine whether contrast-enhanced ultrasound (CEUS) parameters in patients with advanced pancreatic cancer could be used to assess response to treatment with pulsed-wave high intensity focused ultrasound (PW-HIFU). METHODS: We prospectively recorded the pretreatment and posttreatment CEUS related parameters, CA19-9, pain scores of 30 patients with advanced pancreatic cancer treated with PW-HIFU treatment. Correlation of clinical parameters, tumor characteristics, and PW-HIFU treatment energy with CEUS parameters were analyzed. RESULTS: Pain score decreased after treatment (from 4.80±2.14 to 3.28±1.93, p = 0.001). CA19-9 dropped in RT decreased group, 4 weeks after one session PW-HIFU, compared with prolonged group (p = 0.013). According to the display of blood vessels in the mass by CEUS, tumors were classified by vessel grade (VG), VG1: no vessel can be seen; VG 2: vessels diameter < 5 mm; VG 3: vessels diameter > 5 mm. VGs were different between increased and decreased relative rise intensity (rRI) groups (p = 0.008). VG1 group shown a decreased rRI after treatment, while VG3 group showed the opposite trend (p = 0.006). CONCLUSIONS: CEUS can evaluating response to PW-HIFU in advanced pancreatic cancer. Quantitative analysis may help to assess the short-term efficacy of patients and help for individualized treatment.

Modified percutaneous ethanol injection method combined with microwave ablation for the treatment of symptomatic, predominantly cystic, benign thyroid nodules: a retrospective study of 201 cases.

OBJECTIVE: Percutaneous ethanol injection (PEI) and microwave ablation (MWA) are both important methods used in treating benign thyroid nodules. This study aimed to investigate the efficacy and safety of a modified PEI method combined with MWA for the treatment of symptomatic, predominantly cystic and benign thyroid nodules. MATERIALS AND METHODS: This study included 201 patients who underwent treatment in our department between April 2015 and August 2018. Predominantly cystic thyroid nodules were treated by the modified PEI procedure, which included short-term boiling ethanol ablation (STBEA) and was combined with MWA. Complications, the volume reduction ratio (VRR), symptoms and cosmetic scores were recorded at 1, 3, 6 and 12 months after treatment and every 6 months thereafter. RESULTS: No major complications were observed during or after the treatment. Ten patients (4.8%) experienced temporary voice change, which resolved within 3 months. Of 200 (97.6%) out of 205 nodules showed significant volume reduction at the final follow-up. Recurrence occurred for only 5 (2.4%) nodules. The mean thyroid nodule volume decreased from 17.40 ± 3.21 mL at baseline to 1.17 ± 0.37 mL at 12 months. The greatest VRR was observed within the first 3 months after treatment. CONCLUSIONS: The modified PEI method combined with MWA is safe and effective for the treatment of predominantly cystic benign thyroid nodules and provides a shorter operating time and lower recurrence rate than traditional treatments.

Diagnosis and spontaneous healing of asymptomatic renal allograft extra-renal pseudo-aneurysm: A case report.

BACKGROUND: Transplant renal artery stenosis is a relatively frequent vascular complication after transplantation. However, extra-renal pseudo-aneurysms (EPSAs) are rare after transplantation; they can be life-threatening and usually need open surgical repair. We discuss the diagnosis and spontaneous healing of an asymptomatic renal allograft EPSA caused by renal artery anastomotic stenosis, which was diagnosed in a timely manner and managed by conservative treatments. CASE SUMMARY: We present a 37-year-old male patient diagnosed with a renal allograft EPSA caused by renal artery anastomotic stenosis due to multiple atherosclerotic plaques with ultrasonographic examination 6 mo post transplantation. The stenosis rate of 90% and the EPSA were verified by computed tomography angiography. The diagnosis was further confirmed with digital subtraction angiography. Percutaneous transluminal angiography was conducted, and a metallic stent was successfully implanted at the stenosed site of the main renal artery trunk. No further intervention for the EPSA was undertaken due to the difficulty of stenting and the risk of bleeding; regular ultrasonographic follow-ups were recommended. The stenosis was significantly relieved immediately after stent implantation and the EPSA was healed spontaneously by completely filling with hypo-echoic thrombosis 8 mo after stenting. CONCLUSION: Ultrasonography combined with a high-frequency linear probe can detect vascular complications post renal transplantation at an early stage and improve prognosis.

Predictive Factors for Occult Bilateral Papillary Thyroid Carcinoma.

BACKGROUND: Bilateral papillary thyroid carcinoma (PTC) requires aggressive treatment, such as total thyroidectomy (TT). If there is only an isolated PTC focus in one lobe that can be diagnosed preoperatively, and it is unknown whether there are foci in the contralateral lobe that are too small to be detected, it is difficult to know whether to perform TT or to remove only the lobe with the isolated PTC focus. Here, we investigated the prevalence of and predictive factors for occult bilateral PTC that was only diagnosed unilaterally before surgery. METHODS: This retrospective study involved 586 patients with unilateral PTC who were diagnosed preoperatively by ultrasound. They underwent TT and cervical lymph node dissection. According to the pathology, they were divided into unilateral PTC and bilateral (Bil)-PTC groups. Student's t test, chi-squared test, and multivariate analysis were performed to identify features of the malignant tumor that increased the likelihood of malignancy in the contralateral lobe. The prevalence of occult Bil-PTC was calculated. RESULTS: Bil-PTC was found in 70 of 586 (11.95%) PTC patients. Multivariate analysis showed that vascularity (odds ratio[OR]: 2.180, 95% confidence interval [CI]: 1.142-4.162, p = 0.018) and ultrasound diagnosis of lymph node metastasis (USLNM) (OR: 2.056, 95% CI: 1.056-4.004, p = 0.034) were independent predictors of occult Bil-PTC. CONCLUSION: The prevalence of occult PTC in the contralateral lobe was only 11.95%. Vascularity and USLNM were risk factors for Bil-PTC. In terms of these preoperative risk factors for PTC, TT should be cautiously performed in patients with preoperative diagnosis of PTC with isolated focus.

Diagnostic Model of Superficial Lymph Nodes Based on Clinical History and Ultrasound Findings: A Prospective Cohort Study.

OBJECTIVES: Differentiation of benign and malignant changes in lymph nodes is extremely important. We aimed to identify the ultrasound and clinical diagnostic criteria permitting this differentiation. METHODS: Clinical and ultrasound data were collected at Beijing Friendship Hospital from May 2019 to November 2020. Univariate and multivariate analysis were performed using statistical methods, and a mathematical model was established to evaluate benign and malignant lymph nodes. RESULTS: A total of 1343 LNs (person) with US-guided core needle or fine needle biopsy (CNB or FNB) were evaluated in the analysis. Variables with a high predictive power were sex (odds ratio, OR: 3.360, p<0.001), short diameter (OR: 4.660, p<0.001), short/long diameter (S/L) ratio (OR: 1.515, P=0.007), border (OR: 1.626, p=0.002), cortex echogenicity (OR: 2.089, P<0.001), fusion (OR: 2.313, p=0.002), vascularity (peripheral vascularity, OR: 3.424, p<0.001; mixed vascularity, OR: 4.127, p<0.001), and medical history (fever/local pain, OR: 0.316, p<0.001; tumor history in the drainage area, OR: 4.595, p<0.001; both, OR: 5.554, p<0.001). The cut-off score on receiver operating characteristic (ROC) curve analysis using these eight variables was 2.5. The largest area under the ROC curve (Az) value was 82.3% (95% confidence interval (CI), 0.805-0.851), and the sensitivity (79.4%), specificity (72.3%), and accuracy (74.8%) were higher than those for nearly all the single indices. CONCLUSION: The model of combination of ultrasound and clinical symptoms can preliminarily evaluate the benign and malignant of lymph nodes.

Hypocalcemia after ultrasound-guided microwave ablation and total parathyroidectomy for secondary hyperparathyroidism: a retrospective study.

OBJECTIVE: To compare the postoperative hypocalcemia between ultrasound-guided microwave ablation (MWA) and total parathyroidectomy (TPTX) for secondary hyperparathyroidism (SHPT). METHODS: The retrospective study reviewed 286 SHPT patients (171 received MWA and 115 underwent TPTX) between March 2018 and May 2019. Propensity-score matching was used to assemble a cohort of patients with similar baseline characteristics. A total of 184 SHPT patients (92 in each group) were finally enrolled, the occurrence and prognosis of postoperative hypocalcemia were compared. And the risk factors associated with severe hypocalcemia (SH) in each group were analyzed. RESULTS: Hypocalcemia encountered in 95cases (49 in the MWA group and 46 in the TPTX group). SH occurred in 76 cases (40 in the MWA group and 36 in the TPTX group). There were no statistically significant differences in the detection time, incidence, minimum value of serum calcium and symptomatic hypocalcemia between MWA and TPTX group (all p values > 0.05). Of patients developing hypocalcemia, serum calcium did not recover to normal range in 5 cases (10.2%) in the MWA group, while 13 cases (28.3%) were still hypocalcemia at 6 months follow-up in TPTX group (p = 0.035). The time to recovery from hypocalcemia in the TPTX group (mean 30 days, range 3-180 days) was longer than the WA group (mean 14 days, range 3-126 days) (p = 0.000). High serum alkaline phosphatase (ALP) level and low serum calcium level were the main risk factors of postoperative SH. CONCLUSION: There was no difference in hypocalcemia between MWA and TPTX group. Hypocalcemia in the TPTX group might need a longer time to recover.

Subcapsular Injection of Ultrasonic Contrast Agent Distinguishes between Benign and Malignant Lymph Node Lesions Exhibiting Homogeneous Enhancement in Intravenous Contrast-Enhanced Ultrasound Images.

We aimed to evaluate whether subcapsular injection of ultrasonic contrast agent (UCA) can distinguish between benign and malignant lymph node (LN) lesions exhibiting homogeneous enhancement in intravenous contrast-enhanced ultrasound (CEUS) images. From November 2012 to July 2015, 32 patients with superficial lymphadenopathy exhibiting homogeneous enhancement after intravenous CEUS were enrolled. A small amount of UCA was injected into LNs using a subcapsular approach, and perfusion characteristics were recorded. Using the pathology identified via core needle biopsy as the gold standard, we calculated the sensitivity, specificity and accuracy of the technique in terms of distinguishing between benign and malignant LN lesions. Pathology revealed 23 cases of true benign and 9 cases of true malignant LN lesions; the former included 2 cases of tuberculosis and 21 cases of reactive hyperplasia, and the latter included 7 lymphomas and 2 metastases. Subcapsular CEUS diagnosed 24 benign and 8 malignant LN lesions. Most lymphomas (6 of 7, 85.7%) exhibited heterogeneous perfusion, with lymphatic tract distortion in the absence of interruption. Reactive hyperplasia LNs manifested as diffuse homogeneous or brush-like perfusion from the subcapsular region to the center, without lymphatic tract distortion. Metastatic LNs had lymphatic tract interruptions. The sensitivity, specificity, consistency and positive and negative predictive values were 77.8%, 95.6%, 90.6%, 87.5% and 91.7%, respectively. For LNs exhibiting uniform enhancement in intravenous CEUS imaging, subcapsular CEUS may help to distinguish between benign and malignant lesions. In particular, lymphatic distortion without interruption may specifically indicate a lymphoma.

Multimodality-imaging manifestations of primary renal-allograft synovial sarcoma: First case report and literature review.

BACKGROUND: Primary renal synovial sarcoma (PRSS) is an extremely rare tumor with a poor prognosis. Its imaging and immunohistochemical characteristics may overlap with other renal tumors, which renders its early diagnosis in a dilemma. The diagnosis of primary renal synovial sarcoma requires histopathology and the confirmation of SYT-SSX gene fusion using molecular techniques. Cases of primary renal synovial sarcoma have been previously reported in the literature. However, to our knowledge, primary renal allograft synovial sarcoma was never described. CASE SUMMARY: A 43-year-old male patient who underwent kidney transplantation 9 months ago came to our hospital for regular follow-up. Traditional ultrasonography revealed multiple hypo-echo neoplasms in the renal allograft. Contrast-enhanced computed tomography (CECT) showed slightly hyper-density masses with slow homogeneous enhancement. Ultrasound-guided biopsy was conducted for accurate pathological diagnosis. The neoplasms were diagnosed as synovial sarcoma by pathological, immunohistochemical, and genetic analyses. Positron emission tomography/CT showed no evidence of metastasis. At approximately one week post biopsy, contrast-enhanced ultrasound was conducted to eliminate active hemorrhage. One month later, CECT showed that the biggest neoplasm grew from 3.3 cm to 5.7 cm in diameter. Parametric imaging was conducted with SonoLiver CAP to conduct further quantitative analysis, which showed that the enhancement pattern was heterogeneous hyper-vascular enhancement. Radical surgical resection of the whole renal allograft and ureter was conducted without additional adjuvant chemotherapy or external radiotherapy. Anlotinib was chosen for targeted therapy with a good response. CONCLUSION: We propose multimodality imaging for accurate diagnosis of renal allograft synovial sarcoma especially when it is formed by spindle-shaped cells.

Diagnostic value of two dimensional shear wave elastography combined with texture analysis in early liver fibrosis.

BACKGROUND: Staging diagnosis of liver fibrosis is a prerequisite for timely diagnosis and therapy in patients with chronic hepatitis B. In recent years, ultrasound elastography has become an important method for clinical noninvasive assessment of liver fibrosis stage, but its diagnostic value for early liver fibrosis still needs to be further improved. In this study, the texture analysis was carried out on the basis of two dimensional shear wave elastography (2D-SWE), and the feasibility of 2D-SWE plus texture analysis in the diagnosis of early liver fibrosis was discussed. AIM: To assess the diagnostic value of 2D-SWE combined with textural analysis in liver fibrosis staging. METHODS: This study recruited 46 patients with chronic hepatitis B. Patients underwent 2D-SWE and texture analysis; Young's modulus values and textural patterns were obtained, respectively. Textural pattern was analyzed with regard to contrast, correlation, angular second moment (ASM), and homogeneity. Pathological results of biopsy specimens were the gold standard; comparison and assessment of the diagnosis efficiency were conducted for 2D-SWE, texture analysis and their combination. RESULTS: 2D-SWE displayed diagnosis efficiency in early fibrosis, significant fibrosis, severe fibrosis, and early cirrhosis (AUC > 0.7, P < 0.05) with respective AUC values of 0.823 (0.678-0.921), 0.808 (0.662-0.911), 0.920 (0.798-0.980), and 0.855 (0.716-0.943). Contrast and homogeneity displayed independent diagnosis efficiency in liver fibrosis stage (AUC > 0.7, P < 0.05), whereas correlation and ASM showed limited values. AUC of contrast and homogeneity were respectively 0.906 (0.779-0.973), 0.835 (0.693-0.930), 0.807 (0.660-0.910) and 0.925 (0.805-0.983), 0.789 (0.639-0.897), 0.736 (0.582-0.858), 0.705 (0.549-0.883) and 0.798 (0.650-0.904) in four liver fibrosis stages, which exhibited equivalence to 2D-SWE in diagnostic efficiency (P > 0.05). Combined diagnosis (PRE) displayed diagnostic efficiency (AUC > 0.7, P < 0.01) for all fibrosis stages with respective AUC of 0.952 (0.841-0.994), 0.896 (0.766-0.967), 0.978 (0.881-0.999), 0.947 (0.835-0.992). The combined diagnosis showed higher diagnosis efficiency over 2D-SWE in early liver fibrosis (P < 0.05), whereas no significant differences were observed in other comparisons (P > 0.05). CONCLUSION: Texture analysis was capable of diagnosing liver fibrosis stage, combined diagnosis had obvious advantages in early liver fibrosis, liver fibrosis stage might be related to the hepatic tissue hardness distribution.

Effect of ligation on the viscoelastic properties of liver tissues.

It has been reported that ex vivo viscoelastic properties of liver tissues usually differ from those measured in in vivo state due to the reasons such as the effects of perfusion, temperature, and native pre-stress. Therefore, the development of an appropriate ex vivo protocol, which enables the measurement of liver mechanical properties close to those in vivo, is of great importance and has been pursued over the years. In this paper, we propose a simple protocol by ligating the liver when performing ex vivo indentation relaxation tests. Our results show that the viscoelastic kernel function, which measures the intrinsic time-dependent mechanical behavior of a viscoelastic material, determined with the present protocol can describe the in vivo viscoelasticity of liver tissues well in comparison with the ex vivo result measured on a liver without ligation and that obtained in vitro. The performance of the protocol reported here is similar to the ex vivo perfusion system developed by Kerdok et al. (2006). However, the present experimental set-up is much easier to realize.

In vivo and ex vivo elastic properties of brain tissues measured with ultrasound elastography.

Determining the mechanical properties of brain tissues is essential in the field of brain biomechanics. In this paper, we use ultrasound-based shear wave elastography to measure both in vivo and ex vivo elastic properties of brain tissues. Our results demonstrate that the shear modulus from in vivo measurements is about 47% higher than that given by the ex vivo measurements (p value = 0.0063). The change in ex vivo elastic properties within 60-min post-mortem is negligible. The results also show that within 60-min post-mortem and in a temperature range of 37-23 °C, the elastic properties of brain tissues approximately linearly depend on the temperature in both cooling and re-heating processes.

Ultrasound-guided microwave ablation in the treatment of benign thyroid nodules in 435 patients.

The objective of the present study was to investigate the effectiveness and safety of ultrasound-guided microwave ablation in the treatment of benign thyroid nodules. A total of 474 benign thyroid nodules in 435 patients who underwent ultrasound-guided microwave ablation from September 2012 to August 2015 were included. Nodule volume and thyroid function were measured before treatment and at 1, 3, 6, and 12 months and subsequently after every 6 months. The nodule volume reduction rate and changes of thyroid function were evaluated. The volume of all thyroid nodules significantly decreased after ultrasound-guided microwave ablation. The average volume was 13.07 ± 0.95 ml before treatment, and 1.14 ± 0.26 ml at 12-months follow-up. The mean volume reduction rate was 90% and the final volume reduction rate was 94%. The volume reduction rate of mainly cystic nodules was significantly higher than that of simple solid and mainly solid nodules (all P < 0.05). The pretreatment volume of nodules was positively correlated with the final volume reduction rate at final follow-up ( P = 0.004). No serious complications were observed after treatment. In conclusion, ultrasound-guided microwave ablation is an effective and safe technique for treatment of benign thyroid nodules, and has the potential for clinical applications. Impact statement Ultrasound-guided MWA is an effective and safe technique for the treatment of benign thyroid nodules. It can significantly reduce the nodule volume, improve the patients' clinical symptoms, has less complication, guarantees quick recovery, meets patients' aesthetic needs, and shows less interference on the physiological and psychological aspects of the body. MWA should be a good complement to traditional open surgery and has potentials in clinical applications.

Supersonic Shear Wave Imaging of the Spleen for Staging of Liver Fibrosis in Rats.

The goal of the work described here was to explore the cause of spleen stiffness (SS) in hepatic fibrogenesis and evaluate the value of SS in liver fibrosis (LF) staging. LF was induced with carbon tetrachloride (CCl4) in rats (n = 40). Supersonic shear wave imaging and contrast-enhanced ultrasound were performed to determine liver stiffness (LS), SS and splenic hemodynamics. SS, LS and free portal pressure exhibited moderate correlations with fibrosis stage (r = 0.744-0.835, p < 0.001). Time-intensity curves of contrast-enhanced ultrasound for the spleen were presented as decreasing peak intensity and slope of decrease, and increasing time to peak. Splenic sinus dilation and congestion were observed on histopathologic analysis. The area under the receiver operating characteristic curve of SS was higher than that of LS for differentiating LF stages 0-2 from stages 3-4 (Z = 2.293, p = 0.02). SS is a reliable diagnostic marker for the assessment of LF in the CCl4 model, especially for severe fibrosis. Elevated portal pressure is the cause of increasing SS.

Effect of a poloxamer 407-based thermosensitive gel on minimization of thermal injury to diaphragm during microwave ablation of the liver.

AIM: To assess the insulating effect of a poloxamer 407 (P407)-based gel during microwave ablation of liver adjacent to the diaphragm. METHODS: We prepared serial dilutions of P407, and 22.5% (w/w) concentration was identified as suitable for ablation procedures. Subsequently, microwave ablations were performed on the livers of 24 rabbits (gel, saline, control groups, n = 8 in each). The P407 solution and 0.9% normal saline were injected into the potential space between the diaphragm and liver in experimental groups. No barriers were applied to the controls. After microwave ablations, the frequency, size and degree of thermal injury were compared histologically among the three groups. Subsequently, another 8 rabbits were injected with the P407 solution and microwave ablation was performed. The levels of alanine aminotransferase (ALT), aspartate aminotransferase (AST), blood urea nitrogen (BUN) and creatinine (Cr) in serum were tested at 1 d before microwave ablation and 3 and 7 d after operation. RESULTS: In vivo ablation thermal injury to the adjacent diaphragm was evaluated in the control, saline and 22.5% P407 gel groups (P = 0.001-0.040). However, there was no significant difference in the volume of ablation zone among the three groups (P > 0.05). Moreover, there were no statistical differences among the preoperative and postoperative gel groups according to the levels of ALT, AST, BUN and Cr in serum (all P > 0.05). CONCLUSION: Twenty-two point five percent P407 gel could be a more effective choice during microwave ablation of hepatic tumors adjacent to the diaphragm. Further studies for clinical translation are warranted.

Value of Shear Wave Elastography Versus Contrast-Enhanced Sonography for Differentiating Benign and Malignant Superficial Lymphadenopathy Unexplained by Conventional Sonography.

OBJECTIVES: This study aimed to compare the efficacy of shear wave elastography (SWE) and contrast-enhanced sonography in the differential diagnosis of superficial lymphadenopathy with abnormal imaging findings, which could not be otherwise confirmed by conventional sonography. METHODS: Forty-two enlarged superficial lymph nodes in 42 patients who met the screening criteria for this study were evaluated by both contrast-enhanced sonography and SWE. All lymph nodes underwent both methods using biopsy pathologic findings as a reference standard. RESULTS: The maximum elastic modulus, mean elastic modulus, and standard deviation of the elastic modulus were the main distinguishing features on SWE; they were significantly higher in malignant lesions than benign ones. The threshold value for the maximum elastic modulus was set at 37.9 kPa, and the sensitivity, specificity, and accuracy of differential diagnosis of superficial lymph nodes were 81.8%, 80.0%, and 81.0%, respectively. The diagnosis of benignity and malignancy by this index was statistically significant (P < .001). The lymph nodes were divided into benign and malignant groups according to different types based on the degree and range of intensity on contrast-enhanced sonography: intense or moderate homogeneous enhancement (n = 26) and heterogeneous, low homogeneous, or absent enhancement (n = 16). The sensitivity, specificity, and accuracy of contrast-enhanced sonography were 27.3%, 50.0%, and 38.1%. There was no statistically significant difference in the values between the benign and malignant groups (χ2 = 2.295; P = .130). CONCLUSIONS: Compared with contrast-enhanced sonography, SWE has better diagnostic value and efficiency in differentiation of superficial lymph nodes unexplained by conventional sonography. When conventional sonography cannot differentiate malignant superficial lymph nodes from benign ones, SWE is a useful adjunctive tool for assessment of lymph nodes.

Shear wave elastography results correlate with liver fibrosis histology and liver function reserve.

AIM: To evaluate the correlation of shear wave elastography (SWE) results with liver fibrosis histology and quantitative function reserve. METHODS: Weekly subcutaneous injection of 60% carbon tetrachloride (1.5 mL/kg) was given to 12 canines for 24 wk to induce experimental liver fibrosis, with olive oil given to 2 control canines. At 24 wk, liver condition was evaluated using clinical biochemistry assays, SWE imaging, lidocaine metabolite monoethylglycine-xylidide (MEGX) test, and histologic fibrosis grading. Clinical biochemistry assays were performed at the institutional central laboratory for routine liver function evaluation. Liver stiffness was measured in triplicate from three different intercostal spaces and expressed as mean liver stiffness modulus (LSM). Plasma concentrations of lidocaine and its metabolite MEGX were determined using high-performance liquid chromatography repeated in duplicate. Liver biopsy samples were fixed in 10% formaldehyde, and liver fibrosis was graded using the modified histological activity index Knodell score (F0-F4). Correlations among histologic grading, LSM, and MEGX measures were analyzed with the Pearson linear correlation coefficient. RESULTS: At 24 wk liver fibrosis histologic grading was as follows: F0, n = 2 (control); F1, n = 0; F2, n = 3; F3, n = 7; and F4, n = 2. SWE LSM was positively correlated with histologic grading (r = 0.835, P < 0.001). Specifically, the F4 group had a significantly higher elastic modulus than the F3, F2, and F0 groups (P = 0.002, P = 0.003, and P = 0.006, respectively), and the F3 group also had a significantly higher modulus than the control F0 group (P = 0.039). LSM was negatively associated with plasma MEGX concentrations at 30 min (r = -0.642; P = 0.013) and 60 min (r = -0.651; P = 0.012), time to ½ of the maximum concentration (r = -0.538; P = 0.047), and the area under the curve (r = -0.636; P = 0.014). Multiple comparisons showed identical differences in these three measures: significantly lower with F4 (P = 0.037) and F3 (P = 0.032) as compared to F0 and significantly lower with F4 as compared to F2 (P = 0.032). CONCLUSION: SWE LSM shows a good correlation with histologic fibrosis grading and pharmacologic quantitative liver function reserve in experimental severe fibrosis and cirrhosis.

Comparison of Different Pulse Waveforms for Local Pulse Wave Velocity Measurement in Healthy and Hypertensive Common Carotid Arteries in Vivo.

Pulse wave velocity (PWV), a measurement of arterial stiffness, can be estimated locally by determining the time delay of the pulse waveforms for a known distance as measured in an ultrasound image. Our aim was to compare three ultrasound-based methods for estimation of local PWV based on the measurement of diameter distension waveforms, displacement waveforms of the anterior wall and displacement waveforms of the posterior wall, respectively, in human common carotid arteries in vivo. The local PWVs at both systolic foot (PWVsf) and dicrotic notch (PWVdn) were estimated from ultrasound radiofrequency data of 25 healthy and 24 hypertensive patients for each method. PWV estimation using the distension waveform method was found to have the highest precision in both groups. Both PWVsf and PWVdn were significantly higher in the hypertensive group compared with the healthy group using the distension waveform method (PWVsf: 6.08 ± 1.70 m/s vs. 4.75 ± 0.92 m/s, p = 0.000014; PWVdn: 7.83 ± 2.26 m/s vs. 5.21 ± 0.95 m/s, p < 0.000001), whereas there was no significant difference at a significance level of 0.01 between the two groups when the anterior or posterior wall waveform method was used. Thus, the difference in arterial stiffness between the two groups could be discriminated well by the distension waveform method. The local PWV estimated using distension waveforms might be a promising index for arterial stiffness characterization and hypertension management.

Determining the in vivo elastic properties of dermis layer of human skin using the supersonic shear imaging technique and inverse analysis.

PURPOSE: Human skin consists of several layers including epidermis, dermis, and hypodermis. The determination of the in vivo mechanical properties of an individual skin layer represents a great challenge to date. In this study, the authors explore the use of the supersonic shear imaging (SSI) technique and inverse analysis to determine the in vivo elastic properties of the dermis layer of human skin. METHODS: The measurements are conducted on the volar forearms and dorsal forearms of 18 healthy volunteers (nine females and nine males) using the SSI technique that gives the velocities of the shear wave generated by the acoustic force. Finite element analysis is carried out to simulate the propagation of the shear wave in the multilayer soft media and the results are used to interpret the experimental data and deduce the shear modulus of the dermis layer. RESULTS: The shear moduli of the skin dermis layer obtained for the 18 healthy volunteers exhibit significant anisotropy. A standard statistical analysis demonstrates the differences between sexes. CONCLUSIONS: This study demonstrates that the SSI technique together with the inverse analysis represents a useful tool to characterize the in vivo elastic properties of human skin.

Contrast-enhanced ultrasound for quantitative assessment of portal pressure in canine liver fibrosis.

AIM: To explore the feasibility of non-invasive quantitative estimation of portal venous pressure by contrast-enhanced ultrasound (CEUS) in a canine model. METHODS: Liver fibrosis was established in adult canines (Beagles; n = 14) by subcutaneous injection of carbon tetrachloride (CCl4). CEUS parameters, including the area under the time-intensity curve and intensity at portal/arterial phases (Qp/Qa and Ip/Ia, respectively), were used to quantitatively assess the blood flow ratio of the portal vein/hepatic artery at multiple time points. The free portal venous pressures (FPP) were measured by a multi-channel baroreceptor using a percutaneous approach at baseline and 8, 16, and 24 wk after CCl4 injections in each canine. Liver biopsies were obtained at the end of 8, 16, and 24 wk from each animal, and the stage of the fibrosis was assessed according to the Metavir scoring system. A Pearson correlation test was performed to compare the FPP with Qp/Qa and Ip/Ia. RESULTS: Pathologic examination of 42 biopsies from the 14 canines at weeks 8, 16, and 24 revealed that liver fibrosis was induced by CCl4 and represented various stages of liver fibrosis, including F0 (n = 3), F1 (n = 12), F2 (n = 14), F3 (n = 11), and F4 (n = 2). There were significant differences in the measurements of Qp/Qa (19.85 ± 3.30 vs 10.43 ± 1.21, 9.63 ± 1.03, and 8.77 ± 0.96) and Ip/Ia (1.77 ± 0.37 vs 1.03 ± 0.12, 0.83 ± 0.10, and 0.69 ± 0.13) between control and canine fibrosis at 8, 16, and 24 wk, respectively (all P < 0.001). There were statistically significant negative correlations between FPP and Qp/Qa (r = -0.707, P < 0.001), and between FPP and Ip/Ia (r = -0.759, P < 0.001) in the canine fibrosis model. Prediction of elevated FPP based on Qp/Qa and Ip/Ia was highly sensitive, as assessed by the area under the receiver operating curve (0.866 and 0.895, respectively). CONCLUSION: CEUS is a potential method to accurately, but non-invasively, estimate portal venous pressure through measurement of Qp/Qa and Ip/Ia parameters.