Nodule Depth Research Articles

Impact of the Size and Depth of Pulmonary Nodules on the Surgical Approach for Lung Resection in the Treatment of Early-stage Lung Cancer ≤2 cm

Current studies suggest that for early-stage lung cancers with a component of ground-glass opacity measuring ≤2 cm, sublobar resection is suitable if it ensures adequate margins. However, lobectomy may be necessary for some cases to achieve this. The aim of this study was to explore the impact of size and depth on surgical techniques for wedge resection, segmentectomy, and lobectomy in early-stage lung cancer ≤2 cm, and to determine methods for ensuring a safe resection margin during sublobar resections. Clinical data from 385 patients with early-stage lung cancer ≤2 cm, who underwent lung resection in 2022, were subject to a retrospective analysis, covering three types of procedures: wedge resection, segmentectomy and lobectomy. The depth indicator as the OA value, which is the shortest distance from the inner edge of a pulmonary nodule to the opening of the corresponding bronchus, and the AB value, which is the distance from the inner edge of the nodule to the pleura, were measured. For cases undergoing lobectomy and segmentectomy, three-dimensional computed tomography bronchography and angiography (3D-CTBA) was performed to statistically determine the number of subsegments required for segmentectomy. The cutting margin width for wedge resection and segmentectomy was recorded, as well as the specific subsegments and their quantities removed during lung segmentectomy were documented. In wedge resection, segmentectomy, and lobectomy, the sizes of pulmonary nodules were (1.08±0.29) cm, (1.31±0.34) cm and (1.50±0.35) cm, respectively, while the depth of the nodules (OA values) was 6.05 (5.26, 6.85) cm, 4.43 (3.27, 5.43) cm and 3.04 (1.80, 4.18) cm for each procedure, showing a progressive increasing trend (P<0.001). The median resection margin width obtained from segmentectomy was 2.50 (1.50, 3.00) cm, significantly greater than the 1.50 (1.15, 2.00) cm from wedge resection (P<0.001). In wedge resections, cases where AB value >2 cm demonstrated a higher proportion of cases with resection margins less than 2 cm compared to those with margins greater than 2 cm (29.03% vs 12.90%, P=0.019). When utilizing the size of the nodule as the criterion for resection margin, the instances with AB value >2 cm continued to show a higher proportion in the ratio of margin distance to tumor size less than 1 (37.50% vs 17.39%, P=0.009). The median number of subsegments for segmentectomy was three, whereas lobectomy cases requiring segmentectomy involved five subsegments (P<0.001). The selection of the surgical approach for lung resection is influenced by both the size and depth of pulmonary nodules. This study first confirms that larger portions of lung tissue must be removed for nodules that are deeper and larger to achieve a safe margin. A distance of ≤2 cm from the inner edge of the pulmonary nodule to the nearest pleura may be the ideal indication for performing wedge resection.

Factors influencing the accuracy and safety of preoperative computed tomography (CT)-guided soft hook-wire localization for pulmonary nodules: a comprehensive analysis.

The necessity of localization of pulmonary nodules lies in ensuring the ability to locate the nodule quickly and accurately during surgery, thereby improving the success rate of the operation. The accuracy and risk of preoperative localization of pulmonary nodules need further exploration. Therefore, the purpose of this study was to investigate the factors of accuracy and safety of computed tomography (CT)-guided localization of pulmonary nodules using a flexible wire hook positioner. In this retrospective cross-sectional analysis, 281 patients with a single pulmonary nodule underwent video-assisted thoracoscopic surgery (VATS) following localization with a soft hook-wire guided by CT scan from January 2021 to July 2022 at Nanjing Drum Tower Hospital. The patients underwent VATS to remove pulmonary nodules within 24 hours after localization. The demographic, pulmonary nodule, and technical factors were analyzed retrospectively. Univariate and multivariate analysis were used to analyze the identified factors that influence pulmonary nodule localization accuracy and complications. Localization was successfully performed in 280 patients, with only 1 patient being excluded due to a displaced positioner and the hook wire failing to enter the lung parenchyma as a result of pneumothorax. Out of the total cases, 191 (68.2%) were accurately positioned in group G0, whereas 89 cases (31.7%) were inaccurately positioned in group G1. Hemorrhage and self-limited hemoptysis were observed in 64 patients (22.8%), whereas pneumothorax was observed in 84 patients (29.9%). There were no serious complications such as air embolism or death. The accuracy of localization was found to be influenced by both the depth of pulmonary nodules [odds ratio (OR) =22.610, 95% confidence interval (CI): 10.351-49.391, P=0.001] and the depth of the needle used (OR =0.322, 95% CI: 0.136-0.765, P=0.010). Additionally, postoperative hemorrhage was found to be affected by several important factors, including the diameter (P=0.036) and depth of the nodule (P=0.011), as well as the thickness of the chest wall (P=0.043) and the depth of the needle used (P=0.005). The CT-guided flexible wire hook positioner has been found to be a safe and effective device for locating pulmonary nodules. The depth of pulmonary nodules and needle penetration are key factors affecting the accuracy of lung nodule localization under CT guidance and are important factors affecting postoperative bleeding.

A novel localization device for small pulmonary nodules in thoracoscopic wedge resection with adequate margin distance: a retrospective study.

Thoracoscopic wedge resection of small pulmonary nodules (SPNs) is a common surgical procedure. Adequate surgical margin distance is challenging and key to successful resection for malignant nodules. The aim of this study was to evaluate the feasibility of a novel localization needle in wedge resection for SPNs with adequate margin distance. A retrospective review of needle localization cases from November 2021 to August 2022 was performed, in which 58 patients who underwent modified computed tomography (CT)-guided needle localization following thoracoscopic wedge resection were enrolled. Nodules were localized by placing a novel device characterized by a 4-hook anchor and a tricolored suture with a scale. The clinical characteristics were collected to evaluate the feasibility of the procedure in obtaining a sufficient margin distance. A total of 68 SPNs were collected, and the median size of SPNs was 10.0 mm with a median depth of 18.9 mm. Needle localization was successful in 65 nodules (95.6%), and all nodules were completely removed. The median resection margin distance was 14 mm (range, 8-26 mm). There were 62 (91.2%) SPNs with a margin distance to tumor size ratio ≥1, 38 (92.7%) SPNs with a depth <20 mm, and 24 (88.9%) SPNs with a depth ≥20 mm, respectively. Regardless of the nodule depth, the median resection margin distances were both 14 mm. This study indicated that modified preoperative CT-guided 4-hook needle with scaled suture localization is a safe, efficient strategy for the wedge resection of SPNs via thoracoscopic surgery. Furthermore, it was considerably advantageous for obtaining adequate margins distance, especially for deep nodules.

Efficacy of Near-Infrared Fluorescence Video-Assisted Thoracoscopic Surgery for Small Pulmonary Nodule Resection with Indocyanine Green Inhalation: A Randomized Clinical Trial.

Small pulmonary nodules (<3cm) can sometimes be unrecognizable and nonpalpable in video-assisted thoracoscopic surgery (VATS). Near-infrared fluorescence (NIF) VATS after indocyanine green (ICG) inhalation may effectively guide surgeons to locate the nodules. This study aimed to investigate the safety, feasibility, and efficacy of ICG inhalation-based NIF imaging for guiding small pulmonary nodule resections. Between February and May 2021, the first-stage, non-randomized trial enrolled 21 patients with different nodule depth, ICG inhalation doses, post-inhalation surgery times, and nodule types at a tertiary referral hospital. Between May 2021 and May 2022, the second-stage randomized trial enrolled 56 patients, who were randomly assigned to the fluorescence VATS (FLVATS) or the white-light VATS (WLVATS) group. The ratio of effective guidance and the time consumption for nodule localization were compared. The first-stage trial proved this new method is safe and feasible, and established a standardized protocol with optimized nodule depth (≤1cm), ICG dose (0.20-0.25 mg/kg), and surgery window (50-90min after ICG inhalation). In the second-stage trial, the FLVATS achieved 87.1% helpful nodule localization guidance, which was significantly higher than the WLVATS (59.1%, p<0.05). The mean nodule locating time (standard deviation) was 1.8 [0.9] and 3.3 [2.3] min, respectively. Surgeons adopting FLVATS were significantly faster (p<0.01), especially when locating small ground-glass opacities (1.3 [0.6] min vs. 7.0 [3.5] min, p<0.05). Five of 31 nodules (16.1%) were only detectable by FLVATS, whereas both white light and palpation failed. This new method is safe and feasible for small pulmonary nodule resection. It significantly improves nodule localization rates with less time consumption, and hence is highly worthy for clinical promotion. Clinical Trial Registration Chinese Clinical Trial Registry Identifier: ChiCTR2100047326.

Risk prediction of intraoperative pain in percutaneous microwave ablation of lung tumors under CT guidance.

To evaluate the effect of intraoperative pain in microwave ablation of lung tumors (MWALT) on local efficacy and establish the pain risk prediction model. It was a retrospectively study. Consecutive patients with MWALT from September 2017 to December 2020 were divided into mild and severe pain groups. Local efficacy was evaluated by comparing technical success, technical effectiveness, and local progression-free survival (LPFS) in two groups. All cases were randomly allocated into training and validation cohorts at a ratio of 7:3. A nomogram model was established using predictors identified by logistics regression in training dataset. The calibration curves, C-statistic, and decision curve analysis (DCA) were used to evaluate the accuracy, ability, and clinical value of the nomogram. A total of 263 patients (mild pain group: n = 126; severe pain group: n = 137) were included in the study. Technical success rate and technical effectiveness rate were 100% and 99.2% in the mild pain group and 98.5% and 97.8% in the severe pain group. LPFS rates at 12 and 24months were 97.6% and 87.6% in the mild pain group and 91.9% and 79.3% in the severe pain group (p = 0.034; HR: 1.90). The nomogram was established based on three predictors: depth of nodule, puncture depth, and multi-antenna. The prediction ability and accuracy were verified by C-statistic and calibration curve. DCA curve suggested the proposed prediction model was clinically useful. Severe intraoperative pain in MWALT reduced the local efficacy. An established prediction model could accurately predict severe pain and assist physicians in choosing a suitable anesthesia type. This study firstly provides a prediction model for the risk of severe intraoperative pain in MWALT. Physicians can choose a suitable anesthesia type based on pain risk, in order to improve patients' tolerance as well as local efficacy of MWALT. • The severe intraoperative pain in MWALT reduced the local efficacy. • Predictors of severe intraoperative pain in MWALT were the depth of nodule, puncture depth, and multi-antenna. • The prediction model established in this study can accurately predict the risk of severe pain in MWALT and assist physicians in choosing a suitable anesthesia type.

Ultrasound-Guided Conventional Versus Trans-isthmic Fine Needle Aspiration: Comparison of Post-biopsy Hematoma Rates and Patients' Pain.

Objective Fine needle aspiration (FNA) is an invasive procedure;however, it is the simplest and safest method of identifying thyroid nodules that is well tolerated by patients. The most common complication is minor bleeding and pain. The objective of this study was to evaluate pain and complications among patients with thyroid nodules undergoing ultrasound (US)-guided FNA procedures. Materials and methods A total of 757 patients who underwent US-guided biopsy of the thyroid nodule in our institution between January 2017 and July 2022 were reviewed retrospectively. Demographic characteristics, US features, nodule depth and size, developing hematoma dimensions, and visual analogscale (VAS) scores during the procedure and at the 30th minute after the procedure were recorded in all cases. Results Overall, 272 (206 female and 66 male) patients who underwent US-guidedconventionalFNA (US-CFNA) procedure and 485 (361 female and 124 males) patients who underwent US-guided trans-isthmic FNA (US-TIFNA) were included. There was no significant difference between the two groups in terms of gender or age (p=0.691 and p=0.539, respectively). Although the mean nodule size of the US-TIFNA group was larger than that of the US-CFNA group, there was no statistically significant difference between the groups (p=0.137). There was a statistically significant difference between the two groups regarding the mean pain score during the procedures and 30 minutes after the procedure (p=0.032 and p=0.001, respectively).A total of 18 patients had procedural bleeding complications. While hematoma was detected in 11 (4.04%) patients who underwent the US-CFNA procedure, it was detected in seven (1.44%) patients who underwent the TIFNA procedure(p=0.024). Conclusion We compared the incidence of hematoma and the comfort of patients during and after the procedure between the US-TIFNA procedure and the US-CFNA procedure. The frequency of hematoma was higher in US-CFNA patients during and after the biopsy, and it was statistically significant. Moreover, the evaluation of patients' pain levels has shown that the US-TIFNA procedure resulted in significant patient satisfaction.

Ultrasound-Guided Fine Needle Aspiration of Deep Thyroid Nodule: Is There a Correlation between the Nodule's Depth and Nondiagnostic Results?

Objective To evaluate whether thyroid nodule depth correlates with nondiagnostic results in ultrasound-guided fine needle aspiration cytopathology. Background Many factors correlate with nondiagnostic ultrasound-guided fine needle aspiration cytology (FNAC) results, including older age, macrocalcification, small-sized nodules, aspirin medication, and cystic portion in more than 50% of the thyroid nodules. However, there are few studies which have examined whether there is a relationship between the depth of nodules and the percentage of nondiagnostic results in cytology (Bethesda category I). We conducted this study in order to investigate if such a correlation exists. Materials and Methods FNAC was performed on 283 thyroid nodules between January 2019 and December 2020. Cytological analyses of the nodules were reviewed and sorted as nondiagnostic and diagnostic according to the Bethesda score. Patient files and ultra sound (US) scans were reviewed for clinical information (such as age, sex, and ethnic group) and sonographic features of nodules (such as depth, size, cystic portion, type of calcification, and echogenicity) and were compared between the nondiagnostic and diagnostic nodule results. The depth of a nodule was calculated as the shortest distance from the skin to the most superficial border of the nodule in the axial plane, using our medical center's computer program, which allows reviewing all saved shots of the US scan. Results Age, sex, and ethnicity were not significantly different between the nondiagnostic group and the diagnostic group (p > 0.05). Nodule diameter, cystic portion, calcification, and echogenicity were also not associated with the frequency of nondiagnostic results. The depth of nodules ≥9 mm was correlated with nondiagnostic US-guided FNA cytological results (OR = 2.55, p=0.018). Conclusions Deep thyroid nodules correlated with nondiagnostic US-guided FNA cytological results. Further studies are needed for optimizing the approach to deep thyroid nodules in order to improve the efficacy of FNA in deep thyroid nodules.

Characteristics and morphology of lipohypertrophic lesions in adults with type 1 diabetes with ultrasound screening: an exploratory observational study

IntroductionLipohypertrophy is a common complication of exposure to insulin therapy. Despite the prevalence of lipohypertrophy and its potentially hazardous effects on glucose regulation, it remains a relatively understudied problem in...

Detecting pulmonary nodules by using ultrasound multiple scattering.

Although X-Ray Computed Tomography (CT) is widely used for detecting pulmonary nodules inside the parenchyma, it cannot be used during video-assisted surgical procedures. Real-time, non-ionizing, ultrasound-based techniques are an attractive alternative for nodule localization to ensure safe resection margins during surgery. Conventional ultrasound B-mode imaging of the lung is challenging due to multiple scattering. However, the multiple scattering contribution can be exploited to detect regions inside the lung containing no scatterers. Pulmonary nodules are homogeneous regions in contrast to the highly scattering parenchyma containing millions of air-filled alveoli. We developed a method relying on mapping the multiple scattering contribution inside the highly scattering lung to detect and localize pulmonary nodules. Impulse response matrices were acquired in ex-vivo pig and dog lungs using a linear array transducer to semi-locally investigate the backscattered field. Extracting the multiple-scattering contribution using singular-value decomposition and combining it with a depression detection algorithm allowed us to detect and localize regions with less multiple scattering, associated with the nodules. The feasibility of this method was demonstrated in five ex-vivo lungs containing a total of 20 artificial nodules. Ninety-five percent of the nodules were detected. Nodule depth and diameter significantly correlated with their ex-vivo CT-estimated counterparts (R = 0.960, 0.563, respectively).

Computed Tomography-Guided Methylene Blue Localization: Single vs. Multiple Lung Nodules.

Background: Preoperative localization for small invisible and impalpable pulmonary nodules is important in single-port video-assisted thoracoscopic surgery (VATS). Localization of multiple pulmonary nodules during VATS resection remains challenging. The aim of our study is to elucidate the efficacy of preoperative CT-guided methylene blue localization of both single and multiple pulmonary nodules.Methods: Consecutive patients undergoing preoperative CT-guided methylene blue dye localization for lung nodules, followed by VATS resection, were retrospectively analyzed between January 2014 and November 2019. Chi-square tests, Fisher's exact test and independent T-test were used to compare variables between the groups. Logistic regression was used to identify risk factors for procedure-related complications.Results: A total of 388 patients, including 337 with single nodule and 51 with multiple nodules, were analyzed. The success rate of preoperative CT-guided methylene blue localization for both single and multiple pulmonary nodules were comparable as 98.8% (333/337) vs. 100% (108/108). The procedure time was longer (23.2 ± 9.4 vs. 7.6 ± 4.8 min, p < 0.001) and risk of pneumothorax was higher (47.1 vs. 25.5%, p = 0.002) in the multiple nodule group. The procedure time (OR 1.079; 95% CI = 1.041–1.118; p < 0.001) was an independent risk factor for pneumothorax. Nodule depth (OR 2.829; 95% CI = 1.259–6.356; p = 0.011) was an independent risk factor for pulmonary hemorrhage.Conclusions: Preoperative CT-guided methylene blue localization for both single and multiple pulmonary nodules is safe, feasible, and effective.

A computed tomography-based nomogram to predict pneumothorax caused by preoperative localization of ground glass nodules using hook wire.

To develop and validate a CT-based nomogram to predict the occurrence of loculated pneumothorax due to hook wire placement. Patients (n = 177) were divided into pneumothorax (n = 72) and non-pneumothorax (n = 105) groups. Multivariable logistic regression analysis was applied to build a clinical prediction model using significant predictors identified by univariate analysis of imaging features and clinical factors. Receiver operating characteristic (ROC) was applied to evaluate the discrimination of the nomogram, which was calibrated using calibration curve. Based on the results of multivariable regression analysis, transfissure approach [odds ratio (OR): 757.94; 95% confidence interval CI (21.20-27099.30) p < 0.0001], transemphysema [OR: 116.73; 95% CI (12.34-1104.04) p < 0.0001], localization of multiple nodules [OR: 8.04; 95% CI (2.09-30.89) p = 0.002], and depth of nodule [OR: 0.77; 95% CI (0.71-0.85) p < 0.0001] were independent risk factors for pneumothorax and were included in the predictive model (p < 0.05). The area under the ROC curve value for the nomogram was 0.95 [95% CI (0.92-0.98)] and the calibration curve indicated good consistency between risk predicted using the model and actual risk. A CT-based nomogram combining imaging features and clinical factors can predict the probability of pneumothorax before localization of ground-glass nodules. The nomogram is a decision-making tool to prevent pneumothorax and determine whether to proceed with further treatment. A nomogram composed of transfissure, transemphysema, multiple nodule localization, and depth of nodule has been developed to predict the probability of pneumothorax before localization of GGNs.

Effect of the location and size of thyroid nodules on the diagnostic performance of ultrasound elastography: A retrospective analysis

OBJECTIVES:Ultrasound-guided fine-needle aspiration biopsies are recommended for the detection of suspicious thyroid nodules. However, the best approach regarding suspicious ultrasound features for thyroid nodules is still unclear. This study aimed to evaluate the effect of location and size of thyroid nodules on the diagnostic performance of strain ultrasound elastography. In addition, this study evaluated whether ultrasound elastography predicts malignancy in thyroid nodules.METHODS:Data regarding the size, depth, and distance from the carotid artery of nodules, the elasticity contrast index, and the nature of nodules were analyzed.RESULTS:There was no significant difference in the depth (p=0.092) and the distance from the carotid artery (p=0.061) between benign and suspicious nodules. Suspicious nodules were smaller than benign nodules (p<0.0001, q=23.84) and had a higher elasticity contrast index (p<0.0001, q=21.05). The depth of nodules and the size of the nodule were not associated with the correct value of the elasticity contrast index (p>0.05 for both). The diagnostic performance of ultrasound elastography was not affected by the distance of the nodules from the carotid artery if they were located ≥15 mm from the carotid artery (p=0.5960). However, if the suspicious nodules were located <15 mm from the carotid artery, the diagnostic accuracy was hampered (p=0.006).CONCLUSIONS:The strain ultrasound elastography should be carefully evaluated when small thyroid nodules are located near the carotid artery.

Nondiagnostic cytological results on ultrasound-guided fine needle aspiration: Does the thyroid nodule depth matter?

To evaluate whether thyroid nodule depth and other ultrasound features can predict nondiagnostic cytological results on ultrasound-guided fine needle aspiration. This retrospective study included 412 thyroid nodules that underwent ultrasound-guided fine needle aspiration from 2014 to 2015. The nodules were classified as nondiagnostic and diagnostic by the cytopathological results. Clinical information of the patients (ie., age, sex) and ultrasound features (ie., size, depth, calcification, cystic content, vascularity) of the nodules were recorded and compared between the nondiagnostic group and diagnostic group. Age and sex were not significantly different between the nondiagnostic group and diagnostic group (P > 0.05). Nodule depth >15 mm (OR, 7.128; P < 0.001), peripheral rim calcification (OR, 5.725; P = 0.01) and cystic content >50% (OR, 2.995; P = 0.018) were factors for the nondiagnostic ultrasound-guided fine needle aspiration cytopathological results. Macrocalcification in the nodule sized 5-10 mm was associated with the nondiagnostic results (P = 0.04). Nodule size and vascularity were not associated with the nondiagnostic results (P > 0.05). Nodule depth >15 mm, peripheral rim calcification and cystic content >50% were three independent predictors of the nondiagnostic cytopathological results. Macrocalcification in the nodule sized 5-10 mm was also associated with the nondiagnostic results.

Preoperative Computed Tomography-Guided Pulmonary Lesion Marking in Preparation for Fluoroscopic Wedge Resection—Rates of Success, Complications, and Pathology Outcomes

In this study, we describe our experience of lesion marking with fiducial markers (FM) and microcoils (MC) facilitating same-day surgical wedge resection, including success rates, pathology outcomes, and complications. We also explored patient/nodular characteristics associated with developing complications. An IRB-approved single-institutional retrospective study of 136 patients who had 148 pulmonary nodules was conducted. All patients had CT-guided pulmonary nodule labeling with either FM (121) or MC (15) patients with plan for same-day fluoroscopic-guided wedge resection. Of 136 (98%) patients, 133 had successful same-day wedge resection as planned; 2 had delayed but successful wedge resection surgery due to complications at the time of marker placement (fiducial embolization and hemorrhage/pneumothorax, respectively). A third patient ultimately needed lobectomy due to deep lesion location. Eighty percent [118/148] of resected nodules were malignant. Further, 68% of the total group of patients [93/136] had mild complications of various types including hemorrhage [44/136, 32%], pneumothorax [35/136, 26%], a combination of both hemorrhage and pneumothorax [10/136, 7%], or migration/embolization [4/136, 3%]. Depth of nodule from skin (P = 0.011) and pleura (P = 0.027) was significantly associated with complications. CT-guided marking of small or deep pulmonary lesions using either fiducial markers or microcoils provides an effective means to aid surgeons to accomplish minimally invasive wedge resection. The importance of the success of this technique is supported by the high incidence (80%) of malignant lesion etiology found at postresection pathology. Although complications occurred, the vast majority were mild and did not alter planned same-day resection.

Virtual touch tissue imaging and quantification (VTIQ) in the evaluation of thyroid nodules: the associated factors leading to misdiagnosis

To evaluate the associated factors leading to misdiagnosis with VTIQ for differentiation between benign from malignant thyroid nodules (TNs). The study included 238 benign TNs and 150 malignant TNs. Conventional ultrasound (US) features and VTIQ parameters were obtained and compared with the reference standard of histopathological and/or cytological results. Binary logistic regression analysis was performed to select independent variables leading to misdiagnosis. The maximum shear wave speed (SWS) (SWS-max), mean SWS (SWS-mean), SWS-ratio and standard deviation of SWS (SWS-SD) were significantly higher for malignant TNs compared with benign TNs (all P < 0.001). SWS-mean achieved the highest diagnostic performance with a cut-off value of 3.15 m/s. False positive rate was 13.4% (32/238) while false negative rate was 35.3% (53/150). Intranodular calcification (OR: 1.715) was significantly associated with false positive VTIQ findings, while nodule size (OR: 0.936) and echotexture of the thyroid gland (OR: 0.033) were negatively associated with them. Nodule depth (OR: 0.881) and TI-RADS category (OR: 0.563) were negatively associated with false negative VTIQ findings. These US characteristic of TNs should be taken into consideration when interpreting the results of VTIQ examinations.

The experimental study of the impact factors of real-time shear wave elastography

Objective To investigate the impact factors of real-time shear wave elastography (SWE) by using the ultrasound phantoms. Methods The noduled phantoms with different densities and viscosities and background phantoms with three textures (soft,medium,and hard) were prepared by using gelatin as the main ingredient. Nodule phantoms were embedded in background phantom in different depths. The elasticity (Emax) was measured by SWE. Factorial designed was used to evaluate the effects of various factors,including density,viscosity and depth of nodule phantom and texture of background phantom on Emax of nodule phantom. Binary Logistic regression was used to analysis the effects of various factors,including density,viscosity,diameter,depth of nodule phantom and texture of background phantom on the window phenomenon. Results The density,viscosity and the Emax of nodule phantoms increased as the gelatin ratio increased. The Emax of nodule phantoms in shallow position (depth<3.0 cm) were higher than those in deep position (depth≥3.0 cm). In hard-background phantoms,the Emax of nodule phantoms was maximal,soft-background phantoms was minimal. Main effects of the density,viscosity,depth of nodule phantoms and texture of background phantoms on Emax of nodule phantoms were different,and all of the factors had interactive effects (P<0.05). The density,viscosity,diameter and depth of nodule phantoms were independent risk factors of the window phenomenon (P<0.05). According to OR (23.846,0.093,and 0.003,respectively),reduced density and viscosity,or increased diameter and depth of nodule phantoms,could increase the incidence of the window phenomenon. Conclusions The density and viscosity of self-making ultrasound phantoms can be easily and flexibly controlled.Density,viscosity,diameter,depth of nodule and texture of background are the impact factors of shear wave elastography. Key words: Shear wave elastography; Ultrasound phantoms; Viscosity

Quality measurement on shear wave speed imaging: diagnostic value in differentiation of thyroid malignancy and the associated factors.

To evaluate the associated factors for quality measurement (QM) on shear wave speed (SWS) imaging and the additional value of QM for differentiation of thyroid nodules. A consecutive series of 238 patients with 254 thyroid nodules were enrolled. They were all evaluated by conventional ultrasound and SWS imaging and were finally proven pathologically. QM was used to assess whether SWS propagation was authentic and was classified as high QM and Low QM. Twelve variables were analyzed to evaluate the associated factors for QM using binary logistic regression. Receiver operating characteristic (ROC) curve was plotted on SWS and SWS+QM. Sensitivity, specificity, positive predictive value (PPV), negative predictive value (NPV), accuracy and area under ROC curve (AUC) were calculated. The study included 170 benign thyroid nodules (160 high QM and 10 low QM) and 84 malignant thyroid nodules (56 high QM and 28 low QM) (P < 0.001). The mean SWS of benign and malignant nodules were 2.51 ± 0.47 m/s and 3.43 ± 1.21 m/s respectively (P < 0.001). The sensitivities, specificities, PPVs, NPVs, accuracies and AUCs were 77.4%, 80.0%, 65.7%, 87.7%, 79.1%, 0.82 for SWS alone with SWS ≥ 2.78 m/s; 33.3–34.5%, 91.2–94.1%, 65.9–73.7%, 73.8–74.1%, 72.4–74.0%, 0.63–0.64 for QM alone and 84.5–85.7%, 72.4–75.9%, 60.5–63.4%, 90.8–91.0%, 76.8–78.7%, 0.79–0.80 for SWS+QM. Nodule depth was identified to be the strongest associated factor for QM of SWS, followed by malignancy and SWS. In conclusion, QM for thyroid nodule is associated with nodule depth, malignancy, and SWS. QM improves the specificity in comparison with SWS alone, whereas SWS+QM does not improve the overall diagnostic performance.

Effects of fine-needle aspiration biopsy (FNAB) nodule depth on pain score

Fine-needle aspiration biopsy (FNAB) of the thyroid is generally a well-tolerated procedure associated with weak levels of pain. However, pain may be very intense in some patients. The cause for the pain in these patients has not been identified. The hypothesis of this study is that there is a likely relationship between pain level and nodule depth during FNAB. Included in the study were 98 patients with euthyroid nodular goiter who underwent FNAB. When ultrasound guided thyroid fine-needle aspiration biopsy was performed findings such as the distance of the nodule to the skin, the size of the nodule, visual analogue scale (VAS) score values were recorded. The distance of nodule to skin and nodule size was measured, respectively, as 10.7±2.8mm and 21.7±8.6mm. Mean VAS score was 36±16. FNAB-related pain was correlated with the nodule depth (r=0.43, p<0.001). In the logistic regression analysis, we also found that high VAS score class was effected by only nodule depth (B=-1.619; OR 1.287; CI 1.057-1.565, p<0.05). Our results show that pain increased significantly during FNAB in patients who had more deeply situated nodules. Local anesthetic methods may be recommended for these patients.

Frequency and Intensity of Pain Related to Thyroid Nodule Fine-Needle Aspiration Cytology

Quality of life is an important issue in endocrine tumors because of the high prevalence of benign tumors and the indolent course of most malignant tumors. To evaluate the frequency and the intensity of pain and anxiety in patients undergoing thyroid nodule fine-needle aspiration cytology (FNAC) and to identify factors associated with pain. Single center prospective study in the setting of a one-stop outpatient diagnostic clinic for thyroid nodules. Pain was evaluated using a 100-mm visual analogue scale (VAS) immediately following (VAS1) and 30 minutes after (VAS2) FNAC and was considered significant if ≥ 30. Anxiety symptoms were assessed prior to FNAC using a self-report measure questionnaire: the state form of Spielberger State-Trait Anxiety Inventory (STAI, form Y-A). FNAC was performed with a 25-gauge needle and a moderate aspiration and two passes for each nodule. Two hundred eighteen consecutive patients (163 females, 55 males; mean age 53 years, range 12-84 years) undergoing FNAC of one to three nodules were included. VAS1 was ≥ 30 in 24% of the patients and VAS(2) was ≥ 30 in 13% of the patients. Independent significant factors correlated to a VAS1 of ≥ 30 were age under 25 years and the number of nodules being biopsied. Independent significant factors correlated to a VAS2 of ≥ 30 were VAS1 ≥ 30 and female sex. No correlation was found between pain and nodule size or nodule depth, nor the duration of application of the eutectic mixture of local anesthetics (EMLA) patch prior to FNAC. The mean STAI score for anxiety was 37 ± 12. The average STAI score was significantly higher in women (39) than in men (33; p = 0.01). There was no significant correlation between STAI score and age under 25 years, previous FNAC, number of nodules biopsied, or acetaminophen administration, but the STAI score was significantly correlated to VAS1 and VAS2. FNAC-related pain is frequent and correlates with the number of nodules biopsied, age under 25 years, female sex, and anxiety.

Crystalline silicon growth in the aluminium-induced glass texturing process

Aluminium-induced texturing (AIT) is a method to texture glass surfaces by utilising the reaction between aluminium (Al) and glass at high temperature (above 500°C) and a subsequent wet-chemical treatment that removes the reaction products. In this work, we studied the solid state reaction between a sputtered Al layer and a borosilicate glass sheet during AIT annealing. Raman spectroscopy showed that crystalline silicon (c-Si) is formed during the AIT process. An optical microscope was used to visualise the evolution of the c-Si growth. Plan-view scanning electron microscopy (SEM) investigations performed on samples after completed AIT reaction showed that separate c-Si clusters formed at the glass surface. Atomic force microscopy revealed that the c-Si clusters grew upwards and were on top of the glass surface. Cross-sectional SEM examination showed that the c-Si layer is not uniform and that crater-shaped nodules are embedded into the glass. The widths and depths of the nodules are in the micrometre range. Energy-dispersive X-ray spectroscopy showed that the nodules consist mainly of aluminium oxide (Al2O3). X-ray diffraction analysis showed that the c-Si grains are preferentially (111) oriented. The activation energy of the reaction between Al and borosilicate glass is 3.0±0.2eV based on in-situ XRD analysis of the c-Si growth. Finally, a phenomenological model of the AIT process is proposed and we suggest that the topology of the glass texture strongly depends on the size, depth and lateral separation of the Al2O3 nodules embedded in the glass.